Graf Christophe E, Karsegard Véronique L, Spoerri Adrian, Makhlouf Anne-Marie, Ho Sylvain, Herrmann François R, Genton Laurence
From the Division of Geriatrics, Department of Internal Medicine, Rehabilitation and Geriatrics, Geneva University Hospitals and University of Geneva, Geneva, Switzerland (CEG and FRH); Clinical Nutrition, Geneva University Hospitals, Geneva, Switzerland (VLK, A-MM, SH, and LG); and the Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland (AS).
Am J Clin Nutr. 2015 Apr;101(4):760-7. doi: 10.3945/ajcn.114.102566. Epub 2015 Feb 11.
A low or high body mass index (BMI) has been associated with increased mortality risk in older subjects without taking fat mass index (FMI) and fat-free mass index (FFMI) into account. This information is essential because FMI is modulated through different healthcare strategies than is FFMI.
We aimed to determine the relation between body composition and mortality in older subjects.
We included all adults ≥65 y old who were living in Switzerland and had a body-composition measurement by bioelectrical impedance analysis at the Geneva University Hospitals between 1990 and 2011. FMI and FFMI were divided into sex-specific quartiles. Quartile 1 (i.e., the reference category) corresponded to the lowest FMI or FFMI quartile. Mortality data were retrieved from the hospital database, the Geneva death register, and the Swiss National Cohort until December 2012. Comorbidities were assessed by using the Cumulative Illness Rating Scale.
Of 3181 subjects included, 766 women and 1007 men died at a mean age of 82.8 and 78.5 y, respectively. Sex-specific Cox regression models, which were used to adjust for age, BMI, smoking, ambulatory or hospitalized state, and calendar time, showed that body composition did not predict mortality in women irrespective of whether comorbidities were taken into account. In men, risk of mortality was lower with FFMI in quartiles 3 and 4 [HR: 0.78 (95% CI: 0.62, 0.98) and 0.64 (95% CI: 0.49, 0.85), respectively] but was not affected by FMI. When comorbidities were adjusted for, FFMI in quartile 4 (>19.5 kg/m(2)) still predicted a lower risk of mortality (HR: 0.72; 95% CI: 0.54, 0.96).
Low FFMI is a stronger predictor of mortality than is BMI in older men but not older women. FMI had no impact on mortality. These results suggest potential benefits of preventive interventions with the aim of maintaining muscle mass in older men. This trial was registered at clinicaltrials.gov as NCT01472679.
在未考虑脂肪量指数（FMI）和去脂体重指数（FFMI）的情况下，低或高体重指数（BMI）与老年受试者死亡风险增加相关。这一信息至关重要，因为FMI和FFMI受不同医疗策略的调节。
我们旨在确定老年受试者身体成分与死亡率之间的关系。
我们纳入了所有年龄≥65岁、居住在瑞士且于1990年至2011年期间在日内瓦大学医院通过生物电阻抗分析进行身体成分测量的成年人。FMI和FFMI按性别分为四分位数。四分位数1（即参考类别）对应最低的FMI或FFMI四分位数。死亡率数据从医院数据库、日内瓦死亡登记册和瑞士国家队列中获取，直至2012年12月。使用累积疾病评定量表评估合并症。
在纳入的3181名受试者中，766名女性和1007名男性死亡，平均年龄分别为82.8岁和78.5岁。用于调整年龄、BMI、吸烟、门诊或住院状态以及日历时间的性别特异性Cox回归模型显示，无论是否考虑合并症，身体成分均不能预测女性的死亡率。在男性中，第3和第4四分位数的FFMI对应的死亡风险较低[风险比（HR）分别为0.78（95%置信区间：0.62，0.98）和0.64（95%置信区间：0.49，0.85）]，但不受FMI影响。调整合并症后，第4四分位数（>19.5 kg/m²）的FFMI仍可预测较低的死亡风险（HR：0.72；95%置信区间：0.54，0.96）。
在老年男性中，低FFMI比BMI更能预测死亡率，但在老年女性中并非如此。FMI对死亡率无影响。这些结果表明，旨在维持老年男性肌肉量的预防性干预可能有益。该试验在clinicaltrials.gov上注册，注册号为NCT01472679。
