Introduction:
Obesity is linked with heightened vulnerability to cardiovascular diseases including hypertension. Nonetheless, mechanistic studies addressing the effects of experimental weight gain on blood pressure are lacking. We sought to examine whether experimental weight gain raises ambulatory blood pressure in healthy individuals and identify any relationship between changes in blood pressure and changes in regional fat distribution.
Methods:
Twenty-six normal weight subjects were randomized to a 8-week period of weight gain through overfeeding (N=16; age 30.4±6.6 years, BMI 23.5±3.5 kg/m
2
) or weight maintenance (N=10; age 27.1±7.7 years, BMI 23.6±2.7 kg/m
2
). Measurements of body composition by dual-energy X-ray absorptiometry and abdominal computed tomographic scans and 24-h ambulatory blood pressure monitoring were obtained at baseline and at follow-up.
Results:
Overfeeding resulted in an increase in body weight of 3.7±1.5 kg (
p
<0.001) in weight gainers, with increments seen in total (21994±8247.4 to 25180.7±8563.1 gr,
p
<0.001), visceral (61.6±32.7 to 75.5±30.9 cm
2
,
p
=0.002) and subcutaneous fat (135.5±77.4 to 167.9±82.9 cm
2
,
p
<0.001). No changes occurred in the maintenance group. Weight gainers exhibited an increase in 24-h systolic blood pressure at follow-up (113.7±8 to 117.7±7.9 mmHg,
p
=0.009) and mean blood pressure (MAP) (85.1±4.9 to 86.8±5.1 mmHg,
p
=0.02), while blood pressure was unchanged in controls. Changes in MAP were positively correlated only with changes in visceral fat (rho=0.452,
p
=0.02) but not with changes in weight or any other body composition measure.
Conclusion:
Modest weight gain leads to marked elevation in 24-h blood pressure in lean healthy subjects. The association between increased MAP and abdominal visceral fat accumulation suggests that visceral deposition of adipose tissue may contribute specifically and mechanistically to the enhanced risk of hypertension associated with weight gain.
Experimental Weight Gain Increases Ambulatory Blood Pressure in Healthy Subjects: Implications of Visceral Fat Accumulation
