Increased central body fat deposition precedes a significant rise in resting blood pressure in male offspring of essential hypertensive parents: a 5 year follow-up study

OBJECTIVES: As long as offspring of essential hypertensive parents (OHyp) are lean, their blood pressure usually remains within normal limits. The mechanism(s) transforming this 'genetically dysregulated normotension' into hypertension are unclear. We hypothesized that OHyp are not only genetically prone to develop hypertension, but may also have a particular propensity to accumulate central body fat. DESIGN: A 5-year follow-up cohort study. SETTING: University Hospital in Switzerland. PARTICIPANTS: Seventeen young (25 +/- 1 years, mean +/- SD), lean healthy normotensive male OHyp and 17 age- and sex-matched offspring of normotensive parents (ONorm) paired for baseline blood pressure with the OHyp. MAIN OUTCOME MEASURES: Resting and exercise blood pressure, body weight, body mass index (BMI) and waist-to-hip ratio were assessed at baseline and after 5 years. RESULTS: At baseline, body weight, BMI, waist-to-hip ratio and blood pressure did not differ significantly between OHyp and ONorm. At follow-up, body weight was increased in both groups (from 73.9 +/- 6.0 to 77.7 +/- 8.1 kg in OHyp, P = 0.008, and from 71.5 +/- 6.9 to 73.5 +/- 6.6 kg in ONorm, P = 0.03). BMI followed a similar pattern. In contrast, waist-to-hip ratio increased in OHyp (from 0.84 +/- 0.03 to 0.87 +/- 0.03, P = 0.012), but not in ONorm (from 0.84 +/- 0.03 to 0.84 +/- 0.04, P = 0.79) and was therefore higher in OHyp at follow-up (P = 0.011, OHyp versus ONorm). Peak systolic blood pressure during dynamic exercise also rose at 5 years in the OHyp (from 182 +/- 10 to 214 +/- 17 mmHg, P = 0.0001) while resting systolic blood pressure only tended to do so (from 121 +/- 7 to 128 +/- 12 mmHg, P = 0.07). In ONorm, resting and peak dynamic exercise systolic blood pressure remained unchanged (119 +/- 11 versus 121 +/- 9 mmHg, baseline versus follow-up, P = 0.40, and 186 +/- 12 versus 196 +/- 22 mmHg, P = 0.10, respectively). Thus, systolic peak exercise blood pressure was significantly (P = 0.014) elevated at follow-up in OHyp compared to ONorm, while resting systolic blood pressure only tended (P = 0.06) to do so. CONCLUSIONS: Initially lean normotensive OHyp have a disparate long-term course of central body fat as compared to ONorm. Thus, OHyp are not only genetically prone to develop hypertension, but they also have a particular propensity to accumulate central body fat, even before a distinct rise in resting blood pressure occurs. The exaggerated blood pressure response to exercise observed at follow-up in the OHyp represents another marker that confers them a greater risk of developing future hypertension.