[The problem of obstructive sleep apnea syndrome in asthmatic patients]. / Problema sindroma obstruktivnogo apnoé vo sne u patsientov s bronkhial'noi astmoi.

Asthma and obstructive sleep apnea syndrome (OSAS) are one of the most common chronic respiratory diseases. These have common risk factors that include obesity, gastroesophageal reflux disease (GERD) and impaired nasal breathing (allergic rhinitis, sinusitis). At the same time, experimental evidence demonstrates common pathophysiological mechanisms of these diseases, such as involvement in the process of the respiratory tract, a systemic inflammatory response, and implementation of neuromechanical reflexes. Thus, there is an obvious synergism between these conditions, which affects symptoms, response to therapy, and prognosis. The available data allow discussion on whether there is a need to identify and treat OSAS in asthmatic patients. By keeping in mind the high incidence of OSAS in patients with severe asthma, it may be suggested that treatment for OSAS can reduce the number of exacerbations, improve the quality of life, and decline the number of obstinate asthma cases. It is very important for general practitioners to assess risk factors, such as body weight, nasal stuffiness, and GERD, and to utilize screening tools for more efficient use of healthcare resources. Considering the known positive effects of CPAP therapy in short-term studies, future investigations should focus on the impact of CPAP therapy on asthma symptoms in the long-term, as well as on the effects of asthma drugs on the course of OSAS.

Influence of TRPV4 gene polymorphisms on the development of osmotic airway hyperresponsiveness in patients with bronchial asthma.

The effect of single nucleotide polymorphisms (SNP) of TRPV4 gene on the development of airway hyperresponsiveness (39.7% of cases) in response to the decrease in osmolarity under inspiration of distilled water aerosol was studies in 189 patients with uncontrolled bronchial asthma. rs6606743 SNP was found to significantly contribute to the development of osmotic airway hyperresponsiveness. Analysis of the dominant genetic model revealed substantial prevalence of AG + GG genotype frequency in the group of patients with asthma with osmotic hyperresponsiveness in comparison with the patients who had negative response to bronchoprovocation. In addition, carriers of GG or AG genotypes had significantly more profound decrease of lung function parameters in relation to A homozygous patients.

Role of ß2 adrenoreceptor gene polymorphism in the formation of cold hyperreactivity of the airways in asthmatics.

The relationship between ß(2)-adrenoreceptor gene Arg16Gly polymorphism and bronchial cold reactivity has been studied. Genotype Arg16Arg and allele Arg16 carriership is associated with the development of cold bronchospasm in asthmatics. In addition, a significant reduction of 3,5'-cyclic adenosine monophosphate (cAMP) level has been recorded in Arg16Arg homozygotes on minute 30 after cold provocation in comparison with Gly16Gly genotype carriers. These data indicate the influence of primary dysfunction of ß(2)-adrenoreceptors for the formation of bronchial cold hyperreactivity in the patients. Reduced cAMP synthesis by cells in Arg16Arg carriers indicates congenital liability of their ß(2)-adrenoreceptors to desensitization during cold air isocapnic hyperventilation test.