Plasma leptin concentration in patients with Type 2 diabetes: Relationship to cardiovascular disease risk factors and insulin resistance

Aims: The aim of this study was to evaluate the relationship of obesity, leptin, insulin resistance and C-reactive protein (CRP) with coronary heart disease (CHD) risk factors in patients with Type 2 diabetes mellitus (DM) with CHD compared with those with Type 2 DM without CHD. Methods: Leptin, CRP (high sensitivity assay), fasting plasma insulin, glucose, HbA_1c and full lipid profile were determined in 58 Type 2 diabetic patients with CHD and 87 Type 2 DM patients without CHD. Results were compared between those with and without CHD. Univariate correlation as well as logistic regression analyses were used to relate these markers with traditional CHD risk factors. Results: Leptin showed significant correlations with BMI (r = 0.59; P≤ 0.0001), waist circumference (r = 0.45; P < 0.0001), CRP (r = 0.36; P < 0.0001), and fasting insulin (r = 0.53; P < 0.0001) as well as with systolic (r = 0.23; P = 0.007) and diastolic (r = 0.23; P = 0.007) blood pressure. However, when those with and without CHD were compared only age (P < 0.0001), duration of diabetes (P < 0.001) and degree of microalbuminuria (P = 0.02) were significantly higher in patients with CHD. Leptin (P = 0.49), CRP (P = 0.19) and lipid parameters were not significantly different between the two groups. Conclusion: Our study confirms a relationship between leptin and CRP with CHD risk factors. The lack of significant difference when patients with and without CHD are compared may be due to the potential confounding effects of treatment with aspirin and statins.