Leptin levels are not related to risk factors for coronary heart disease in patients with type 2 diabetes mellitus or normal controls

This study investigated the relationship between leptin and risk factors fo r coronary heart disease (CHD) in patients with type 2 diabetes mellitus an d nondiabetic controls. A total of 21 patients with diabetes mellitus (grou p A, 19 men and 2 women) were compared with 10 nondiabetic subjects (group B, 5 men and 5 women). Insulin-treated patients with diabetes mellitus, sub jects receiving antihyperlipidemic therapy, and patients with CHD, renal, t hyroid, or hepatic disorders were excluded from the study. Body-mass index (BMI), waist-to-hip ratio (WHR), glycosylated hemoglobin A(1c), total chole sterol, triglycerides, apolipoprotein A, apolipoprotein B, apo-lipoprotein E, fibrinogen, tissue plasminogen activator, and plasminogen inhibitor-1 le vels were determined for all patients after an overnight. fast. In addition , plasma levels of insulin, proinsulin, and leptin were estimated. The 2 gr oups were comparable in terms of age (group A, 52.52 +/- 4.64 years; group B, 49.50 +/- 4.90 years), BMI (group A, 27.50 +/- 1.83 kg/m(2); group B, 25 .79 +/- 2.90 kg/m2), and WHR (group A, 0.98 +/- 0.07; group B, 0.92 +/- 0.0 9). Plasma leptin levels were significantly higher (P = 0.038) in nondiabet ic subjects than in patients with diabetes mellitus (11.51 +/- 8.14 ng/mL v s 5.96 +/- 3.85 ng/mL, respectively), possibly because of the higher propor tion of women in the nondiabetic group. Leptin levels were significantly co rrelated with BMI in patients with diabetes mellitus (r = .51); a tendency toward a positive correlation with insulin levels was noted in this group ( r = .41). No statistically significant correlations were observed regarding leptin with the other risk factors of GHD in either group. Except for the degree of obesity in patients with diabetes mellitus, leptin does not appea r to be related to most risk factors for CBD in patients ai th diabetes or nondiabetic subjects. Additional studies with more patients are needed to h elp explain the complex interactions of leptin with other CHD risk factors.