29 Oct Beta Blockers May Reduce Ability To Lose Weight
MedicalResearch.com Interview with:
Mirna Azar MD
Division of Endocrinology and Metabolism
University of Ottawa Weight Management Clinic
The Ottawa Hospital Ottawa, ON, Canada
Medical Research: What is the background for this study? What are the main findings?
Dr. Azar: Previous studies have shown an association between beta-blockers and weight gain but little is known about the effect of beta-blockers on weight loss.
Here we demonstrate that patients treated with beta-blockers exhibit a reduced ability to lose weight in response to a standardized 900 kcal meal replacement program.
From a database of 3,582 patients who participated in a 6-week 900 kcal/day Optifast meal replacement weight loss program, 173 patients were on beta-blockers. We determined differences in rate of weight loss and changes in waist circumference in the first 6 weeks of meal replacement program in these subjects as compared to controls, matched for sex, age and initial weight and to the entire population with adjustment for age, sex, initial body weight, ACE inhibitor and diuretic therapy and existing cardiovascular disease.
In comparison with matched controls, beta-blocker treated subjects lost a mean of 0.67 kg less than their matched controls (P = 0.01) and their percent weight loss was 0.6% lower (P = 0.0001). Differences were also noted for changes in waist circumference (-24.2 vs -25.2 cm, P= 0.04). Findings were not altered after adjustment for cardiovascular indications for beta-blocker therapy.
Medical Research: What should clinicians and patients take away from your report?
Dr. Azar: Our study demonstrates that individuals treated with beta-blockers exhibit a small but significant impairment in the ability to lose weight in a clinically supervised hypocaloric dietary intervention.
This is of particular importance for obese patients for whom alternative anti-hypertensive medications such as ACEI, ARBs or diuretics should be offered as first-line therapy. It should be noted that beta-blockers are still listed as first-line therapy in the management of hypertension in French and European guidelines and for those under 60 years in Canadian guidelines and are not uncommonly prescribed for hypertension in North America. However, they are not recommended as first-line therapy in the USA and UK guidelines.
Our study supports the idea that in the absence of a clear medical indication, such as angina symptoms, recent acute coronary syndrome, heart failure or tachy-arrhythmias, alternatives to beta-blockers should be considered for the treatment of hypertension in obese individuals and greater attention to weight control is required from the patient and health care providers when these drugs are clinically indicated.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Azar: Several mechanisms such as altered regulation of lipolysis and release of energy stores, decreased energy expenditure secondary to decreased exercise capacity and increased symptoms of fatigue may underlie the findings in our study. Unanswered questions are whether the effects are similar for all beta-blockers including those with intrinsic sympathomimetic activity (ISA).
Mirna Azar MD (2015). Beta Blockers May Reduce Ability To Lose Weight