Objective

To examine associations between systemic inflammation, sex hormones, and vitamin D levels in U.S. women.

Methods

A cross-sectional study was conducted using NHANES 2021–2023 data from 3179 women aged 18–80 years. Participants were grouped by high-sensitivity C-reactive protein (hs-CRP) quartiles. Demographic, anthropometric, lifestyle, dietary, and clinical variables were analyzed. Serum biomarkers included hs-CRP, sex hormones, lipid parameters, and 25-hydroxyvitamin D3 (25OHD3). Multivariable linear regression assessed independent associations between hs-CRP and endocrine markers after adjustment for confounders.

Results

Women in the highest hs-CRP quartile had higher age, body weight, waist circumference, body mass index, and prevalence of hypertension and diabetes than those in the lowest quartile. Higher hs-CRP levels were associated with lower concentrations of 17α-hydroxyprogesterone, androstenedione, anti-Müllerian hormone (AMH), dehydroepiandrosterone sulfate, follicle-stimulating hormone (FSH), sex hormone-binding globulin, and 25OHD3. After adjustment, hs-CRP remained positively associated with AMH (β = 0.212, p = 0.007), estrone (β = 0.142, p = 0.048), low-density lipoprotein cholesterol (β = 0.241, p = 0.002), and total cholesterol (β = 0.224, p = 0.001), and inversely associated with FSH (β = −0.194, p = 0.039) and luteinizing hormone (β = −0.191, p = 0.019).

Conclusion

Systemic inflammation was associated with reproductive hormones and lipid profiles, while many associations weakened after adjustment for adiposity. These findings highlight complex links between inflammation, endocrine function, and cardiometabolic health, influenced by obesity-related factors.