Association of polypharmacy with incidence of CKD: a retrospective cohort study: a letter to the Editor

Abstract

Kimura et al.’s recently published report on a retrospective examination of the Fukushima chronic kidney disease (CKD) patient cohort provides an interesting perspective on this rising therapeutic morbidity [1]. The study investigated the association between polypharmacy and the incidence of CKD in n = 1221 patients with a mean age of 62 years who were followed up for an average of 4.5 years. Compared to the non-polypharmacy phenogroups, patients with hyper-polypharmacy had higher overall risks of incident CKD and associated adverse cardiovascular outcomes [1]. The adjusted hazard ratios for these outcomes were 1.41 (95% confidence interval [CI] 1.01–1.99) and 2.24 (95% CI1.05–4.78) for the incidence of CKD and cardiovascular events, respectively. The stability of the point estimates of these associations reported by Kimura et al. even after adjusting for the “usual” commonly reported confounding variables of polypharmacy (such as gender, age, and multimorbidity) suggests that these associations are indeed organic and less likely to be “statistical noise.” Despite its rapidly rising profile as a therapeutic morbidity in the general population, polypharmacy and its phenotypic themes (such as its prevalence, definitional thresholds, as well as other determinants of adverse outcomes) continue to remain subjects of unresolved ongoing debate [2,3,4]. The very often cited downstream consequences of polypharmacy and its other numerical variants include bidirectional interactions (drug-drug, drug-food, etc.) and adverse drug reactions amongst others.