Circulating acute phase mediators and skeletal muscle performance in hospitalized geriatric patients.

BACKGROUND There is growing evidence for the significant involvement of inflammatory processes in the development of muscle wasting in old age. Therefore, any disease accompanied by inflammation can be threatening to the muscle function in geriatric patients. METHODS Sixty-three hospitalized geriatric patients (42 female, 21 male; mean age 84.2 +/- 5.7 years) were monitored weekly for muscle function (grip strength, fatigue resistance, shoulder extension strength, and hip extension strength) and for concentration of circulating C-reactive protein (CRP), fibrinogen, interleukin 6 (IL-6), and tumor necrosis factor-alpha alpha (TNF-alpha). RESULTS On the basis of circulating CRP and fibrinogen concentrations, 42 patients were categorized on admission as inflammatory and 21 as noninflammatory. Inflammatory patients presented significantly weaker grip strength, shoulder extension strength, and a worse fatigue resistance than did noninflammatory patients. These muscle functions were negatively correlated with the concentrations of circulating CRP and IL-6, but not with fibrinogen or TNF-alpha. In noninflammatory patients, the fatigue resistance improved significantly during the first week of hospitalization. In patients admitted with inflammation, no improvement of muscle function was observed. Patients who remained inflammatory for 2 weeks or more presented a significant worsening of fatigue resistance. CONCLUSIONS Geriatric hospitalized patients presenting with inflammation show significantly worse muscle functions, which do not improve during hospitalization despite adequate treatment of the primary disease. Reduced strength and fatigue resistance are significantly related to the concentration of circulating CRP and IL-6. Standard treatment of the underlying illness and classic physical therapy are not sufficient to normalize the skeletal muscle strength and fatigue resistance in these hospitalized patients.