Hypotensive mechanism induced by calorie restriction in overweight hypertensive patients

为探讨钠摄入量对10例超重高血压病患者热量限制所致血压下降的影响，对10例超重高血压病患者进行了钠摄入量的测定。他们接受了一周的低钠饮食，每天摄入2克NaCI，然后切换到每天12克的高钠饮食，持续一周。然后，他们接受持续2-3周的低卡路里饮食(450卡路里/天)。在初始体重下降后，重复限钠和负荷。在每个饮食周期结束时测量24小时动态血压。低热量饮食的平均体重减轻为6.0×2.8 kg，显著降低了低钠饮食下的平均血压，从103×13 mm Hg降至98×13 mm Hg。在高钠饮食下，体重减轻与血压从107*16毫米汞柱降至10*716毫米汞无关。因此，体重减轻显著增加了血压对盐的敏感性，从4毫米汞增加到9毫米汞。低钠饮食与高钠饮食之间血浆肾素活性、尿醛固酮和去甲肾上腺素排泄量的变化在减重前显著高于减重后。结论：限制热量摄入可显著降低血压。过量的钠摄入似乎通过增加对盐的敏感性而削弱了这种有利的效果。对于超重的高血压病患者，推荐在限制钠的情况下减少体重，以降低血压。

The present study was conducted to determine the effect of sodium intake on the blood pressure decrease induced by calorie restriction in 10 overweight patients with essential hypertension. They received a low sodium diet containing 2 g of NaCI/day for a week, and were then switched to a high sodium diet that contained 12 g per day for another week. They then received a low calorie diet (450 kcal/day) for 2-3 weeks. After the initial weight loss, sodium restriction and loading were repeated. The 24-hour ambulatory blood pressure was measured at the end of each dietary period. Mean weight loss on the low calorie diet was 6.0*2.8 kg, which significantly reduced the mean blood pressure under the low sodium diet from 103*13 mmHg to 98*13 mimHg. Weight loss was not associated with the reduction in blood pressure under the high sodium diet from 107*16 mmHg to 10*716 mmHg. Thus, weight loss significantly increased the salt-sensitivity of blood pressure from 4 mmHg to 9 mmHg. The change in plasma renin activity and urinary excretions of aldosterone and norepinephrine between lowsodium diet and high sodium diet was significantly higher in pre-weight loss than post-weght loss. ffi conclusion, calorie restriction significantly decreased the blood pressure. Excess sodium intake appeared to blunt the favourable effect via an increase in salt-sensitivity. Weght loss with sodium restriction is recommended for reducing the blood pressure of overweight patients with essential hypertension.