HYPERTENSION

80 90

30 40 50 60 70

10 20

0 16-24 15-34 35-44 45-54 Age group Figure 1: Prevalence of hypertension in the UK

Causes of hypertension The exact causes of up to 95% of hypertensive cases are unclear. However most cases are thought to be a result of increased peripheral resistance as opposed to increased cardiac output. Increased peripheral resistance may be caused by a thickening of artery walls or a narrowing of smaller blood vessels, chronic prob- lems which could have developed as a consequence of poor lifestyle habits (2,3,6). In a small number of cases kidney disease, or pharmacological and/or complementary medicines (eg. decon- gestants, anti-inflammatory drugs, herbal remedies) may be underlying causes.

Benefits of exercise Recent reviews have reported average reductions of 10 mm Hg in both diastolic and systolic blood pressures following endurance

Type of medication Effects Diuretics

Common indications Increased excretion of salt and water

May often be used in conjunction with other antihyperten- sive medications

55-64 65-74 75+

Men Women

Beta blockers

Reduced pulse rate caused by the inhibition of adrenaline and/or receptors in heart and vessels leading to decreased cardiac rate, force of contraction and output

ACE inhibitors

Dilation of blood vessels thereby reducing total peripheral resistance and arterial BP

Patients with concurrent angina or heart rhythm disturbances

The lack of effect on heart rate or airway resistance means they are useful in patients with respiratory disease, peripher- al vascular disease, and diabetes. They have less affect on Afro-Caribbeans

Calcium (Ca++) antagonists (also known as calcium channel blockers)

Alpha blockers (alpha-1 antagonists)

Relaxation of arteries, decreased heart rate by reducing Ca++ levels

They do not adversely effect plasma lipids, glucose metabolism or cause sodium or water retention and are appropriate for use in elderly and Afro-Caribbean patients along with those suffering from co-existing asthma, diabetes and vascular disease (ie.Raynauds, claudication)

Dilation of blood vessels

Their use may be cautioned in the elderly but they generally have few adverse effects and are beneficial in reducing total cholesterol and triglyceride while increasing the ‘good’ high density lipids (HDLs)

Angiotensin II antagonists

12 SportEX Dilation of blood vessels Table 2: Medications indicated in hypertension

Unlike ACE inhibitors they do not increase bradykinin levels and therefore do not produce a dry cough

Percent