Chronoeffect of the diurnal cortisol rhythm on lipid and carbohydrate metabolism in Indian and local first-year students of medical universities in Kyrgyzstan

Foreign students studying in Kyrgyzstan mainly come from Southeast Asia, and they have to adapt to living conditions in a new climatic (geographic), socio-cultural, and educational environment that is different from the previous one. Therefore, it is challenging to study the chronostructural characteristics of the hormonal regulation of lipid and carbohydrate metabolism in students, as these characteristics are main part of the metabolic balance. The aim of the study is to determine chronostructural characteristics of lipid and carbohydrate metabolism regulation by adrenal cortex hormones in foreign and local 1st-year university students in Kyrgyzstan. Materials and Methods. The study enrolled 120 students. The average age of Indian students (30 young women and 30 young men) was 19.45±0.24 years; the average age of local students (30 young women and 30 young men) was 18.50±0.25 years. The authors analyzed correlation of daily cortisol rhythm with lipoproteins and blood serum glucose indicators. Results. The chronoeffects of evening cortisol (6 p.m.) and daily cortisol level influenced lipid blood fractions in students in both ethnic groups, however, with the opposite effect. In Indian students, cortisol chro-noeffect was mainly resulted in accumulation of atherogenic fractions, while in local students - in utilization of such fractions. These opposite processes can be regarded as different phases of the same adaptive energy supply reorganization, when the body starts consuming energy from fatty acids, and activates cholesterol-dependent plastic processes with the photoperiod (autumn-winter) changes. The greatest influence on carbohydrate metabolism was exerted by the daily cortisol level and reactivity, i.e. the rate of change in its plasma concentration. As an additional energy substrate, the young women demonstrated stimulated glucose disposal and young men demonstrated glucose production. The reactivity of the diurnal cortisol rhythm was statistically significantly higher in foreign students, which indicates a reactive adaptive restructuring of regulatory mechanisms.