Objective:

To investigate factors associated with plasma levels of the ketone body β-hydroxybutyrate (BHB) in a general population cohort, focusing on both dietary and non-dietary influences.

Key Findings:

• Women had significantly higher BHB levels than men (123 vs 119 µmol/L, P < .001).
• Hormonal status was the most significant determinant of BHB levels in women, with oral contraceptive use associated with a 45% increase in BHB concentration (P-value needed).
• Postmenopausal status was associated with an 11% decrease in BHB levels compared to premenopausal women without OC use (P-value needed).
• In men, age was the most significant determinant, with a 1% increase in BHB levels per year (P-value needed).
• Other determinants of higher BHB levels included lower protein intake, habitual alcohol use, higher N-terminal pro-B-type natriuretic peptide, and higher free thyroxine levels (specific values needed).

Interpretation:

A complex interplay of metabolic, hormonal, and lifestyle factors influences BHB levels, with distinct differences between sexes; hormonal status is crucial for women, while age is significant for men. These findings suggest the need for tailored interventions based on sex.

Limitations:

• The study is observational and cannot establish causality, which may limit the interpretation of the results.
• The cohort may not be representative of the general population due to specific inclusion criteria, potentially affecting the generalizability of the findings.

Conclusion:

Understanding the determinants of BHB levels can help tailor interventions for optimizing ketone metabolism, considering sex-specific differences, which is crucial for effective health strategies.