Symptomatic hand osteoarthritis in healthy older women: A preliminary cross-sectional analysis using body composition.

Abstract

Hand osteoarthritis (HOA) is common in older adults, yet joint deformities do not always cause symptoms. While reduced skeletal muscle mass links to lower-limb osteoarthritis severity, its relation to HOA symptoms remains unclear. We investigated muscle characteristics in older women with HOA. This cross-sectional study included community-dwelling women aged ≥60 years from a Japanese aquatic exercise programme. HOA was diagnosed per American College of Rheumatology criteria. Participants were classified as symptomatic (sHOA) or asymptomatic (aHOA). Body composition was assessed via bioelectrical impedance analysis; physical performance and handgrip strength were measured. Locomotive function, health-related quality of life, and hand function were assessed using the 25-question Geriatric Locomotive Function Scale, Short Form-8, and the Functional Index for Hand Osteoarthritis (FIHOA). Groups were compared using non-parametric tests. Among 97 participants, 53 had sHOA and 44 had aHOA. The sHOA group showed slightly greater appendicular and total skeletal muscle mass and a lower prevalence of low muscle mass, although the magnitude of these differences was small. FIHOA scores were marginally higher in the sHOA group, whereas clinically relevant functional impairment was uncommon. Handgrip strength did not differ between groups. Falls in the past year and repetitive hand use were more frequent in the sHOA group. In older women, sHOA was associated with slightly greater skeletal muscle mass and subtle functional differences versus aHOA. Unlike lower-limb osteoarthritis, findings suggest the muscle mass-symptom relationship differs between upper and lower extremities. IV (cross-sectional observational study).