Association of proteinuria and risk of incident atrial fibrillation in the general population: A prospective study of Kailuan study participants

Background
Proteinuria is a well-known cardiovascular risk factor, but whether it independently increases the risk for atrial fibrillation (AF) in Chinese population is unknown. To address this deficiency, herein, we investigated the association between proteinuria detected using urine dipstick test and the risk of AF.

Methods
This was a prospective cohort study of Kailuan study participants who underwent the 2006–2007 and 2010–2011 health checkups and was free from AF. Participants were classified into four groups based on the level of proteinuria: [-, trace (±), 1+, ≥2+]. The outcome was incident AF as confirmed by 12-lead electrocardiography.

Results
During a median of 11.90 years of follow-up, we documented 514 incident AF cases among 60,599 participants. Proteinuria was found in 6302 (10.40%) participants. Relative to participants without proteinuria at the baseline, those with proteinuria (≥2+) had an 83.9% higher risk (95% CI, 1.073-3.154, P = 0.0267) of developing AF, after adjusted for confounding variables. The result was consistent in the sensitivity analysis. Compared to consistently negative proteinuria, the risk of AF significantly increased in the aggravated proteinuria group (HR 1.552, 95% CI 1.140-2.114) and the persistent proteinuria group (HR 2.485, 95% CI 1.414-4.366). Among participants with resolved proteinuria (from positive to negative), the risk of incident AF was not significantly increased compared to those with persistently negative proteinuria (HR 1.300, 95% CI 0.743–2.276).

Conclusions
Proteinuria could be a modifiable risk factor for predicting AF development. Knowing the presence of proteinuria may improve risk stratification for decision-making about AF prevention.