The Effect of Exercises Performed According to Circadian Rhythm in Type 2 Diabetes (Circadian)

Type 2 diabetes is a metabolic disease characterized by partial insulin deficiency or insulin resistance in peripheral tissue. Type 2 diabetes, which has a very high prevalence worldwide, is a socially serious health problem. Exercise has beneficial effects on the glycemic profile, such as decreased glycemic hemoglobin (HbA1c) level, increased maximum oxygen consumption (VO2max) and improved insulin sensitivity in diabetes patients. When the literature is examined, it is seen that exercise is also effective in improving metabolic health. Although the metabolic benefits of exercise have been shown, there is no study of which type of exercise is more beneficial in what time of day in individuals with Type 2 diabetes. Circadian rhythm plays an important role in clarifying this issue because the circadian rhythm is impaired in the glucose metabolism of individuals with type 2 diabetes.The aim of this study is to investigate which exercise is more effective in which time period for individuals with Type 2 diabetes

INTRODUCTION: Type 2 diabetes is a metabolic disease characterized by partial insulin deficiency or insulin resistance in peripheral tissue. Type 2 diabetes, which has a very high prevalence worldwide, is a socially serious health problem. Complications seen with the disease negatively affect human health. Physical activity and regular exercise are shown in the first place with pharmacological treatment and diet approaches in the treatment of Type 2 diabetes. Exercise has beneficial effects on the glycemic profile, such as decreased glycemic hemoglobin (HbA1c) level, increased maximum oxygen consumption (VO2max) and improved insulin sensitivity in diabetes patients. When the literature is examined, it is seen that exercise is also effective in improving metabolic health. Although the metabolic benefits of exercise have been shown, there is no study of which type of exercise is more beneficial in what time of day in individuals with Type 2 diabetes. Circadian rhythm plays an important role in clarifying this issue because the circadian rhythm is impaired in the glucose metabolism of individuals with type 2 diabetes. AIM: The aim of this study is to evaluate the effectiveness of structured exercises given in accordance with the circadian rhythm of individuals with type 2 diabetes. METHOD: 30 people with Type 2 diabetes in accordance with the criteria for inclusion in the Department of Endocrine and Metabolism Diseases of Medipol University Hospital in Istanbul will be included in this study. Individuals who have been diagnosed with Type 2 diabetes between the ages of 35-65, who have body mass index between 25 and 30, who have HbA1c value> 6.5%, who have fasting blood glucose>126 mg/dl, who have Type 2 diabetes between 5-10 years, who have inactive physical activity, who independently can walk and volunteer to exercise for at least 3 days a week will be included in our study. Type 1 diabetes individuals, diagnosed with Latent Autoimmune Diabetes in Adults (LADA), having diabetic Ketoacidosis coma, orthopedic or surgical problems to prevent walking and exercising, foot ulcers, individuals have any neurologıcal problem and individuals with cardiac, pulmonary or systematic diseases that will cause contraindications will not be included in the study. Blood sample evaluations, circadian rhythm evaluation, 6-minute walking test, 30-second sit to stand test, quality of life assessment with Ferrans&Powers Quality of Life Index of the individuals included will be carried out at the beginning of the study (T0) and at 6 (T1), 12 (T2) and 18 (T3) weeks after the study started Participants will be divided into two groups, morning (MC) and evening chronotypes (EC), according to their circadian rhythms. In both groups, there was a 6-week control period in which the participants continued to their routine treatment and did not perform any specific exercises. In the MC group, exercises were applied in the morning hours for the first 6 weeks and in the evening hours for the next 6 weeks. The EC exercises were applied in the evening hours for the first 6 weeks and in the morning hours for the next 6 weeks. A structured exercise program with aerobic and strengthening exercises was carried out in both groups for 3 days a week over 12 weeks. . Individuals were evaluated in terms of the blood test, functional capacity and quality of life at the baseline, 6 weeks before the exercise, 6 and 12 weeks after the exercises.

In the MC group, exercises were applied in the morning hours for the first 6 weeks and in the evening hours for the next 6 weeks.

The EC exercises were applied in the evening hours for the first 6 weeks and in the morning hours for the next 6 weeks

Scores can range from 16-86. Scores of 41 and below indicate "evening types". Scores of 59 and above indicate "morning types". Scores between 42 and 58 indicate "intermediate types" in Morningness Eveningness Questionnaire

Inclusion Criteria: Clinical diagnosis of Type 2 diabetes Between the ages of 35-65 Body mass index between 25 and 30 HbA1c value> 6.5% Fasting blood glucose>126 mg/dl Inactive physical activity level Who independently can walk and volunteer to exercise for at least 3 days a week Exclusion Criteria: Clinical diagnosis of Type 1 diabetes Clinical diagnosis of Latent Autoimmune Diabetes in Adults (LADA) Having diabetic Ketoacidosis coma Orthopedic or surgical problems to prevent walking and exercising Foot ulcers Neurologıcal, cardiac, pulmonary or systematic diseases

Savikj M, Gabriel BM, Alm PS, Smith J, Caidahl K, Bjornholm M, Fritz T, Krook A, Zierath JR, Wallberg-Henriksson H. Afternoon exercise is more efficacious than morning exercise at improving blood glucose levels in individuals with type 2 diabetes: a randomised crossover trial. Diabetologia. 2019 Feb;62(2):233-237. doi: 10.1007/s00125-018-4767-z. Epub 2018 Nov 13.

Menek MY, Budak M. Effect of exercises according to the circadian rhythm in type 2 diabetes: Parallel-group, single-blind, crossover study. Nutr Metab Cardiovasc Dis. 2022 Jul;32(7):1742-1752. doi: 10.1016/j.numecd.2022.04.017. Epub 2022 Apr 29.