#2025 Associations of obesity, sarcopenia, and sarcopenic obesity with chronic kidney disease development in the elderly population

Abstract

Abstract Background and Aims Previous studies indicate that sarcopenia and obesity increase the risk of chronic kidney disease (CKD) in middle-aged populations. Despite noting reverse epidemiology for cardiovascular disease in the elderly, the relationship between sarcopenic obesity and CKD incidence in older populations is insufficiently explored. This study aims to assess whether obesity modifies the association between sarcopenia and CKD development in elderly adults with preserved kidney function. Method Elderly individuals aged over 65 with preserved kidney function among UK Biobank participants were examined. Participants with an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m² or albuminuria were excluded. The individuals were categorized based on the presence of sarcopenia and obesity, with sarcopenia defined as hand grip strength <27 kg in males and <16 kg in females. Obesity was defined as having a BMI of 30 kg/m² or higher, and sarcopenic obesity was identified in those with concomitant obesity and sarcopenia. The development of CKD was determined using ICD-10 codes in claim and death register records. Results A total of 62,735 individuals were assessed, with a mean age of 66.9 ± 1.5 years and 44.3% being male. Sarcopenia was identified in 8,648 individuals (13.8%), while obesity was present in 13,075 individuals (20.8%), resulting in a 3.29% prevalence of sarcopenic obesity. Over a median follow-up of 13.3 years (770,179 person-years), 5,567 participants (8.9%) developed CKD. A significant interaction between sarcopenia and obesity was observed for CKD development (P < 0.001). Incident CKD rates were 7.8% in non-obese without sarcopenia, 9.5% in obese without sarcopenia, 11.7% in non-obese with sarcopenia, and 14.7% in obese with sarcopenia. Compared to the non-obese without sarcopenia group, hazard ratios (HRs) and 95% confidence intervals (CIs) were 1.26 (1.16-1.37) in the obese without sarcopenia group, 1.55 (1.45-1.65) in the non-obese with sarcopenia group, and 2.02 (1.80-2.27) in the obese with sarcopenia group. After adjusting for confounding factors, the risk of CKD development in the obese without sarcopenia group was comparable to the non-obese without sarcopenia group (HR, 1.07, 95% CI, 0.99-1.15). However, elevated risk persisted in participants with sarcopenia and was most accentuated in those with sarcopenic obesity (non-obese with sarcopenia; HR, 95% CI, 1.22 [1.11-1.34]; obese with sarcopenia, 1.32 [1.15-1.50]). Conclusion Sarcopenia, not obesity, was significantly associated with an increased risk of chronic kidney disease (CKD) development in elderly individuals, with sarcopenic obesity showing the highest risk elevation for incident CKD in this group.