Effects of the nutritional improvement resulting from a long-term intervention on life expectancy and active-life expectancy in a large-scale community-living elderly population

目的：本研究的目的是探讨为期四年的社区定向干预对功能胜任的社区生活老年人全因死亡风险的影响。设计：一项为期10年的随访研究。设置和方法：研究人群是生活在农村地区（日本北方南盖村）的具有代表性的功能胜任老年人样本，年龄为106岁（243名男性，386名女性，平均年龄：71.0岁）。由于4年的营养干预（从1996年到2000年），该人群的白蛋白水平显著升高（4.11 g/dL → 4.27 g/dL）。根据干预期间白蛋白（t alb）的变化水平，将人群分为三组;第1组：0.0 g/dL（25百分位数）≤ Δalb，第2组; 0.0 g/dL < Δalb <+0.3 g/dL（75百分位数），第3组;+0.3 g/dL ≤ Δalb。采用考克斯比例风险模型对干预后6年（2000 - 2006年）三组患者的全因死亡风险进行评估。结果：在6年的随访中，88例（14.0%）男性和女性死亡。干预期间全因死亡风险与白蛋白水平升高呈负相关，多变量风险比为1.00（参比品）组1，0.69（95%置信区间[CI]，0.42-1.12）组2，0.47第3组（0.24-0.90），调整性别、年龄、1996年时的白蛋白水平、2000年时的高水平功能能力、运动习惯、中风、心脏病、糖尿病、吸烟、饮酒。结论：结果表明，改善营养状况的干预措施降低了功能胜任的社区生活老年人的全因死亡风险。营养强化的干预可能延缓老年人的衰老。

Objective : The purpose of the study is to examine effects of the nutritional improvement resulting from a four-year community-directed intervention on the risk of all-cause mortality in the functionally competent community-living senior citizens. Design : a ten-year follow-up study. Setting and methods : The study population was a representative sample of functionally competent seniors aged≧65 years (243 men, 386 women, mean age : 71.0 years) living in a rural area (Nangai village, Northern Japan). The population showed a significant increase of albumin level (4.11g/dL → 4.27g/dL) resulting from a four-year nutritional intervention (from 1996 to 2000). The population was divided into three-group based on level of change in albumin (t alb) over the intervention period ; Group 1 : 0.0g/dL (25 percentile) ≦ Δalb, Group2 ; 0.0g/dL < Δalb < +0.3g/dL (75 percentile), Group3 ; +0.3g/dL ≦ Δalb. Risks of all-cause mortality of the three groups over the 6-year (from 2000 to 2006) of the post-intervention was assessed, using the Cox proportional hazard model. Results : Over the 6-year of follow-up, 88(14.0%) men and women died. The risk of all-cause mortality was inversely associated with increase level of albumin over the intervention period, The multivariate hazard ratios were 1.00 (reference) for group1, 0.69 (95% confidence interval [CI], 0.42-1.12) for group2, 0.47 (0.24-0.90) for group3, adjusting for sex, age, albumin level at 1996 year, high-level functional capacity at 2000 year, exercise habits, stroke, heart disease, diabetes, smoking, drinking. Conclusions : The results suggested that intervention for enhancing nutritional status reduced the risk of all cause mortality in the functionally competent community-living senior citizens. The intervention of nutritional enhancement may postpone aging in the elderlypeople.