Association of Coffee Consumption with Serum Copeptin Levels and Cardiac Diastolic Function in Patients with Autosomal Dominant Polycystic Kidney Disease

In autosomal dominant polycystic kidney disease (ADPKD), arginine vasopressin (AVP) and copeptin, a marker of AVP secretion, play important roles. This study aimed to investigate the associations between coffee consumption, serum copeptin levels, and echocardiographic parameters in patients with ADPKD. The study included 75 patients with ADPKD. Serum copeptin levels were measured, monthly coffee consumption was recorded in g/month, and transthoracic echocardiography was performed. Copeptin levels were lower in coffee consumers (262.73 vs. 331.28 ng/L; p = 0.009) and were inversely correlated with coffee consumption status (r = −0.329; p = 0.008). After adjustment, the negative association between coffee consumption and copeptin levels remained significant (B = −0.284, β = −0.306; p = 0.030). Mitral annular e′ velocity was higher in coffee consumers (0.92 vs. 0.69 m/s; p = 0.029) and was significantly associated with coffee consumption after adjustment (B = 0.226, β = 0.263; p = 0.033). No significant associations were found with eGFR, left ventricular mass index, ejection fraction, or the E/e′ ratio. Coffee consumption was associated with lower copeptin levels and higher e′ velocity. These findings are hypothesis-generating and do not demonstrate causality, further comparative studies are needed to determine whether these associations are specific to ADPKD.