title: Grip work estimation during sustained maximal contraction: Validity and relationship with dependency and inflammation in elderly persons Association between physical activity, physical performance, and inflammatory biomarkers in an elderly population: the InCHIANTI study. Inflammatory markers are associated with ventilatory limitation and muscle dysfunction in obstructive lung disease in well functioning elderly subjects Muscle cytokine mRNA changes after 2.5 h of cycling: influence of carbohydrate. Serum IL-6 level and the development of disability in older persons. Change in muscle strength explains accelerated decline of physical function in older women with high interleukin-6 serum levels. Inflammatory markers and physical performance in older persons: the InCHIANTI study. Response of bone mineral density, inflammatory cytokines, and biochemical bone markers to a 32-week combined loading exercise programme in older men and women.
abstract: 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 BACKGROUND Our aim was to determine the association between physical activity and physical performance , and inflammatory biomarkers in elderly persons . METHODS One thous and four persons aged 65 years or more , participants in a cross-sectional population -based study , were included . Interviewers collected information on  self-reported physical activity during the previous year . Moreover , 841 participants performed a 400-meter walking test  to assess physical performance . Plasma concentrations of inflammatory biomarkers were determined . RESULTS Compared to sedentary men , men practicing light and moderate-high physical activity had a significantly lower erythrocyte sedimentation rate ( -0.33 and -0.40 mm/h ; p = .023 and p = .006 , respectively ) , fibrinogen level ( -43 and -39 mg/dL ; p = .001 and p = .004 , respectively ) , and logarithm of C-reactive protein ( CRP ) ( -0.43 and -0.73 mg/L ; p = .025 and p < .001 , respectively ) , whereas only those men practicing moderate-high physical activity had a significantly lower uric acid level ( -0.57 mg/dL ; p = .023 ) , log(interleukin 6 ) levels ( -0.33 pg/mL ; p = .014 ) , and log(tumor necrosis factor-alpha ) ( -0.31 pg/mL ; p = .030 ) . In women , those practicing light and moderate-high physical activity had significantly lower uric acid ( -0.45 and -0.34 mg/dL ; p = .001 and p = .039 , respectively ) and log(interleukin 6 ) levels ( -0.18 and -0.30 pg/mL ; p = .043 and p = .004 , respectively ) ; only those women practicing moderate-high physical activity had significantly lower log(CRP ) ( -0.31 mg/L ; p = .020 ) . In women , when the analysis was adjusted for body mass index , the association between physical activity and CRP was no longer significant . Similar findings were observed when we carried these analyses according to physical performance . CONCLUSIONS Current physical activity practice and performance are associated with inflammatory biomarkers . A significant beneficial association is already observed with light physical activity practice and intermediate performance Background : Inflammatory markers are increased in chronic obstructive pulmonary disease ( COPD ) and are hypothesised to play an important part in muscle dysfunction and exercise intolerance . Methods : The Health Aging and Body Composition ( Health ABC ) study is a prospect i ve observational cohort of well functioning individuals aged 70–79 years . A cross sectional analysis of the baseline data was conducted to examine the association between inflammatory markers and ventilatory limitation , muscle strength , and exercise capacity . These associations were compared in participants with and without obstructive lung disease ( OLD ) . Results : Of the 3075 participants enrolled in the Health ABC cohort , OLD was identified by spirometric testing in 268 participants and 2005 participants had normal spirometric results . Of the participants with OLD , 35 % , 38 % , and 27 % participants had mild , moderate , and severe OLD , respectively . Participants with OLD had lower quadriceps strength ( 102.5 Nm v 108.9 Nm , p = 0.02 ) , lower maximum inspiratory pressure ( 64.7 cm H2O v 74.2 cm H2O , p<0.0001 ) , higher systemic interleukin (IL)-6 levels ( 2.6 pg/ml v 2.2 pg/ml , p<0.0001 ) , and higher C-reactive protein ( CRP ) levels ( 3.5 mg/l v 2.5 mg/l , p<0.0001 ) than those with normal spirometry . In participants with OLD and those with normal spirometry , forced expiratory volume in 1 second ( FEV1 ) was associated with IL-6 ( adjusted regression coefficients ( β ) = −5.3 ( 95 % CI −9.1 to−1.5 ) and −3.1 ( 95 % CI −4.3 to −1.9 ) , respectively ) . IL-6 and TNF were also associated with quadriceps strength among participants with OLD and those with normal spirometry ( β = −6.4 ( 95 % CI −12.8 to −0.03 ) and −3.4 ( 95 % CI −5.4 to −1.3 ) , respectively , for IL-6 and β = −10.1 ( 95 % CI −18.7 to −1.5 ) and −3.8 ( 95 % CI −7 to −0.6 ) , respectively , for TNF ) . IL-6 , quadriceps strength , and maximum inspiratory pressures were independent predictors of reduced exercise capacity in both groups . Conclusions : In well functioning elderly subjects with or without OLD , IL-6 is associated with reduced FEV1 , quadriceps strength , and exercise capacity PURPOSE To study the effect of carbohydrate compared to placebo ingestion on plasma cytokines and muscle cytokine mRNA following 2.5 h of intensive cycling in 15 trained cyclists . METHODS Fifteen trained cyclists cycled for 2.5 h at 60 % Wmax on two occasions while receiving 4 mL.kg.15 min carbohydrate ( 6 % ) ( CHO ) or placebo ( PLA ) beverages in a r and omized , counterbalanced design . Blood and vastus lateralis muscle biopsy sample s were collected before and after exercise and 12 h postexercise and compared to sample s taken from five cyclists who rested in the lab during the exercise sessions . Blood cell counts were determined , and plasma was analyzed for interleukin (IL)-6 , IL-10 , IL-1 receptor antagonist ( ra ) , IL-8 , cortisol , epinephrine , glucose , and insulin . Muscle was analyzed for glycogen content and relative gene expression of four cytokines , IL-6 , IL-8 , tumor necrosis factor ( TNF ) alpha , and IL-1beta , using real-time quantitative reverse transcriptase polymerase chain reaction . RESULTS Plasma glucose and insulin were higher , and epinephrine , cortisol , IL-6 , IL-10 , and IL-1ra , but not IL-8 , were significantly lower postexercise in CHO versus PLA .  Muscle glycogen content decreased 68 % immediately postexercise and the pattern of change did not differ between CHO and PLA .  Muscle IL-6 , IL-8 , TNF-alpha , but not IL-1beta mRNA increased immediately postexercise compared to controls , with no differences between CHO and PLA . CONCLUSION CHO compared to PLA beverage ingestion attenuated the increase in plasma cortisol , epinephrine , IL-6 , IL-10 , and IL-1ra , but not muscle IL-6 , IL-8 , and TNF-alpha mRNA in athletes cycling 2.5 h at 60 % Wmax BACKGROUND The serum concentration of interleukin 6 ( IL-6 ) , a cytokine that plays a central role in inflammation , increases with age . Because inflammation is a component of many age-associated chronic diseases , which often cause disability , high circulating levels of IL-6 may contribute to functional decline in old age . We tested the hypothesis that high levels of IL-6 predict future disability in older persons who are not disabled . METHODS Participants at the sixth annual follow-up of the Iowa site of the Established Population s for Epidemiologic Studies of the Elderly aged 71 years or older were considered eligible for this study if they had no disability in regard to mobility or in selected activities of daily living ( ADL ) , and they were re-interviewed 4 years later . Incident cases of mobility-disability and of ADL-disability were identified based on responses at the follow-up interview . Measures of IL-6 were obtained from specimens collected at baseline from the 283 participants who developed any disability and from 350 participants selected r and omly ( 46.9 % ) from those who continued to be non-disabled . FINDINGS Participants in the highest IL-6 tertile were 1.76 ( 95 % CI , 1.17 - 2.64 ) times more likely to develop at least mobility-disability and 1.62 ( 95 % CI , 1.02 - 2.60 ) times more likely to develop mobility plus ADL-disability compared with to the lowest IL-6 tertile . The strength of this association was almost unchanged after adjusting for multiple confounders . The increased risk of mobility-disability over the full spectrum of IL-6 concentration was nonlinear , with the risk rising rapidly beyond plasma levels of 2.5 pg/mL. INTERPRETATION Higher circulating levels of IL-6 predict disability onset in older persons . This may be attributable to a direct effect of IL-6 on muscle atrophy and /or to the pathophysiologic role played by IL-6 in specific diseases 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 BACKGROUND Some studies have proposed chronic inflammation as an underlying biological mechanism responsible for physical function decline in elderly people . The aim of this study is to evaluate the relationship between several inflammatory markers and physical performance in an older population . METHODS This study is part of the " Invecchiare in Chianti " ( InCHIANTI ) study , a prospect i ve population -based study of older people , aim ed at identifying risk factors for late-life disability . The study sample consisted of 1020 participants aged 65 years and older living in the Chianti area of Italy .  Physical performance  was assessed using walking speed , the chair-st and test , and the st and ing balance test . H and -grip strength  was assessed using a h and -held dynamometer .  Serum levels of C-reactive protein ( CRP ) , interleukin (IL)-6 , tumor necrosis factor-alpha ( TNF-alpha ) , IL-10 , IL-1beta , IL-6sR , and IL-1RA were determined . Linear regression analyses were used to assess the multivariate relationship of inflammatory marker levels with physical performance , scored as a continuous variable from 0 to 3 , and h and -grip strength after adjustment for demographics , chronic conditions , medication use , and other biological variables . RESULTS CRP , IL-6 , and IL1RA were significantly correlated with physical performance ( r=-0.162 , r=-0.251 , and r=-0.127 , respectively ) . Significant correlations with h and -grip strength were found for CRP and IL-6 ( r=-0.081 and r=-0.089 , respectively ) . After adjustment for covariates , high levels of IL-6 and IL-1RA continued to be strongly associated with worse physical performance ( p<.001 and p=0.004 , respectively ) . High levels of CRP ( p<.001 ) and IL-6 ( p<.001 ) were associated with low h and -grip strength . Mean adjusted physical performance scores ranged from 2.21 in the CRP<0.59 mg/dl group to 2.07 in the CRP>0.60 mg/dl group ( p for trend=.004 ) , and from 2.25 in the lowest IL-6 quartile to 2.08 in the highest IL-6 quartile ( p for trend<.001 ) . This trend was also reflected in mean adjusted h and -grip strength , with a range from 28.8 kg for the CRP<0.59 mg/dl group to 26.0 kg for the CRP>0.60 mg/dl group ( p for trend=.001 ) , and from 27.4 kg for the lowest IL-6 quartile to 25.1 kg for the highest IL-6 quartile ( p for trend=.001 ) . CONCLUSIONS Inflammation , measured as high levels of IL-6 , CRP , and IL-1RA , is significantly associated with poor physical performance and muscle strength in older persons . These data also support the biological face validity of physical performance measures . The assessment of inflammatory markers may represent a useful screening test and perhaps a potential target of intervention This study examines the effects of 32 weeks of exercise training on balance , lower-extremity muscle strength , bone mineral density ( BMD ) and serum levels of bone metabolism and inflammatory markers in older adults . Forty-seven healthy older adults ( women=24 , men=23 ; mean age 68.2 years ) participated in a exercise intervention ( 60min/session ) that included resistance exercise training ( 2 days/week ) at 75 - 80 % of maximum plus a multicomponent weight-bearing impact exercise training ( 1 day/week ) . Outcome measures included lumbar spine and proximal femoral BMD , dynamic balance , muscle strength , serum levels of bone metabolism markers [ osteocalcin ( OC ) , C-terminal telopeptide of Type I collagen ( CTX ) , osteoprotegerin ( OPG ) and receptor activator of nuclear factor kappa B lig and ( RANKL ) ] and serum levels of inflammatory markers [ high sensitive (hs)-C-reactive protein ( CRP ) , interleukin (IL)-6 , tumor necrosis factor (TNF)-α , and interferon (IFN)-γ ] . Potential confounding variables included body composition , dietary intake ( using 4-day diet records ) , and accelerometer-based physical activity . After 32 weeks , both men and women increased dynamic balance ( 6.4 % ) , muscle strength ( 11.0 % ) and trochanter ( 0.7 % ) , intertrochanter ( 0.7 % ) , total hip ( 0.6 % ) , and lumbar spine BMD ( 1.7 % ) , while OC , CTX , OPG and RANKL levels remained unchanged . In addition , hs-CRP and IFN-γ levels were decreased , while TNF-α levels were unchanged , and a decrease in IL-6 levels was only observed in men . These findings suggest that our combined impact protocol reduces inflammation and increases BMD , balance , and lower-extremity muscle strength , despite having little effect on bone metabolism markers . This reinforces the role of exercise to counteract the age-related inflammation , and the muscle strength , balance and BMD reduction
target: 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: 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 .