Hypertension, Cardiovascular Risk Factors, and Uterine Fibroid Diagnosis in Midlife.

Importance: Fibroids are benign neoplasms associated with severe gynecologic morbidity. There are no strategies to prevent fibroid development. Objective: To examine associations of hypertension, antihypertensive treatment, anthropometry, and blood biomarkers with incidence of reported fibroid diagnosis in midlife. Design, Setting, and Participants: The Study of Women's Health Across the Nation is a prospective, multisite cohort study in the US. Participants were followed-up from enrollment (1996-1997) through 13 semiannual visits (1998-2013). Participants had a menstrual period in the last 3 months, were not pregnant or lactating, were aged 42 to 52 years, were not using hormones, and had a uterus and at least 1 ovary. Participants with prior fibroid diagnoses were excluded. Data analysis was performed from November 2022 to February 2024. Exposures: Blood pressure, anthropometry, biomarkers (cholesterol, triglycerides, and C-reactive protein), and self-reported antihypertensive treatment at baseline and follow-up visits were measured. Hypertension status (new-onset, preexisting, or never [reference]) and hypertension treatment (untreated, treated, or no hypertension [reference]) were categorized. Main Outcomes and Measures: Participants reported fibroid diagnosis at each visit. Discrete-time survival models estimated hazard ratios (HRs) and 95% CIs for associations of time-varying hypertension status, antihypertensive treatment, anthropometry, and biomarkers with incident reported fibroid diagnoses. Results: Among 2570 participants without a history of diagnosed fibroids (median [IQR] age at screening, 45 [43-48] years; 1079 [42.1%] college educated), 526 (20%) reported a new fibroid diagnosis during follow-up. Risk varied by category of hypertension treatment: compared with those with no hypertension, participants with untreated hypertension had a 19% greater risk of newly diagnosed fibroids (HR, 1.19; 95% CI, 0.91-1.57), whereas those with treated hypertension had a 20% lower risk (HR, 0.80; 95% CI, 0.56-1.15). Among eligible participants with hypertension, those taking antihypertensive treatment had a 37% lower risk of newly diagnosed fibroids (HR, 0.63; 95% CI, 0.38-1.05). Risk also varied by hypertension status: compared with never-hypertensive participants, participants with new-onset hypertension had 45% greater risk of newly diagnosed fibroids (HR, 1.45; 95% CI, 0.96-2.20). Anthropometric factors and blood biomarkers were not associated with fibroid risk. Conclusions and Relevance: Participants with untreated and new-onset hypertension had increased risk of newly diagnosed fibroids, whereas those taking antihypertensive treatment had lower risk, suggesting that blood pressure control may provide new strategies for fibroid prevention.