Weinsier R L, James L D, Darnell B E, Dustan H P, Birch R, Hunter G R
Department of Nutrition Sciences, University of Alabama, Birmingham 35294.
Am J Med. 1991 Apr;90(4):460-8.
Although weight reduction generally lowers blood pressure, it is unclear whether the response is due to concurrent dietary changes or to reduced body mass itself. In this study, the independent effects of energy restriction and weight reduction were examined prospectively in 24 obese, hypertensive, normoglycemic women whose dietary intake was tightly controlled.
Sodium, potassium, and calcium intake, the polyunsaturated/saturated fat ratio, and the proportional composition of carbohydrate, fat, and protein were constant throughout the 5-month protocol. Hemodynamic and neuroendocrine status was evaluated in four 10-day hospital phases: two prior to weight loss (energy balance and then 800-kcal intake), and two after an average loss of 13 kg to normal body weight (800 kcal and then return to energy balance).
Fasting serum insulin, triiodothyronine:reverse triiodothyronine ratio, resting metabolic rate, and heart rate declined, and sodium and potassium balances were negative during energy restriction. Catecholamines, renin, aldosterone, plasma volume, cardiac output, and blood pressure showed no consistent response to changes in energy intake. By contrast, weight reduction independently lowered blood pressure, plasma volume, cardiac output, and plasma renin activity. Body fat pattern remained unchanged.
These results demonstrate that weight loss has a blood pressure-lowering effect that is distinct from energy restriction and that is related to changes in blood volume and cardiac output.
尽管体重减轻通常会降低血压，但尚不清楚这种反应是由于同时发生的饮食变化还是体重本身的减轻。在本研究中，对24名肥胖、高血压、血糖正常且饮食摄入受到严格控制的女性进行了前瞻性研究，以考察能量限制和体重减轻的独立作用。
在整个5个月的实验方案中，钠、钾和钙的摄入量、多不饱和/饱和脂肪比例以及碳水化合物、脂肪和蛋白质的比例组成保持恒定。在四个为期10天的住院阶段对血流动力学和神经内分泌状态进行评估：两个阶段在体重减轻之前（能量平衡，然后摄入800千卡），两个阶段在平均减轻13千克至正常体重之后（摄入800千卡，然后恢复能量平衡）。
在能量限制期间，空腹血清胰岛素、三碘甲状腺原氨酸：反三碘甲状腺原氨酸比值、静息代谢率和心率下降，钠和钾平衡呈负平衡。儿茶酚胺、肾素、醛固酮、血浆容量、心输出量和血压对能量摄入的变化没有一致的反应。相比之下，体重减轻独立地降低了血压、血浆容量、心输出量和血浆肾素活性。身体脂肪分布保持不变。
这些结果表明，体重减轻具有降低血压的作用，这与能量限制不同，且与血容量和心输出量的变化有关。
