Association between smoking nationwide population-based and chronic renal failure in a case-control study

For determining whether smoking is associated with an increased risk for chronic renal failure (CRF) overall and by type of renal disease, smoking data were analyzed from a nationwide population-based case-control study. Eligible as cases were native 18- to 74-yr-old Swedes whose serum creatinine for the first time and permanently exceeded 3.4 mg/dl (men) or 2.8 mg/dl (women). A total of 926 cases (78% of all eligible) and 998 control subjects (75% of 1330 randomly selected subjects from the source population), frequency matched to the cases by gender and age within 10 yr, were included. A face-to-face interview and a self-administered questionnaire provided information about smoking habits and other lifestyle factors. Logistic regression models estimated odds ratios (OR) as measures of relative risk for disease-specific types of CRF among smokers compared with never-smokers. Despite a modest and nonsignificant overall association, the risk increased with high daily doses (OR among smokers of >20 cigarettes/d, 1.51; 95% confidence interval [CI], 1.06 to 2.15), long duration (OR among smokers for > 40 yr, 1.45; 95% CI, 1.00 to 2.09), and a high cumulative dose (OR among smokers with >30 pack-years, 1.52; 95% CI, 1.08 to 2.14). Smoking increased risk most strongly for CRF classified as nephrosclerosis (OR among smokers with >20 packyears, 2.2; 95% CI, 1.3 to 3.8), but significant positive associations were also noted with glomerulonephritis. This study thus suggests that heavy cigarette smoking increases the risk of CRF for both men and women, at least CRF classified as nephrosclerosis and glomerulonephritis.