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 .
Change in muscle strength explains accelerated decline of physical function in older women with high interleukin-6 serum levels.
OBJECTIVES To test whether accelerated sarcopenia in older persons with high interleukin (IL)-6 serum levels plays a role in the prospect i ve association between inflammation and disability found in many studies . DESIGN Cohort study of older women with moderate to severe disability . PARTICIPANTS Six hundred twenty older women from the Women 's Health and Aging Study in whom information on baseline IL-6 serum level was available . MEASUREMENTS Self-report of functional status , objective measures of walking performance , and knee extensor strength were assessed at baseline and over six semiannual follow-up visits . Potential confounders were baseline age , race , body mass index , smoking , depression , and medical conditions . RESULTS At baseline , women with high IL-6 were more often disabled and had lower walking speed . After adjusting for confounders , women in the highest IL-6 tertile ( IL-6>3.10 pg/mL ) were at higher risk of developing incident mobility disability ( risk ratio ( RR ) = 1.50 , 95 % confidence interval ( CI ) = 1.01 - 2.27 ) , disability in activities of daily living ( RR = 1.41 , 95 % CI = 1.01 - 1.98 ) , and severe limitation in walking ( RR = 1.61 , 95 % CI = 1.09 - 2.38 ) and experienced steeper declines in walking speed ( P < .001 ) than women in the lowest IL-6 tertile ( IL-6 < or = 1.78 pg/mL ) . Decline in knee extensor strength was also steeper , but differences across IL-6 tertiles were not significant . After adjusting for change over time in knee extensor strength , the association between high IL-6 and accelerated decline of physical function was no longer statistically significant . CONCLUSIONS Older women with high IL-6 serum levels have a higher risk of developing physical disability and experience a steeper decline in walking ability than those with lower levels , which are partially explained by a parallel decline in muscle strength
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 .