Relationship between mitochondrial respiratory chain complex enzyme Ⅰ, Ⅱ, and Ⅲ activities and fatigue in the patients with type 2 diabetic disease

Objective To explore the potential relationship between mitochondrial respiratory chain complex enzyme Ⅰ,Ⅱ, and Ⅲ activities and fatigue in type 2 diabetic mellitus (T2DM) patients.Methods A total of 130 T2DM patients who were admitted to the First People's Hospital of Sihong County from January 1, 2020 to December 31, 2021 were selected. According to the Fatigue Scale scores, they were divided into two groups:a T2DM without fatigue group and a T2DM with fatigue group. Their blood samples were collected for routine fasting blood glucose (FBG) test and the glycosylated hemoglobin (HbA1c) test. The levels of coenzyme-Q10 (CoQ10) and the activities of respiratory chain complex enzymes Ⅰ,Ⅱ, and Ⅲ were measured by the Coenzyme Q10 ELISA kit and the Mitochondrial Respiratory Chain Complex Activity Quantitative Kit, respectively. Then, independent samples t-test, double correlation Pearson test, ROC curve, and binary logistic regression analysis were performed to assess the correlation between each clinical index and the risk of diabetic fatigue.Results There were no statistical differences in FBG, HbA1c, mean blood glucose within 24 h (24 h MBG) and 24-hour standard deviation of blood glucose (24 h SDBG), and the scores of the Patient Health Questionnaire-9 item (PHQ-9) and the Generalized Anxiety Disorder Scale-7 item (GAD-7) between the two groups (P>0.05). For patients in the fatigue group, their levels of CoQ10 and mitochondrial respiratory chain complex enzyme Ⅰ,Ⅱ, and Ⅲ were lower than those in the non-fatigue group (P<0.05).For T2DM patients, their CoQ10 and mitochondrial respiratory chain complex enzyme Ⅰ,Ⅱ, and Ⅲ activities were negatively correlated with FS-14 scores (r=-0.451--0.906, P<0.05). Sex (female), age (60-69 years/70-79 years), and disease duration (more than 10 years) were the independent risk factors for fatigue in T2DM patients.Conclusions The decrease in mitochondrial respiratory chain complex enzyme Ⅰ/Ⅱ/Ⅲ activity is closely related to fatigue in T2DM patients. Moreover, they display the predictive value for fatigue in T2DM patients.