Snoring, family history, and genetic markers in men. The Copenhagen Male Study

BACKGROUND: No studies have attempted to examine the genetic influence on the habit of snoring. The aim of the present study was to examine whether an association existed between self-reported snoring and family history of snoring and a number of genetic markers.

MATERIAL AND METHODS: The data were derived from a primarily cardiovascular disease cohort study of 3,387 men aged 54 to 74 years. A number of sleep-related questions were included. Some 3,308 men had given valid questionnaire information on snoring and whether they had their own bedroom due to snoring and were regarded eligible for the present study. Men who reported that they snored often or always were considered habitual snorers, and those who reported that they seldom or never snored were considered nonsnorers. We considered habitual snorers who reported that they had their own bedroom due to snoring to be a group with a presumably more severe form of snoring. Information about other health and lifestyle parameters was obtained from a comprehensive questionnaire. Four major blood groups were determined: ABO, Rhesus, MNS, and Lewis, together with complement C3. A saliva sample was taken for determination of ABH secretor status.

RESULTS: There was a strong relationship between habitual snoring and family history of snoring among grandparents, parents, siblings, and children. Odds ratios were from 2.4 to 4.2, and all associations were significant (p < 0.05). In multivariable analysis, the factor which most strongly separated habitual snorers from nonsnorers, was self-reported habitual snoring among family members. Looking at habitual snorers only, the factors most strongly separating those with their own bedroom due to snoring from those without, were the Lewis blood group phenotype, Le(a+b-) (29.6 vs 18.8%; p < 0.001; age, 63.4 vs 62.1 years; p < 0.01), and selfreported family history of habitual snoring (35.2 vs 29.0%; p < 0.05).

CONCLUSION: There was an overall strong association between habitual snoring and family history of snoring. Among habitual snorers, two genetic markers and age, were the only factors that separated men who had their own bedroom due to snoring from others. The results of this study indicate that snoring, to some extent, is hereditary.