Familial aggregation of tobacco use behaviors among Amish men.

INTRODUCTION: Tobacco use is a complex behavior. The Old Order Amish community offers unique advantages for the study of tobacco use because of homogenous ancestral background, sociocultural similarity, sex-specific social norms regarding tobacco use, and large family size. Tobacco use in the Old Order Amish community is almost exclusively confined to males. METHODS: We examined characteristics of tobacco use and familial aggregation among 1,216 Amish males from cross-sectional prospectively collected data. Outcomes examined included ever using tobacco regularly, current use, quantity of use, duration of use, and frequency of use. RESULTS: Sixteen percent of Amish men were current tobacco users, with the majority reporting cigar use only. Higher rates of tobacco use were found among sons of fathers who smoked compared with sons of fathers who did not smoke (46% vs. 22%, p < .001) as well as among brothers of index cases who smoked compared with brothers of index cases who did not smoke (61% vs. 29%, p < .001). After controlling for shared household effects and age, heritability accounted for 66% of the variance in ever smoking regularly (p = .045). CONCLUSIONS: The familial patterns of tobacco use observed among Amish men highlight the important role of family in propagating tobacco use and support the usefulness of this population for future genetic studies of nicotine addiction.