Beta-blockers in the Management of Hypertension in Physically-active Patients

• Cardiorespiratory fitness is related to better outcome in patients with hypertension.
• Beta-blockers, the common medications used to treat hypertension, are known to reduce aerobic exercise activity.
• A review is being conducted to understand and determine which beta-blockers impose a lower physical limitation on physically active patients of hypertension.

Hypertension or high blood pressure affects around 20% of the world’s adult population. Medications like beta-blockers, ACE inhibitors, diuretics, and calcium channel blockers are used in its treatment. Beta blockers like atenolol, nebivolol and metoprolol reduce the heart rate and force of contraction, thereby reducing blood pressure in hypertensive individuals. Many studies over time have revealed that physical activity and cardiorespiratory fitness are important predictors of outcome in patients with hypertension. On the other hand, beta-blockers reduce the aerobic exercise capacity and interfere with physical fitness. A review is being conducted by a five-member team of the Department of Social Medicine and Public Health, Palacky University in the Czech Republic to determine which beta blocker would have the least effect on physical activity.

Physical Activity is One of the Modifiable Risk Factors in Hypertension

Hypertension is a condition in which the arterial blood pressure or the blood pressure in arteries is persistently higher than normal. A systolic blood pressure above 140 mm of Hg and diastolic blood pressure above 90 mm of Hg is classified as hypertension.

Arterial hypertension predisposes a person to heart diseases. Most cases of hypertension are due to non-specific lifestyle and genetic factors. Therefore, lifestyle modifications like salt restriction, diet changes, and physical activity form an important part of the management of hypertension.

The two properties of beta blockers, decrease in heart rate and force of contraction, cause concern with respect to reduction in exercise capacity and resting metabolic rate in hypertensive patients. These could limit the physical activity, which is extremely essential in these patients. Therefore, it becomes relevant to evaluate the magnitude of influence of beta-blockers on physical activity and use the findings in determining the ideal beta-blocker for the treatment of physically active patients of hypertension.

Previous Studies Support the Negative Influence of Beta-Blockers On Exercise Capacity.

In a small study conducted in the past, Billeh R. and his team researched the effect of 50 mg metoprolol and 25 mg carvedilol on 12 healthy subjects. They found that the peak oxygen consumption reduced with metoprolol but not with carvedilol.

In another study, Van Bortel and van Baak compared the effect of 5 mg nebivolol and 100 mg atenolol in healthy volunteers. Atenolol caused a reduction in peak exercise and endurance while no such change was observed with nebivolol. It is important to note that the participants were healthy in both these studies.

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The effects of beta-blockers were also studied in patients with hypertension with cardiac ailments. Nebivolol and carvedilol were found to show similar effects in patients suffering from hypertensive heart failure. A randomized double-blind control study with metoprolol and carvedilol revealed that as metoprolol produced a greater increase in maximal exercise capacity. When the effects of atenolol and nebivolol were studied in patients with hypertension and heart failure, nebivolol showed better improvement in the hemodynamic status.

The systematic review is being conducted by a team of researchers in the Czech Republic. The three-step review started with a search to determine if any other reviews existed in the literature on Cochrane, MEDLINE, and other similar databases but none was found. This reinforced the need for the same.

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The systematic review of existing literature aims to:

• Evaluate studies conducted on an adult population of both genders suffering from hypertension.
• Consider studies that assess effects of treatment of hypertension with a single beta-blocker or in combination with another drug.
• Survey studies that include the outcome of beta-blockers in relation to physical activity in patients suffering from hypertension.
• Include both published and unpublished studies.

The review shall seek to determine which beta-blockers allow a patient of hypertension to be physically active without limiting physical activity. It shall collect data about beta-blockers that display least physical limitation and are most effective in treating hypertension.

The analysis will aim at patients of hypertension. A sub-group analysis shall be used for other associated co-morbidities. Sub-group analyses will also be used for varied age and gender characteristics, as well as for other factors. The review, once completed, will be published in a peer-reviewed journal.

The review will hopefully serve as an important tool for the physicians while determining the pharmacological management of hypertension in physically active patients.

References:

1. BETA-Adrenoceptor Antagonists (BETA-Blockers)http://www.bhsoc.org/pdfs/therapeutics/Beta-adrenoceptor%20Antagonists%20(Beta-Blockers).pdf
2. Effectiveness of β-blockers in physically active patients with hypertension: protocol of a systematic review; Dagmar Tučková, Miloslav Klugar, Eliška Sovová, Markéta Sovová, Lenka Štégnerová; BMJ Open 2016;6:e010534 doi:10.1136/bmjopen-2015-010534

Source-Medindia