Perinephric adipose tissue thickness in relation to blood pressure, plasma apelin and C-reactive protein levels in obese adolescents

Abstract

BACKGROUND: Visceral adiposity plays an important role in the pathogenesis of obesity related hypertension. Measurement of perinephric adipose tissue (PNAT) thickness has not been studied yet. We aimed to define the relation of PNAT with hypertension, and to investigate its correlations with apelin and C-reactive protein. METHODS: Sixty obese adolescents (33 females, 27 males) with a mean age of 14.0 +/- 0.8 years and 29 age-matched lean controls were recruited. Obese subjects were divided as hypertensive (Group 1) and normotensive (Group 2) using 24 hour ambulatory blood pressure monitoring. PNAT was measured using ultrasonography bilaterally. RESULTS: PNAT thickness was found increased by 0.5 mm for each point of increase in body mass index (BMI). Plasma apelin levels were significantly higher in Groups 1 and 2 than those in control group (P<0.001 and P=0.001, respectively). In Group 1 BMI, plasma insulin and cortisol levels were significantly higher. Apelin was positively correlated with BMI and PNAT (P<0.001 for both), and negatively correlated with pubertal stage (rho=-0.313, P=0.003) and age (rho=-0.250; P=0.018). CONCLUSIONS: This is the first study showing direct correlation between PNAT and BMI and also between apelin and BMI in obese adolescents. Hypertension in adolescence is related to degree of obesity. While plasma apelin increases in obesity, it decreases with increasing age and pubertal stage.