Impact of the Kidney-Metabolic Pattern on Multimorbidity and Mortality among Elderly Inpatients in China

Background: As populations age globally, multimorbidity has emerged as a significant challenge, complicating medical decision-making and deteriorating health outcomes. Chronic kidney disease (CKD) is a common condition among the aging population, yet its role and influence on elderly multimorbidity are seldom reported. This study aims to enhance the management and standardization of medical data and chronic disease diagnoses among elderly inpatients in China, investigating the prevalence and patterns of multimorbidity, with a specific focus on CKD-associated multimorbidity patterns and their prognosis. Methods: Our study conducted a cross-sectional analysis using a large dataset from a single center, maintained by the comprehensive hospital at Fudan University, Shanghai, China. Data were collected from the electronic medical records system for patients aged over 60 years at Huashan Hospital, Fudan University, between January 1, 2013, and January 1, 2019. Results: Our database included 163,626 elderly inpatients with a mean age of 69.8±0.1 years. The number of morbidities was positively associated with mortality. 80.7% of patients with CKD had other comorbidities. Factor analysis revealed four multimorbidity patterns in the elderly inpatients, named the “Kidney-metabolic” pattern, “Cerebro-vascular” pattern, “Cardio-pulmonary” pattern, and “Thyroid-digestive” pattern. The "Kidney-metabolic" pattern, characterized by CKD, Hypertension, Diabetes, and Lipid disorders, exhibited the highest prevalence at 13.3%. All four multimorbidity patterns were significantly positively associated with increased mortality. However, the impact of the "Kidney-metabolic" pattern on mortality was the only one that significantly increased with age. Among patients with the "Kidney-metabolic" pattern, the odds ratios (OR) for mortality in those aged 80-89 and ≥90 years were 11.469 (95% CI: 9.066-14.508) and 49.237 (95% CI: 37.455-64.724), respectively, compared to those aged 60-69 years. Conclusion: CKD plays a critical role in the multimorbidity of the elderly. The "Kidney-metabolic" pattern, the most prevalent among the elderly, significantly heightened mortality risk, particularly in the oldest cohorts. Clinical practices should prioritize the management of CKD and associated metabolic diseases within multimorbid contexts to reduce mortality and promote healthy aging.