Dietary chloride as a possible determinant of the severity of exercise-induced asthma

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• 作者：T. Mickleborough ; R. Gotshall ; E. Kluka ; C. Miller and L Cordain
• 关键词：Exercise induced bronchoconstriction Dietary salt Asthma Metabolic acidosis Eicosanoids
• 刊名：European Journal of Applied Physiology
• 出版年：2001
• 出版时间：September 2001
• 年：2001
• 卷：85
• 期：5
• 页码：450-456
• 全文大小：112 KB

文摘

Dietary sodium chloride (NaCl) has been shown to alter the severity of exercise-induced asthma, but it is not known if the sodium and chloride ions have independent effects in this regard. The hypothesis tested in the present study was that both a low sodium, low chloride diet and a high sodium, low chloride diet would improve post-exercise pulmonary function in subjects with exercise-induced asthma (EIA) compared to a normal NaCl diet (NSD); but that neither of these diets would have an effect on post-exercise pulmonary function in control (non-EIA) subjects. Eight subjects who suffered from EIA and eight subjects who did not (control) took part in a double-blind crossover study. Pre- and post-exercise pulmonary function was assessed after 2 weeks on a NSD, a low NaCl diet (LSD, low sodium, low chloride) or a sodium bicarbonate diet (NaHCO₃ diet, high sodium, low chloride). A 1 week washout period occurred between diets. Altering dietary sodium or chloride had no effect on pre-exercise (baseline) pulmonary function in either group or on post-exercise pulmonary function in control subjects. However, both the LSD and the NaHCO₃ diet lessened the deterioration in post-exercise pulmonary function in EIA subjects. Comparing results from pre- to post-exercise, forced expiratory volume in 1 s (FEV₁) at 15 min post-exercise differed significantly (P<0.05) between diets [mean (SEM) 7 (4) % on the LSD, 14 (4) % on the NaHCO₃ diet, and 19 (2) % on the NSD]. Similar patterns were observed for forced vital capacity (FVC), forced expiratory flow rate at 25 % &#8211;75 % FVC and peak expiratory flow rate. The NaHCO₃ diet lessened the deterioration of post-exercise pulmonary function, but not to the extent of LSD. These data suggest that both sodium and chloride contribute to the worsening of EIA symptoms seen after consuming a normal or high NaCl diet.