Experimental Weight Gain Increases Ambulatory Blood Pressure in Healthy Subjects: Implications of Visceral Fat Accumulation

Objective: To examine whether experimentally induced weight gain raises ambulatory blood pressure (BP) in healthy subjects and identify any relationship between changes in BP and changes in regional fat distribution. Patients and Methods: Twenty-six normal weight subjects were randomized to 8 weeks of weight gain through overfeeding (n=16; age, 30.4±6.6 years) or to weight maintenance (controls; n=10; age, 27.1±7.7 years) between July 2004 and August 2010. Measures of body composition via dual energy X-ray absorptiometry and computed tomography, circulating biomarkers, and 24-hour ambulatory BP were obtained at baseline and after the 8-week experimental phase. Results: Overfeeding resulted in 3.7 kg (95% CI, 2.9-4.5) increase in body weight in weight gainers, with increments in total (46.2 cm ² ; 95% CI, 27.6-64.9), visceral (13.8 cm ² ; 95% CI, 5.8-21.9), and subcutaneous fat (32.4 cm ² ; 95% CI, 13.5-51.3). No changes occurred in the maintenance group. Increases in 24-hour systolic BP (4 mm Hg; 95% CI, 1.6-6.3), mean BP (1.7 mm Hg; 95% CI, 0.3-3.3), and pulse pressure (2.8 mm Hg; 95% CI, 1.1-4.4) were evident after weight gain in the experimental group, whereas BP remained unchanged in controls. Changes in mean BP correlated only with changes in visceral fat (ρ=0.45; P=.02), but not with changes in other body composition measures. Conclusion: Modest weight gain causes elevation in 24-hour BP in healthy subjects. The association between increased BP and abdominal visceral fat accumulation suggests that visceral deposition of adipose tissue may contribute specifically to the enhanced risk of hypertension associated with weight gain.