HRT progesterones and oestrogens cause all types of strokes
The re-emergence of the old chestnut, that adverse effects of HRT
(progesterones and oestrogens) depends on the age since the menopause,
betrays a lack of understanding of how hormones act. I observed adverse
changes in endometrial blood vessels, which matched increases in
headaches, migraines and strokes, in previously healthy young women who
volunteered to take these hormones as oral contraceptives in the early
1960s.1
What is the age of the menopause? Post-Pill amenorrhoea and
anovulation at age 20 because of starting OCs at age 15? Hysterectomy and
bilateral oophorectomy at age 30 because of OC-induced wide-spread
endometriosis? Women with ovarian failure at age 40, due to years of
tobacco smoking and Pill taking and who take further hormones as HRT,
already have higher risks of vascular diseases.
In the WHI combined HRT study concluded that excess risk of all
stroke was apparent in all age groups, in all categories of baseline
stroke risk, and in women with and without hypertension, prior history of
cardiovascular disease, use of hormones, statins, or aspirin.2 The
intention-to-treat hazard ratio (HR) for ischemic stroke was 1.44 (95% CI,
1.09-1.90) which is statistically significant.
As OCs and HRT cause hypertension, which is, or should be, a contra-
indication to further hormone use. Only one in 5 strokes were therefore
haemorrhagic. Small numbers in subgroups make statistically significant
results less likely. The WHI studies underestimate risks because most
women randomised to take either combined or oestrogen-only HRT, or
placebos, had previously used these hormones as HRT or for contraception.
Also in 1965 OCs were reported to cause cerebral insufficiency.3 In
1967 neurologists noticed that OCs also caused subarachnoid haemorrhages
and in 1981 the RCGP OC study reported an increased risk of mortality of
4.0 (1.3-12.9) from this condition.4,5 The increased mortality risks were
estimated to be 2.9 (1.3-6.4) for all cerebrovascular diseases and 5.6
(2.0-16.6) for all non-rheumatic heart disease and hypertension.
How many times does the wheel have to be reinvented ?
1 Grant ECG. Relation between headaches from oral contraceptives and
development of endometrial arterioles. Lancet 1965; 1: 1143-4.
2 Wassertheil-Smoller S et al. Effects of Estrogen plus progestin in
postmenopausal women. A women's health initiative randomized trial. JAMA
2003;289:2673-81.
3 Illis L, Kocen RS, McDonald WI, Mondkar VP. Oral contraceptives
and cerebral arterial occlusion. BMJ 1965; 2: 1164-66.
4 Bickerstaff ER, Holmes JM. Cerebral arterial insufficiency and
oral contraceptives. Cerebral arterial insufficiency and oral
contraceptives. BMJ 1967; 1: 726.
5 Royal College of General Practitioners’ Oral Contraception Study.
Further analyses of mortality in oral contraceptive users. Lancet 1981; i:
541-546.
Rapid Response:
HRT progesterones and oestrogens cause all types of strokes
The re-emergence of the old chestnut, that adverse effects of HRT (progesterones and oestrogens) depends on the age since the menopause, betrays a lack of understanding of how hormones act. I observed adverse changes in endometrial blood vessels, which matched increases in headaches, migraines and strokes, in previously healthy young women who volunteered to take these hormones as oral contraceptives in the early 1960s.1
What is the age of the menopause? Post-Pill amenorrhoea and anovulation at age 20 because of starting OCs at age 15? Hysterectomy and bilateral oophorectomy at age 30 because of OC-induced wide-spread endometriosis? Women with ovarian failure at age 40, due to years of tobacco smoking and Pill taking and who take further hormones as HRT, already have higher risks of vascular diseases.
In the WHI combined HRT study concluded that excess risk of all stroke was apparent in all age groups, in all categories of baseline stroke risk, and in women with and without hypertension, prior history of cardiovascular disease, use of hormones, statins, or aspirin.2 The intention-to-treat hazard ratio (HR) for ischemic stroke was 1.44 (95% CI, 1.09-1.90) which is statistically significant.
As OCs and HRT cause hypertension, which is, or should be, a contra- indication to further hormone use. Only one in 5 strokes were therefore haemorrhagic. Small numbers in subgroups make statistically significant results less likely. The WHI studies underestimate risks because most women randomised to take either combined or oestrogen-only HRT, or placebos, had previously used these hormones as HRT or for contraception.
Also in 1965 OCs were reported to cause cerebral insufficiency.3 In 1967 neurologists noticed that OCs also caused subarachnoid haemorrhages and in 1981 the RCGP OC study reported an increased risk of mortality of 4.0 (1.3-12.9) from this condition.4,5 The increased mortality risks were estimated to be 2.9 (1.3-6.4) for all cerebrovascular diseases and 5.6 (2.0-16.6) for all non-rheumatic heart disease and hypertension.
How many times does the wheel have to be reinvented ?
1 Grant ECG. Relation between headaches from oral contraceptives and development of endometrial arterioles. Lancet 1965; 1: 1143-4.
2 Wassertheil-Smoller S et al. Effects of Estrogen plus progestin in postmenopausal women. A women's health initiative randomized trial. JAMA 2003;289:2673-81.
3 Illis L, Kocen RS, McDonald WI, Mondkar VP. Oral contraceptives and cerebral arterial occlusion. BMJ 1965; 2: 1164-66.
4 Bickerstaff ER, Holmes JM. Cerebral arterial insufficiency and oral contraceptives. Cerebral arterial insufficiency and oral contraceptives. BMJ 1967; 1: 726.
5 Royal College of General Practitioners’ Oral Contraception Study. Further analyses of mortality in oral contraceptive users. Lancet 1981; i: 541-546.
Competing interests: None declared
Competing interests: No competing interests