Grip work estimation during sustained maximal contraction: validity and relationship with dependency and inflammation in elderly persons

J Nutr Health Aging. 2011 Aug;15(8):731-6. doi: 10.1007/s12603-010-0317-1.

Abstract

Objectives: To validate muscle endurance estimation and to examine relationships with dependency and inflammation in elderly persons.

Design: Cross sectional validation and explorative study.

Setting: Hospitalized geriatric patients and community-dwelling controls.

Participants: 91 elderly patients (aged 83±5 years), 100 elderly controls (aged 74±5 years) and 100 young controls (aged 23±3 years).

Measurements: Grip strength (GS) was recorded continuously during sustained maximal contraction until exhaustion. Fatigue resistance (FR) was expressed as the time during which GS drops to 50% of its maximum. Grip work (GW) was estimated as GW=GS*0.75*FR, and compared to the measured GW. In the elderly participants, relationships (controlling for age and physical activity) of GS, FR, GW and GW corrected for body weight (GW/BW) with dependency (Katz-scale) and inflammation (circulating IL-6 and TNF-alpha) were analyzed.

Results: Excellent correlation between estimated and measured GW was found (r=0.98, p<0.001). The method error coefficient of variance was 10% for all participants; 7% for all elderly and 8% for young controls. Better GS, FR, GW and GW/BW was significantly related with less dependency (all p<0.05 or p<0.01, except for FR in the male) and with lower circulating IL-6 (all p<0.05 or p<0.01, except for GS in both genders). Higher IL-6 was significantly related to worse dependency (p<0.01). No significant relationships with TNF-alpha were found.

Conclusion: GW estimation is a valid parameter reflecting muscle endurance in elderly persons presenting diverse clinical conditions. GW is significantly related to both dependency and circulating IL-6, and is a promising outcome parameter in comprehensive geriatric assessment.

Publication types

  • Controlled Clinical Trial
  • Validation Study

MeSH terms

  • Activities of Daily Living*
  • Adult
  • Aged
  • Aged, 80 and over
  • Cross-Sectional Studies
  • Cytokines / blood
  • Female
  • Geriatric Assessment
  • Hand Strength / physiology*
  • Humans
  • Inflammation / blood
  • Inflammation / complications*
  • Inflammation Mediators / blood
  • Interleukin-6 / blood
  • Male
  • Muscle Contraction / physiology
  • Muscle Fatigue*
  • Muscle Weakness / etiology*
  • Muscle, Skeletal / physiology*
  • Physical Endurance / physiology*
  • Physical Fitness / physiology
  • Reproducibility of Results
  • Sex Factors
  • Tumor Necrosis Factor-alpha / blood
  • Young Adult

Substances

  • Cytokines
  • Inflammation Mediators
  • Interleukin-6
  • Tumor Necrosis Factor-alpha