According to the CDC’s 2011Youth Risk Behavior Surveillance data on adolescent high school students, AA females were found to be 1.4 times more likely to be overweight and 2.4 times more likely to be obese than Caucasian females. Similarly, AA males were 1.6 times more likely to be obese than Caucasian males. However, there are relatively few similar studies in college students in general, especially AA college students. This is one of the first comprehensive studies with the largest sample size among any studies evaluating the prevalence of MetS among college students and reporting the prevalence of metabolic risks integrating anthropometric, clinical and biochemical parameters in a predominantly AA student population attending an HBCU.
Using the NCEP ATP III criteria, the overall prevalence of MetS in the sample was 12%. When the IDF definition was applied, the overall prevalence of MetS in the sample was 9.3%. Irrespective of the definition used, the overall prevalence of MetS in this sample population located in the South/South-east is significantly higher than any other college based study.
Unlike other reports on college student population, majority (51.3%) of the sample population in the current study was overweight (26.3%) with more females than males being overweight and/or obese (25%)[17, 18, 20, 21, 23–25]. The most prevalent criterion in this sample was low HDL-C (37.3%), which is quite common in college students. Dalleck and Kjelland have reported an occurrence rate of 47.3% for low HDL-C in their study sample. Though the reference values for HDL-C being different for males and females, the difference in the MetS prevalence between the genders was not as large as found in the NHANES 2003–2006 report. To the best of our knowledge, again, this is also the first study to report the highest occurrence rate (22%) for pre-diabetes (elevated GLU) among studies on college students[17, 18, 20, 21, 23, 24]. The prevalence of individuals with one (NCEP 31.4% and IDF-21.3%) and two (NCEP 20.7% and IDF 8.75%) MetS components in the present study are considerably higher than previously reported. Using NCEP criteria, Huang et al. have found lower occurrences of MetS risk factors in a primarily white college student population, with 25.2% and 1.2% possessing 1 and 2 MetS components respectively, while Fernandes and Lofgren reported a prevalence of individuals with either one or two of the MetS criteria to be 28% and 7.7% respectively in their sample of college students in the North-east[18, 25]. Dalleck and Kjelland reported a prevalence of individuals with either one or two of the MetS criteria of 47.2% and 13.0% respectively, from a college in the Midwest region of the US which was the highest so far. Further, significant differences on the basis of BMI were found in the sample, with those in the obese category reporting overall worse outcomes. The current study offers the evidence of ethnic differences in the distribution of individual risk factors in the overall prevalence of MetS and its individual criteria in college student populations along ethnic and geographical lines. The trends typified the distribution of obesity and diabetes as these health conditions, which are more concentrated in the South and Southeast of the US and severely impact AAs, including young adults.
Though the national data from NHANES (2003–2006) reported elevated WC and elevated BP as the most prevalent risk factors in population in this age group, most studies in young adults have reported greater occurrence of low HDL-C and elevated TG[17, 18, 20, 21, 23, 24]. Further it is important to note that the same NHANES study also demonstrated racial differences in the WC cut points that correspond to increased risk for Mets (BMI of 25 kg/m2). In AAs the WC corresponding to a BMI of 25 kg/m2 were 86.4 cm in men and 83.5 cm in women compared with 91.3 cm and 83.4 cm in Caucasian American men and women respectively. The IDF attempts to define MetS in younger populations worldwide. When we applied these cut off values for WC to AA and Caucasian participants in our sample population, more overweight and obese individuals were identified than previously (approximately 14.5% overweight and 19% obese). On applying the IDF definition, incorporating these racial differential values for WC, the total prevalence of MetS in the student population rose to 11.7% from 9.3%. Thus, it is important to identify the racial differences in the WC that confer additional risk in young adults in this age group. In order to better identify those with risk for MetS, our data suggest the need for setting age appropriate cut off points in young AA populations rather than those that are currently in use.
Overall, our study corroborates the evidence of occurrence of metabolic precursors of CHD in this young a population. It is disturbing to observe such high rates of pre-diabetes in very young adults which represents a serious public health concern. According to the American Heart Association, adults with diabetes alone are two to four times more likely to have heart disease or a stroke.
Although college years lay the foundation for future health behaviors and health status, and are the years in life when health education and preventive care may arguably have their greatest impact, typically college aged students perceive themselves to be ‘invincible’. Further, they do not always fully comprehend the seriousness of the prevailing risk factors such as diabetes and its associated risks for debilitating quality of life and chronic health conditions. It has been estimated that the average annual medical cost of treating an adult with risk factors for CHD is approximately $5500 annually. The findings of the current study reveal the need for additional screening of college students, especially those with family history of CHD that can provide more information so as to better design well targeted interventions to decrease the risk of MetS and eventual, yet an early onset of CHD. The data from the current and other studies indicate that it is necessary to design prevention and early intervention programs primarily targeting risk factors such as low HDL, elevated TG and high WC, and also focus on better pre-diabetes and diabetes self-management. MetS being a cluster of criteria, there is a significant likelihood that additional criteria will develop later in life if they are not addressed in time with due modifications in lifestyles[4, 17, 18].
There are several limitations to this study. Some inherent selection bias among the participant was unavoidable due to the following factors; Student motivation/participation rate: Those who volunteered carried a positive perception of body image, while those who knew they were either overweight or obese, opted not to participate. Retention Rate: On an average, almost 50% of the freshmen class would sign up to participate every year, while less than half of those completed all the screening procedures. A few identified reasons behind this phenomenon are: 1. Participation being voluntary and not mandatory, 2. Poor retention rates at the school level (44%), 3. Not all instructors of the University Orientation Class (UNV101) offered extra points for students’ participation, and 4. As mentioned earlier, those who knew they were either overweight or obese opted not to participate.