Estimated salt intake and risk of atrial fibrillation in a prospective community-based cohort.

I read with interest the report by Wuopio et. al. on the 'U' shaped association between salt intake and atrial fibrillation (1). Meta-analysis of randomized controlled trials provide high quality evidence for reductions in dietary sodium decreasing blood pressure and provides moderate quality evidence for lower salt intake reducing death and cardiovascular disease (2). Like many controversial studies relating salt intake to outcomes, Wuopio et. al. estimated salt intake using sodium concentration from a spot urine sample and used the Kawasaki formula to estimate 24 hr. urine sodium excretion (3).