Neuromuscular Electrical Stimulation Preserves Leg Lean Mass in Geriatric Patients.

AIM: This study aimed to examine changes in lean mass during hospitalization in geriatric patients and the effect of muscle activation by neuromuscular electrical stimulation. METHODS: Thirteen patients (69-94 yr) at a geriatric ward completed tests at hospital admission (days 2-3) and discharge (days 8-10). One leg received daily stimulation of the knee extensors, whereas the other leg served as a control leg. Lean mass was evaluated by dual-energy x-ray absorptiometry scans and muscle thickness by ultrasound scans. Muscle biopsies were collected from both legs at admission and discharge in nine patients and analyzed for fiber size, satellite cell number, and activation and expression of genes associated with muscle protein synthesis and breakdown, connective tissue, and cellular stress. RESULTS: The relative decline in leg lean mass and midthigh region lean mass was larger in the control (-2.8% ± 1.5%) versus the stimulated leg (-0.5% ± 1.4%, P < 0.05). Although there were no changes in fiber size or satellite cell number, the mRNA data revealed that, compared with control, the stimulation resulted in a downregulation of myostatin (P < 0.05) and a similar trend for MAFbx (P = 0.099), together with an upregulation of Collagen I (P < 0.001), TenascinC (P < 0.001), CD68 (P < 0.01), and Ki67 (P < 0.05) mRNA. CONCLUSION: These findings demonstrate a moderate decline in leg lean mass during a hospital stay in geriatric patients, whereas leg lean mass was preserved with daily neuromuscular electrical muscle activation. At the cellular level, the stimulation had a clear influence on suppression of atrophy signaling pathways in parallel with a stimulation of connective tissue and cellular remodeling processes.

The effects of age and musculoskeletal pain on force variability among manual workers.

The present study investigated the influence of age and musculoskeletal pain on force variability during a continuous isometric handgrip force task performed at 30% of maximal voluntary contraction carried out until failure. We recruited 96 male manual workers aged 51-72 years. The participants were stratified according to their age (50-59 and 60+ years) and by pain status (no pain, acute pain and chronic pain). The amplitude and structure of variability expressed as respectively standard deviation (SD) and coefficient of variation (CV), and sample entropy (SaEn) were calculated from the endurance task. The oldest group had an approximately 18% longer endurance time than the youngest group. No between-group differences were found in SD or CV, whereas a significant interaction between age and pain stage was found for SaEn. The youngest group showed lower SaEn than the oldest for both those with chronic pain and those without pain, indicating less force complexity, whereas a tendency for the opposite was found in the acute pain group. Within the pain stage groups, workers with acute pain had higher SaEn compared with both the no pain and chronic pain groups. These findings suggest that age and musculoskeletal pain differentially affects the structure of force variability in manual workers.

The Effect of Aging on Physical Performance Among Elderly Manual Workers: Protocol of a Cross-Sectional Study.

BACKGROUND: In 2012, the Danish Parliament decided to increase retirement age. Unfortunately, elderly people working in a physically demanding environment may be rendered unable to retain the ability to adequately perform the physical requirements of their jobs, due to age-related decreases in physical performance. Therefore, increasing the retirement age may not necessarily lead to the goal of keeping everybody in the labor market for a longer time. To date, our knowledge about the variations in physical performance of the elderly workforce is limited. OBJECTIVE: In this cross-sectional study we seek to investigate the effects of aging on physical performance among elderly manual workers. METHODS: Approximately 100 Danish manual workers between 50 and 70 years of age will be recruited. The main measurement outcomes include: (1) inflammatory status from blood samples; (2) body composition; (3) lung function; (4) static and dynamic balance; (5) reaction time, precision, and movement variability during a hammering task; (6) handgrip strength, rate of force development, and force tracking; (7) estimated maximal rate of oxygen consumption; and (8) back mobility. Additionally, information regarding working conditions, physical activity levels, and health status will be assessed with a questionnaire. RESULTS: Data collection is expected to take place between autumn 2017 and spring 2018. CONCLUSIONS: This study will increase the knowledge regarding variations in physical performance in the elderly workforce and may identify potential workplace hazards. Moreover, this study might shed light on the potentially problematic decision to increase retirement age for all Danish citizens.

Handgrip strength shows no improvements in geriatric patients with persistent inflammation during hospitalization.

PURPOSE: Hospital-associated deconditioning due to a combination of illness and inactivity is a serious problem for elderly adults. Here we investigate whether persistence in inflammatory status affects changes in physical function during short-term hospitalization. METHODS: This was a prospective observational study in elderly medical patients at a geriatric department. Measurements were obtained at admission and one week after admission and included de Morton Mobility Index (DEMMI) test, 30-second chair stand test (30-s CST), 4-m gait speed (4-m GST) test, handgrip strength, activity levels determined with ActivPALs, and concentrations of circulating C-reactive protein (CRP) from blood samples. Only patients with inflammation (C-reactive protein levels ≥10mg·L-1) at admission were included in this study. They were divided into those with continued inflammation (CI: CRP remained ≥10mg·L-1) and those that became non-inflammatory (BN: CRP decreased to <10mg·L-1) after one week of admission. RESULTS: On admission 214 patients (67% female) with a median (IQR) age of 86 (81-91) years were categorized as inflammatory. There were no baseline differences in physical function between CI (n=138, 67% female) and BN (n=76, 68% female). DEMMI-score increased similarly in both groups (P<0.05). When normalized to days between tests, only changes in handgrip strength were significantly different between the CI- and BN-group (-0.05 [-0.27-0.28] vs. 0.16 [-0.10-0.41] kg·day-1, respectively, P<0.01). There was a positive association between changes in CRP and length of hospital stay (rs=0.30, P<0.001). CONCLUSION: Hospitalized geriatric patients admitted with inflammation showed only moderate improvement of general mobility during hospital stay, regardless of changes in their inflammatory status. However, handgrip strength increased only in those patients who became non-inflammatory during hospitalization.