Prevalence and associated factors of obesity in patients with major depressive disorder at different ages of onset.

Major depressive disorder (MDD) and obesity are two serious public health problems. Although there have been some research on both, there have few studies on differences in obesity among MDD patients at different ages of onset. The study aims to evaluate the prevalence and factors associated with obesity in MDD patients at different ages of onset. This study totally recruited 1718 first-episode drug-naive MDD patients aged from 18 to 60 years. All subjects were divided into two subgroups: early adulthood onset (EAO, 18-45 years) and mid-adulthood onset (MAO, 45-60 years). Clinical symptoms of patients were evaluated using the 17-item Hamilton Depression Rating Scale (HAMD-17), Hamilton Anxiety Scale (HAMA), and Positive and Negative Syndrome Scale (PANSS) positive subscale. Baseline parameters including body mass index (BMI), blood pressure, and hematological biochemical parameters were assessed to investigate the association between these parameters and weight gain risk. The percentages of overweight and obesity patients with MDD in EAO group were 54.4% and 4.1%, respectively, and the percentages of overweight and obesity patients with MDD in MAO group were 60.4% and 2.8%, respectively. MDD patients in the MAO group had a longer duration of illness and higher scores in HAMD, HAMA, and PANSS positive subscale. They also had higher levels of thyroid stimulating hormone (TSH), anti-thyroglobulin (TgAb), fasting blood glucose (FBG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), systolic and diastolic blood pressures (SBP and DBP) levels. BMI did not differ significantly between the two groups. In the EAO group, statistically significant differences were found among normal weight, overweight and obese group in duration of illness, age of onset, TSH, TgAb, thyroid peroxidase antibody (TPOAb), free thyroxine (FT4), TC, triglycerides (TG), SBP and DBP. The TSH, TgTb and SBP were identified as risk factors for weight gain. In the MAO group, statistically significant differences were found among normal weight, overweight and obese group in TSH and FBG. The two indicators were identified as risk factors for weight gain. There were no significant differences in the weight of MDD patients at different ages of onset, while the factors that could potentially lead to obesity did show some differences.