Abdominal obesity (AO) and metabolic disorders are known to be directly related to cardiovascular diseases (CVDs) leading to fatal events. Pulmonary surfactant proteins SP-A and SP-D are important factors of innate immunity. They are also expressed in other organs. Extrapulmonary effects of these proteins are known in CVDs and some dysmetabolic states.
OBJECTIVE
To evaluate the associations of pulmonary surfactant proteins SP-A and SP-D with metabolic indicators and some risk factors for the development of chronic non-communicable diseases (smoking and arterial hypertension) in abdominal obesity.
MATERIAL AND METHODS
A number of persons equal 174, residents of Novosibirsk aged between 45 and 69 years, who were randomly selected from the base of the Research Institute of Internal and Preventive Medicine — Branch of the Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, were examined. Anthropometric study was conducted. The content of the surfactant protein SP-A and SP-D in the blood was determined by enzyme-linked immunosorbent assay, lipid parameters — by direct enzymatic method, blood glucose level — by Trinder method. Triglyceride-glucose (TyG) index was calculated. Parametric and non-parametric methods of statistics were used in the statistical analysis, correlation analysis was carried out using the Spearman criterion, and multivariate analysis — with the use of covariate analysis and binary logistic regression.
RESULTS
The presence of direct links of the SP-A blood level with the female sex in the total sample of men and women aged 45—69 years, as well as in people without AO has been established. The TyG index has been found to have a reverse influence on the SP-A value in the overall population, whereas in the group with AO the SP-A value was reversely impacted by the body mass and the TyG index, and without AO — directly by the high density lipoprotein cholesterol and reversely by smoking. There were no significant differences in SP-A and SP-D levels in the blood of people with and without AO. Nevertheless, in the total sample of examined persons, low SP-A blood level is directly associated with obesity and, based on covariate analysis, depends on the presence of this condition. Statistically significant associations of SP-A and SP-D with the presence of arterial hypertension in all samples of examined persons (p>0.05) have not been determined.
CONCLUSIONS
The obtained results are representative of differences in factors affecting SP-A of blood in the presence and absence of abdominal obesity. In abdominal obesity, SP-A content is reversely influenced by body mass and the TyG index. In its absence, this surfactant protein is negatively affected by smoking and positively by high-density lipoprotein cholesterol.
