Relationship of Serum 25-Hydroxyvitamin D Levels with Sarcopenia and Body Composition in Community-Dwelling Older Adults: A Paired Case-Control Study

Objectives: Sarcopenia is a leading health problem among older adults. However, few studies have explored the relationship between serum 25-hydroxyvitamin D [25(OH)D] levels, sarcopenia, and body composition in older Chinese individuals. The aim of this study was to investigate the relationship of serum 25(OH)D levels with sarcopenia, sarcopenia indices, and body composition in community-dwelling older Chinese adults.

Design: Paired case-control study.

Setting and participants: This case-control study enrolled 66 older adults newly diagnosed with sarcopenia (sarcopenia group) and 66 older adults without sarcopenia (non-sarcopenia group) after screening in the community.

Methods: The definition of sarcopenia was based on the Asian Working Group for Sarcopenia 2019 criteria. Serum levels of 25(OH)D were measured using an enzyme-linked immunosorbent assay. Conditional logistic regression analysis was performed to estimate odds ratios (ORs) and 95% CIs. Spearman's correlation was used to examine the correlations among sarcopenia indices, body composition, and serum 25(OH)D.

Results: Serum 25(OH)D levels were significantly lower in the sarcopenia group (29.08 ± 15.11 ng/mL) than in the non-sarcopenia group (36.28 ± 14.68 ng/mL) (P < .05). Vitamin D deficiency was associated with an increased risk of sarcopenia (OR, 7.75; 95% CI, 1.96-30.71). Serum 25(OH)D levels in men were positively correlated with skeletal muscle mass index (SMI) (r = 0.286; P = .029) and negatively correlated with gait speed (r = -0.282; P = .032). Serum 25(OH)D levels in women were positively correlated with SMI (r = 0.450; P < .001), skeletal muscle mass (r = 0.395; P < .001), and fat-free mass (r = 0.412; P < .001).

Conclusions and implications: Serum 25(OH)D levels were lower in older adults with sarcopenia than those in adults without sarcopenia. Vitamin D deficiency was associated with increased risk of sarcopenia, and serum 25(OH)D levels were positively correlated with SMI.