Association Between Serum Free Testosterone Levels and Acne Severity in Women with Acne Vulgaris

Background: Androgens contribute to sebaceous gland activity and follicular keratinization, but the relationship between circulating free testosterone and acne severity in women remains inconsistent across studies. Objective: To examine the association between serum free testosterone and acne severity in women with acne vulgaris and to explore whether serum free testosterone differed according to disease duration or age at onset. Methods: This secondary analytical study included all 50 women with acne vulgaris enrolled in the case group of a hospital-based case-control study conducted at Sylhet MAG Osmani Medical College Hospital, Bangladesh, from January 2021 to June 2022. Acne was graded clinically as mild, moderate, or severe. Serum samples were collected between 8:00 and 11:00 AM during days 12-25 of the menstrual cycle, and free testosterone was measured by chemiluminescence immunoassay. Group means were compared using independent-samples t tests; mean differences, 95% confidence intervals, Hedges' g, and a Welch unequal-variance sensitivity analysis were reported. Results: Among 50 participants, 19 (38.0%) had mild acne and 31 (62.0%) had moderate acne; none had severe acne. Mean serum free testosterone was 4.93 ± 2.05 pg/mL in moderate acne and 3.43 ± 0.96 pg/mL in mild acne. The mean difference was 1.50 pg/mL (95% CI, 0.49 to 2.51; p=0.005), with a large standardized difference (Hedges' g=0.86; 95% CI, 0.27 to 1.44). The association remained significant in the Welch sensitivity analysis. Serum free testosterone did not differ significantly by disease duration (p=0.260) or age at onset (p=0.770). Conclusion: Serum free testosterone was higher in women with moderate acne than in those with mild acne. The finding supports a possible relationship between biologically active androgen exposure and acne severity, but it is limited by the single-center design, small sample, absence of severe acne, and lack of multivariable adjustment.