EXERCISE IN THE CONTROL OF BLOOD PRESSURE

As I mentioned last week there is a range of effective drugs for treating hypertension. However all drugs have side effects and it is clearly better to start treatment by tackling any aspect of life style which may be contributing to the high blood pressure (BP).

Life-style causes of hypertension:

1. Obesity: Being overweight or obese significantly increases blood pressure, particularly central obesity. Losing weight reduces blood pressure so should be one of  the first aims of hypertensive patients. I will not repeat all I have said in my recent blogs on this subject – suffice it to say that exercise plays a very important role in this endeavour.
2. Alcohol: Excessive alcohol intake (21 or more units for men and 14 or more for women) contributes to raised BP. Alcohol is also a source of calories and just reducing drinking can have a significant effect on body weight.
3. Salt: Reducing salt consumption usually reduces BP.
4. Inactivity: Exercise is an effective tool in the fight against hypertension

Exercise in the prevention of raised blood pressure

Regular exercise and good levels of physical fitness are associated with lower body weight and this alone results in lower blood pressures. However the role of exercise in control of BP is additional to that of weight control. Physical fitness has a direct effect on blood pressure and the fitter you are the lower your BP. The large Harvard alumni study showed that those who engaged in regular vigorous leisure activities had a 33% lower risk of developing hypertension than those who took little exercise. There is a dose response relationship between physical fitness and BP – that is to say that the fitter you are the lower your BP is likely to be. In a study of 5249 Copenhagen middle aged males every increase in VO_2max of 10ml/min/kg (see glossary) was associated with a 2mm Hg reduction in both systolic and diastolic BP.

Whatever your BP may be you would probably be better off if, by your own efforts, you could bring it down. So avoid too much salt, drinking too much alcohol, being obese and, surprise, surprise, taking too little exercise.  A bout of exercise reduces BP for several hours, while exercise training reduces BP both at rest and during exercise.

In the longer term, regular exercise and good levels of physical fitness also reduce the BP of hypertensive individuals. A meta-analysis involving more that 10,000 subjects found that regular exercise reduced the BP of hypertensives to almost exactly the same extent as drugs commonly used for BP control. The study also confirmed that adding exercise to drug treatment further improved BP control. It also appears that hypertension which is resistant to medication can respond to exercise training.

It has been a challenge to verify the dose of exercise that will produce the maximum health benefits in hypertension. One study aimed to explore the association between level of daily physical activity, all-cause mortality and cardiovascular outcome at different blood pressure levels. A random sample of 18 974 white men and women aged 20 to 98 years were examined in a prospective cardiovascular population study with an assessment of blood pressure and regular exercise habit. . The mean follow-up time was over 23 years. At all levels of blood pressure, higher levels of physical activity were associated with lower all-cause mortality in a dose-response pattern ie the more exercise taken the lower the death rate over the follow-up period. The pattern remained unchanged after adjustment for gender, age, smoking status, education, diabetes, previous cardiovascular disease, and body mass index.

The effect of exercise on blood pressure is greatest in those with hypertension. It is likely that reducing your BP with exercise and other lifestyle changes such as losing weight and cutting back on salt and alcohol intake are more risk-reducing than taking pills because each lifestyle change has many other benefits. Often these can reduce BP sufficiently to allow the previously hypertensive patient to stop taking medication.

After an extensive appraisal of the evidence, the American College of Cardiology concluded that for adult men and women regular aerobic physical activity decreases systolic and diastolic pressure significantly. “The amount of physical activity recommended for lowering BP is congruent with the amount of physical activity recommended in 2008 by the federal government for overall health. Most health benefits occur with at least 150 minutes a week of moderate intensity physical activity such as brisk walking. Additional benefits occur with more physical activity” (My underlines).

QED!

PS

Menopausal symptoms: Yet another area of human distress which can be alleviated by regular exercise! A small study of fifty-six women, aged 50 to 65 years has found that high levels of daily energy expenditure reduce some of the symptoms of the menopause¹. In particular a high VO2max was associated with fewer urogenital symptoms such as urinary frequency and painful sexual intercourse, while too much sedentary time was associated with more “somatic” symptoms such as hot flushes.

1. doi: 10.1097/GME.0000000000001441