Impacts of Climate Warming on the Body Composition of Patients Undergoing Maintenance Hemodialysis

Background: Climate change, with increasing temperatures, poses a health threat to patients on maintenance hemodialysis (MHD). Seasonal variations in body composition have been documented in this population. We hypothesized that climate warming could further exacerbate these effects. In this study we investigated the impact of climate warming on the body composition of MHD patients residing in subtropical Taiwan. Methods: This longitudinal observational study enrolled MHD patients in subtropical northern Taiwan. We assessed monthly blood pressure (BP), laboratory data, and body composition via bioimpedance spectroscopy over a three-year period. Generalized estimating equation (GEE) was employed to analyze the seasonal and annual variations in these parameters. Additionally, we explored associations between climatic variables and body composition parameters. Results: Forty patients completed the study. BP, laboratory values, and body composition exhibited significant seasonal variations. Compared with those in winter, participants had greater relative overhydration (OH) in spring, summer, and fall. Warmer months were associated with a higher lean tissue index (LTI) and a lower fat tissue index (FTI). Notably, summers across the study years showed a further increase in relative OH and FTI, accompanied by a decrease in LTI. While BP and most laboratory parameters remained stable throughout the study period, sodium and potassium levels displayed annual variations. GEE analysis revealed positive associations between rising ambient temperature and increased fluid overload, fat mass, and decreased muscle mass. Conclusions: Our findings demonstrate that climate warming is associated with variations in the body composition of MHD patients residing in a subtropical climate. These changes can have implications in MHD patients due to their heightened vulnerability to environmental changes. Further research is needed across diverse geographic regions to develop optimal care strategies in a warming world.