Association of coffee intake with bone mineral density: a Mendelian randomization study

Area of Science:

• Genetics
• Bone Metabolism
• Nutritional Epidemiology

Background:

• Observational studies on coffee intake and bone mineral density (BMD) show conflicting results.
• Residual confounding in observational studies may bias findings regarding coffee and BMD.
• Mendelian randomization (MR) is employed to investigate potential causal links, mitigating confounding bias.

Purpose of the Study:

• To investigate the potential causal relationship between coffee intake and bone mineral density (BMD).
• To leverage a two-sample Mendelian randomization approach to overcome limitations of previous observational studies.
• To provide robust genetic evidence on the association between coffee consumption and bone health.

Main Methods:

• Utilized a two-sample Mendelian randomization (MR) design.
• Derived genetic instrumental variables (IVs) for coffee intake from large genome-wide association studies (GWAS).
• Analyzed BMD data from a substantial cohort, employing inverse variance weighting (IVW) and sensitivity analyses for robust inference.

Main Results:

• A potential positive correlation was found between coffee intake and total body BMD (Beta: 0.198, P=0.008).
• Subgroup analyses indicated positive associations with total body BMD in specific age groups (45-60 and 30-45 years).
• Significant positive correlations were observed for heel BMD (Beta: 0.173, P=0.002), with consistent results from sensitivity analyses.

Conclusions:

• The study provides genetic evidence suggesting coffee intake may be beneficial for bone density.
• Findings support a potential positive role of coffee consumption in maintaining bone health.
• Further research is warranted to elucidate biological mechanisms and inform clinical guidelines for osteoporosis prevention.