Skip to main content

Hyperglycemia and glucose variability are associated with worse survival in mechanically ventilated COVID-19 patients: the prospective Maastricht Intensive Care Covid Cohort

Abstract

Background

Data on hyperglycemia and glucose variability in relation to diabetes mellitus, either known or unknown in ICU-setting in COVID-19, are scarce. We prospectively studied daily glucose variables and mortality in strata of diabetes mellitus and glycosylated hemoglobin among mechanically ventilated COVID-19 patients.

Methods

We used linear-mixed effect models in mechanically ventilated COVID-19 patients to investigate mean and maximum difference in glucose concentration per day over time. We compared ICU survivors and non-survivors and tested for effect-modification by pandemic wave 1 and 2, diabetes mellitus, and admission HbA1c.

Results

Among 232 mechanically ventilated COVID-19 patients, 21.1% had known diabetes mellitus, whereas 16.9% in wave 2 had unknown diabetes mellitus. Non-survivors had higher mean glucose concentrations (ß 0.62 mmol/l; 95%CI 0.20–1.06; ß 11.2 mg/dl; 95% CI 3.6–19.1; P = 0.004) and higher maximum differences in glucose concentrations per day (ß 0.85 mmol/l; 95%CI 0.37–1.33; ß 15.3; 95%CI 6.7–23.9; P = 0.001). Effect modification by wave, history of diabetes mellitus and admission HbA1c in associations between glucose and survival was not present. Effect of higher mean glucose concentrations was modified by pandemic wave (wave 1 (ß 0.74; 95% CI 0.24–1.23 mmol/l) ; (ß 13.3; 95%CI 4.3–22.1 mg/dl)) vs. (wave 2 (ß 0.37 (95%CI 0.25–0.98) mmol/l) (ß 6.7 (95% ci 4.5–17.6) mg/dl)).

Conclusions

Hyperglycemia and glucose variability are associated with mortality in mechanically ventilated COVID-19 patients irrespective of the presence of diabetes mellitus.

Background

Diabetes mellitus is a comorbid condition often reported in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2, COVID-19) [1, 2] and associated with poor prognosis [3, 4]. Even among COVID-19 patients without a known history of diabetes mellitus, increased glucose concentrations both at and during admission [5,6,7] and, to a lesser extent, elevated glycated hemoglobin (HbA1c) levels [8, 9] are associated with worse disease outcome. In general, hyperglycemia [10, 11] and high glucose variability [12,13,14,15,16,17,18,19] worsen the prognosis of patients admitted to the intensive care unit (ICU) with diabetes mellitus modulating this effect [20, 21]. In COVID-19, the mechanisms through which dysglycemia affects outcome in the ICU is still unknown, although unknown diabetes mellitus status and treatment with dexamethasone may play a role [22,23,24].

Identification of the factors leading to dysglycemia in COVID-19 patients and dismal prognosis is critical to improve glucose control by targeted monitoring. Whereas recent work has focused on glucose concentrations [6, 7, 9] and HbA1c [8, 9, 25] as static parameters, it should be acknowledged that glucose concentrations constantly fluctuate. This may impact the course of the disease and vice versa, necessitating (semi-) continuous monitoring. Acute inflammation by infectious diseases, as well as steroid treatment, affects glucose metabolism. Therefore, it is important to investigate the impact of glucose variability on the outcome in COVID-19 patients. Since data on hyperglycemia and glucose variability in the ICU-setting in COVID-19 are scarce [8, 17, 26, 27] we aimed, in a comprehensive observational prospective study, to investigate the association between daily glucose concentrations and the survival of mechanically ventilated patients with COVID-19. Our hypotheses were that: (1) higher mean glucose concentrations and greater daily glucose variability are independently associated with worse survival; (2) those associations are stronger in steroid-treated patients and in patients with diabetes mellitus, whether known or unknown history.

Methods

Study design and population

The Maastricht Intensive Care COVID (MaastrICCht) cohort study design has been described more extensively elsewhere [28,29,30,31]. Briefly, this prospective cohort study included patients admitted to the Intensive Care of the Maastricht University Medical Centre+ (Maastricht UMC+), a tertiary care university teaching hospital in the southern part of the Netherlands. The local institutional review board (Medisch Ethische Toetsingscomissie (METC) 2020 − 1565/ 300,523) of the Maastricht UMC + approved the study, which was performed based on the declaration of Helsinki. Despite the challenging times of the COVID-19 pandemic [32], all patients and their families provided complete informed consent for the utilization of the collected data and storage of leftover serum samples for critical COVID-19 research purposes. The study has been registered in the Netherlands Trial Register (registration number NL8613). This study included all participants with respiratory insufficiency requiring mechanical ventilation and at least one positive PCR test for SARS-CoV-2 and/or a chest CT scan strongly suggestive of SARS-CoV-2 infection, based on a COVID-19 Reporting and Data System (CORADS)-score of 4–5 [33]. Participants were followed from the moment of intubation until the primary outcome (death during ICU admission or discharge from the ICU). Clinical, physiological, and laboratory variables were collected using a predefined study protocol described elsewhere [28]. For the present study, participants were included based on the day of the start of mechanical ventilation/intubation in wave 1 from March 15th, 2020, until July 2020, and in wave 2 from October 2020 until March 23th, 2021. Thus data from the first and second waves were included. During the first wave, patients were intubated according to early Dutch intensive care guidelines, as there were concerns about the virus spread using other modes of oxygen or ventilator support [34]. However, since accumulating evidence shows its safety [35] high-flow nasal oxygen was applied in the second wave onwards. As we aimed to investigate the development of variables over time, like in previous reports [30, 36], we included intubated and mechanically ventilated patients and set intubation as day one. This makes patients at inclusion to be assumed at similar time-points of disease and severity during their COVID-19 disease, i.e., an inception cohort. In addition, this allows us to take all observations into account over time, also if a patient is transported after intubation from another ICU, facilitating the investigation of the development of variables over time [29, 30, 36].

Diabetes Mellitus, glucose, insulin, and HbA1c

Diabetes mellitus was defined as a reported history of diabetes mellitus and/or the use of glucose-lowering medication. As diabetes mellitus may drive severe COVID-19 disease [3, 4] and might be undetected, we measured HbA1c. HbA1c was prospectively measured in the cohort from wave 2 onwards, as dexamethasone became the standard of care [37] to improve the monitoring of patients at risk of dysglycemia. HbA1c was defined as high when equal to or above 48 mmol/mol (6.5%), aligning with the diagnostic criteria for a diagnosis of diabetes mellitus according to the guidelines of the American Diabetes Association [38] and the World Health Organization [39]. The comprehensive cohort data were enriched with serial glucose variables extracted from the electronic patient files by automation. Glucose measurements were conducted following standards of care and obtained from blood gas analysis, point-of-care testing, and venous sampling procedures. The prescription and administration of insulin was carried out by the hospital’s standard medical personnel in accordance with established care protocols. Glucose data were expressed as two variables: mean glucose concentration in mmol/l and mg/dl per day and maximum glucose difference (max glucose - min glucose) in mmol/l and mg/dl per day. We have chosen maximum difference in glucose concentration since it is a straight-forward measure and has a strong predictive ability in ICU patients [40]. Nasal-gastric feeding was protocolized care in mechanically ventilated patients and accompanied by continuous insulin therapy. Additionally, we also collected data on continuous insulin dosing and summarized this as the total insulin dose per day (in total units administered).

Ascertainment of comorbidities and mortality

As previously described, data on comorbidities and ICU discharge or death were collected using an electronic case report form (eCRF) [28]. Briefly, information on the presence of comorbidities (liver disease, chronic lung disease, and chronic kidney disease was recorded when diagnosed by a medical specialist) was retrieved from medical records. Next, information on cardiovascular risk factors was extracted from each patient’s medical file. We defined cardiovascular risk as a history of hypertension, previous myocardial infarction, cerebrovascular disease, peripheral vascular disease, history of smoking, and/or coronary artery disease. Finally, ICU discharge or death was extracted from the medical files.

Statistical analyses and reporting

The manuscript was written following the Strengthening the Reporting of OBservational studies in Epidemiology (STROBE) guideline [41]. Automatic data extraction was performed using Matlab 2019b. Data were analyzed using R version 4.1.1. Continuous variables are expressed as mean +/- SD, or median with 25th – 75th percentile. For illustrative purpose, we divided the sample into six predefined strata: patients included during the first wave of the pandemic (HbA1c not measured) without [1] and with [2] a known history of diabetes mellitus; patients included during the second wave of the pandemic without [3] and with [4] a known history of diabetes mellitus with low HbA1c, and patients included during the second wave of the pandemic without [5] and with [6] a known history of diabetes mellitus with high HbA1c. For these six strata, serial glucose concentrations per day from intubation onwards are shown. In addition, mean insulin units per day are shown.

The associations between glycemic parameters (mean glucose, maximal glucose difference, and additionally insulin use per day) and ICU mortality were estimated. In order to do so, the full cohort was categorized into survivors and non-survivors. We used linear-mixed effect models to investigate the development of mean glucose concentration per day over time, to investigate the development of maximum difference in glucose concentration per day over time, and compared ICU survivors and non-survivors. First, model 1 consisted of crude models whereas model 2 included crude models adjusted for covariates as age, sex, body mass index (BMI), Acute Physiology and Chronic Health Evaluation-score II (APACHE II score), chronic kidney, pulmonary and liver diseases, and cardiovascular risk factors. Next, effect-modification by pandemic wave (wave one without protocolized dexamethasone therapy and wave 2 with protocolized dexamethasone therapy), reported history of diabetes mellitus and low vs. high HbA1c (in wave 2 only) were investigated. Additionally, the development of total insulin units for ICU survivors and non-survivors per day over time was investigated. We considered a p-value < 0.05 and a p-value for interaction < 0.10 statistically significant.

Results

During the inclusion period, 269 patients were screened (Figure 1), 37 (13.8%) of whom did not receive invasive ventilation, so that 232 intubated and mechanically ventilated patients were included (wave 1, n = 94; wave 2, n = 138; Table 1).

Fig. 1
figure 1

Selection of study participants. Wave 1 = March 2020 – July 2020; Wave 2 = October 2020 – March 2021

All patients admitted to the Intensive Care Unit (ICU) were admitted for their initial hospitalization, with no instances of readmission. Diabetes mellitus was present in 49 patients (21.1%). In wave 2, 23 patients (16.9%) had high HbA1c (Above 48mmol/mol (6.5%)) without a previous diagnosis of diabetes mellitus. During a median ICU length of stay of 14 [8-22.5] days, glucose was measured 4 [3–5] times daily, leading to a total of 19,191 measurements.

Table 1 Baseline characteristics for the total sample and pre-specified groups

Figure 2 shows descriptive data on the development of serial glucose concentrations and Fig. 3 shows mean insulin units per day for the six predefined strata (i.e., wave 1 without [1] and with [2] diabetes mellitus; the second wave without [3] and with [4] diabetes mellitus with low HbA1c and without [5] and with [6] diabetes mellitus with high HbA1c).

Fig. 2
figure 2

Descriptive data of mean daily glucose concentrations over time from intubation onwards, according to predefined strata. Group 1: wave 1, no previous diagnosis of diabetes mellitus. Group 2: wave 1, previously diagnosed diabetes mellitus. Group 3: wave 2, no previous diagnosis of diabetes mellitus, low HbA1c. Group 4: wave 2, previously diagnosed diabetes mellitus, low HbA1c. Group 5: wave 2, no previous diagnosis of diabetes mellitus, high HbA1c. Group 6: wave 2, previously diagnosed diabetes mellitus, high HbA1c. In wave 1, no HbA1c was measured. High HbA1c is defined as above 48mmol/mol (6.5%)

Fig. 3
figure 3

Insulin units per day from intubation onwards, according to predefined strata. Group 1: wave 1, no previous diagnosis of diabetes mellitus. Group 2: wave 1, previously diagnosed diabetes mellitus. Group 3: wave 2, no previous diagnosis of diabetes mellitus, low HbA1c. Group 4: wave 2, previously diagnosed diabetes mellitus, low HbA1c. Group 5: wave 2, no previous diagnosis of diabetes mellitus, high HbA1c. Group 6: wave 2, previously diagnosed diabetes mellitus, high HbA1c. In wave 1, no HbA1c was measured. High HbA1c is defined as above 48mmol/mol (6.5%)

Associations between serial dysglycemia over time and ICU mortality

ICU non-survivors had higher mean glucose per day of 0.67 (0.25; 1.10) mmol/l (11.2 mg/dl ) 3.6; 19.1) per day as compared to ICU-survivors, which decreased over time with − 0.06 (-0.08; 0.04) mmol/l.

(-1.08 (-1.44; 0.72) mg/dl) per day (Table 2; Model 2). After adjustment for age, sex, BMI, APACHE II score, chronic kidney-, pulmonary- and liver diseases, and cardiovascular risk factors, results showed a similar association over time (Table 2; Model 2). The effect of glucose concentrations on ICU-survival was modified by wave (wave one vs. wave 2) (p-interaction = 0.029), but not by known history of diabetes mellitus (p-interaction = 0.96) or HbA1c (high vs. low) (p-interaction 0.964). Mean glucose results stratified per wave, in adjusted models 2, showed for wave one that ICU non-survivors had a higher mean glucose per day of 0.74 (0.24; 1.23) mmol/l (13.3 (4.3; 22.1) mg/dl) as compared to ICU-survivors, which decreased over time with − 0.04 (-0.06; -0.02) mmol/l per day (-0.72 (-1.08;-0.36) mg/dl); whereas for wave 2 ICU non-survivors had a numerically higher mean glucose per day of 0.37 (-0.25; 0.98) mmol/l (6.7 (4.5; 17.6) mg/dl) as compared to ICU-survivors, which decreased over time with − 0.06 (-0.09; -0.03) mmol/l (-1.08 (-1.62; -0.54 mg/dl)) per day without statistical significance.

From intubation onwards, ICU non-survivors had a greater maximum glucose difference of 3.1979 ± 2.6298 mmol/l (57.6 vs. 57.3 mg/dl) survivors having a maximum glucose difference of 2.6461 ± 2.2318 mmol/l (47.6 vs. 40.1 mg/dl). Non-survivors had a greater maximum glucose difference per day of 0.86 (0.38; 1.34) mmol/l (15.5 (6.8; 24.1 mg/dl) over time as compared to ICU-survivors, which decreased over time with − 0.03 (-0.05; -0.01) mmol/l (-0.54 (-0.09; -0.18) mg/dl) per day (Table 2; Model 1). Adjustment for age, sex, BMI and APACHE II score, chronic kidney, pulmonary and liver diseases, and cardiovascular risk factors resulted in a similar association over time (Table 2; Model 2). The effect of glucose concentration variability on ICU-survival was not shown to be modified by wave (wave 1 vs. 1 wave 2) (p-interaction = 0.199), known history of diabetes mellitus (p-interaction = 0.282) or HbA1c (high vs. low) (p-interaction 0.254).

From intubation onwards, over time, insulin units per day did not differ between ICU non-survivors and ICU survivors in adjusted models (p = 0.755), neither in those with diabetes mellitus, whether known or unknown history nor in those with diabetes mellitus.

Table 2 Associations between serial glycemic parameters over time and ICU mortality

Discussion

This prospective study of critically ill COVID-19 patients with comprehensive serial data has four main findings. First, in our study, diabetes mellitus and previously unknown diabetes mellitus were highly prevalent. Second, we showed that non-survivors had higher mean glucose levels and higher maximum differences in glucose concentrations per day during ICU stay compared to survivors. These associations were independent of age, sex, BMI, APACHE II score, chronic kidney, pulmonary, and liver diseases, and cardiovascular risk factors. However, the association between mean glucose and survival weakened and was no longer significant during the second compared to the first COVID-19 wave. Third, we found no evidence to support our hypothesis that the presence of known and previously unknown diabetes mellitus (by high HbA1c) or steroid use worsens glycemic variability associated with prognosis. Finally, total insulin dosage did not differ between survivors and non-survivors, irrespective of diabetes mellitus status, in this cohort of critically ill COVID-19 patients.

Glucose concentrations and glucose variability are independent risk factors for ICU and hospital mortality among various ICU populations [14,15,16,17,18,19]. The prevalence of known and previously unknown diabetes mellitus in severe COVID-19 is high and associated with a poor prognosis due to glucose dysregulation and other risk factors such as obesity, hypertension [42, 43] and possibly attributable to microvascular abnormalities, rendering them more susceptible after COVID infection to complications or mortality. Furthermore, recent studies on critically ill COVID-19 patients showed that those with glucose concentrations between 3.9 and 10.0 mmol/l had lower mortality than those with higher glucose concentrations [7] and high fasting glucose concentrations [5, 6]. In addition, data on COVID-19 patients admitted to the general ward showed that fasting glucose variability is associated with poor outcome [26, 27, 44]. However, in these studies, only fasting glucose concentrations were used in the first week [44], the first two days [27], or the first three days [26] of general admission. Our study extends these observations by showing adverse effects of 24-h glucose variability on ICU survival that decreased over time. Therefore, we establish glucose variability as a biomarker of dismal prognosis in COVID-19 in ICU.

From this perspective, it is somewhat unexpected that we observed that HbA1c had no interaction with the association between high glucose variability and mortality. However, it should be acknowledged that an HbA1c below 48mmol/mol (6.5%) does not exclude diabetes mellitus [45,46,47]. This could have had a possible diluting effect on the results of disease outcome. Nevertheless, we observed similar results for a history of known diabetes mellitus not influencing the association between higher maximum glucose difference per day and mortality. Thus, we found no evidence that diabetes mellitus, whether known or previously unknown, based on high HbA1c, and a diagnosis of diabetes mellitus, leads to unfavorable outcomes independent of glycemic parameters/dysglycemia. Alternatively, the observation that glucose variability, as reflected by daily maximum glucose difference, is associated with mortality may also be explained by the suggestion that glucose concentrations are suggested as a biomarker of systemic inflammation, whereas HbA1c is a proxy of glucose control in the past three months [8].

We found no evidence to support our hypothesis that steroid use worsens glycemic variability-induced prognosis. Mean glucose concentrations were higher in non-survivors compared to survivors, which is in line with earlier findings that hyperglycemia worsens prognosis in ICU-populations [10, 11, 19] and COVID-19 [5,6,7]. Furthermore, this association was only present in the pre-steroid era wave (1) Thus, even though steroids exposed more patients to hyperglycemia, any association between mean glucose concentration and mortality was weaker rather than stronger (hence losing statistical significance) in wave (2) These observations suggest that the beneficial effects of steroids on mortality in COVID-19 seem to outweigh the harmful effects of steroids on glucose control in this cohort and aligns with a previous observational study which reported steroids to be associated with dysglycemia in COVID-19 but did not have a significant association with 30-day mortality [23]. Despite the aforementioned, maximum glucose difference is shown to be a strong determinant of worse outcome in previous studies in general critical care, regardless of pre-existing diabetes mellitus [40]. Increased glycemic variability has been studied before and found to be associated with worse outcome in terms of mortality and length of stay in various ICU and non-ICU populations [48,49,50] However, since we observed an association between higher maximum glucose difference per day and higher mortality, independent of known risk factors, comorbidities, without effect-modification by wave and known or unknown diabetes mellitus, we provide evidence to focus supportive care on in order to ameliorate survival of critically ill COVID-19 patients.

Daily total insulin dosage was administered following a standard ICU regimen. This variable not being statistically significantly different between survivors and non-survivors could be due to our relative insensitive approach to lump total insulin dose within one day, in contrast to an hour-to-hour insulin variability. However, we had no hour-to-hour data on insulin, which is a limitation of our study. It could also be that insulin dosage has considerable confounding by illness severity precluding the study of direct beneficial/harmful effects of insulin itself. Previous work by Uyttendaele and colleagues however found higher insulin sensitivity in non-survivors, whereas hour-to-hour insulin variability was equivalent in both non-survivors and survivors among a mixed-medical ICU population, suggesting equal controllability [51]. Perhaps not directly generalizable to the present severe COVID-19 population, our results in the perspective of the previous findings by Uyttendaele strengthen the importance of improving glucose control in critical care.

We need to address some limitations. First, the study is a single-center study. It is observational, so no conclusions with regard to causality can be drawn. Next, we used pandemic waves as a proxy of steroid use as steroids became standard of care and were protocoled in the Netherlands from wave 2 onwards. This per-protocol approach allowed for investigating effect modification in an interpretable way as adding daily dexamethasone data would be more complicated, and due to the protocolized administration of dexamethasone to all wave 2 ICU-admitted COVID-19 patients, an intention-to-treat approach would likely not change our results. Another limitation that requires addressing is the absence of information regarding specific diabetes treatment (such as SGLT2 inhibitors that aside from diabetes mellitus, can have other indications including heart failure) and diabetic complications at the time of inclusion when a diagnosis of diabetes was present. Furthermore, glucose measurements were conducted in accordance with established standards of care, albeit without adherence to a predefined and standardized study protocol, which could have introduced its own sources of variability. Furthermore, we used HbA1c for diagnostic purposes since it is a reliable measure of chronic dysglycemia. However, a value less than 48 mmol/mol (or 6.5%) does not completely exclude diabetes mellitus diagnosed using glucose tests [46, 47]. For future studies, it would be interesting to see which glycemic patterns our population had in terms of fasting and non-fasting glucose concentrations before their admission to the intensive care unit. At last although we did not have information on whether patients had type 1 or type 2 diabetes mellitus, in light of the biometric and comorbid attributes it is highly likely that the predominant diabetes type is 2. The strengths of our study are the prospective and extensively phenotyped cohort having systematic data collection performed using a predefined protocol [28]. Furthermore, we provide serial glucose measurements daily, which is very informative in providing measures of glucose variability.

Conclusions

In conclusion, known and unknown history of diabetes mellitus were often present in patients with COVID-19 admitted to the ICU. Non-survivors had significantly higher daily maximum glucose differences throughout their ICU stay compared to patients with COVID-19 that survived their ICU stay. This effect was independent of age, sex, BMI and APACHE II score, chronic kidney, pulmonary, and liver diseases, and cardiovascular risk factors but was not modified by a history of diabetes mellitus or dexamethasone use during ICU stay. Our results point toward preventing hyperglycemia and large glucose variability in critically ill COVID-19 patients in the ICU.

List of abbrevations

SARS-CoV-2: Severe Acute Respiratory Syndrome Coronavirus 2; HbA1c: glycated haemoglobin; ICU: intensive care unit; MaastrICCht: Maastricht Intensive Care COVID cohort study; CORADS: COVID-19 Reporting and Data System; eCRF: electronic case report form; STROBE: Strengthening the Reporting of OBservational studies in Epidemiology; Apache II: Acute Physiology and Chronic Health Evaluation; BMI: body mass index;

Data Availability

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

References

  1. Zhou F, Yu T, Du R, Fan G, Liu Y, Liu Z, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. The Lancet. 2020;395(10229):1054–62.

    Article  CAS  Google Scholar 

  2. Guan Wjie, Ni Z yi, Hu Y, Liang W, hua, Ou C, quan, He Jxing et al. Clinical Characteristics of Coronavirus Disease 2019 in China. N Engl J Med [Internet]. 2020 Feb 28 [cited 2022 Jan 10]; Available from: https://www.nejm.org/doi/https://doi.org/10.1056/nejmoa2002032.

  3. Shi Q, Zhang X, Jiang F, Zhang X, Hu N, Bimu C, et al. Clinical characteristics and risk factors for mortality of COVID-19 patients with Diabetes in Wuhan, China: a Two-Center, Retrospective Study. Diabetes Care. 2020;43(7):1382–91.

    Article  CAS  PubMed  Google Scholar 

  4. Wu Z, McGoogan JM. Characteristics of and important lessons from the Coronavirus Disease 2019 (COVID-19) outbreak in China: Summary of a report of 72 314 cases from the Chinese Center for Disease Control and Prevention. JAMA. 2020;323(13):1239–42.

    Article  CAS  PubMed  Google Scholar 

  5. Wang S, Ma P, Zhang S, Song S, Wang Z, Ma Y, et al. Fasting blood glucose at admission is an Independent predictor for 28-day mortality in patients with COVID-19 without previous diagnosis of Diabetes: a multi-centre retrospective study. Diabetologia. 2020;63(10):2102–11.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Zhang J, Kong W, Xia P, Xu Y, Li L, Li Q, et al. Impaired fasting glucose and Diabetes are related to higher risks of Complications and mortality among patients with Coronavirus Disease 2019. Front Endocrinol. 2020;11:525.

    Article  CAS  Google Scholar 

  7. Zhu L, She ZG, Cheng X, Qin JJ, Zhang XJ, Cai J, et al. Association of Blood Glucose Control and outcomes in patients with COVID-19 and pre-existing type 2 Diabetes. Cell Metab. 2020;31(6):1068–1077e3.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Klein SJ, Mayerhöfer T, Fries D, Preuß Hernández C, Joannidis M, Bellmann R, et al. Elevated HbA1c remains a predominant finding in severe COVID-19 and may be associated with increased mortality in patients requiring mechanical ventilation. Crit Care. 2021;25(1):300.

    Article  PubMed  PubMed Central  Google Scholar 

  9. Wang Z, Du Z, Zhu F. Glycosylated hemoglobin is associated with systemic inflammation, hypercoagulability, and prognosis of COVID-19 patients. Diabetes Res Clin Pract [Internet]. 2020 Jun 1 [cited 2021 Nov 15];164. Available from: https://www.diabetesresearchclinicalpractice.com/article/S0168-8227(20)30464-2/fulltext.

  10. Falciglia M, Freyberg RW, Almenoff PL, D’Alessio DA, Render ML. Hyperglycemia-related mortality in critically ill patients varies with admission diagnosis. Crit Care Med. 2009;37(12):3001–9.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Umpierrez GE, Isaacs SD, Bazargan N, You X, Thaler LM, Kitabchi AE. Hyperglycemia: an Independent marker of in-hospital mortality in patients with undiagnosed Diabetes. J Clin Endocrinol Metab. 2002;87(3):978–82.

    Article  CAS  PubMed  Google Scholar 

  12. Eslami S, Taherzadeh Z, Schultz MJ, Abu-Hanna A. Glucose variability measures and their effect on mortality: a systematic review. Intensive Care Med. 2011;37(4):583–93.

    Article  PubMed  PubMed Central  Google Scholar 

  13. Hermanides J, Vriesendorp TM, Bosman RJ, Zandstra DF, Hoekstra JB, Devries JH. Glucose variability is associated with intensive care unit mortality. Crit Care Med. 2010;38(3):838–42.

    Article  CAS  PubMed  Google Scholar 

  14. Egi M, Bellomo R, Stachowski E, French CJ, Hart G. Variability of blood glucose concentration and short-term mortality in critically Ill patients. Anesthesiology. 2006;105(2):244–52.

    Article  CAS  PubMed  Google Scholar 

  15. Ali NA, O’Brien JM, Dungan K, Phillips G, Marsh CB, Lemeshow S, et al. Glucose variability and mortality in patients with sepsis. Crit Care Med. 2008;36(8):2316–21.

    Article  PubMed  PubMed Central  Google Scholar 

  16. Bagshaw SM, Bellomo R, Jacka MJ, Egi M, Hart GK, George C, et al. The impact of early hypoglycemia and blood glucose variability on outcome in critical Illness. Crit Care. 2009;13(3):R91.

    Article  PubMed  PubMed Central  Google Scholar 

  17. Chao WC, Tseng CH, Wu CL, Shih SJ, Yi CY, Chan MC. Higher glycemic variability within the first day of ICU admission is associated with increased 30-day mortality in ICU patients with sepsis. Ann Intensive Care. 2020;10(1):17.

    Article  PubMed  PubMed Central  Google Scholar 

  18. Kalfon P, Le Manach Y, Ichai C, Bréchot N, Cinotti R, Dequin PF, et al. Severe and multiple hypoglycemic episodes are associated with increased risk of death in ICU patients. Crit Care Lond Engl. 2015;19:153.

    Article  Google Scholar 

  19. Badawi O, Waite MD, Fuhrman SA, Zuckerman IH. Association between intensive care unit–acquired dysglycemia and in-hospital mortality*. Crit Care Med. 2012;40(12):3180–8.

    Article  PubMed  Google Scholar 

  20. Krinsley JS, Egi M, Kiss A, Devendra AN, Schuetz P, Maurer PM, et al. Diabetic status and the relation of the three domains of glycemic control to mortality in critically ill patients: an international multicenter cohort study. Crit Care Lond Engl. 2013;17(2):R37.

    Article  Google Scholar 

  21. Sechterberger MK, Bosman RJ, Oudemans-van Straaten HM, Siegelaar SE, Hermanides J, Hoekstra JBL, et al. The effect of Diabetes Mellitus on the association between measures of glycaemic control and ICU mortality: a retrospective cohort study. Crit Care Lond Engl. 2013;17(2):R52.

    Article  Google Scholar 

  22. Unnikrishnan R, Misra A. Diabetes and COVID19: a bidirectional relationship. Nutr Diabetes. 2021;11(1):1–5.

    Article  Google Scholar 

  23. Réa RR, Bernardelli RS, Kozesinski-Nakatani AC, Olandoski M, Martins-Junior MJ, Oliveira MC, et al. Dysglycemias in patients admitted to ICUs with severe acute respiratory syndrome due to COVID-19 versus other causes - a cohort study. BMC Pulm Med. 2023;23(1):173.

    Article  PubMed  PubMed Central  Google Scholar 

  24. Klein SJ, Fries D, Kaser S, Mathis S, Thomé C, Joannidis M. Unrecognized Diabetes in critically ill COVID-19 patients. Crit Care. 2020;24(1):406.

    Article  PubMed  PubMed Central  Google Scholar 

  25. Cariou B, Hadjadj S, Wargny M, Pichelin M, Al-Salameh A, Allix I, et al. Phenotypic characteristics and prognosis of inpatients with COVID-19 and Diabetes: the CORONADO study. Diabetologia. 2020;63(8):1500–15.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Xie W, Wu N, Wang B, Xu Y, Zhang Y, Xiang Y et al. Fasting plasma glucose and glucose fluctuation are associated with COVID-19 prognosis regardless of pre-existing diabetes. Diabetes Res Clin Pract [Internet]. 2021 Oct 1 [cited 2022 Jan 13];180. Available from: https://www.diabetesresearchclinicalpractice.com/article/S0168-8227(21)00400-9/fulltext.

  27. Lazzeri C, Bonizzoli M, Batacchi S, Di Valvasone S, Chiostri M, Peris A. The prognostic role of hyperglycemia and glucose variability in covid-related acute respiratory distress syndrome. Diabetes Res Clin Pract. 2021;175:108789.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Tas J, van Gassel RJJ, Heines SJH, Mulder MMG, Heijnen NFL, Acampo-de Jong MJ et al. Serial measurements in COVID-19-induced acute Respiratory Disease to unravel heterogeneity of the Disease course: design of the Maastricht Intensive Care COVID cohort (MaastrICCht). BMJ Open. 2020;10(9).

  29. Ghossein MA, Driessen RGH, van Rosmalen F, Sels JWEM, Delnoij T, Geyik Z, et al. Serial Assessment of Myocardial Injury markers in mechanically ventilated patients with SARS-CoV-2 (from the prospective MaastrICCht Cohort). Am J Cardiol. 2022;170:118–27.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. Mulder MMG, Brandts Li, Brüggemann RAG, Koelmann M, Streng AS, Olie RH, et al. Serial markers of coagulation and inflammation and the occurrence of clinical pulmonary thromboembolism in mechanically ventilated patients with SARS-CoV-2 Infection; the prospective maastricht intensive care COVID cohort. Thromb J. 2021;19(1):35.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  31. Hulshof AM, Brüggemann RAG, Mulder MMG, van de Berg TW, Sels JWEM, Olie RH, et al. Serial EXTEM, FIBTEM, and tPA rotational thromboelastometry observations in the Maastricht Intensive Care COVID Cohort-Persistence of Hypercoagulability and Hypofibrinolysis despite Anticoagulation. Front Cardiovasc Med. 2021;8:654174.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Wilmes N, Hendriks CWE, Viets CTA, Cornelissen SJWM, van Mook WNKA, Cox-Brinkman J, et al. Structural under-reporting of informed consent, data handling and sharing, ethical approval, and application of Open Science principles as proxies for study quality conduct in COVID-19 research: a systematic scoping review. BMJ Glob Health. 2023;8(5):e012007.

    Article  PubMed  PubMed Central  Google Scholar 

  33. Prokop M, van Everdingen W, van Rees Vellinga T, van Quarles H, Stöger L, Beenen L, et al. CO-RADS: a categorical CT Assessment Scheme for patients suspected of having COVID-19—Definition and evaluation. Radiology. 2020;296(2):E97–104.

    Article  PubMed  Google Scholar 

  34. Elshof J, Hebbink RHJ, Duiverman ML, Hagmeijer R. High-flow nasal cannula for COVID-19 patients: risk of bio-aerosol dispersion. Eur Respir J [Internet]. 2020 Oct 1 [cited 2022 Jan 12];56(4). Available from: https://erj.ersjournals.com/content/56/4/2003004.

  35. Mellado-Artigas R, Ferreyro BL, Angriman F, Hernández-Sanz M, Arruti E, Torres A, et al. High-flow nasal oxygen in patients with COVID-19-associated acute Respiratory Failure. Crit Care. 2021;25(1):58.

    Article  PubMed  PubMed Central  Google Scholar 

  36. Bels JLM, van Kuijk SMJ, Ghossein-Doha C, Tijssen FH, van Gassel RJJ, Tas J, et al. Decreased serial scores of severe organ failure assessments are associated with survival in mechanically ventilated patients; the prospective Maastricht Intensive Care COVID cohort. J Crit Care. 2021;62:38–45.

    Article  CAS  PubMed  Google Scholar 

  37. Dexamethasone in Hospitalized Patients with Covid-19. N Engl J Med. 2021;384(8):693–704.

    Article  Google Scholar 

  38. International Expert Committee Report on the Role of. The A1C assay in the diagnosis of Diabetes. Diabetes Care. 2009;32(7):1327–34.

    Article  Google Scholar 

  39. Use of glycated haemoglobin. (HbA1c) in the diagnosis of Diabetes Mellitus. Diabetes Res Clin Pract. 2011;93(3):299–309.

    Article  Google Scholar 

  40. Issarawattana T, Bhurayanontachai R. Maximal glycemic difference, the possible Strongest Glycemic Variability parameter to Predict Mortality in ICU patients. Crit Care Res Pract. 2020;2020:1–8.

    Article  Google Scholar 

  41. von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP, et al. The strengthening the reporting of Observational studies in Epidemiology (STROBE) Statement: guidelines for reporting observational studies. PLOS Med. 2007;4(10):e296.

    Article  Google Scholar 

  42. Guo W, Li M, Dong Y, Zhou H, Zhang Z, Tian C, et al. Diabetes is a risk factor for the progression and prognosis of COVID-19. Diabetes Metab Res Rev. 2020;36(7):e3319.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  43. Shang J, Wang Q, Zhang H, Wang X, Wan J, Yan Y, et al. The Relationship between Diabetes Mellitus and COVID-19 prognosis: a retrospective cohort study in Wuhan, China. Am J Med. 2021;134(1):e6–14.

    Article  CAS  PubMed  Google Scholar 

  44. Chen L, Sun W, Liu Y, Zhang L, Lv Y, Wang Q, et al. Association of Early-Phase In-Hospital glycemic fluctuation with mortality in adult patients with Coronavirus Disease 2019. Diabetes Care. 2021;44(4):865–73.

    Article  CAS  PubMed  Google Scholar 

  45. Serdar MA, Serteser M, Ucal Y, Karpuzoglu HF, Aksungar FB, Coskun A, et al. An Assessment of HbA1c in Diabetes Mellitus and pre-diabetes diagnosis: a Multi-centered Data Mining Study. Appl Biochem Biotechnol. 2020;190(1):44–56.

    Article  CAS  PubMed  Google Scholar 

  46. Lim WY, Ma S, Heng D, Tai ES, Khoo CM, Loh TP. Screening for Diabetes with HbA1c: test performance of HbA1c compared to fasting plasma glucose among Chinese, malay and Indian community residents in Singapore. Sci Rep. 2018;8(1):12419.

    Article  PubMed  PubMed Central  Google Scholar 

  47. World Health Organization. Use of glycated haemoglobin (HbA1c) in diagnosis of diabetes mellitus: abbreviated report of a WHO consultation [Internet]. World Health Organization; 2011 [cited 2022 Sep 29]. Report No.: WHO/NMH/CHP/CPM/11.1. Available from: https://apps.who.int/iris/handle/10665/70523.

  48. Krinsley JS. Glycemic variability: a strong Independent predictor of mortality in critically ill patients. Crit Care Med. 2008;36(11):3008–13.

    Article  CAS  PubMed  Google Scholar 

  49. Mendez CE, Mok KT, Ata A, Tanenberg RJ, Calles-Escandon J, Umpierrez GE. Increased glycemic variability is independently associated with length of stay and mortality in noncritically ill hospitalized patients. Diabetes Care. 2013;36(12):4091–7.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  50. Olsen MT, Dungu AM, Klarskov CK, Jensen AK, Lindegaard B, Kristensen PL. Glycemic variability assessed by continuous glucose monitoring in hospitalized patients with community-acquired Pneumonia. BMC Pulm Med. 2022;22(1):83.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  51. Uyttendaele V, Dickson JL, Shaw GM, Desaive T, Chase JG. Untangling glycaemia and mortality in critical care. Crit Care. 2017;21(1):152.

    Article  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

The authors are grateful to the study participants, their families and the nursing staff from the.

The Maastricht Intensive Care COVID cohort study.

Funding

The authors have not declared a specific grant for this research from any funding agency in.

the public, commercial or not-for-profit sectors.

Author information

Authors and Affiliations

Authors

Contributions

TvH, FR, HpH, AnH, RJ, MD, NZ, BdG, ICCvdH, SvK and BCTvB conceived and designed the study. TvH, FR, RJ, MD, ICCvdH, BCTvB were involved in the data acquisition process. All authors have interpreted the data, drafted the work, edited and critically revised the manuscript. BCTvB is the guarantor of this study. All authors read and approved the submitted version.

Corresponding author

Correspondence to Thijs T.W. van Herpt.

Ethics declarations

Ethical approval

Ethical approval was obtained from the medical ethics committee (METC 2020–1565/300 523) of Maastricht UMC+. The study was performed in accordance with the General Data Protection Regulation (GDPR) act and the national data privacy laws. Patient data were collected according to good clinical practice and in accordance with relevant guidelines and regulations. Informed consent was obtained from all participants included in the study.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

van Herpt, T.T., van Rosmalen, F., Hulsewé, H.P. et al. Hyperglycemia and glucose variability are associated with worse survival in mechanically ventilated COVID-19 patients: the prospective Maastricht Intensive Care Covid Cohort. Diabetol Metab Syndr 15, 253 (2023). https://doi.org/10.1186/s13098-023-01228-1

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s13098-023-01228-1

Keywords