OBJECTIVE ASSESSMENT OF SMOKING-HABITS BY URINARY COTININE MEASUREMENT IN ADOLESCENTS AND YOUNG-ADULTS WITH TYPE-1 DIABETES - RELIABILITY OF REPORTED CIGARETTE CONSUMPTION AND RELATIONSHIP TO URINARY ALBUMIN EXCRETION

OBJECTIVE -To examine the relationship of objective smoking status to age, sex, long-term metabolic control, and urinary albumin excretion. Patients with type 1 diabetes who smoke are at increased risk to devel op diabetic microvascular and macrovascular complications, While this has repeatedly been demonstrated in adults, smoking habits have rarely been investigated in adolescents. RESEARCH DESIGN AND METHODS -Urinar y cotinine excretion has been determined by radioimmunoassay in 238 ad olescents and young adults with type 1 diabetes. This biochemical para meter of nicotine use was related to age, to the number of cigarettes allegedly consumed per day, and to urinary albumin excretion. RESULTS -A total of 46 patients (19.3%) with urinary cotinine values >500 ng/m l were classified as smokers. In 26 patients (10.9%), cotinine values between 100 and 500 ng/ml were found (infrequent smokers or environmen tal nicotine exposure), while the remaining 166 patients excreted <100 ng/ml of cotinine in the urine (nonsmokers). Smokers were significant ly older (20.2 +/- 0.6 years [mean +/- SE]) compared with the intermed iate group (18.3 +/- 0.7 years) or with nonsmokers (15.9 +/- 0.4 years ; P < 0.0001, Wilcoxon's signed-rank test). Of 46 smokers, 12 denied s moking cigarettes entirely, and among biochemically defined smokers, n o correlation was present between urinary cotinine excretion and the r eported number of cigarettes consumed per day. Urinary albumin excreti on was significantly higher in smokers compared with nonsmokers (P < 0 .003). CONCLUSIONS -These data demonstrate that cigarette smoking is c ommon among German adolescents and young adults with type 1 diabetes i n this stud)! Many patients deny nicotine use or refuse to disclose th eir smoking habits. Increased urinary albumin excretion is consistent with an increased risk of nephropathy in subjects with diabetes who sm oke. Pediatricians in charge of adolescents with type 1 diabetes shoul d actively discuss the risk of nicotine consumption with their patient s.