[Sportschosun, Jang Jong-ho] A study has found that exercising after being diagnosed with diabetes can reduce the risk of depression by as much as 25%.
A joint research team involving Choi Su-jeong of Gachon University Gil Hospital's Department of Family Medicine, Park Sang-min of Seoul National University Hospital's Department of Family Medicine, Park Sang-woo and Kim Baek of Seoul National University College of Medicine, and Lee Dae-ho of Shihwa Medical Center's Department of Internal Medicine, found that changes in physical activity before and after a diagnosis of type 2 diabetes directly affect the later risk of developing depression.
Type 2 diabetes can lead to a range of complications and comorbidities, including cardiovascular disease. Depression is especially common among diabetes patients. When it occurs alongside diabetes, it can lower treatment adherence, make blood sugar control more difficult, and significantly reduce quality of life.
Studies showing that regular physical activity helps prevent depression in the general population have been published consistently. However, there has been a lack of large-scale research analyzing whether the risk of depression changes depending on how physical activity levels shift before and after a new diabetes diagnosis.
According to the joint research team, patients who increased their physical activity after being diagnosed with diabetes saw their risk of depression fall by up to 25%, while those who stopped exercising saw their risk rise by 25%. The findings suggest that, after a diabetes diagnosis, maintaining or increasing physical activity is important not only for blood sugar management but also for protecting mental health.
The team used a diabetes database of about 2.2 million people from the National Health Insurance Service (NHIS). Among patients newly diagnosed with type 2 diabetes between 2009 and 2015, the final analysis included 254,619 people who underwent health checkups within two years before and after diagnosis and had no history of depression before their diabetes diagnosis.
The average age of the study participants was 56.6, and men accounted for about 51.2% of the group. The team followed the participants for an average of about 7.76 years and analyzed newly developed depression after the diabetes diagnosis.
Physical activity levels were calculated by converting the frequency and duration of low-, moderate-, and high-intensity activity reported in the national health screening questionnaire into metabolic equivalent of task, or MET, values. MET-minutes are an index that reflects both the intensity and duration of exercise to show total physical activity.
Based on weekly physical activity, the team divided participants into four groups: 0 MET-minutes for the inactive group, 1-499 MET-minutes, 500-999 MET-minutes, and 1,000 MET-minutes or more. They then compared the results of two health checkups before and after the diabetes diagnosis to analyze changes in each individual's physical activity.
The results showed that among patients who had not exercised at all before their diabetes diagnosis, increasing physical activity to 500-999 MET-minutes per week after diagnosis reduced the risk of depression by 23%. For those who raised their activity level to 1,000 MET-minutes or more per week, the risk fell by 25%.
In particular, the study confirmed a dose-response relationship, with larger increases in physical activity leading to greater reductions in depression risk. It also found that even starting with a relatively light level of activity, after previously being completely inactive, could help prevent depression.
On the other hand, patients who had been doing 1-499 MET-minutes of physical activity per week before their diabetes diagnosis saw their risk of depression rise by 25% if they stopped completely after diagnosis. Patients who had been doing moderate or higher levels of physical activity before diagnosis also showed a consistent pattern: the more they reduced their activity after diagnosis, the higher their depression risk became.
These results remained valid even after adjusting for a range of factors that could affect depression risk, including age, sex, body mass index, smoking, drinking, income, blood pressure, fasting glucose, total cholesterol, and comorbidities. Subgroup analyses also generally showed a consistent trend in which increased physical activity lowered the risk of depression.
The research team said exercise may have helped prevent depression by improving glucose and lipid metabolism, suppressing neuroinflammation, and stabilizing the hypothalamic-pituitary-adrenal axis, which regulates stress responses. They also pointed to reduced psychosocial stress from physical activity as another factor that may protect mental health.
Choi Su-jeong, a co-author of the study, said, "A diabetes diagnosis is a crucial moment when patients are most likely to make active changes to their lifestyle." She added, "Even patients who have never exercised before can help lower their risk of depression by starting physical activity after diagnosis in a way that fits their health condition."
The team said the findings could serve as evidence for more actively linking personalized physical activity counseling and exercise support to treatment and health management programs for diabetes patients.
The study was recently published in the international journal Diabetes & Metabolism Journal.
Jang Jong-ho, bellho@sportschosun.com
This article has been translated by GripLabs Mingo AI.
