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：本研究的目的是检验四年的社区指导干预对功能正常的社区老年人全死因死亡风险的影响。设计：为期十年的随访研究。地点和方法：研究对象是居住在日本北部南盖村的65岁(男243人，女386人，平均年龄71.0岁)的有功能的老年人的代表性样本。经过四年的营养干预(1996年至2000年)，该人群的白蛋白水平(4.11g/dL，→为4.27g/dL)显著增加。根据干预期间白蛋白水平的变化将人群分为3组：第1组：0.0g/dL(25%)≦ΔAlb，第2组；0.0g/dL+ΔAlb；+0.3g/dL(75%)，第3组；+0.3g/dL≦ΔAlb。使用COX比例风险模型评估干预后6年(从2000年至2006年)三组患者全因死亡的风险。结果：在6年的随访期内，88例(14.0%)男性和女性死亡。全因死亡的风险与干预期间白蛋白水平的升高呈负相关，多因素风险比分别为：1组1.00(参考)、2组0.69(95%可信区间0.42~1.12)、3组0.47(0.24~0.90)，调整性别、年龄、1996年白蛋白水平、2000年高功能水平、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正常的社区老年人全因死亡的风险。加强营养干预可延缓老年人衰老。

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.