哮喘联盟

    有些观察研究指出低钠饮食可以改善哮喘控制。Pogson ZE等进行了一项随机双盲安慰剂对照的研究来观察哮喘患者经6周的低钠饮食是否可改善哮喘症状。入选的患者均经医生诊断为哮喘，并接受了气道反应性测定。入选者随机分为两组：正常钠量摄入组和低钠摄入组，共6周。观察指标包括：气道反应性的变化、肺功能、晨起和夜间呼气峰流速、哮喘症状评分、每日支扩剂使用情况、Juniper标准生活质量问卷评分。入选的220例哮喘者中共199例完成了整个研究。研究结果显示：低钠摄入者平均每日尿钠排出量较标准减少20mmol，正常钠摄入者尿钠排出较标准增加28mmol。两组患者在上述观察的指标的对比上无明显差异。
    因此作者认为：低钠饮食做为成人哮喘常规治疗以外的辅助治疗对哮喘症状的控制和气道反应性改善无任何作用。

                    （王苹莉 浙江医科大学附属第二医院呼吸科 310009  摘译）
              （Am J Respir Crit Care Med. 2008 Jul 15;178(2):132-138.）

Pogson ZE, Antoniak MD, Pacey SJ, Lewis SA, Britton JR, Fogarty AW. Does a low sodium diet improve asthma control? A randomized controlled trial. Am J Respir Crit Care Med. 2008 Jul 15;178(2):132-8.

RATIONALE: Observational studies and initial randomized trials have indicated that a low sodium diet may improve asthma control.
OBJECTIVES: We tested the hypothesis that a low sodium diet would improve asthma control over a 6-week period.
METHODS: Participants with a physician diagnosis of asthma and measurable bronchial reactivity to methacholine entered a randomized double-blind placebo-controlled trial. All adopted a low sodium diet and were randomized to receive either 80 mmol/day of oral sodium supplements (normal sodium intake) or matched placebo (low sodium intake) for 6 weeks. The primary outcome was change in bronchial reactivity to methacholine; secondary outcomes were change in lung function, morning and evening peak expiratory flow, asthma symptoms score, daily bronchodilator use, Juniper Standardized Asthma Quality of Life Questionnaire score, and atopy.
MEASUREMENTS AND MAIN RESULTS: A total of 220 individuals entered the study, of whom 199 completed the protocol. In the low sodium-intake group, mean daily urinary sodium excretion decreased by 20 mmol (SD, 64 mmol) and in the normal-sodium-intake group increased by 28 mmol (SD, 74 mmol). There were no differences between the two groups in the primary or secondary outcome measures; the mean difference in bronchial reactivity between the low- and normal-intake groups was -0.03 doubling doses of methacholine (95% confidence interval, -0.60 to 0.53).
CONCLUSIONS: The use of a low sodium diet as an adjunctive therapy to normal treatment has no additional therapeutic benefit in adults with asthma and bronchial reactivity to methacholine.