Multimorbidity and the risk of major adverse kidney events: findings from the UK Biobank cohort

Background: Multimorbidity (the presence of two or more long-term conditions) is associated with a heightened risk of mortality, but little is known about its relationship with the risk of kidney events. Methods: Associations between multimorbidity and major adverse kidney events (MAKE: the need for long-term kidney replacement therapy, doubling of serum creatinine, fall of estimated glomerular filtration rate (eGFR) to < 15 ml/min/1.73m2 or 30% decline in eGFR) were studied in 68,505 participants from the UK Biobank cohort. Participants were enrolled in the study between 2006 and 2010. Associations between long-term condition counts and MAKE were tested using survival analyses accounting for the competing risk of death. Results: Over a median follow-up period of 12.0 years, 2,963 participants had MAKE. There were associations between long-term condition count categories and the risk of MAKE (one long-term condition adjusted subhazard ratio (sHR) 1.29 (95% Confidence Interval 1.15-1.45), 2 long-term conditions sHR 1.74 (1.55-1.96), three or more long-term conditions sHR 2.41 (2.14-2.71)). This finding was more pronounced when only cardiometabolic long-term conditions were considered (one long-term condition sHR 1.58 (1.45-1.73), two long-term conditions sHR 3.17 (2.80-3.59), three or more long-term conditions sHR 5.24 (4.34-6.33)). Combinations of long-term conditions associated with MAKE were identified. Diabetes, hypertension and coronary heart disease featured most commonly in high-risk combinations. Conclusions: Multimorbidity, and in particular cardiometabolic multimorbidity, is a risk factor for MAKE. Future research should study groups of patients who are at high risk of progressive kidney disease based on the number and type of long-term conditions.