Background Obesity and arterial hypertension are important public health problems. Insulin resistance plays a fundamental role in complex pathogenesis of obesity related hypertension.
The aim of the study was to evaluate concentrations of insulin and value of insulin sensitivity in patients with hypertension and obesity. The relationship between insulin, insulin sensitivity ratio and systolic (SBP) and diastolic (DBP) blood pressure were also studied.
Material and methods 30 lean hypertensives and 30 obese patients with hypertension were qualified. As a control group 15 healthy lean volunteers were enrolled. Each subject underwent physical examination. Anthropometric parameters (body mass index - BMI, waist to hip ratio - WHR) were measured. Percentage body fat (%BF) was evaluated with bioelectric impendance - Bodystat 1500 apparatus. Routine laboratory tests were performed. Insulin concentrations were determined by radioimmunoassay methods. Insulin sensitivity (M) ratio was calculated after euglycemic clamp performance.
Results Serum levels of insulin in all studied groups were significantly higher and M ratio significantly lower in comparison with the control group. Concentrations of insulin were significantly higher and M ratio lower in obese patients with hypertension than in the group of lean hypertensives. Outcomes of lean patients with hypertension:
— positive correlations between logarithm of insulin (lnINS) and lnTG, %BF, WHR;
— negative correlations between logarithm of M ratio (lnM) and lnTG, %BF.
Outcomes of hypertensive patients with obesity:
— positive correlations between logarithm of insulin (lnINS) and BMI, %BF, WHR, SBP;
— negative correlations between logarithm of M ratio (lnM) and BMI, SBP.
In multivariate regression analysis lnM (in model with BMI or lnHDL) emerged as an independent predictor of SBP.
Conclusions 1. Hypertension and obesity associate with increased plasma insulin level and decreased insulin sensitivity.
2. Obesity related hypertension increases insulin and insulin resistance.
3. Negative correlation between systolic blood pressure (SBP) and M ratio in obese subjects with hypertension should be considered in complex pathogenesis of obesity related hypertension.