Analyses Suggest No Causal Effect of Smoking Behavior on Chronic Kidney Disease

THURSDAY, Jan. 9, 2025 (HealthDay News) — Smoking behavior seems to not have a causal effect on chronic kidney disease (CKD) risk in White individuals, according to a study published online Nov. 4 in Health Data Science.

In a traditional observational study, Zhilong Zhang, from the Peking University Health Science Center in Beijing, and colleagues used data from the U.K. Biobank cohort for adults aged 40 to 69 years to examine the associations between smoking indices, including smoking status and lifetime smoking index, and incident CKD stages 3 to 5. A potential causal effect was then estimated using Mendelian randomization (MR) approaches. The causal associations with CKD stages 3 to 5 were examined in one-sample MR using genetic variants associated with lifetime smoking index among 344,255 U.K. Biobank participants with White British ancestry. The findings were validated by a two-sample MR analysis using information from the Chronic Kidney Disease Genetics Consortium genome-wide association study.

The researchers found that both smoking status and lifetime smoking index were associated with a higher risk for incident CKD in the traditional observational study (hazard ratios, 1.26 and 1.22, respectively). However, in one- and two-sample MR analyses, no causal association was seen between lifetime smoking index and CKD. The genetic instruments were validated by statistical tests; similar results to the main model were seen in all sensitivity analyses.

“Given the substantial evidence linking smoking to CKD, further mediation analysis is needed to understand the intricate mechanisms between smoking behavior and CKD,” the authors write. “Such an analysis is essential for generating valuable insights that can inform and enhance public health strategies focused on mitigating CKD risk factors and improving overall kidney health.”

One author reported being deputy editor of Health Data Science.

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