Grip work estimation during sustained maximal contraction: validity and relationship with dependency and inflammation...

Area of Science:

• Gerontology
• Muscle Physiology
• Biomarkers of Inflammation

Background:

• Muscle endurance is crucial for maintaining independence in elderly individuals.
• Inflammation and dependency are common issues in aging populations.
• Accurate assessment of muscle function is vital for geriatric care.

Purpose of the Study:

• To validate a method for estimating muscle endurance, specifically grip work (GW).
• To explore the relationship between muscle endurance and dependency in the elderly.
• To examine the association between muscle endurance and inflammatory markers in older adults.

Main Methods:

• A cross-sectional study involving elderly patients, elderly controls, and young controls.
• Grip strength (GS) was measured during sustained maximal contraction to determine fatigue resistance (FR) and estimate grip work (GW).
• Relationships between grip endurance parameters (GS, FR, GW, GW/BW) and dependency (Katz-scale) and inflammation (IL-6, TNF-alpha) were analyzed, controlling for age and physical activity.

Main Results:

• Estimated GW strongly correlated with measured GW (r=0.98, p<0.001) with a low method error.
• Improved grip endurance (GS, FR, GW, GW/BW) was significantly associated with lower dependency and reduced circulating IL-6 levels.
• Higher IL-6 levels were linked to increased dependency, while TNF-alpha showed no significant associations.

Conclusions:

• Grip work estimation is a valid and reliable measure of muscle endurance in diverse elderly populations.
• Grip work is significantly related to both functional dependency and IL-6 levels.
• Grip work is a promising outcome parameter for comprehensive geriatric assessment.