The Impact Of Strength Training In An Elderly Cohort With Dementia

PURPOSE: The purpose of this study was to investigate the impact of a supervised resistance training (RT) program on biomarker (BM) assessments in a cohort of cognitively impaired elderly. We sought to determine whether a quantitative relationship exists between the amount of weight lifted over time and changes in inflammatory (IL-6, IL-16, TNF-α), metabolic (IGF-1) and neurotrophic (BDNF) plasma BM. METHODS: 24 elderly subjects (age 87.0 + 5.9 years) with cognitive impairment participated in a supervised RT protocol over the course of 26 weeks. Cognitive and frailty assessments included the Mini Mental State Examination (MMSE) and the Short Physical Performance Battery (SPPB). Subjects also underwent plasma BM assessments on a monthly basis. A linear mixed model regression analysis accounting for repeated measures was used to determine whether baseline BM were associated with other baseline independent variables and baseline cognitive performance. In order to quantify the impact of RT over time, separate linear mixed models were fitted for each dependent variable which took account for all independent variables and repeated measures. In order to quantify weight lifted over time, a work variable was created defined by the weight moved in each repetition of each exercise, and multiplied by the number of repetitions. This metric was used for each exercise, and a total composite score for each session comprising the total amount of weight moved, entered the statistical model to determine the association of the “work” completed with BM measured over time. RESULTS: At baseline, IGF-1 was associated with MMSE score such that decreases in baseline IGF-1 correlated with poorer cognitive performance. Decreases in frailty were associated with significantly increased circulating levels of IGF-1. Each unit increase in SPPB score was associated with an estimated increase in IGF-1 of 3.705 ng/mL. Similarly, the composite measure of weight lifted at each session was significantly associated over time with reductions in IL-6 production. Each additional pound lifted over time was associated with a 2.800 ng/mL reduction in IL-6. CONCLUSIONS: The results of this study suggests that RT may be a valuable intervention for the elderly, to attenuate frailty, improve ADLs, and possibly, combat cognitive impairment.