Circulating leptin levels are not associated with cardiovascular morbidity and mortality in women with diabetes: a prospective cohort study

Aims/hypothesis Leptin, an adipocyte-secreted hormone, plays an important role in regulating neuroendocrine and immune function as well as insulin resistance and metabolism. Our objective was to examine the relationship between leptin levels and cardiovascular morbidity and overall mortality in women with type 2 diabetes. Subjects and methods This prospective cohort study included 1,194 women with a confirmed diagnosis of type 2 diabetes, who provided a blood sample at baseline in 1989–1990. Participants were followed for 12 years for the development of health outcomes including cardiovascular disease (CVD) events as well as total mortality. Results There were 218 new CVD events and 228 deaths from all causes. Cox proportional hazards analysis was used to estimate the relative risks (RRs) for each quintile level of leptin compared with the lowest quintile. Leptin levels were positively associated with several CVD risk factors including BMI and inflammatory markers, but were not independently associated with the incidence of CVD or total mortality in women with diabetes. The multivariate RRs (95% CIs) for CVD across the quintiles of leptin were 0.96 (0.61–1.53), 0.99 (0.61–1.61), 1.04 (0.63–1.71), 1.02 (0.59–1.75) (p for trend = 0.83). Conclusions/interpretation Although circulating leptin levels are associated with obesity and inflammatory markers, they are not significantly related to the risk of CVD or mortality in women with diabetes.