Relationships between baseline serum leptin levels and 2-year changes in body mass index, blood pressure and metabolic parameters in Japanese male adolescents and middle-aged men

We and others have reported that serum leptin levels are positively correla ted with body mass index (BMI), blood pressure and heart rate (HR) in cross -sectional clinical studies. However, only a few longitudinal studies have focused on the relationships between leptin, BMI and blood pressure. The pr esent study was performed to elucidate the relationships between baseline s erum leptin levels and 2-year changes in BMI, blood pressure, HR and metabo lic parameters in 314 Japanese male adolescents aged 16-17 years and in 225 Japanese men aged 30-63 years. Height, weight, systolic blood pressure (SB P), diastolic blood pressure (DBP), HR, fasting plasma glucose (FPG), serum lipids [total cholesterol (TC), triacylglycerols (TG), high-density-lipopr otein cholesterol (HDL-C) and low-density-lipoprotein cholesterol (LDL-C)I, uric acid (UA), insulin and leptin levels were measured in the morning aft er an overnight fast. In the male adolescents, serum leptin levels in 1996 (log[leptin'96]) were significantly correlated with BMI, SEP. mean blood pr essure and HR in 1998 (r = 0.40, 0.13, 0.11 and 0.14, respectively). The pe rcentage change in BMI per year (Delta BMI) was negatively correlated with log [leptin'96], even after adjustment for baseline BMI (r = -0.12, P = 0.0 30). in men aged 30-63 years, log[leptin'96] was also positively correlated with BMI'98, SBP'98, DBP'98, FPG'98, TC'98, log[TG'98], LDL-C'98 and UA'98 (all P < 0.05), and negatively correlated with HDL-C'98, <Delta>BMI, Delta FPG, Delta TC and Delta LDL-C. The relationship between log [leptin'96] an d Delta TC was significant, even after adjustment for initial BMI (r = -0.1 5, P = 0.023). These findings therefore suggest that serum leptin levels ar e correlated with subsequent decreases in BMI and TC in Japanese men.