Background: Low grip strength is recognized as one of the characteristics of frailty, as are systemic inflammation and the sensation of fatigue. Contrary to maximal grip strength, the physical resistance of the muscles to fatigue is not often included in the clinical evaluation of elderly patients. The aim of this study was to investigate if the grip strength and the resistance of the handgrip muscles to fatigue are related to self-perceived fatigue, physical functioning and circulating IL-6 in independently living elderly persons. Methods: Forty elderly subjects (15 female and 25 male, mean age 75 ± 5 years) were assessed for maximal grip strength, as well as for fatigue resistance and grip work (respectively time and work delivered until grip strength drops to 50% of its maximum during sustained contraction), self perceived fatigue (VAS-Fatigue, Mob-Tiredness scale and the energy & fatigue items of the WHOQOL-100), self rated physical functioning (domain of physical functioning on the MOS short-form) and circulating IL-6. Relationships between handgrip performance and the other outcome measures were assessed. Results: In the male participants, fatigue resistance was negatively related to actual sensation of fatigue (VAS-F, p < .05) and positively to circulating IL-6 (p < .05). When corrected for body weight, the relations of fatigue resistance with self-perceived fatigue became stronger and also apparent in the female. Grip strength and grip work were significantly related with several items of self-perceived fatigue and with physical functioning. These relations became more visible by means of higher correlation coefficients when grip strength and grip work were corrected for body weight. Conclusion: Well functioning elderly subjects presenting less handmuscle fatigue resistance and weaker grip strength are more fatigued, experience more tiredness during daily activities and are more bothered by fatigue sensations. Body weight seems to play an important role in the relation of muscle performance to fatigue perception. Elderly patients complaining from fatigue should be physically assessed, both evaluating maximal grip strength and fatigue resistance, allowing the calculation of grip work, which integrates both parameters. Grip work might best reflect the functional capacity resulting from the development of a certain strength level in relation to the time it can be maintained.

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-α alpha (TNF-α). 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-α. 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.

Heat‐shock proteins (Hsps) are highly conserved throughout evolution and evoke great interest both in basic biology and in medicine. They are expressed in small quantities under normal conditions, and their expression can be strongly induced by several stressors. Although their action is basically intracellular, it is now obvious that these proteins can be released into the extracellular environment from viable cells. In this study, the human Hsp 70 serum concentrations were determined using an optimized, cost‐effective enzyme‐linked immunosorbent assay (ELISA). The average intra‐assay variation was 6%, whereas the average interassay variation was 9%. The sensitivity of the assay was 10 ng/ml, and spiking experiments showed recoveries between 101 and 109%. As an application of the technique, we have investigated the serum levels of human Hsp 70 in patients with infection and in healthy subjects. Our data show significantly higher levels of Hsp 70 (P = 0.003) in patients compared to control subjects. Positive correlations were noticed between the serum levels of Hsp 70 and various markers of inflammation (IL‐6; r = 0.579, P = 0.009, TNF‐α; r = 0.552, P = 0.012, IL‐10; r = 0.361, P = 0.002). We conclude that Hsp 70 is involved in inflammation of infectious origin. The interindividual variation in the serum concentration of Hsp 70 precludes the use of serum Hsp 70 levels to distinguish patients from healthy subjects.