Low lean tissue index and muscle strength combined with high fat tissue index are associated with cardiovascular disease-related hospitalisation in patients on haemodialysis

Introduction: The combined clinical impact of muscle mass, muscle function and adipose mass on hospitalisation events, especially those that have exact causes, such as cardiovascular diseases (CVDs), had been rarely studied in patients on haemodialysis (HD). This study aimed to determine the influence of lean tissue index (LTI), fat tissue index (FTI) and hand grip strength (HGS) on the risk of CVD-related hospitalisation in patients undergoing chronic HD.Methods: This multi-centre observational study enrolled a total of 2,041 clinically stable patients aged >18 years and who had undergone HD for at least three months at 17 HD units in 2019. The follow-up period was up to two years. LTI and FTI were assessed using a body composition monitoring machine, and HGS was measured by a CAMRY (R) dynamometer. Cox regression models were fit to estimate the associations of body composition and HGS with CVD-related hospitalisation risk.Results: During a mean follow-up of 22.6 months, CVD-related hospitalisation occurred in 492 patients. Compared with the non-CVD group, patients with CVD-related hospitalisation were older; had lower diastolic blood pressure; were more likely to have a history of diabetes; had worse activity status scores and lower levels of LTI, HGS, serum uric acid and serum creatinine and had higher FTI levels, body mass index and extracellular water/ intracellular water ratio. In the Cox regression models, low LTI and high FTI were independently associated with CVD-related hospitalisation in both men and women. In men, low HGS was an independent risk factor for CVD-related hospitalisation. When patients were further stratified into four distinct groups according to the sex-specific median values of LTI and FTI, the combination of low LTI and high FTI was an independent risk factor for CVD-related hospitalization (hazard ratio =1.79 in men, 95% confidence interval 1.26-2.55; hazard ratio =2.48 in women, 95% confidence interval 1.66-3.71; reference: high LTI/low FTI group).Conclusions: Among patients on chronic HD, low LTI and high FTI were associated with CVD-related hospitalisation in men and women, whereas HGS was an independent risk factor for CVD-related hospitalisation in men but not in women. Combining low LTI and high FTI increased the association with hospitalisation risk and was an independent predictor of CVD-related hospitalisation.