Background: The metabolic syndrome predicts future coronary artery disease and type II diabetes and often emerges in childhood. Tobacco smoke potentially contributes to insulin resistance in this syndrome. This study evaluates the association of environmental tobacco smoke (ETS) exposure and active smoking with the prevalence of the metabolic syndrome in US adolescents.
Methods and results: Data from 2273 subjects 12 to 19 years of age were examined from the National Health and Nutrition Examination Survey III (NHANES III, 1988 to 1994). Serum cotinine levels, presence of household smokers, and self-report of smoking were used to determine ETS exposure and active smoking. The metabolic syndrome was defined as having > or =3 criteria from the National Cholesterol Education Panel definition. Bivariate and multivariable analyses were conducted. Among adolescents, 5.6% met the criteria for metabolic syndrome, and prevalence increased with tobacco exposure: 1.2% for nonexposed, 5.4% for those exposed to ETS, and 8.7% for active smokers (P<0.001). In adolescents at risk for overweight and overweight adolescents (body mass index above the 85th percentile), a similar relationship was observed: 5.6% for nonexposed, 19.6% for those exposed to ETS, and 23.6% for active smokers (P=0.01). In multivariable logistic regression analyses among all adolescents, ETS exposure was independently associated with the metabolic syndrome (ETS exposure: odds ratio, 4.7, 95% CI, 1.7 to 12.9; active smoking: odds ratio, 6.1; 95% CI, 2.8 to 13.4).
Conclusions: Considering that tobacco and obesity are the 2 leading causes of preventable death in the United States, these findings of a dose-response, cotinine-confirmed relationship between tobacco smoke and metabolic syndrome among adolescents may have profound implications for the future health of the public.