Although recent clinical studies have suggested that water intake enhances muscle mass, its impact on muscle strength remain unclear, especially in older adults. This cross-sectional, population-based study using a representative sample of Koreans investigated the relationship of water intake with hand grip strength (HGS) in 4443 older adults, including 2090 men aged ≥50 years and 2253 postmenopausal women. A digital grip strength dynamometer was used for HGS assessment. Low muscle strength was defined by the Korean-specific HGS cut-off value and adequate water intake was defined according to the Korean dietary reference intakes. In an unadjusted model, water intake was significantly higher in men and women without than with low muscle strength (both p < 0.001), but this difference disappeared after adjustment for confounding variables in both men (p = 0.050) and women (p = 0.245). Similarly, the correlation between water intake and HGS, the difference in HGS depending on adequate water intake status, and the risk of low muscle strength depending on water intake quartile were significant only in the unadjusted model. These data indicate that factors such as age, body size, and resistance exercise contribute to improvements in HGS in older adults, whereas water intake may not.
Keywords: hand grip strength; muscle strength; sarcopenia; water intake.