Relation between waist circumference and the renal hemodynamic in patients with uncomplicated hypertension grade 1-2

Objective: Abdominal adiposity, measured by waist circumference (WC), is associated with increased mortality in patients with hypertension. Little is known about the impact of abdominal obesity on the renal perfusion and function in patients with hypertension. We analyzed whether abdominal adiposity changes renal hemodynamics in 36 patients with uncomplicated hypertension grade 1-2 without other cardiovascular (CV) disease. Design and method: We analysed the renal hemodynamic using steady state input clearance with infusion of para-aminohippuric acid and inulin, respectively. Intraglomerular pressure and resistances of the afferent (RA) and efferent (RE) arterioles were calculated according to the Gomez equation. The study population was divided in into two groups based on median of WC of the total study population. Results: The study cohort consisted of 36 male, non-smoking individuals, aged 36 ± 10 years with mean WC of 96.1 ± 10.4 cm and mean BMI of 27 ± 3.8 kg/m 2 . True hypertension was confirmed using 24-hour ambulatory blood pressure (BP) measurement. Patients in the high WC group (19 patients) showed mean office BP of 145/ 90 mmHg and mean 24-hour ambulatory BP of 139/ 86 mmHg, whereas patients in the low WC group (17 patients) showed mean office BP of 144/ 88 mmHg and mean 24-hour-ambulatory BP of 140/ 86 mmHg (office BP: p = 0.895/ p = 0.662, 24-hour-ambulatory BP: p = 0.645/ p = 0.918). Renal vascular resistance and RA were higher in the high WC compared to the low WC group, whereas glomerular filtration rate and renal plasma flow were lower in the high WC compared to the low WC group (table 1). Conclusions: Higher WC in young, male patients with hypertension grade 1-2 without other cardiovascular disease was associated with increased renal vascular resistance predominantly at the afferent site leading to reduced glomerular filtration rate.