High Blood Pressure in Women: An Under-recognized Problem

High blood pressure is equally prevalent in both sexes although till the age of 45 years men suffer from it more often. However, the situation reverses after 65 years of age. With increasing longevity there will be more women with HT as compared to males in future. The life expectancy on an average is 5 years shorter in ladies with HT.

Women dying of strokes, heart attacks and heart failure have a 65 to 75 % chance of having HT as one of the important causes besides diabetes, obesity and physical inactivity. Post-menopausal women have a high burden of sudden cardiac death, which accounts for around 10 to 15% of all deaths and about half of all heart attack deaths.

Awareness of HT is fairly low in women because of not getting it checked unless symptomatic, which is quite late. Around half of those diagnosed have BP readings more than the target of 140/90 mms Hg in spite of treatment. Although HT treatment has improved over the years this figure still is not showing any significant change. This finding is consistent with international data on population studies which shows a more pronounced age-related reduction in Hypertension control in women than in men. This is likely to increase the number of uncontrolled HT in the female population in years to come as the longevity of our population increases. This could be either because of sub-optimal treatment, non-compliance or true resistance. Adverse life style is common in urban women. Staying indoors, consuming very high quantity of salt in the form of chutneys, pickles etc and lack of exercise are important contributors.

Women Specific Causes of HT

Post-Menopausal HT:

BP always rises by up to 5 mms Hg after menopause and hormonal imbalance is the main reason for this. It is mainly related to increased salt sensitivity and stiffness of the arteries of the body and the inner lining becoming rough due to reduction in the release of protective substances. The with drawl of oestrogens is the chief culprit leading to excessive retention of salt in the body.

Hormone replacement therapy in low doses (oestrogen progesterone combinations) has been advocated to get over the symptoms of hot flushes, swings of mood and vaginal dryness etc. However, it should be avoided in ladies with previous history of heart disease and strokes etc because of the data showing more strokes and heart attacks in them.

Oral Contraceptive Pill induced HT:

These pills contain a combination of oestrogen and progesterone and are associated with small but significant risk of HT and vascular events, particularly stroke, in the population of women consuming it. The main reason being stiffening of the arteries because of salt retention secondary to hormone effects. Their continued usage leads to HT as compared to non-users. This is much more frequent if the person smokes, is in the higher age bracket and is obese. Medical experts advise use of less than 6 months in continuation and also BP measurement. These agents can sometimes lead to very high blood pressures needing a very aggressive treatment.

HT Related to Pregnancy:

High BP during pregnancy can be seen in a number of situations: Chronic HT, gestational HT, Pre-Eclampsia and Eclampsia. All these can be responsible for a high maternal, foetal and neo natal (new born) morbidity and mortality.

Management of a lady with pre-existent HT is directed to protect the mother from getting into problems like heart failure, stroke and kidney damage which can be at times be fatal. The foetus by far is not affected. The choice of drugs is however, important because some agents used to lower BP can harm the foetus.

Life style modification especially exercise and diet rich in fruits and vegetables etc. are very important initial measures. For ladies with BP more than 160/100 mms Hg drug treatment using a combination of 2 different class of drugs is recommended. Even in those with a BP between 140/90 to 150/95 mms Hg during gestation drugs are needed. This is important if there is asymptomatic target organ damage like protein in the urine or features of hypertrophy of the left ventricle as seen by echo cardiography or ECG.

The drugs recommended are labetalol, methyldopa or nifedipine, which are time tested agents for foetal safety. When BP has to be reduced rapidly in a hypertensive emergency intravenous labetalol is the agent of choice and other options are intravenous nitroprusside or nitro-glycerine. These drugs should always be administered in a hospital setting under expert supervision.

While the beneficial effects of treating HT are similar in both men and women, the side effects of commonly used drugs for treating HT in women are often different. Women get 3 times more cough with ACEI (ramipril, enalapril) and more oedema with calcium channel blockers (amlodipine). Drugs of the group of ACEI and ARB’S (ramipril, enalapril and losartan, telmisartan or Olmesartan etc are absolutely contraindicated during pregnancy or even in ladies planning a pregnancy. These are known to produce foetal developmental abnormalities. Same is true for drugs like spironolactone and eplerenone. Women are more prone to get electrolyte deficiency with diuretics while men get high uric acid with these agents.

Thiazide and thiazide-like diuretics (water pills) are particularly attractive for use in elderly women because of decreased risk of hip fracture, because of gentle BP reduction.  Initial treatment of high-risk women with acute coronary syndrome or myocardial infarction should be with beta-blockers and/or ACEI/ARBs, with addition of other drugs such as thiazides as needed to achieve goal BP.

Take home Messages:

Normal BP in women like in men is 120/80 mms Hg. Post-menopausal ladies and those taking oral contraceptives for prolonged periods have a high tendency of developing HT. Drug therapy is needed when it is more than 140/90 mms Hg. The response to treatment and benefits are the same in both sexes.

Some group of drugs like (ACEI. ARBs and spironolactone and eplerenone) should never be given during pregnancy. ACEI when generally used in women produce cough very frequently. Water pills are useful in elderly ladies with HT and produce much less fractures but produce salt depletion commonly. Calcium channel blockers like amlodipine are very effective but swelling of feet and legs is more common than in men. Life style measures of low salt intake, exercise and consuming fruits and vegetables is always the key whether or not needing drugs to lower BP.