Sex differences in the association between suicide attempts and glucose disturbances in first-episode and drug naive patients with major depressive disorder

Glucose metabolism is related to depression, but the relationship between blood glucose and suicide attempts in patients with major depressive disorder (MDD) remains unclear. This large-scale sample explores the relationship between suicide attempts and fasting blood glucose, in addition to sex differences in first-episode and drug naive (FEDN) MDD patients. 1718 FEDN MDD patients diagnosed for the first time were recruited, and their demographic data, clinical data, and blood glucose indicators were collected. 17-item Hamilton Depression Rating Scale (HAMD), 14-item Hamilton Anxiety Rating Scale (HAMA), and positive subscale of the Positive and Negative Syndrome Scale (PANSS) were used to assess their depression, anxiety and psychotic symptoms, respectively. The depression, anxiety, psychotic symptoms and blood sugar levels of the suicide attempt group were higher than those of the non-suicide attempt group. Correlation analysis showed that blood glucose was significantly associated with suicide attempts in male and female patients. While binary logistic regression showed that blood glucose levels were significantly associated with suicide attempts in male patients, it showed that suicide attempts were not significantly associated with blood glucose levels in female patients. The main limitations are cross-sectional design and inability to control selection bias. In male MDD patients, fasting blood glucose level is a potential biomarker of suicide attempt, which deserves attention to avoid suicide risk. However, in female patients, fasting blood glucose has no significant correlation to suicide attempts. • This study is the first study to explore the relationship between blood sugar and suicide attempts in male and female patients with major depressive disorder. • This study found a significant association between blood glucose and suicide attempts in male patients with major depressive disorder, but no such association was found in female patients. • The sample size of this study is as high as 1718. All participants are first-episode and drug naive patients, which will better rule out the effects of medication. • Fasting blood glucose may be a biomarker of suicide risk in male patients with major depressive disorder. • This study has reference value for understanding the neurophysiological mechanism of suicide and preventing the risk of suicide in patients with major depressive disorder.