[Fat tissue distribution and metabolic alterations in boys with primary hypertension]

Abstract

Metabolic alterations related to obesity are regarded as significant risk factor for target organ damage in hypertensive patients. Fat tissue distribution seems to play significant role in metabolic alterations related to cardiovascular damage. The aim of the study was to test hypothesis that fat tissue distribution and excess of visceral fat is related to cardiovascular damage and metabolic cardiovascular risk factors in obese boys with yet untreated, primary hypertension.

Patients: 40 boys (14.8 +/- 3.0 yrs) with untreated essential hypertensions.

Methods: amount of visceral (VAT), intraperitoneal visceral (ipVAT), extraperitoneal visceral (epVAT) and subcutaneous fat (SAT) was measured by nuclear magnetic imaging (NMR). Carotic intima media thickness (cIMT), fenoral intima media thickness (fIMT) and left ventricular mass index (LVMi) were evaluated by sonography. Oral glucose loading test was done, lipids, homocysteine, CRP, uric acid, microalbuminuria, adipocytokines, IGF-1 and IGF binding proteins (IGFBP) were determined.

Results: The ratio of VAT to epVAT (V/Ve) correlated with carotid IMT (p=0.0001; r=0.561), standard deviation from median of the norm of cIMT (cIMT-SDS) (p=0.0001; r=0.681), femoral IMT (p=0.015; r=0.480) and fIMT-SDS (p=0.002; r=0.579). SAT correlated negatively with cIMT (p=0.0016; r=-0.355) and cIMT-SDS (p=0.01; r=-0.391). Waist to hip ratio (WHR) correlated with cIMT-SDS (p=0.03; r=0.401). VAT correlated positively and SAT negatively with HDL, apoA1, uric acid concentration and HOMA-IR value. VAT/epVAT correlated with HOMA-IR (p=0.02; r=0.402), free IGF-1 (p=0.001; r=0.478). epVAT also correlated with free IGF-1 (p=0.006; r=-0.494) and IGFBP3 (p=0.02; r=-0.471). Step-wise regression analysis revealed that relative excess of intraperitoneal visceral fat (VAT/epVAT) and WHR were independent predictors of cIMT-SDS(p=0.022, R2=0.755).

Conclusions: Fat tissue distribution correlates with early vascular injury and metabolic alterations in boys with primary hypertension. Relative excess of visceral fat assessed by NMR and truncal obesity expressed as WHR are independent risk factors for early vascular damage in overweight boys with primary hypertension.