Association between worsening renal function severity during hospitalization and low physical function at discharge: a retrospective cohort study of older patients with heart failure and chronic kidney disease from Japan.

Worsening of renal function during hospitalization in older patients with heart failure and chronic kidney disease was strongly associated with low physical function at discharge, even after adjusting for other potentially confounding factors, such as pre-hospitalization walking levels, walking start day, and Geriatric Nutrition Risk Index at discharge. Notably, worsening renal function of mild or moderate severity (grade II/I) did not show a significant association with low physical function.