Objectives

To evaluate lean mass index (LMI) measured by bioimpedance (BIA) and anthropometry compared to densitometry (DXA) in elderly outpatients from a tertiary care hospital.

Methods

Participants were over 60-year-old men, presenting no dementia or disability, from a tertiary geriatric ambulatory. LMI obtained by BIA, anthropometry and DXA were submitted to Baumgartner, Janssen and Delmonico calculations respectively. Sarcopenia was calculated as LMI by DXA and handgrip strength. Data were analyzed by T student's test, ANOVA for repeated measures and pos hoc Bonferroni test, Pearson's correlation test, regression equation and Bland Altman analysis, ROC curve and contingency table 2 × 2 for sensitivity, specificity and predictive values.

Results

A total of 92 participants completed the study. Most of them were married, aged 72.9 ± 6.6, lived a sedentary lifestyle, presented multiple morbidities, and in use of polypharmacy. Appendicular lean mass was lower in sarcopenic participants when compared to that in nonsarcopenic ones (20.2 kg/m² and 23 kg/m² respectively, p < 0.0001). BIA sensitivity, specificity and correlation to DXA were 37%, 98% and r = 0.81 (p < 0.001), and for anthropometry 67%, 92% and r = 0.77 (p < 0.0001) respectively. Bland Altman's analysis showed congruence between methods and DXA (anthropometry: bias = −0,05 ± 0,66, limits of agreement (LoA) = −1.37 and 1.26; BIA: bias = 2,2; LoA = 0,7 and 3,7).

Conclusion

Aging and multiple chronic and degenerative morbidities affect LM in vulnerable elderly patients. Both anthropometry and BIA, are accurate to measure LMI independently in this population but Anthropometry presented better agreement to DXA than Bioimpedance and has the advantage of lower price, easier application and cheaper equipment to be applied.

中文翻译：

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人体测量学，生物阻抗和光密度测量法：三级医院老年门诊患者瘦体重分析的比较方法。

目标

为了评估通过生物阻抗（BIA）和人体测量法与密度测量法（DXA）进行比较的三级医院老年门诊患者的瘦体重指数（LMI）。

方法

参加者是60岁以上的男性老人，没有老年痴呆症或残疾。通过BIA，人体测量法和DXA获得的LMI分别提交给Baumgartner，Janssen和Delmonico计算。肌肉减少症通过DXA和握力计算为LMI。数据通过T学生检验，方差分析（ANOVA）进行重复测量和posfer hoc Bonferroni检验，皮尔逊相关检验，回归方程和Bland Altman分析，ROC曲线和列联表2×2进行敏感性，特异性和预测值分析。

结果

共有92位参与者完成了这项研究。他们大多数已婚，年龄为72.9±6.6，久坐不动，出现多种疾病，并使用多药店。肌肉减少症参与者的阑尾瘦质量低于非肌肉减少症参与者（分别为20.2 kg / m ²和23 kg / m ²，p  <0.0001）。BIA对DXA的敏感性，特异性和相关性分别为37％，98％和r  = 0.81（p  <0.001），而人体测量学则为67％，92％和r  = 0.77（p <0.0001）。Bland Altman的分析显示了方法与DXA之间的一致性（人体测量法：偏差= −0.05±0.66，一致极限（LoA）= −1.37和1.26; BIA：偏差= 2,2; LoA = 0.7和3 ，7）。

结论

衰老以及多种慢性和退行性疾病影响易受伤害的老年患者的LM。人体测量法和BIA均可独立准确地测量该人群中的LMI，但人体测量法与DXA相比，生物阻抗法与DXA的一致性更好，并且具有价格低廉，易于使用且设备便宜的优点。