Houston Denise K, Tooze Janet A, Garcia Katelyn, Visser Marjolein, Rubin Susan, Harris Tamara B, Newman Anne B, Kritchevsky Stephen B
Wake Forest School of Medicine, Winston-Salem, North Carolina.
Vrije Universiteit, Amsterdam, The Netherlands.
J Am Geriatr Soc. 2017 Aug;65(8):1705-1711. doi: 10.1111/jgs.14856. Epub 2017 Mar 17.
The current Recommended Dietary Allowance (RDA) for protein is based on short-term nitrogen balance studies in young adults and may underestimate the amount needed to optimally preserve physical function in older adults. We examined the association between protein intake and the onset of mobility limitation over 6 years of follow-up in older adults in the Health ABC study.
Prospective cohort study.
Memphis, Tennessee and Pittsburgh, Pennsylvania.
Community-dwelling, initially well-functioning adults aged 70-79 years (n = 1998).
Protein intake (g/kg body weight/d) was calculated using an interviewer-administered 108-item food frequency questionnaire at baseline. Mobility limitation was assessed semi-annually and defined as reporting any difficulty walking one-quarter of a mile or climbing 10 steps on 2 consecutive 6-month contacts. The association between protein intake and incident mobility limitation was examined using Cox proportional hazard regression models adjusting for demographics, behavioral characteristics, chronic conditions, total energy intake, and height.
Mean (SD) protein intake was 0.91 (0.38) g/kg body weight/d, with 43% reporting intakes less than the RDA (0.8 g/kg body weight/d). During 6 years of follow-up, 705 participants (35.3%) developed mobility limitations. Compared to participants in the upper tertile of protein intake (≥1.0 g/kg body weight/d), participants in the lower two tertiles of protein intake (<0.7 and 0.7 -<1.0 g/kg body weight/d) were at greater risk of developing mobility limitation over 6 years of follow-up (RR (95% CI): 1.86 (1.41-2.44) and 1.49 (1.20-1.84), respectively).
Lower protein intake was associated with increased risk of mobility limitation in community-dwelling, initially well-functioning older adults. These results suggest that protein intakes of ≥1.0 g/kg body weight/d may be optimal for maintaining physical function in older adults.
当前的蛋白质膳食推荐摄入量（RDA）基于对年轻人的短期氮平衡研究，可能低估了老年人最佳维持身体功能所需的蛋白质量。我们在健康ABC研究中，对老年人进行了6年随访，研究蛋白质摄入量与行动能力受限发生之间的关联。
前瞻性队列研究。
田纳西州孟菲斯市和宾夕法尼亚州匹兹堡市。
社区居住的、初始功能良好的70 - 79岁成年人（n = 1998）。
在基线时，使用由访员管理的包含108个条目的食物频率问卷计算蛋白质摄入量（克/千克体重/天）。每半年评估一次行动能力受限情况，定义为在连续两次6个月的随访中，报告行走四分之一英里或爬10级台阶有任何困难。使用Cox比例风险回归模型，对人口统计学、行为特征、慢性病、总能量摄入和身高进行调整，研究蛋白质摄入量与行动能力受限发生之间的关联。
平均（标准差）蛋白质摄入量为0.91（0.38）克/千克体重/天，43%的人报告摄入量低于RDA（0.8克/千克体重/天）。在6年的随访期间，705名参与者（35.3%）出现了行动能力受限。与蛋白质摄入量处于上三分位数（≥1.0克/千克体重/天）的参与者相比，蛋白质摄入量处于下两个三分位数（<0.7和0.7 - <1.0克/千克体重/天）的参与者在6年随访中出现行动能力受限的风险更高（风险比（95%置信区间）：分别为1.86（1.41 - 2.44）和1.49（1.20 - 1.84））。
在社区居住的、初始功能良好的老年人中，较低的蛋白质摄入量与行动能力受限风险增加有关。这些结果表明，蛋白质摄入量≥1.0克/千克体重/天可能对维持老年人的身体功能最为适宜。
