The results of recent studies indicate the potential role of gamma-aminobutyric acid (GABA), as an inhibitory mediator of the central nervous system, in the pathogenesis of obstructive sleep apnea syndrome (OSAS) ‒ a common disorder that often accompanies asthma. The aim of the study was to investigate the possible role of some GABAergic system genetic polymorphisms in the formation of OSAS in asthma patients. Overnight cardiorespiratory monitoring was performed to diagnose OSAS and spirometry was conducted to evaluate the airway reactivity to the bronchodilator fenoterol in 184 asthma patients. Polymorphisms of GAD1, GAD2, GABBR1 and GABBR2 genes (15 polymorphisms in total) were genotyped by LATE-PCR method. Significant results were obtained for rs3749034 polymorphism of GAD1 gene and rs35400353 of GABBR2 in association analysis with the presence of OSAS. rs3749034 significantly influenced the presence of OSAS in males, which was accompanied by the predominance of the CC genotype among patients with OSAS, while CT+TT genotypes were more common in patients without OSAS (OR 3.9 95%CI [1.36–11.67], p=0.01). In total sample GAD1 rs3749034 polymorphism was an independent factor increasing the likelihood of having OSAS after adjustment for significant confounders (OR 1.9 95%CI [1.23–3.15], p=0.005). rs35400353 polymorphism was also associated with OSAS after adjustment for confounders, although its relationship was less significant (OR 1.5 95%CI [1.1–2.3], p=0.04). There was a tendency for interrelation with airway hyperresponsiveness to bronchodilator for both polymorphisms: rs3749034 ‒ in case of CT+TT genotypes, rs35400353 ‒ in case of DD genotype. rs3749034 polymorphism also significantly influenced lung function parameters. After additional verification of the results, the identified genetic polymorphisms may be used to individually predict the risk of OSAS as well as for the development of personalized approaches in asthma treatment using GABA.
ROLE OF GABAERGIC SYSTEM GENETIC POLYMORPHISMS IN THE DEVELOPMENT OF OBSTRUCTIVE SLEEP APNEA SYNDROME IN ASTHMA PATIENTS
