Prehypertension

Article Author:
Anshuman Srivastava
Article Editor:
Shweta Sharan
Updated:
6/5/2019 1:25:07 PM
PubMed Link:
Prehypertension

Introduction

High or elevated blood pressure continues to be a classic worldwide problem and a major global health burden. Hypertension (HTN) or Prehypertension (PreHTN) alone or combined with other metabolic diseases such as obesity and diabetes, increases the risk of cardiovascular diseases such as ischemic heart disease and stroke.[1] PreHTN, the intermediate stage between HTN and normal blood pressure, is associated with sub-clinical atherosclerosis and target-organ damage.[2] PreHTN and HTN pose significant clinical and public health challenges for both economically developing and developed nations. Because of its silence nature, the prevalence of both PreHTN and HTN are underreported.[3]

Etiology

According to the TLGS study done in Tehran, the incidence of pre-HTN in older age groups and has higher numbers of cardiovascular risk factors in both females and males. Systolic blood pressure (SBP), age and body mass index (BMI) are considered significant predictors of preHTN. In both females and males, incidence of pre HTN is higher in those with higher BMI, are older in age, has higher blood pressure (both systolic blood pressure and diastolic blood pressure), has higher total cholesterol, has higher triglyceride, has higher fasting blood glucose, and higher homeostasis model assessment- insulin resistance (HOMA-IR). In this study, it was also found that people with lower eGFR, lower 2-hour post-challenge plasma glucose are an independent predictor only in men. While diastolic blood pressure and waist-to-hip ratio were significant predictors only in women.[4] According to a study done in India, it was observed that active military service could protect from HTN and its associated complications most likely due to better lifestyle modifications. It was also seen that sedentary lifestyle, positive family history, and obesity are common risk factors for HTN.[5] Interestingly, according to one study, it was also seen that people who have chronic exposure to soft drinking water increases their risk of HTN.[6]

Epidemiology

PreHTN and HTN is an epidemic, which is also responsible for about 6.7 million deaths from stroke and 7.4 million deaths from coronary artery disease. A study that was done in 21 regions on the grouping of cardiovascular ailment load (disease burden) revealed in excess of nine million deaths linked to complications of HTN. Among all people, it was found that about 40 % of adults over 25 years of age have been clinically diagnosed with HTN.[1]

Pathophysiology

Human blood vessels and microcirculation systems change with increasing BP. These changes are especially obvious for patients with severe hypertension. Hypertension in various stages can prompt fluctuating degrees of cardiovascular dissemination change; a few changes are gentle or reversible (unstable changes, for example, prehypertension or stage 1 hypertension), while others are subjective (chronic changes, for example, stage 2 hypertension and serious hypertension, for which it is difficult to reestablish the ordinary BP level). Subsequently, the cardiovascular circulatory framework will display distinctive reflections for various BP levels.[7]

History and Physical

History and Physical examination can play an important role in the early and timely detection of PreHTN and HTN. People with a strong family history of HTN (first-degree relatives) is an important part of the diagnosis. People with a history of smoking or other illicit drug abuse are at higher risk to develop HTN. On exam, overweight and obese people (BMI > 25) are at a higher risk to develop PreHTN and HTN. 

Evaluation

According to a study, serotonin (5-HT), Nitric Oxide ( NO) and Endothelin -1 (ET-1) can be diagnostic biomarkers of HTN and pre HTN. In prehypertensives and hypertensives, plasma 5-HT, NP and ET-1 are elevated while platelet 5-HT levels are lower.[8] When a normotensive patient when in office translates into HTN, when out of the office, this phenomenon is called masked hypertension. According to a study published in the European Heart Journal, the percentage of people with masked HTN is higher in people with untreated HTN, and it’s even higher in people after initiation of antihypertensive medications. People with preHTN are more likely to have masked HTN than people with optimal blood pressure. These groups of people are more likely to develop target end-organ damage even before developing sustained HTN. It was also observed that the frequency of masked HTN is higher in the presence of diabetes, chronic renal failure, and other cardiovascular risk factors. Non-dipping blood pressure and nocturnal HTN can be early markers of masked HTN. Twenty-four-hour ambulatory blood pressure monitoring (ABPM) can detect night time, and 24-hour elevated blood pressure is the gold standard for diagnosing masked HTN. About one-third of patients with masked HTN has masked uncontrolled HTN. So it is very important to diagnose and treat HTN effectively.[9]

Treatment / Management

Even though pre-HTN is not yet considered as a disease, its early detection can prevent the risk of development of HTN and cardiovascular risk.[1] Primary intervention with lifestyle modification is recommended for prevention of PreHTN and HTN in young adults. The benefits of future cardiovascular and cerebrovascular risk are mediated by the multisystem physiological adaption to exercise. Both pharmacological and non-pharmacological interventions are required for the proper management of HTN. Non-pharmacological interventions help in delaying the progression from PreHTN to HTN and also reduce the required daily dose of antihypertensive medications.

Non-pharmacological interventions incorporate/include exercise, staying away from pressure (avoiding stress), dietary alterations, and way of life adjustments and limiting liquor(alcohol) intake. DASH diet along with the Mediterranean, diet is a recommended diet which meets the dietary requirements of people with hypertension. These diets promote the utilization of vegetables, natural products, dairy items, grains, and food rich in magnesium, potassium, phosphorous and calcium. Restriction of sodium consumption has the greatest role in bringing down the blood pressure. DASH diet itself has equal efficacy to that of single drug therapy for hypertension. Exercise and weight reduction are the second significant intervention after dietary alteration for hypertension management. Limiting liquor(alcohol) utilization helps significantly to control blood pressure. As the way of life change (lifestyle modification) is a dynamic process, it requires nonstop adherence.

In stage 1 HTN without any cardiovascular complications, 6 to 12 months of lifestyle modifications can be attempted as a measure to reduce hypertension.[10] According to a study, the probability of achieving optimal blood pressure is increased by intake of low dose diuretic therapy, but most of these patients who were treated continued to have blood pressure in preHTN range, or it progressed to having overt HTN.[11]

Pertinent Studies and Ongoing Trials

HTN is considered the most significant modifiable risk factor for cardiovascular disease. HTN contributes to the highest global burden of disease. Measurement of blood pressure is one of the most important of all medial and clinical tests. Thus it is critical that blood pressure monitoring devices should be accurate. According to a study published in the journal of human HTN, showed evidence from a meta-analysis that many BP monitoring devices do not accurately represent the BP with the arteries of the upper arm. Inaccurate BP measurements can lead to confusion around the optimal HTN guideline thresholds. Also, inaccurate BP (underestimation of true BP) can be a missed opportunity to lower cardiovascular risk. On the other hand, the overestimation of BP can lead to overmedication. So there is a need to improve the accuracy of BP readings with better BP monitoring devices.[12]

Staging

According to 2017 American College of Cardiology/American Heart Association guidelines for different stages of HTN[6]:

  • Normal BP: BP <120/80 mm Hg;
  • Elevated BP: BP ≥120 and ≤ 129/<80 mm Hg;
  • Stage 1 HTN: BP ≥130 and ≤139/≥80 and ≤89 mm Hg,
  • Stage 2 HTN: BP ≥140/≥90 mm Hg

Prognosis

Elevated Blood pressure can be controlled with various non-pharmacological and pharmacological means. Blood pressure if controlled can decrease the incidence of cardiovascular events. 

Complications

One of the major risk factors for cardiovascular disease is uncontrolled HTN.[13] According to a study published in Frontiers of Neurology, it was observed that pre-HTN and HTN were frequent in patients with multiple sclerosis. White and gray matter integrity is related to increased blood pressure, and both of them are related to multiple sclerosis disability outcomes. All these findings in the study suggested and advocated for control of blood pressure in patients with multiple sclerosis.[14] In patients with Pre HTN who have progressed to sustained HTN, the risk of developing new left ventricular hypertrophy was greater as compared with persistent normotensive patients.[15] Even without a past medical history of chronic renal disease, diabetes mellitus, patients with PreHTN should be cautioned when they have high pulse pressure or high systolic blood pressure as PreHTN and HTN is associated with increased incidence of the cardiovascular event as compared to normotensive patients.[16]

Enhancing Healthcare Team Outcomes

The management of HTN is multidisciplinary. The key is to educate the patient on the silent disease and its devastating complications. The pharmacist should educate the patient on compliance with medications to lower blood pressure. The primary care provider and nurse practitioner should encourage a change in lifestyle, discontinuation of smoking, a healthy diet, and regular exercise. Unfortunately, despite 3 decades of patient education compliance to antihypertensives remain low. Further, the population remains sedentary – which has its morbidity.


References

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