サルコペニアの血中マーカー候補：Hsp72

血漿熱ショックタンパク質（heat shock protein）72が高齢者のサルコペニアの血中マーカーとなりうるという報告を紹介します。

Kishiko Ogawa, Hun-kyung Kim, Takahiko Shimizu, Sigeaki Abe, Yumi Shiga and Stuart K. Calderwood. Plasma heat shock protein 72 as a biomarker of sarcopenia in elderly people. Cell Stress and Chaperones DOI: 10.1007/s12192-011-0310-6

結果だけですが、Hsp72が高い高齢者では、筋肉量が少なく、握力が弱く、歩行速度が遅く、血中マーカーとなる可能性があるとしています。この結果は年齢、性別、関連疾患で調整後も残存しました。

この研究結果だけで血中マーカーとして使用できるとはいえません。ただ、サルコペニアの血中マーカーは今のところありませんので、Hsp72とサルコぺニアに関する研究がさらに行われることを期待したいです。

Abstract
Sarcopenia is a geriatric syndrome in which there is a decrease of muscle mass and strength with aging. In age-related loss of muscle strength, there are numerous observations supporting the assertion that neural factors mediate muscle strength. A possible contributing cause may be that aging changes systemic extracellular heat shock protein (eHsp)72 activity. The present study was designed to assess the plasma levels of eHsp72 in elderly people and to investigate its potential interaction with components of sarcopenia. A total of 665 men and women participated in an official medical health examination and an integrated health examination, including psychological and physical fitness tests. Blood samples were assayed for levels of plasma Hsp72, serum C-reactive protein, interleukin 6, tumor necrosis factor α, and regular biomedical parameters. We found that higher Hsp72 in plasma is associated with lower muscle mass, weaker grip strength, and slower walking speed, and may be a potential biomarker of sarcopenia in elderly people. This finding was supported by other results in the present study: (1) older age and shrinking body and lower hemoglobin levels, all of which characterize sarcopenia, were related to higher eHsp72 tertiles and (2) the ORs of the highest tertile of eHsp72 for the lowest tertiles of muscle mass, grip strength, and walking speed were 2.7, 2.6, and 1.8, respectively. These ORs were independent of age, sex, and the incidence of related diseases. Our results would reveal that eHsp72 in plasma is linked to sarcopenia factors and is a potential biomarker or predictor of sarcopenia.