- Prehypertension or high normal BP is considered a precursor to stage-1 hypertension and a predictor of excessive cardiovascular risk.
- There has been much work done recently that has demonstrated the benefits of patients with prehypertension being treated with medication to lower their BP.
- Individuals with prehypertension or high normal BP - BP 130-139/85-89mmHg - are at increased risk of cardiovascular disease and MI.
What is the evidence?
- Compared with patients who had optimal BP, the relative risk of developing cardiovascular disease (CVD) has been found to be 2.49 for those with prehypertension, after adjustment for recognised cardiovascular risk factors (Am J Med 2006; 119: 133).
- Another study used data from Framingham Heart Study participants to examine the association between prehypertension, hypertension and the incidence of CVD.
They reported that individuals with prehypertension were 3.5 times more likely to experience MI, and 1.7 times more likely to develop heart disease than individuals with normal BP (Stroke 2005; 36: 1,859).
- One study has demonstrated that giving patients with prehypertension candesartan for two years reduced the risk of progression to hypertension by an impressive 66 per cent (N Engl J Med 2006; 354: 1,685).
- Metabolic syndrome, obesity, overweight, impaired fasting glucose and elevated triglycerides to HDL ratio have been shown to be independent risk factors for the progression from normotension to prehypertension (Am J Hypertens 2006; 19: 189).
- Another study has shown that there is a high prevalence of prehypertension in diabetic patients and it is associated with higher risks of CVD in these patients (Hypertension 2006; 47: 410).
Implication for practice
- Unsurprisingly, people with prehypertension are more likely to develop hypertension compared with those with normal BP.
- These studies raise the question of whether patients with prehypertension should be treated with antihypertensive medication to reduce their risk of future CVD.
- The current British Hypertension Society guidelines state that people with 'high normal' systolic BP or diastolic BP should have their BP measured annually.
The guidelines recommend that people with high normal BP should initiate lifestyle measures and have other risk factors corrected.
www.bhsoc.org - British Hypertension Society
www.bhf.org.uk - British Heart Foundation
- Dr Louise Newson is a GP in the West Midlands and author of 'Hot Topics for MRCGP and General Practitioner' Pas Test 2006
- Prehypertension is a risk factor for CVD.
- Candesartan may have a role in the management of prehypertension.
- Prehypertension is very prevalent in diabetics.