Cardiovascular-Related Polypharmacy and Its Association with Liver and Kidney Function: A Cross-Sectional Study Using...

Individuals at high risk of cardiovascular disease (CVD) often require multiple concurrent medications, resulting in polypharmacy. Although necessary for disease management, polypharmacy may increase the risk of adverse outcomes, including kidney and liver dysfunction. This study aimed to examine the association between CVD-related polypharmacy and biochemical indicators of kidney and liver dysfunction among patients prescribed lipid-lowering therapy in Australian primary care.

We conducted a retrospective cross-sectional study of electronic medical records of adults prescribed lipid lowering therapy between January 2013 and December 2022. CVD-related polypharmacy was defined as the concurrent use of more than five cardiovascular medications within a 365-day sliding window. Liver dysfunction was defined by elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), or bilirubin levels and kidney dysfunction was defined by reduced estimated glomerular filtration rate (eGFR). Multivariable logistic regression was used to assess associations, adjusting for age, sex, and comorbidities.

Among 13,568 participants (median age 63 years, interquartile range [IQR] 54-72; 54% male), 33.7% had CVD-related polypharmacy. Diabetes (odds ratio [OR] 5.40, 95% confidence interval [CI] 4.96-5.93), chronic kidney disease (OR 2.39, 95% CI 2.00-2.86), and hypertension (OR 1.91, 95% CI 1.75-2.07) were significant predictors. Older adults (≥80 years) had higher odds of CVD-related polypharmacy (OR 8.17, 95% CI 5.47-12.21). CVD-related polypharmacy was significantly associated with kidney dysfunction (OR 1.45, 95% CI 1.30-1.62), but not statistically significantly associated with liver dysfunction (OR 1.19, 95% CI 0.59-2.37).

CVD-related polypharmacy is common among individuals receiving lipid-lowering therapy and is strongly linked to ageing and multimorbidity. Its association with kidney dysfunction suggests an interplay between cardiovascular risk, physiological decline, and treatment burden, highlighting the need for integrated, patient-centred prescribing in high-risk populations.