Older Women with Osteosarcopenic Obesity Have Lower Handgrip Strength and Knee Extension Strength than Osteopenic or Obese-Only Women

A recently recognized osteosarcopenic obesity (OSO) syndrome, in which older adults suffer from osteopenia/osteoporosis, sarcopenia, and obesity simultaneously, may affect mobility, balance, and overall health outcomes more than each of the individual conditions. Our objective was to compare handgrip strength, knee extension, and muscle quality among women divided into groups according to their body-composition status. Fifty-nine white women aged ≥65 y were classified into 4 groups: 1) osteopenic/osteoporotic nonobese (n = 4), 2) obese-only (n = 10), 3) osteopenic/osteoporotic obese (n = 35), and 4) osteosarcopenic obese (n = 10). Body composition was assessed by using dual-energy X-ray absorptiometry. Osteopenia/osteoporosis was identified from femoral neck/lumbar spine T-scores. Sarcopenic obesity was determined from appendicular lean mass (ALM) adjusted to height and body fat followed by linear regression to find the cutoff at the 20th percentile. The cutoff for obesity was at ≥32% body fat. Handgrip strength was measured with a hand dynamometer by using the highest value from the dominant hand, and knee extension was measured on a knee extensor adjusted for lower ALM to obtain muscle quality. Data were analyzed by using SAS version 9.4, with significance set at P ≤ 0.05. The obese-only group had significantly higher handgrip strength than did groups 1, 3, and 4 with group 4 (OSO) having the lowest values. Knee extension strength and muscle quality were lowest in the OSO group and significantly lower than in the obese-only group. The OSO group also had significantly lower lean mass and bone mineral density than the obese-only group. Older women with the combined condition of OSO have reduced physical performance abilities manifested in lower handgrip and knee extension strength and muscle quality, putting them at greater risk of morbidity, falls, and bone fractures.