International Medical Journal, Vol. 23., Iss. 1, 2017, P. 16−20.
IMPACT OF NONALCOHOLIC FATTY LIVER DISEASE ON ENDOTHELIUM OF PATIENTS WITH ARTERIAL HYPERTENSION AND HYPOTHYROIDISM
Kharkiv National Medical University
L. T. Malaya National Institute of Therapy, Kharkiv, Ukraine
It is known that even a slight increase in the level of thyroid−stimulating hormone is a significant predictor of liver steatosis, disorders of carbohydrate and lipid metabolism which creates preconditions for detailed investigation of the combined course of non−alcoholic fatty liver disease (NAFLD), arterial hypertension and subclinical hypothyroidism. To study the influence of NAFLD on endothelial function in patients with hypertension and subclinical hypothyroidism we investigated 75 patients. The study protocol included anthropometric data evaluation, measurement of mean arterial pressure, concentration of thyroid hormones, lipid and carbohydrate metabolism indices, assessment of vascular endothelium condition and its degree of damage. Antioxidant system was evaluated by glutathione peroxidase activity and the level of sulfhydryl groups (SH−groups), the level of malondialdehyde (MDA) was used as a marker of the oxidative stress severity. Our findings suggest that the changes in the level of circulating endothelial cells in patients with hypertension and subclinical hypothyroidism is associated with severe dyslipidemia, insulin resistance and confirm higher risk of developing cardiovascular complications in these patients. The course of hypertension combined with subclinical hypothyroidism and nonalcoholic fatty liver disease produces abnormal metabolic phenotype characterized by the presence of dyslipidemia, hyperinsulinemia and insulin resistance against a background of oxidative stress and endothelial dysfunction. Significant changes of vascular endothelial dysfunction markers in patients both with combination of hypertension and subclinical hypothyroidism and in greater extent, when associated with NAFLD, indicate that this category of patients has a high cardio−vascular risk. The study of endothelial function, oxidative stress against a background of hormonal and metabolic parameters will contribute to better understanding of common pathogenetic processes of a combined course of hypertension and subclinical hypothyroidism, will help to assess the extent of increase in cardiovascular risk when non−alcoholic fatty liver disease accedes, to predict the characteristics of comorbid course of these diseases.
Key words: hypertension, hypothyroidism, nonalcoholic fatty liver disease, endothelial dysfunction, oxidative stress.