Headache in transgender men using gender-affirming hormone therapy: A case-control study.

Objectives: This study aimed to compare the frequency, characteristics, and impact of primary headaches in transgender men (TM), cisgender men (CM), and cisgender women (CW).

Background: Gender is a social construct shaped by roles and norms and influenced by cultural and environmental factors. Studies on primary headaches typically only consider sex and generally overlook gender.

Methods: This was a case-control study conducted at the Hospital das Clínicas, Universidade Federal de Pernambuco, Brazil. A pilot study comparing 25 TM and 25 CM individuals was conducted to determine sample size requirements. After that, 50 TM (cases), 50 CM (controls), and 50 CW (controls) were included. The controls were age matched to cases. A semi-structured questionnaire, the six-item Headache Impact Test (HIT-6), and the Hospital Anxiety and Depression Scale were used. Data collection occurred from April 2022 to November 2023.

Results: All the TM were taking gender-affirming hormone therapy (testosterone cypionate, 41; testosterone undecanoate/undecylenate, six; testosterone esters, three). According to the sample size calculation, adequate power was only achieved for the frequency of tension-type headache (TTH) and for headache impact. No differences were observed between TM and CW in the frequency of migraine (odds ratio [OR] 1.14, 95% confidence interval [CI] 0.45-2.91), TTH (OR 0.74, 95% CI 0.28-1.96), or headache severity (frequency ≥8 days/month: OR 0.54; 95% CI 1.18-1.63; moderate/severe intensity: OR 1.24, 95% CI 0.49-3.18; HIT-6 score ≥56 points: OR 0.66, 95% CI 0.25-1.75) (OR adjusted for higher education and depression by conditional logistic regression). The TM group exhibited significantly lower rates of all types of headache (OR 0.20, 95% CI 0.05-0.85) and TTH (OR 0.18, 95% CI 0.07-0.45) and a significantly higher prevalence of any migraine (OR 3.93, 95% CI 1.60-9.63) and migraine without aura (OR 3.12, 95% CI 1.10-8.84) compared to the CM group (OR adjusted for anxiety and depression by conditional logistic regression). There were no differences between TM and CM in headache severity (frequency, intensity, and impact).

Conclusions: There are no differences in the headache type or severity between the TM and CW groups. TM have a higher prevalence of migraine than CM, but no difference in headache severity.