Hirayama Fumi, Lee Andy H, Terasawa Koji, Kagawa Yasuo
School of Public Health, Curtin Health Innovation Research Institute, Curtin University of Technology, Perth, WA, Australia.
Asia Pac J Clin Nutr. 2010;19(1):103-9.
A case-control study was conducted in central Japan to investigate the relationship between dietary intake of folate and lung function, breathlessness and chronic obstructive pulmonary disease (COPD). A total of 278 referred patients (244 men and 34 women) aged 50-75 years with COPD diagnosed within the past four years and 340 community-based controls (272 men and 68 women) were assessed for dyspnoea and undertook spirometric measurements of lung function. A structured questionnaire was administered face-to-face to obtain information on demographics, lifestyle and habitual food consumption. Folate intake was derived from the Japanese food composition tables. The COPD patients had significantly lower habitual intake of folate (mean 231, SD 90 microg/day) than control subjects (mean 261, SD 110 microg/day), p<0.001. Lung function measures were found to be positively associated with dietary folate level. Reductions in prevalence of COPD and especially breathlessness were observed, the respective adjusted odds ratio (OR) being 0.74 (95% confidence interval (CI) 0.35 to 1.58) and 0.43 (95% CI 0.21 to 0.91) for the highest versus lowest quartile of folate intake. The corresponding tests for linear trend were also significant (p<0.05). In conclusion, an inverse association was evident between dietary folate intake and the prevalence of breathlessness for Japanese adults, together with a significant dose-response relationship for the COPD risk. Moreover, increased folate intake might be beneficial to lung function.
在日本中部地区开展了一项病例对照研究，以调查叶酸的饮食摄入量与肺功能、呼吸急促及慢性阻塞性肺疾病（COPD）之间的关系。共有278名转诊患者（244名男性和34名女性）参与研究，年龄在50至75岁之间，在过去四年内被诊断为患有COPD；另有340名社区对照者（272名男性和68名女性）接受了呼吸困难评估，并进行了肺功能的肺活量测定。通过面对面发放结构化问卷，获取有关人口统计学、生活方式和习惯性食物消费的信息。叶酸摄入量来自日本食物成分表。COPD患者的叶酸习惯性摄入量（平均231，标准差90微克/天）显著低于对照者（平均261，标准差110微克/天），p<0.001。研究发现，肺功能指标与饮食叶酸水平呈正相关。观察到COPD患病率，尤其是呼吸急促患病率有所降低，叶酸摄入量最高四分位数与最低四分位数相比，相应的调整优势比（OR）分别为0.74（95%置信区间（CI）0.35至1.58）和0.43（95%CI 0.21至0.91）。线性趋势的相应检验也具有显著性（p<0.05）。总之，日本成年人的饮食叶酸摄入量与呼吸急促患病率之间存在明显的负相关，且与COPD风险存在显著的剂量反应关系。此外，增加叶酸摄入量可能有益于肺功能。
