Serotonin-2A and 2C receptor gene polymorphisms in Japanese patients with obstructive sleep apnea.
OBJECTIVE
The serotonin (5-HT) 2A and 2C receptor subtype plays an important role in the maintenance of upper airway stability and normal breathing in obesity. Polymorphisms in the 5-HT 2A receptor gene (HTR2A) and 5-HT 2C receptor gene (HTR2C) are associated with various diseases. The aim of this study was to investigate whether or not the HTR2A/C genotypes are associated with obstructive sleep apnea (OSA).


METHODS
The PCR-restriction fragment length polymorphism method was used to determine genotypes of the HTR2A/C gene. The genotype distributions and allele frequencies were statistically analyzed.


METHODS
We studied 177 consecutive male patients with excessive daytime somnolence and an apnea plus hypopnea number [apnea-hypopnea index (AHI)] of greater than five per hour of sleep established by full polysomnography. One hundred Japanese men in whom OSA was clinically excluded were randomly selected as a control group.


RESULTS
Genotypes and allele frequencies of 102T/C polymorphism of the HTR2A and 796G/C polymorphism of the HTR2C did not differ between controls and patients with OSA. HTR2C polymorphism was considered inappropriate for association studies because of low frequency of the mutant allele. Multiple regression analysis showed that age and body mass index (BMI) were significantly associated with OSA, but HTR2A polymorphisms were not. HTR2A polymorphisms had no significant relationship with AHI or BMI, although further study with more samples will be needed for powerful statistical analyses.


CONCLUSIONS
These results indicate that age and BMI, not these polymorphisms, are associated with OSA in this population.
Sakai
Kunihiko
K
Division of Respiratory Medicine, Niigata University Graduate School of Medical and Dental Sciences, Japan.
Takada
Toshinori
T
Nakayama
Hideaki
H
Kubota
Yukiko
Y
Nakamata
Masami
M
Satoh
Makoto
M
Suzuki
Eiichi
E
Akazawa
Kohei
K
Gejyo
Fumitake
F
D000328:Adult; D000483:Alleles; D001483:Base Sequence; D016022:Case-Control Studies; D004247:DNA / Q000235:genetics; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D044402:Receptor, Serotonin, 5-HT2A / Q000235:genetics*; D044405:Receptor, Serotonin, 5-HT2C / Q000235:genetics*; D020181:Sleep Apnea, Obstructive / Q000235:genetics*
D044402:Receptor, Serotonin, 5-HT2A; D044405:Receptor, Serotonin, 5-HT2C; D004247:DNA