Menopausal hormone therapy and risk of incident hypertension: role of the route of estrogen administration and progestogens in the E3N cohort.

OBJECTIVES

Although menopausal hormone therapy (MHT) remains the most effective treatment for vasomotor symptoms of menopause, its association with the development of arterial hypertension remains unclear. We sought to explore associations between different formulations of MHT and incident hypertension among menopausal women in a prospective cohort study.

METHODS

We used the Etude Epidémiologique de femmes de la Mutuelle Générale de l'Education (E3N) cohort, a French prospective population-based study initiated in 1990 on 98,995 women. Out of these, 49,905 menopausal women with complete information on the use of MHT, and without prevalent hypertension at inclusion were included.

RESULTS

The mean age of the population at baseline was 54.2 ± 4.3 years, and 32,183 (64.5%) reported ever using MHT. Among these women, 10,173 cases of incident hypertension were identified over an average follow-up time of 10.6 years. Compared with women who never used MHT, those who ever used it had an increased risk of incident hypertension (adjusted HR 1.07, 95% CI 1.02-1.12) after adjustment for body mass index and other potential confounders. Oral but not transdermal estrogen use was associated with an increased risk of hypertension (adjusted HR = 1.09; 95% CI: 1.04-1.14 and HR = 1.03; 95% CI: 0.99-1.07, respectively). However, the HRs associated with oral and transdermal estrogens did not differ significantly (P-homogeneity = 0.09). Regarding the role of concomitant progestogens, pregnane and norpregnane derivatives were significantly associated with hypertension risk (HR = 1.12; 95% CI: 1.06-1.19 and HR = 1.06; 95% CI: 1.01-1.13, respectively).

CONCLUSIONS

MHT was associated with a modest but significant increased risk of incident hypertension, especially when using oral estrogen in combination with a progestogen such as pregnane and norpregnane derivatives. Surveillance of blood pressure should be added to the medical surveillance of MHT users.