Obstructive sleep apnea syndrome in siblings: an 8-year Swedish follow-up study.
BACKGROUND
Understanding the genetic transmission of obstructive sleep apnea syndrome (OSAS) will help clinicians identify patients at risk and offer opportunities for intervention and treatment at specialist clinics.


OBJECTIVE
To estimate familial risk of hospitalization for OSAS in the adult population of Sweden, and to determine if there are any differences by age and sex.


METHODS
Using the MigMed database at the Karolinska Institute, we divided the population of Sweden into sibling groups based on a shared mother and father and ascertained the presence or absence of a primary hospital diagnosis of OSAS in each individual during the follow-up period, 1997 to 2004. Individuals were categorized as having or not having a sibling with OSAS, based on the presence or absence of the disorder in at least 1 of their siblings. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were estimated for men and women with a sibling with OSAS, compared with men and women in the reference group (SIR = 1).


RESULTS
After accounting for socioeconomic status, age, geographic region, and period of diagnosis, men with at least 1 sibling who had OSAS had a SIR of 3.42 (95% CI, 2.18-5.36); the corresponding SIR in women was 3.25 (95% CI, 1.84-5.65).


CONCLUSIONS
Our results indicate that physicians should consider family history of OSAS when deciding whether to refer a patient for further sleep examinations.
Karolinska Institute, Center for Family and Community Medicine, Huddinge, Sweden.
Jan
J
Sundquist
Xinjun
X
Li
Danielle
D
Friberg
Kari
K
Hemminki
Kristina
K
Sundquist
D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D035781:Siblings; D020181:Sleep Apnea, Obstructive / Q000235:genetics* / Q000534:rehabilitation; D013548:Sweden / Q000453:epidemiology