Association of cigarette smoking with albuminuria in the United States: the third National Health and Nutrition Examination Survey.

BACKGROUND

The association of cigarette smoking with albuminuria has been reported but not examined in a representative U.S. population. No study has evaluated the association between serum cotinine (a biological marker for tobacco exposure) and kidney damage.

METHODS

A cross-sectional analysis was conducted among 15,719 adult participants of the third National Health and Nutrition Examination Survey to assess the association between smoking exposure and kidney damage. Smoking was assessed by self-reported lifetime cigarette use and serum cotinine. Kidney damage was assessed by urine albumin-to-creatinine ratio (ACR), with albuminuria defined as ACR of > or =17 microg/mg in males and > or =25 microg/mg in females.

RESULTS

The analysis included 13,121 with normal albumin (mean ACR 6.3 microg/mg) and 2,414 with albuminuria (mean ACR 143 microg/mg); hypertension was prevalent in 27% and 59%, respectively. Former smoking was similar between groups (21%), while current smoking was more common in persons with albuminuria (26%) compared to normal ACR (21%). Adjusted for other risk factors, among hypertensives, current smokers were 1.85 (95% CI: 1.29, 2.64) times more likely to have albuminuria than never smokers. Current smokers with a > or =40 pack-year history were at highest risk for albuminuria. Among non-smoking hypertensives, those exposed to passive smoke (highest versus lowest quartile of serum cotinine) were 1.41 (95% CI: 1.04, 1.90) times more likely to have albuminuria. Former smoking with cessation of > or =1 year among hypertensives was not associated with albuminuria. Among non-hypertensives, smoking and albuminuria were not consistently associated.

CONCLUSION

Current and passive smoking, but not former smoking, were associated with the presence of albuminuria in the general U.S. population with hypertension, indicating a benefit to the kidney from smoking cessation.