Analysis of Cardiovascular Fitness, Sleep Quality, Depression, Fatigue, and Quality of Life among Individuals with Respect to the Glycated Hemoglobin Level in Type 2 Diabetes Mellitus

Background: Diabetes as a metabolic disorder can affect the various systems of the body, resulting in a decrease in cardiovascular fitness, sleep quality, and life quality that can lead to depression and fatigue. Aim: We analyzed cardiovascular fitness, sleep quality, depression, fatigue, and quality of life among individuals with a glycated hemoglobin (HBA1C) level >6.5% and ≤6.5%, as well as the relationship among glycated hemoglobin, maximal oxygen consumption (VO₂max), obesity, sleep quality, depression, and duration of diabetes. Method: HBA1C (mean: 5.90 ± 0.93%) was studied in a total of 70 subjects (mean age: 62.37 ± 7.5 years). The 2 study groups were as follows: group A, HBA1C >6.5%, and group B, HBA1C ≤6.5%. BMI, VO₂max, quality of sleep and life, depression, and fatigue were assessed in both groups. Results: There was a statistically significant difference between the groups at a significance level of p < 0.001. Group A had a lower cardiovascular fitness, a poor sleep quality, and increased depression compared to group B. A statistically significant negative linear correlation was found between VO₂max and glycated hemoglobin, and a significant positive linear correlation was found between glycated hemoglobin and duration of diabetes, poor quality of sleep, and depression for all subjects, which was insignificant in the groups. Conclusions: A long duration of diabetes and an increased glycemic status may influence cardiovascular fitness, sleep quality, and life quality, leading to depression and fatigue.