Alcohol Consumption, Aldehyde Dehydrogenase Gene Polymorphism And Obstructive Sleep Apnea Syndrome

Objective:To evaluate the effects of chronic alcohol ingestion upon obstructive sleep apnea hypopnea syndrome(OSAHS)and the relationship between aldehyde dehydrogenase-2(ALDH₂)G1951A gene polymorphism and OSAHS in males with hypertension.Methods:Males with hypertension were enrolled in this study having a standard polysomnography.The number of apneas and hypopneas per hour of sleep (apnea-hypopnea index,AHI)≥10 was considered diagnostic for OSAHS.AHI＜20 times/h was considered as none-OSAHS group(control group).A questionnaire was used to investigate alcohol drinking history,including the type of alcoholic beverages,the frequency of drinking during a typical month,the volume of alcohol intake per occasion and the dinking years.1)304 males with hypertension were divided into 220 OSAHS group and 84 control group in the first study.Mean monthly and cumulative alcohol consumption was calculated to analyze the effects of chronic alcohol ingestion upon OSAHS.2)226 males with hypertension were recruited in the next study.They were all alcohol drinkers whom were diagnosed as mean monthly alcohol consumption≥50g and divided into 166 OSAHS group and 60 control group.ALDH₂ genotypes were detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)to test the association of G1951A gene polymorphism with OSAHS. Results:1).There were no statistical differences in alcohol consumption per occasion(Chinese white liquor),mean monthly alcohol consumption and cumulative alcohol consumption between OSAHS group and control group in 304 males with hypertension(P＞0.05).2)There were no statistical differences in the prevalence of OSAHS and sleep respiratory data between alcohol drinking group and none-alcohol drinking group(P＞0.05).3)In subjects with AHI＜20 times/h,AHI increased significantly and mean or longest apnea duration was significantly higher in alcohol drinking group than none-alcohol drinking group after controlling for age,body mass index(BMI)and blood pressure(P＜0.05).Alcohol drinking group were classified into two groups according to the median of cumulative alcohol consumption(108kg).The lowest oxygen saturation(SaO₂)decreased significantly and mean or longest apnea duration was significantly higher in males whose cumulative alcohol consumption＞108 kg than none-alcohol drinking group after controlling for age,BMI and blood pressure(P＜0.05). But there were no statistical differences of sleep respiratory data between different drinking groups in subjects with AHI≥20times/h.4)We detected three kinds of genotypes and two kinds of allele of ALDH₂ gene G1951A polymorphism in 226 male drinkers with hypertension.The frequency of ALDH₂ genotype GG,GA,AA were 0.854, 0.137,0.009 and allele G and A were 0.923,0.077 respectively.The genotypic and allelic frequencies were in Hardy-Weinberg equilibrium(x²=0.3606,P=0.5482).5)The frequency of ALDH₂ genotype GG/(GA+AA)(0.855/0.145)and allele G/A(0.925/0.075) in OSAHS group had no statistical differences comparing with the control group(P＞0.05). Analyzing the data stratified with BMI,there was also no significant differences of the frequency of ALDH₂ genotype and allele between OSAHS group and the control group either in normoweight or overweight subjects(P＞0.05).6)There were also no any differences in AHI,the lowest SaO₂,mean and the longest apnea duration between subjects with the two genotypes(GG and(GA+AA))either in OSAHS group or the control group(P＞0.05).7)Comparing with genotype GG,the subjects with ALDH₂ mutant genotypes(GA+AA)were significantly lower in alcohol consumption per occasion(Chinese white liquor),mean monthly alcohol consumption and cumulative alcohol consumption(P＜0.05).Conclusion:1)Chronic alcohol ingestion aggravated obstructive sleep apnea frequency,duration and the lowest SaO₂ in males with hypertension whose AHI＜20times/h.2)A LDH₂ gene G1951A polymorphism was found in male drinkers with hypertension,it had no any association with OSAHS.3) ALDH₂ gene G1951A polymorphism was associated with alcohol consumption in male drinkers with hypertension;the mutant of ALDH₂ gene was most likely to play a protective role against excessive alcohol consumption.