Secondhand smoke exposure ups kidney stone risk

Exposure to secondhand smoke seems to increase the risk of developing kidney stone disease, a recent study has found.

Drawing from the Taiwan Biobank from 2008 to 2019, researchers assessed a total of 19,430 never-smokers (mean age 51 years, 81 percent women) who had no history of kidney stone disease. Most (n=17,905) had no exposure to secondhand smoke, while the remaining 1,525 reported that they had been exposed. Participants were followed for a mean of 47 months to monitor for kidney stone development.

A total of 402 incident cases of kidney stone disease were detected, corresponding to 2.1 percent of the study sample. Unadjusted analysis identified the following factors to be potential predictors of kidney stones: age, sex, body mass index, blood pressure, comorbidities, fasting glucose, uric acid, lipid profile, and secondhand smoke exposure.

In particular, univariate analysis identified a nearly 70-percent increase in the odds of developing kidney stones among those who were vs were not exposed (odds ratio [OR], 1.69, 95 percent confidence interval [CI], 1.25–2.28; p=0.001). Multivariable adjustment did not attenuate the significance of this interaction and only slightly weakened its magnitude (OR, 1.64, 95 percent CI, 1.21–2.23; p=0.002).

Further disaggregating according to the frequency of exposure revealed that participants exposed to secondhand smoke for >1.2 hours per week were significantly at risk of incident kidney stone disease (OR, 1.92, 95 percent CI, 1.29–2.86; p=0.002).

“Public health implications include enhancing smoke-free rules and educating the public about the adverse effects of secondhand smoke,” the researchers said.