Glycemic Indicators and Mental Health Symptoms: Result from the Greater Beirut Area Cardiovascular Cohort.

Abstract

Background: Mental health disorders are a growing public health priority; with the most common being depression and anxiety. These conditions also present high and complex comorbidity with diabetes; however, the exact mechanisms underlying their co-occurrence remain unknown.

Objective: This study aims to address the more direct links between metabolic indices (HbA1c and fasting blood glucose) and depression and anxiety symptoms in a community sample of middle-aged Lebanese adults.

Methods: The project is based on a secondary data analysis of the Greater Beirut Area Cardiovascular Cohort (GBACC). The GBACC sample was first examined in 2014 (n=501) and a five-year follow-up wave was completed in 2019 (n=198). Sociodemographic, lifestyle, medical, and biological data were collected at both waves and mental health was assessed only at the follow-up study examination. We investigated associations between glycemic indicators and continuous mental health scores using piecewise regression models to identify specific ranges of glycemic indicators where associations might potentially be different. Regression models were adjusted for Sociodemographic, lifestyle, and health characteristics.

Results: In bivariate analysis, there was a pattern for associations between higher FBG levels in 2014, having diabetes in 2014 and more depression and anxiety symptoms measured five years later. Graphical representations and piecewise regression models showed that there are different associations between glycemic indices in the diabetic/clinical versus non-diabetic range: Among participants with <126 mg/dl FBG range, higher baseline (2014) FBG levels were associated with lower depressive (beta=-0.093, 95%CI= [-0.0177, -0.009]; p=0.03) and anxiety symptoms (beta=-0.095, 95%CI= [-0.1763, -0.0147]; p=0.02). In contrast, among participants with FBG levels ≥ 126 mg/dl FBG, higher FBG levels in that range were significantly associated with higher anxiety symptoms (beta=0.054; 95%CI= 0.007, 0.101; p=0.02). Higher 2014 FBG levels in the ≥126 mg/dl range showed a trend -but not significant- for higher depressive symptoms. Although not significant, HbA1c levels in 2014 showed similar patterns of associations with negative associations with mental health symptoms in the below 6.5% range (beta= -1.436, 95%CI= [-3.477 0.604]; p=0.16) for depression and (beta= -1.526, 95%CI= [-3.520,0 .467];p= 0.133) for anxiety symptoms . Conclusion: Our results showed that FBG levels are associated with worst mental health symptoms only in the clinical/diabetic range, and not in the normal range. Results also suggests the presence of delayed or longer-term associations, with baseline FBG and diabetes status being associated with depression and anxiety symptoms assessed five-years later. Together these findings highlight the importance of clinical and pathological changes in glycemic indicators for mental health and motivate further research into the diabetes-mental health co-morbidity.