Leptin is associated with increased risk of myocardial infarction

Objectives and design. Leptin is involved in the regulation of bodyweight a nd metabolism in man and might also be involved in the pathophysiology of t he insulin resistance syndrome, which is associated with the development of cardiovascular diseases. We tested whether leptin is a risk factor for acu te myocardial infarction (AMI) in a nested case-referent study. Subjects and methods. Sixty-two men with first-lever AMI were identified wh o, prior to AMI, had participated in population-based health surveys in Nor thern Sweden. Referents were matched for sex, age, date and type of health survey, and geographical region. Blood pressure, body mass index (BMI) and the presence of smoking, diabetes and hypertension were recorded. Total cho lesterol, apolipoprotein A-1 (apo A-1), apolipoprotein B (apo B), plasminog en activator inhibitor (PAI-1), insulin, and leptin were analysed in stored samples. Their influences on first-ever AMI were analysed by conditional l ogistic regression analysis. Results. Men with first-ever AMI had higher BMI, plasma insulin and leptin, and diastolic blood pressure than the referents. Furthermore, they had low er plasma ape A-1 and were more often smelters. Smoking, high leptin, PAI-1 and cholesterol, and low ape A-1 levels were significant risk factors for first-ever AMI in univariate analysis. High leptin (OR 8.97; 95% CI: 1.73-4 6.5) and cholesterol (OR 5.18; 95% CI: 1.34-20.0) levels remained significa nt risk factors for AMI in a multivariate model. High ape A-1 was protectiv e (OR = 0.13; 95% CI: 0.03-0.55). The combination of high leptin and low ap o A-1 was associated with a particularly pronounced increased risk for AMI. Conclusion. Plasma leptin strongly predicts first-ever AMI. Our data suppor t the hypothesis that leptin is an important link in the development of car diovascular disease in obesity.