Reduced kidney function is a risk factor for atrial fibrillation

There is limited knowledge on the relationship between kidney function and incidence of atrial fibrillation. Thus, this prospective study was designed to evaluate whether various biomarkers of kidney function are associated to the risk of atrial fibrillation. The study population consisted of 1840 subjects (615 women and 1225 men) aged 61-82 years. Cystatin C-and creatinine-based estimation of glomerular filtration rate (eGFRcys and eGRFcreat, respectively) and urinary albumin/creatinine ratio (ACR) were assessed to investigate their relationship with the risk of atrial fibrillation. During a median follow-up of 3.7 years, a total of 159 incident atrial fibrillation cases occurred. After adjustment for potential confounders, the risk of atrial fibrillation was increased (hazard ratio 2.74, 95% confidence interval (CI) 1.56-4.81, P>0.001) in subjects with reduced kidney function (eGFRcys, 15-59 mL/min per 1.73 m(2)) compared to subjects with normal kidney function (>= 90 mL/min per 1.73 m(2)). Similar results were also found when comparing the respective groups of subjects defined by their eGRFcreat levels (hazard ratio 2.41, CI 1.09-5.30, P=0.029). Consistently, subjects with ACR >= 300 mg/g had an increased risk of incident atrial fibrillation (hazard ratio 2.16, CI 1.35-2.82, P>0.001) compared to those with ACR >30 mg/g. Reduced eGFR and albuminuria were associated with an increased risk of atrial fibrillation.