サルコペニアと骨密度の関連：男性

サルコペニアと骨密度の関連を中年～高齢のヨーロッパ男性で調査した論文を紹介します。

S. Verschueren, E. Gielen, T. W. O’Neill, S. R. Pye, J. E. Adams, K. A. Ward, F. C. Wu, P. Szulc, M. Laurent and F. Claessens, et al. Sarcopenia and its relationship with bone mineral density in middle-aged and elderly European men. Osteoporosis International 2012, DOI: 10.1007/s00198-012-2057-z

サルコペニアと骨密度に関しては、女性ではすでに報告があります。下記のブログもその1つです。

大腿骨頸部骨折女性のサルコペニア有病割合
http://rehabnutrition.blogspot.jp/2012/05/blog-post_09.html

今回は男性でサルコペニアと骨密度の関連を調査しています。サルコペニアはDEXAによる四肢筋肉量低下およびEWGSOPによる筋肉量低下＋筋力低下で評価しています。

結果ですが679人の男性（平均年齢59.6歳）のうち、11.9％にサルコペニアを認めました。サルコペニアの男性はそうでない男性よりも、有意に骨密度が低かったです。これは多変量解析でも同様で、サルコペニアの場合、骨粗鬆症のオッズ比が3倍でした。

以上より、サルコペニアと骨密度・骨粗鬆症は、中年～高齢の男性で関連するという結論です。筋肉量維持が骨粗鬆症の予防につながるかどうかのさらなる研究が必要です。

サルコペニアと骨粗鬆症の関連は確かなようですので、一緒に考えていくべきかもしれません。骨粗鬆症がある場合にはサルコペニアを疑うべきですし、サルコペニアがある場合には骨粗鬆症を疑うべきです。転倒・骨折予防では特に両者を一緒に考えることが重要です。

Abstract

Summary

The aim of this study was to determine the relationship between reduced muscle mass (sarcopenia) and areal bone mineral density (BMD_a) in middle-aged and elderly community-dwelling European men. Men with sarcopenia had significantly lower BMD_a and were more likely to have osteoporosis compared with men without sarcopenia.

Introduction

In men, the relationship between reduced muscle mass (sarcopenia) and BMD_a is unclear. This study aimed to determine this relationship in middle-aged and elderly community-dwelling men.

Methods

Men aged 40–79 years from the Manchester (UK) and Leuven (Belgium) cohorts of the European Male Ageing Study were invited to attend for assessment including dual-energy X-ray absorptiometry, from which appendicular lean mass (aLM), fat mass (FM) and whole-body, spine and hip BMD_a were determined. Relative appendicular skeletal muscle mass (RASM) was calculated as aLM/height². Muscle strength was assessed in subjects from Leuven. Sarcopenia was defined by RASM at <7.26 kg/m² and by the recent definition of the European Working Group on Sarcopenia in Older People (RASM at < 7.26 kg/m² plus low muscle function). Linear regression was used to determine the associations between aLM, FM, muscle strength and BMD_a and logistic regression to determine the association between sarcopenia and osteoporosis.

Results

Six hundred seventy-nine men with a mean age of 59.6 (SD = 10.7), contributed data to the analysis; 11.9 % were sarcopenic by the conventional definition. After adjustment for age and centre, aLM, RASM and FM were positively associated with BMD_a. Men with RASM at <7.26 kg/m² had significantly lower BMD_a compared with those with RASM at ≥7.26 kg/m². In a multivariable model, aLM was most consistently associated with BMD_a. Men with sarcopenia were more likely to have osteoporosis compared with those with normal RASM (odds ratio = 3.0; 95 % CI = 1.6–5.8).

Conclusions

Sarcopenia is associated with low BMD_a and osteoporosis in middle-aged and elderly men. Further studies are necessary to assess whether maintaining muscle mass contributes to prevent osteoporosis.