Depression may be causally linked with risk of T2D and CAD

Takeaway

• Genetic liability to major depressive disorder (MDD) was significantly associated with an increased risk of type 2 diabetes (T2D) and coronary artery disease (CAD).
• Liability to T2D, CAD, and heart failure (HF) was not related to MDD in the reverse Mendelian randomisation (MR) analysis.

Why this matter

• Findings strengthen the casual inference that depression is a potential casual risk factor for T2D and CAD.

Study design

• This bidirectional MR study used summary-level data from meta analyses of genome-wide association studies of MDD, T2D, CAD, and HF, mainly of European ancestry.
• 96 single-nucleotide polymorphisms for MDD, 202 for T2D, 44 for CAD, and 12 for HF reached genome-wide significance and were used as instrumental variables.
• Funding: Uppsala University.

Key results

• The OR of T2D per one-unit increase in log_e odds of MDD liability was 1.26 (95% CI, 1.10-1.43).
• The ORs per one-unit increase in log_e odds of MDD liability for CAD and heart failure were 1.16 (95% CI, 1.05-1.29) and 1.11 (95% CI, 1.01-1.21), respectively.
• There was limited evidence supporting any causal association in the reverse direction.

Limitations

• Potential risk of pleiotropy.
• Population stratification may have affected the result for the association between CAD and MDD.