Fig. 1

Diabetes is associated with increased fasting plasma GLP-1 levels in patients with disease of the aortic valve. Diabetic subjects had significantly higher levels of fasting plasma total and active GLP-1 as compared to non-diabetic subjects (a, b), n = 30–45 for individual groups, and a significant positive correlation between BMI and fasting plasma GLP-1 was detected (c). Increased fasting plasma levels of total GLP-1 in diabetic patients was observed in BAV as well as TAV patients, with no significant difference in the average GLP-1 plasma level between BAV and TAV patients within the two groups (d), n = 12–30 for individual groups. Fasting plasma GLP-1 was not significantly different in diabetic patients receiving pharmacological treatment with anti-diabetics (e), n = 6–13 for individual groups. *p < 0.05; **p < 0.01; ***p < 0.001 compared with non-diabetic subjects. Comparisons between groups were made using an unpaired t-test/one-way ANOVA, and Student-Newman-Keul’s post hoc test. Significant correlations were assessed using the Pearson correlation coefficient