Mail-Based Intervention for Sarcopenia Prevention Increased Anabolic Hormone and Skeletal Muscle Mass in Community-Dwelling Japanese Older Adults: The INE (Intervention by Nutrition and Exercise) Study

Objective: The aim of the Intervention by Nutrition and Exercise (INE) study was to investigate the effects of a mail-based intervention for sarcopenia prevention on muscle mass and anabolic hormones in community-dwelling older adults.

Design: A cluster-randomized controlled trial.

Setting and participants: This trial recruited community-dwelling adults aged 65 years and older in Japan. The 227 participants were cluster randomized into a walking and nutrition (W/N) group (n = 79), a walking (W) group (n = 71), and a control (C) group (n = 77). We analyzed the physical and biochemical measurements in this substudy.

Intervention: Six months of mail-based intervention (a pedometer-based walking program and nutritional supplementation).

Measurements: The skeletal muscle mass index (SMI) using the bioelectrical impedance data acquisition system, biochemical measurements, such as those of insulinlike growth factor (IGF-1), dehydroepiandrosterone sulfate (DHEA-S), and 25-hydroxy vitamin D (25[OH]D), as well as frailty, were assessed by the Cardiovascular Health Study criteria.

Results: Participants in the W/N and W groups had significantly greater improvements in SMI, IGF-1, and 25(OH)D (P < .05) than those in the C group. Participants in the W/N group had significantly greater improvements in DHEA-S (P < .05) than in the other groups. These effects were more pronounced in frail, older adults.

Conclusion: These results suggest that the mail-based walking intervention of the remote monitoring type for sarcopenia prevention can increase anabolic hormone levels and SMI in community-dwelling older adults, particularly in those who are frail.