Hogan SL et al. (2007) Association of cigarette smoking with albuminuria in the United States: the Third National Health and Nutrition Examination Survey. Ren Fail 29: 133–142

Researchers have investigated the association between smoking status and albuminuria among 15,535 adult participants of the third National Health and Nutrition Examination Survey. Smoking and albuminuria were not consistently associated in nonhypertensive individuals, but associations were found in people with high blood pressure.

In total, 13,121 participants in the analysis were normoalbuminuric (with a mean urine albumin:creatinine ratio 6.3 µg/mg) and 2,414 were albuminuric (with a mean urine albumin:creatinine ratio 143 µg/mg). Smoking status was assessed by self-reported lifetime cigarette use in pack-years (the number of years a full pack of 20 cigarettes was smoked every day) and by serum cotinine, a nicotine metabolite. Participants were categorized as current smokers (smoking >1 cumulative pack-year up until 12 months before examination), former smokers (smoking ceased for ≥12 continuous months before examination) or nonsmokers (never smoked or smoked ≤1 cumulative pack-year).

Albuminuria was present in 1,567 of 5,596 hypertensives (28%) and 847 of 9,939 nonhypertensives (8.5%). Independent of other risk factors, hypertensive current smokers were at 1.85-fold greater risk of albuminuria than were hypertensive nonsmokers. In general, former smoking was not associated with albuminuria in hypertensives, which indicates that smoking cessation might benefit the kidney. The most striking observation was that among hypertensive nonsmokers, a serum cotinine level in the highest quartile was associated with a 41% higher risk of albuminuria than was a serum cotinine level in the lowest quartile. These findings indicate that exposure to passive smoking might have adverse effects on renal health in people with high blood pressure.