Plasma leptin levels strongly correlate with plasma renin activity in patients with essential hypertension

Previous studies demonstrated elevated plasma leptin and angiotensinogen (P RA) levels in essential hypertension. However, a few studies investigated t he relationship between leptin and angiotensinogen levels in both lean and overweight/obese hypertensives. The aim of the present study was therefore to examine the relationship between blood pressure, leptin and plasma renin activity in normotensives and in both lean and overweight/obese patients w ith essential hypertension. Two groups of subjects who were carefully match ed for age, gender, waist:hip ratio and body mass index (BMI) were studied: 28 normotensives (NT) (age: 40.1+/-9.1 years old, BMI: 28.1+/-3.6 kg/m(2), male/female: 18/10) and 33 newly diagnosed mild to moderate essential hype rtensives (EHT) (age: 38.9+/-10 years old, BMI: 27.9+/-4.8 kg/m(2), male/fe male: 22/11). No significant differences in age, gender, waist:hip ratio, f asting blood glucose and BMI were detected between EHT and NT groups. Howev er, systolic and diastolic pressures, mean arterial blood pressures, plasma leptin levels and PRA were significantly higher in EHT group than in NT gr oup (P=0.001). Plasma leptin levels were strongly correlated with BMI in EH T (r=0.67, P=0.001) and NT groups (r=0.44, P=0.001). Plasma leptin levels w ere correlated with plasma PRA levels in both EHT and NT groups (r=0.66 and r=0.44; both P<0.05, respectively). There was no correlation between lepti n or PRA and systolic, diastolic pressures, or mean arterial blood pressure s. Furthermore, the patients were divided as lean (n=16) and overweight/obe se (n=17) and compared with BMI-matched controls. In both subgroups, plasma leptin and PRA levels were also higher than those of controls. Our results showed that elevated plasma leptin and PRA are associated with hypertensio n in both lean and overweight/obese hypertensives. Moreover, plasma leptin was significantly correlated with plasma angiotensinogen levels. These find ings suggest that adipose mass is an important determinant of blood pressur e, although the mechanism is not clear.