Dietary factors and postmenopausal bleeding: A Mendelian randomization investigation

Area of Science:

• Reproductive health
• Nutritional epidemiology
• Genetic epidemiology

Background:

• Modifiable risk factors for postmenopausal bleeding (PMB) are essential for prevention, yet dietary influences remain under-researched.
• Few studies have specifically examined the causal links between various dietary components and the risk of PMB.

Purpose of the Study:

• To investigate the potential causal relationships between 20 distinct dietary factors and the risk of postmenopausal bleeding (PMB).
• To leverage genetic data for robust causal inference, minimizing confounding factors common in observational studies.

Main Methods:

• Mendelian randomization (MR) analysis was performed using large-scale genetic data from the UK Biobank and FinnGen Biobank.
• Three MR methods were employed: inverse-variance-weighted (IVW), weighted median (WM), and MR-Egger regression.
• Genetic variants associated with 20 dietary intakes were used as instrumental variables to assess causal effects on PMB.

Main Results:

• The IVW analysis indicated that higher poultry intake is associated with an increased risk of PMB (OR=3.00, P=0.0394).
• Conversely, non-oily fish intake (OR=0.372, P=0.0145) and coffee intake (OR=0.508, P<0.0001) showed a reduced risk of PMB in the IVW analysis.
• The weighted median method confirmed the association for coffee intake, while MR-Egger did not support significant associations for poultry, non-oily fish, or coffee.

Conclusions:

• Poultry consumption may represent a modifiable risk factor for increasing postmenopausal bleeding (PMB) risk.
• Non-oily fish and coffee intake may exert protective effects against postmenopausal bleeding (PMB).
• Further research is warranted to confirm these dietary associations and explore underlying biological mechanisms for PMB.