ALDH2 Expression, Alcohol Intake and Semen Parameters among East Asian Men.

Abstract

Inactivating mutations in mitochondrial aldehyde dehydrogenase 2 (ALDH2) are highly prevalent. The most common variant allele, <i>ALDH2*2</i>, is present in 40%-50% of East Asians, and causes acetaldehyde accumulation, flushing and tachycardia after alcohol intake. The relationship between alcohol intake and ALDH2 genotype on semen parameters remains unknown. We conducted a cross-sectional study to determine the association between ALDH2 genotype, alcohol consumption and semen parameters among East Asian men. Volunteers completed a survey and submitted a semen sample for analysis. Participants were genotyped to determine ALDH2 status (<i>ALDH2*1/*1</i>, <i>ALDH2*1/*2</i>, <i>ALDH2*2/*2</i>), and immunohistochemical staining was used to determine protein expression of ALDH2 in spermatozoa. Of 112 men 45 (40.2%) were <i>ALDH2*2</i> carriers. Among <i>ALDH2*2</i> carriers, alcohol consumption was associated with significantly lower total sperm motility (median 20% [interquartile range 11%-42%] vs 43% [IQR 31%-57%], p=0.005) and progressive sperm motility (19% [IQR 11%-37%] vs 36% [IQR 25%-53%], p=0.008). Among alcohol consumers, <i>ALDH2*2</i> carriers had significantly lower total sperm motility (20% [IQR 11%--42%] vs 41% [IQR 19%-57%], p=0.02), progressive sperm motility (19% [IQR 11%-37%] vs 37% [IQR 17%-50%], p=0.02) and total motile sperm count (28 million [M; IQR 9-79M] vs 71M [IQR 23-150M], p=0.05) compared to <i>ALDH2*1/*1</i> individuals. Secondly, ALDH2 expression in human spermatozoa was significantly lower in <i>ALDH2*2</i> carriers (<i>ALDH2*1/*1</i> vs <i>ALDH2*1/*2</i>, p=0.01; <i>ALDH2*1/*1</i> vs <i>ALDH2*2/*2</i>, p <0.001). Our findings suggest genotyping ALDH2, coupled with alcohol cessation counseling, may improve semen parameters among men.