Alpha-linolenic acid supplementation and resistance training in older adults. Protein supplementation increases postexercise plasma myostatin concentration after 8 weeks of resistance training in young physically active subjects. Development of a simple screening test for sarcopenia in older adults. Strength measures are better than muscle mass measures in predicting health-related outcomes in older people: time to abandon the term sarcopenia? Muscle strength after resistance training is inversely correlated with baseline levels of soluble tumor necrosis factor receptors in the oldest old. Low vitamin D and high parathyroid hormone levels as determinants of loss of muscle strength and muscle mass (sarcopenia): the Longitudinal Aging Study Amsterdam. Change in muscle strength explains accelerated decline of physical function in older women with high interleukin-6 serum levels. Muscle Mass Gain After Resistance Training Is Inversely Correlated With Trunk Adiposity Gain in Postmenopausal Women
Increased inflammation with aging has been linked to sarcopenia . The purpose of this study was to evaluate the effects of supplementing older adults with alpha-linolenic acid ( ALA ) during a resistance training program , based on the hypothesis that ALA decreases the plasma concentration of the inflammatory cytokine tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 , which in turn would improve muscle size and strength . Fifty-one older adults ( 65.4 + /- 0.8 years ) were r and omized to receive ALA in flax oil ( ~14 g.day-1 ) or placebo for 12 weeks while completing a resistance training program ( 3 days a week ) . Subjects were evaluated at baseline and after 12 weeks for muscle thickness of knee and elbow flexors and extensors ( B-mode ultrasound ) , muscle strength ( 1 repetition maximum ) , body composition ( dual energy X-ray absorptiometry ) , and concentrations of TNF-alpha and IL-6 . Males supplementing with ALA  decreased IL-6 concentration over the 12 weeks ( 62 + /- 36 % decrease ; p = 0.003 ) , with no other changes in inflammatory cytokines . Chest and leg press strength , lean tissue mass , muscle thickness , hip bone mineral content and density , and total bone mineral content significantly increased , and percent fat and total body mass decreased with training ( p < 0.05 ) , with the only benefit of ALA being a significantly greater increase in knee flexor muscle thickness in males ( p < 0.05 ) . Total-body bone mineral density improved in the placebo group , with no change in the ALA group ( p = 0.05 ) . ALA supplementation lowers the IL-6 concentration in older men but not women , but had minimal effect on muscle mass and strength during resistance training Myostatin ( MSTN ) is a negative regulator of muscle growth even if some studies have shown a counterintuitive positive correlation between MSTN and muscle mass ( MM ) . Our aim was to investigate the influence of 2 months of resistance training ( RT ) and diets with different protein contents  on plasma MSTN , interleukin 1 beta ( IL-1β ) , interleukin 6 ( IL-6 ) , tumor necrosis factor alpha ( TNF-α ) , and insulin-like growth factor 1 ( IGF-1 ) .  Eighteen healthy volunteers were r and omly divided in two groups : high protein ( HP ) and normal protein ( NP ) groups . Different protein diet contents were 1.8 and 0.85 g of protein·kg bw(-1)·day(-1 ) for HP and NP , respectively . Subjects underwent 8 weeks of st and ardized progressive RT  . MSTN , IGF-1 , IL-1β , IL-6 , and TNF-α were analyzed before and after the first and the last training sessions . Lean body mass , MM , upper-limb muscle area , and strength were measured . Plasma MSTN showed a significant increase ( P<.001 ) after the last training in the HP group compared with NP group and with starting value . IGF-1 plasma concentration showed a positive correlation with MSTN in HP after the last training ( r(2)=0.6456 ; P=.0295 ) . No significant differences were found between NP and HP for IL-1β , IL-6 , TNF-α , and strength and MM or area . These findings suggest a " paradoxical " postexercise increase of plasma MSTN after 8 weeks of RT and HP diets . This MSTN elevation correlates positively with IGF-1 plasma level . This double increase of opposite ( catabolic/anabolic ) mediators could explain the substantial overlapping of MM increases in the two groups AIM To develop a simple screening test to identify older adults at high risk for sarcopenia . METHODS We studied 1971 functionally independent , community-dwelling adults aged 65 years or older r and omly selected from the resident register of Kashiwa city , Chiba , Japan . Data collection was carried out between September and November 2012 . Sarcopenia was defined based on low muscle mass measured by bioimpedance analysis and either low muscle strength characterized by h and grip or low physical performance characterized by slow gait speed . RESULTS The prevalence of sarcopenia was 14.2 % in men and 22.1 % in women . After the variable selection procedure , the final model to estimate the probability of sarcopenia included three variables : age , grip strength and calf circumference . The area under the receiver operating characteristic curve , a measure of discrimination , of the final model was 0.939 with 95 % confidence interval ( CI ) of 0.918 - 0.958 for men , and 0.909 with 95 % CI of 0.887 - 0.931 for women . We created a score chart for each sex based on the final model . When the sum of sensitivity and specificity was maximized , sensitivity , specificity , and positive and negative predictive values for sarcopenia were 84.9 % , 88.2 % , 54.4 % , and 97.2 % for men , 75.5 % , 92.0 % , 72.8 % , and 93.0 % for women , respectively . CONCLUSIONS The presence of sarcopenia could be detected using three easily obtainable variables with high accuracy . The screening test we developed could help identify functionally independent older adults with sarcopenia who are good c and i date s for intervention Summary There is no clear consensus on definition , cut-points or st and ardised assessment s of sarcopenia . We found a lower limb strength assessment  was at least as effective in predicting balance , mobility and falls in 419 older people as muscle mass-based measures of sarcopenia . Introduction There is currently no consensus on the definition , cut-points or st and ardised assessment s of sarcopenia . This study aim ed to investigate whether several published definitions of sarcopenia differentiate between older people with respect to important functional and health outcomes . Methods Four hundred nineteen community-living older adults ( mean age 81.2 ± 4.5 , 49 % female ) completed assessment s of body composition ( dual-energy X-ray absorptiometry ) , strength , balance , mobility and disability . Falls were recorded prospect ively for a year using monthly calendars . Sarcopenia was defined according to four skeletal mass-based definitions , two strength-based definitions ( h and grip or knee extensor force ) and a consensus algorithm ( low mass and low strength or slow gait speed ) . Obesity was defined according to percentage fat mass or waist circumference . Results The four skeletal mass-based definitions varied considerably with respect to the percentage of participants classified as sarcopenic and their predictive accuracy for functional and health outcomes . The knee extension strength-based definition was equivalent to or better than the mass-based and consensus algorithm definitions ; i.e. weaker participants performed poorly in tests of leaning balance , stepping reaction time , gait speed and mobility . They also had higher physiological fall risk scores and were 43 % more likely to fall at home than their stronger counterparts . Adding obesity to sarcopenia definitions identified participants with greater self-reported disability . Conclusions A simple lower limb strength assessment was at least as effective in predicting balance , functional mobility and falls in older people as more expensive and time-consuming muscle mass-based measures . These findings imply that functional terms such as muscle weakness or motor impairment are preferable to sarcopenia OBJECTIVES To test the hypothesis that physical exercise induces an antiinflammatory response that is associated with reduced chronic activation of the tumor necrosis factor (TNF)-alpha system in frail elders and that the increase in muscle strength after resistance training is limited by systemic low- grade inflammation . DESIGN A 12-week controlled resistance-training study . SETTING Nursing homes in Copenhagen , Denmark . PARTICIPANTS Twenty-one frail nursing home residents aged 86 to 95 completed the study . INTERVENTION Ten participants were r and omized to a program of resistance training of knee extensors and flexors three times a week for 12 weeks ; the remaining 11 participants served as a control group who joined social activities supervised by an occupation therapist . MEASUREMENTS Muscle strength , plasma levels of TNF-alpha , soluble TNF receptor (sTNFR)-1 , and interleukin (IL)-6 were measured before and at the end of the intervention period . RESULTS The training program improved muscle strength but did not affect plasma levels of TNF-alpha and sTNFR-I or IL-6 . However , plasma levels of sTNFR-I at baseline were inversely correlated with the increase in muscle strength . CONCLUSION Low- grade activation of the TNF system could limit the increase in muscle strength after resistance training in the oldest old . Furthermore , data suggest that the antiinflammatory response induced by 12 weeks of resistance training is not sufficient to reduce chronic activation of the TNF system , but the small sample size limited this interpretation The age-related change in hormone concentrations has been hypothesized to play a role in the loss of muscle mass and muscle strength with aging , also called sarcopenia . The aim of this prospect i ve study was to investigate whether low serum 25-hydroxyvitamin D ( 25-OHD ) and high serum PTH concentration were associated with sarcopenia . In men and women aged 65 yr and older , participants of the Longitudinal Aging Study Amsterdam , grip strength ( n = 1008 ) and appendicular skeletal muscle mass ( n = 331 , using dual-energy x-ray absorptiometry ) were measured in 1995 - 1996 and after a 3-yr follow-up . Sarcopenia was defined as the lowest sex-specific 15th percentile of the cohort , translating into a loss of grip strength greater than 40 % or a loss of muscle mass greater than 3 % . After adjustment for physical activity level , season of data collection , serum creatinine concentration , chronic disease , smoking , and body mass index , persons with low ( < 25 nmol/liter ) baseline 25-OHD levels were 2.57 ( 95 % confidence interval 1.40 - 4.70 , based on grip strength ) and 2.14 ( 0.73 - 6.33 , based on muscle mass ) times more likely to experience sarcopenia , compared with those with high ( > 50 nmol/liter ) levels . High PTH levels ( > or=4.0 pmol/liter ) were associated with an increased risk of sarcopenia , compared with low PTH ( < 3.0 pmol/liter ) : odds ratio = 1.71 ( 1.07 - 2.73 ) based on grip strength , odds ratio = 2.35 ( 1.05 - 5.28 ) based on muscle mass . The associations were similar in men and women . The results of this prospect i ve , population -based study show that lower  25-OHD  and higher  PTH levels increase the risk of sarcopenia in older men and women 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 Abstract Orsatti , FL , Nahas , EAP , Orsatti , CL , de Oliveira , EP , Nahas-Neto , J , da Mota , GR , and Burini , RC . Muscle mass gain after resistance training is inversely correlated with trunk adiposity gain in postmenopausal women . J Strength Cond Res 26(8 ) : 2130–2139 , 2012—The aim of this study was to evaluate alterations in trunk adiposity ( TA ) over 9 months of resistance training ( RT ) and associate these changes with the hypertrophy of muscle mass ( MM ) in postmenopausal women ( PW ) . The investigation used a sample that consisted of 22 PW ( 44–69 years old ) . The group was subjected to RT ( 60–80 % of 1 repetition maximum ) for the total body 3 d·wk−1 . Body composition  ( dual-energy x-ray absorptiometry )  and plasma levels of insulin-like growth factor-1 ( IGF-1 ) , follicle-stimulating hormone , E2 ( Immulite system )  , and interleukin-6 ( IL-6  ; enzyme-linked immunosorbent assay ) were assessed at the beginning and end of the experiment . After RT , only women who acquired up to 5 % TA gained MM , whereas women who acquired > 5 % TA exhibited increased IL-6 and no MM gain ( p < 0.05 ) . The & Dgr;MM was negatively associated with time of menopause ( r = −0.45 , p < 0.05 ) and positively associated with baseline IGF-1 ( r = 0.47 , p < 0.05 ) . Only & Dgr;LE ( leg extension ) was negatively associated with baseline IL-6 ( p < 0.05 ) . Trunk adiposity growth ( & Dgr;TF , kilograms ) was positively correlated with changes in IL-6 ( r = 0.68 , p < 0.05 ) . The MM gain was negatively correlated with & Dgr;TF ( r = −0.63 , p < 0.05 ) and changes in IL-6 ( r = −0.73 , p < 0.05 ) . After adjusting all of the confounding variables , only baseline IGF-1 ( positively ) and changes in IL-6 ( negatively ) influenced MM , and only the increase in TA influenced IL-6 . Our study suggests that increased levels of TA during RT increase IL-6 concentrations , which is a significant negative predictor of MM gain in PW
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 .