Restoring the sleep-wake cycle helps overcome insulin resistance in rats

Oleksandra Yuriivna Kushnir; Iryna Yaremii; Kyrylo Pantsiuk; Oleksandra Oleksandrivna Kushnir; Kateryna Yaremii; Volodymyr Vivsyannuk; Oksana Kushnir

Oleksandra Yuriivna Kushnir Department of Bioorganic and Biological Chemistry and Clinical Biochemistry, Bukovynian State Medical University, Chernivtsi, Ukraine https://orcid.org/0000-0002-8011-6825
Iryna Yaremii Department of Bioorganic and Biological Chemistry and Clinical Biochemistry, Bukovynian State Medical University, Chernivtsi, Ukraine https://orcid.org/0000-0001-7969-345X
Kyrylo Pantsiuk Department of Heart Failure, 4th Military Clinical Hospital in Wroclaw, Poland https://orcid.org/0009-0007-7020-2723
Oleksandra Oleksandrivna Kushnir Department of Bioorganic and Biological Chemistry and Clinical Biochemistry, Bukovynian State Medical University, Chernivtsi, Ukraine https://orcid.org/0009-0007-1930-4708
Kateryna Yaremii Department of Bioorganic and Biological Chemistry and Clinical Biochemistry, Bukovynian State Medical University, Chernivtsi, Ukraine https://orcid.org/0009-0000-5120-6728
Volodymyr Vivsyannuk Department of Internal Medicine, Bukovynian State Medical University, Chernivtsi, Ukraine https://orcid.org/0000-0003-4728-1500
Oksana Kushnir Department of Hygiene and Ecology, Bukovynian State Medical University, Chernivtsi, Ukraine https://orcid.org/0000-0003-1472-9137

Keywords: circadian rhythm, glucose, blood, rats

Abstract

Our goal was to establish the possibility of increasing insulin sensitivity as a result of restoring the sleep-wake cycle in rats after the formation of insulin resistance under conditions of circadian rhythm disruption due to weekly 24-hour light exposure. Rats were kept under different circumstances: natural day-night change for a week, then – in conditions of 24-hour lighting (>30 lux white 460–480 nm) during one more week, and then rats were transferred to a natural day-night change for another seven days. Animals were subjected to blood sampling from the tail vein on the eighth, fifteenth and twenty second days of the experiment. In the blood samples were determined: fasting glucose level, insulin level, HOMA-IR index, total triglycerides, glucose tolerance test. Statistical processing of the obtained results was carried out using the Student’s t-test and the Mann-Whitney method. The value of p≤0.05 was considered reliable. Changing the regime from natural day and night to 24-hour lighting led to disturbances at the level of dysregulation of metabolic processes in experimental rats. Under these conditions, we observed an increase in the levels of glucose, an increase of insulin concentration and the HOMA-IR index as well as total triglycerides. The restoration of normal living conditions allowed the restoration of indicators. In conclusion, a change in the sleep-wake cycle was manifested in some chages. The return to a normal sleep-wake cycle was marked by the restoration of blood glucose and insulin levels, indicating the overcoming of insulin resistance.