Antonios T F, MacGregor G A
Department of Medicine, St George's Hospital Medical School, London, UK.
J Hum Hypertens. 1995 Jun;9(6):511-5.
Increasing evidence from animal, epidemiological, intervention studies and treatment trials all clearly point to the important role that salt intake plays in determining blood pressure (BP). Of more current interest is whether salt may have other deleterious effects independent of its role in high BP. For instance, salt intake plays an important role in left ventricular hypertrophy independent of its effect on BP. Experimental evidence and some epidemiological evidence also suggest that salt intake may have an adverse effect on stroke mortality which may be independent of its effect on BP. In animal models of renal failure, dietary salt restriction has been found to slow the progression of the renal impairment, but no studies as yet have been reported in humans. Salt intake has also been associated with asthma, stomach and nasopharyngeal cancer. Increasing salt intake produces changes in the chemical composition of urine, particularly an increase in calcium excretion which will predispose to kidney stone formation and has also been shown to increase hydroxyproline excretion indicating increased bone resorption. It is likely that a high salt intake may be one of several factors aggravating osteoporosis. This may be particularly relevant in patients with essential hypertension who already have an increased urinary calcium excretion and may in the long term be at greater risk of osteoporosis. Restriction of salt intake reduces urinary calcium excretion and, perhaps, like thiazide diuretics may be beneficial in the long-term prevention of bone demineralisation.
来自动物研究、流行病学研究、干预性研究及治疗试验的越来越多的证据均明确指出，盐的摄入量在决定血压方面发挥着重要作用。当前更受关注的是，盐是否可能具有除了在高血压中所起作用之外的其他有害影响。例如，盐的摄入量在左心室肥厚中起着重要作用，而与其对血压的影响无关。实验证据和一些流行病学证据还表明，盐的摄入量可能对中风死亡率产生不利影响，这可能与其对血压的影响无关。在肾衰竭的动物模型中，已发现限制饮食中的盐可减缓肾功能损害的进展，但目前尚未有在人类中的相关研究报道。盐的摄入量还与哮喘、胃癌和鼻咽癌有关。盐摄入量增加会导致尿液化学成分发生变化，尤其是钙排泄增加，这会增加肾结石形成的易感性，并且还已表明会增加羟脯氨酸排泄，提示骨吸收增加。高盐摄入很可能是加重骨质疏松症的几个因素之一。这在原发性高血压患者中可能尤为相关，这些患者本来就有尿钙排泄增加的情况，长期来看可能面临更高的骨质疏松风险。限制盐的摄入量可减少尿钙排泄，并且或许与噻嗪类利尿剂一样，可能对长期预防骨质脱矿有益。
