[The relationship between tumor necrosis factor-alpha gene promoter polymorphism and obstructive sleep apnea-hypopnea syndrome].

Objective: To investigate the relationship between tumor necrosis factor-alpha (TNF-alpha) gene promoter polymorphism and obstructive sleep apnea-hypopnea syndrome (OSAHS).

Methods: The plasma TNF-alpha level of OSAHS group and non-OSAHS group was detected by enzyme-linked immunosorbent assay (ELISA). Eighteen patients with severe OSAHS were treated with continuous positive airway pressure (CPAP) for 1 month, and the serum levels of TNF-alpha was also measured. The genotypes of TNF-alpha gene promoter polymorphism were determined by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). The genotypes and allele 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), polysomnography (PSG), systolic blood pressure (SBP), diastolic blood pressure (DBP) were analyzed.

Results: The plasma level of TNF-alpha in OSAHS group was higher than the control group [(12.3 +/- 3.62) ng/L and (8.59 +/- 1.62) ng/L, respectively, t = 7.716, P < 0.01]. CPAP significantly decreased the serum levels of TNF-alpha, but its level (10.31 +/- 1.91) ng/L was still higher in the patients than the control group. The frequencies of TNF-alpha AA/AG genotype in OSAHS group (frequencies 31/76, 40.8%) was higher than the control one (frequencies 7/42, 16.7%) (chi(2) = 7.485, P < 0.05). Statistical analysis showed that OSAHS group had a significantly higher TNF-alphaA allele frequency (frequencies 39/152, 25.7%) than that of the control one (frequencies 39/152, 9.5%) (chi(2) = 8.830, P < 0.01). The OSAHS patients with AA/AG genotype had significantly higher serum levels of TNF-alpha, NC, WHR and aphea-hypopnea index [(13.39 +/- 3.71) ng/L, (45.2 +/- 4.2) cm, (0.91 +/- 0.12), and (34.8 +/- 15.6)/h, respectively] than those with GG genotype group [(11.09 +/- 3.54) ng/L, (42.7 +/- 4.9) cm, (0.85 +/- 0.12) and (26.4 +/- 12.3)/h, respectively] (t = 2.725, 2.278, 2.150, 2.609 respectively, P < 0.05 or < 0.01). The L SaO(2) (the lowest SaO(2)) in patients with AA/AG genotype [(78.8 +/- 10.9)%] was significantly lower than that in patients with GG genotype [(83.4 +/- 8.6)%] (t = 2.039, P < 0.05). There was no significant difference in BMI, SBP and DBP.

Conclusion: The presence of the TNF-alphaA allele may be associated with susceptibility to OSAHS, and it maybe an important candidate gene for OSAHS.