Our study demonstrated that TNF-α 308 G/A, 5-HTT LPR, and 5-HTT-VNTR polymorphisms were associated with OSAS risk, whereas little association was observed between 5-HTR2A 102C/T, 5-HTR2A A1438G, ACE I/D, or LEPR-Gln 223Arg polymorphism and risk of OSAS in the Chinese population.
Eight studies were finally included in the meta-analysis of the association between 5-HTR2A gene variants (including 102T/C and 1438G/A), 5-HTT gene polymorphisms (including 5-HTT gene-linked promoter region (5-HTTLRP), and serotonin transporter intron 2 variable number tandem repeat (STin2VNTR) and OSAS risk.
For the T102C genotype, no significantly increased OSA risk was associated with the two variant genotypes (CC vs. CT+TT: OR 1.065, 95 % CI 0.787-1.442, P = 0.361 for heterogeneity; C allele carriers vs. TT: OR 0.979, 95 % CI 0.737-1.3, P = 0.9 for heterogeneity).In conclusions, meta-analysis indicated that the -1438G/A, and not T102C, polymorphism of 5-HT2A is a positive risk factor of OSA, especially in males.