Abdominal Obesity Increases the Risk for Depression by Sex: A Nationwide Cohort Study in South Korea

Objective: Previous studies have investigated obesity and appetite changes in patients with depression, which consisted of a small age range of adults and used body mass index rather than abdominal obesity. The objective of this study is to examine the relationship between abdominal obesity and the risk of depression by sex and age groups.

Methods: This study utilized the National Health Insurance Sharing Service (NHISS) database of South Korea, which includes those over 20 years old and who had undergone a health examination in 2009 and their claims data between 2009 and 2018. The diagnosis of depressive episodes was based on the International Statistical Classification of Disease and Related Health Problems 10th revision. Abdominal obesity was measured by waist circumference (WC) and was divided into six levels (cm). Cox proportional-hazard regression analyses were conducted to examine the relationship between abdominal obesity and the risk of depression by sex and age groups.

Results: Among 9,041,751 participants, 1,376,279 were diagnosed with depression. Those with higher WC (90 cm or higher for males, 85 cm or higher for females) showed an increased risk for depression in both sexes (hazard ratio [HR]=1.09, 95% confidence interval [CI]: 1.07-1.11 for males, HR=1.03, 95% CI: 1.02-1.05 for females). Underweight males (WC<80 cm) also showed an increased risk for depression (HR=1.05, 95% CI: 1.04-1.05).

Conclusion: It has been found that higher WC was associated with increased risks of depression in both sexes. Although underweight males showed an elevated risk of depression, a healthy weight is associated with fewer depression symptoms.