Heavy drinkers at risk of salt-induced albuminuria

People who drink alcohol at a high frequency are more likely to develop albuminuria due to their salt intake, a recent study has found. Dietary salt restrictions of these people may have a renoprotective effect.

The study included 448 participants who were categorized into three according to self-reported drinking frequency: rarely, occasionally, and daily. Salt intake was estimated from single-spot urine specimens and the resulting urinary albumin-to-creatinine ratio (UACR) was calculated.

Most participants (n=235) reported occasional alcohol consumption, while 122 said that they drank daily; only 91 did so rarely. The three groups differed significantly in terms of age (p<0.001), with the daily drinkers being much older than the other two groups. Body mass index and current smoking were also greater among participants who drank daily.

Adjusted linear regression analysis found that the change in salt intake over a year of observation correlated significantly with changing log UACR (β, 0.16, 95 percent confidence interval [CI], 0.14–0.19; p<0.001). This meant that for every 1 g/day of change in salt intake, UACR increased by 1.17 times.

Because drinking frequency and changing salt intake also shared a significant adjusted interaction (p=0.088), the researchers sought to investigate the potential modifying effect alcohol consumption could exert on the link between salt intake and UACR.

They found that among higher-frequency drinkers, changes in UACR were much more sensitive to changing salt intake. For each 1g/day of change in salt intake, for instance, the β estimate for daily drinkers was 0.20 (95 percent CI, 0.13–0.27; p<0.001) while it was only 0.13 (95 percent CI, 0.06–0.19; p<0.001) in rare drinkers.

These suggest that the link between changing salt intake and UACR was around 1.5 times stronger in daily vs rare drinkers, the researchers pointed out.