High Plasma Immunoreactive Leptin Level in Essential Hypertension

Abstract

Insulin resistance, the most important factor in metabolic syndrome X, has been considered to raise blood pressure. Recently it was reported that insulin resistance was related to an elevated plasma level of leptin, which is an adipocyte-specific ob gene product and which plays a role in food intake suppression, thermogenesis, and energy expenditure through the activation of the hypothalamus. However there are no reports that deal with the relationship of insulin resistance to plasma leptin and blood pressure. To evaluate the role of leptin in essential hypertensives, two groups of subjects who were carefully matched for body mass index (BMI) were studied; 22 normotensives (NT, age: 46.5 +/- 2.6 years, BMI: 23.9 +/- 0.4 kg/m2, male/female: 14/8) and 45 mild-to-moderate essential hypertensives (EHT, age: 51.9 +/- 2.0 years, BMI: 24.5 +/- 0.4 kg/m2, male/female: 21/24). We applied the euglycemic hyperinsulinemic glucose clamp technique to all subjects and insulin sensitivity was evaluated as the M value. EHT showed a significantly lower M value (160.2 +/- 7.4 v 184.3 +/- 7.3 mg/m2/min, P < .05) and higher basal plasma immunoreactive leptin level (7.6 +/- 0.8 v 5.0 +/- 0.8 ng/mL, P < .05) than NT, despite the fact that there was no significant difference between NT and EHT in age, gender, or BMI. The relationship between mean blood pressure and leptin showed a significant positive correlation in all of the subjects (r = 0.31, P < .05), suggesting that leptin may be related to a pathophysiology of essential hypertension.

Sympathetic Activity and Body Mass Index Contribute to Blood Pressure Levels.

“…The primary findings of the present study are as follows: 1) systolic BP, pulse rate and plasma NE, insulin, and leptin levels in the obese group of the tertile were significantly higher than those in lean group, as has been previously reported (23)(24)(25)(26)(27); 2) BP levels correlated with plasma NE, insulin, and leptin levels in the whole cohort in Pearson's correlation analysis, as has been previously reported (28)(29)(30). However, the novel finding of the present study is that in multiple regression analyses only BMI and plasma NE levels, but not insulin or leptin levels, are predictors of BP levels in a non-diabetic, young, but with a wide range of BMI, male population.…”

A Positive Association between Leptin and Blood Pressure of Normal Range in Japanese Men

“…However, leptin has also been reported to have depressor effects; that is, leptin was shown to function as a diuretic/ natriuretic factor (39) and to induce a release of nitric oxide that opposes the pressor action (25). Although many epidemiologic researchers had studied the association of leptin with blood pressure and the sympathetic nervous system, these results were not consistent (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(40)(41)(42)(43)(44)(45). Our results may partly explain this diversity of findings.…”

Association between adipocytokines and insulin resistance in Indian hypertensive patients

“…Some studies report significantly higher leptin levels in essential HT than in control 26,27 or a significant correlation between HT and BP. [26][27][28] However, these results were not confirmed by others. 29,30 In the present study, serum leptin levels increased significantly in obese hypertensive patients.…”