Polyunsaturated fatty acids and diabetic microvascular complications: a Mendelian randomization study

Area of Science:

• Nutritional Epidemiology
• Genetic Epidemiology
• Metabolic Disorders

Background:

• Observational studies suggest polyunsaturated fatty acids (PUFAs) may prevent diabetic microvascular complications.
• Conflicting findings necessitate causal inference studies to clarify these relationships.
• Mendelian randomization (MR) is employed to investigate the causal impact of PUFAs on diabetic microvascular complications.

Purpose of the Study:

• To determine the causal effect of omega-3 and omega-6 fatty acids on diabetic microvascular complications.
• To assess the impact on diabetic neuropathy (DN), retinopathy (DR), and kidney disease (DKD) in type 1 and type 2 diabetes.
• To explore potential reverse causation and confounding factors using multivariable MR (MVMR).

Main Methods:

• Utilized UK Biobank for instrumental variables of PUFAs (omega-3 and omega-6).
• Sourced outcome data for diabetic microvascular complications from the FinnGen Study.
• Performed MR, inverse MR, and MVMR analyses, including sensitivity analyses for robustness.

Main Results:

• Genetically predicted higher omega-6 fatty acid levels significantly reduced the risk of DN (OR: 0.62) and DR (OR: 0.75) in type 2 diabetes.
• MVMR analysis confirmed these protective effects of omega-6 fatty acids.
• No significant associations were found for omega-6 fatty acids with DKD in type 2 diabetes or any complications in type 1 diabetes; omega-3 fatty acids showed no significant links.

Conclusions:

• Mendelian randomization analysis reveals a causal role for omega-6 fatty acids in reducing the risk of specific microvascular complications in type 2 diabetes.
• Findings suggest potential therapeutic targets for preventing or managing diabetic complications.
• Further mechanistic and clinical research is warranted to validate these insights.