Conclusion This is the first study to demonstrate that a higher predictive IL-6 cut-off level should be determined for aging sarcopenia in men than in women
Background Aging sarcopenia characterized by low muscle mass with low muscle strength affects men and women differently .
The contribution of interleukin-6 ( IL-6 ) to sarcopenia has been suggested based on a negative correlation between plasma IL-6 and muscle function described by some studies .
However , no consensus regarding clinical ly relevant cut-off criteria has been reached .
Another question arises whether pooling male and female data is an accurate way to determine the predictive value of IL-6 in sarcopenia .
The present meta- analysis was design ed to assess : ( 1 ) whether plasma IL-6 in aged population s in fact correlates negatively to muscle strength ; ( 2 ) whether such a correlation exists both in men and in women ; and ( 3 ) whether plasma IL-6 shows a gender difference in old age .
Grip work estimation during sustained maximal contraction: Validity and relationship with dependency and inflammation in elderly persons
Objectives To vali date 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
Conclusion This is the first study to demonstrate that a higher predictive IL-6 cut-off level should be determined for aging sarcopenia in men than in women
Background Aging sarcopenia characterized by low muscle mass with low muscle strength affects men and women differently .
The contribution of interleukin-6 ( IL-6 ) to sarcopenia has been suggested based on a negative correlation between plasma IL-6 and muscle function described by some studies .
However , no consensus regarding clinical ly relevant cut-off criteria has been reached .
Another question arises whether pooling male and female data is an accurate way to determine the predictive value of IL-6 in sarcopenia .
The present meta- analysis was design ed to assess : ( 1 ) whether plasma IL-6 in aged population s in fact correlates negatively to muscle strength ; ( 2 ) whether such a correlation exists both in men and in women ; and ( 3 ) whether plasma IL-6 shows a gender difference in old age .