Objective: To investigate the association of polymorphisms in the beta(2) and beta(3) adrenergic receptor (beta(2)-ADR and beta(3)-ADR) genes with obstructive sleep apnea/hypopnea syndrome (OSAHS).
Methods: The genotypes and alleles of beta(2)-ADR and beta(3)-ADR genes were identified by polymerase chain reaction-restricted fragment length polymorphism assay in 318 unrelated subjects of North region Han population of China (including 165 male OSAHS subjects and 153 male non-OSAHS subjects). The genotypes and allele frequencies of the polymorphisms were compared between OSAHS group and non-OSAHS group. The effects of the polymorphisms in OSAHS group on body mass index (BMI), neck circumference (NC), waist/hip rate (WHR), apnea-hypopnea index (AHI), systolic blood pressure (SBP), diastolic blood pressure (DBP) were analyzed.
Results: There were significant differences in genotypes distribution in beta(3)-ADR polymorphism between the two groups (chi(2) = 10.434, P = 0.006). Compared with the control group, OSAHS group had significantly higher Arg allele frequency in beta(3)-ADR polymorphism (chi(2) = 12.742, P = 0.004). There were independent effects of beta(3)-ADR polymorphism on BMI, NC, WHR in OSAHS group; carriers of the Arg allele of beta(3)-ADR polymorphism had greater BMI, NC, and WHR (P = 0.019, 0.025, 0.012), while the carriers of the Arg allele had greater AHI and SBP (P = 0.032, 0.035), but after adjusted for BMI, AHI and age, there were no differences in SBP between the carriers and non-carriers of Arg allele (P = 0.097). There were no significant differences in the genotypes and allele frequencies in beta(2)-ADR polymorphism between the two groups (chi(2) = 1.406 and 0.809, P = 0.465 and 0.382).
Conclusion: beta(3)-ADR polymorphism may be involved in the development of central obesity and may be related to OSAHS by the central obesity in male OSAHS subjects of North region Han population of China, and may be induce hypertension in OSAHS patients of the population indirectly through obesity and sleep apnea. On the contrary, beta(2)-ADR polymorphism may not be correlated with central obesity and OSAHS in the population.