Lifestyle factors fail to explain the variation in plasma leptin concentrations in women.

To assess the relationship between circulating leptin concentrations, metabolic parameters, and lifestyle factors such as alcohol intake, physical activity level, smoking habits, and reproductive history, a cohort of 359 women was drawn from a population-based study conducted in Victoria, Australia. The parameters measured included body mass index (BMI); waist and hip circumference; blood pressure; and fasting glucose, insulin, triacylglycerol, cholesterol, and leptin concentrations. In addition, a self-administered questionnaire was used to assess reproductive history, physical activity level, alcohol intake, and smoking habits. Our results demonstrated that BMI, body weight, waist circumference, and hip circumference were all strongly correlated with circulating leptin concentrations in this population (r > 0.56, P < 0.001 in all cases). Waist/hip ratio, triacylglycerols, insulin, glucose, and cholesterol were also associated with leptin (P < 0.05), but there was no association between leptin and age, height, or blood pressure. When these associations were adjusted for BMI, age, glucose, and waist circumference were significantly associated with leptin. The lifestyle factors examined did not help to explain the observed variation in leptin concentrations between individuals when results were adjusted for degree of adiposity and age.