OA: Beta-Blockers May Reduce Need for Painkillers | Medpage Today| by Diana Swift, October 17, 2016
Use of beta-blockers was associated with less pain and decreased use of opioid and other prescription analgesics in individuals with symptomatic large-joint osteoarthritis (OA), according to a U.K. observational study in Arthritis Care & Research.
“This finding raises the possibility that this class of drugs may be used as analgesics for joint pain,” wrote the researchers, led by Ana M. Valdes, PhD, of the University of Nottingham — noting, however, that beta-blockers are no longer the preferred first-line treatment for hypertension and that the study needs further confirmation.
the researchers evaluated joint pain in 873 individuals with symptomatic hip and/or knee OA and hypertension, a common co-morbidity in this patient population. The mean age of patients was about 69, a total of 46% were women, and mean body mass index (BMI) was just over 30. All participants were taking at least one class of prescription antihypertensives, and 45% were taking beta-blockers.
- Beta-adrenergic blockers were associated with lower WOMAC pain scores and lower prevalence of joint pain.
- No associations with pain emerged for alpha-blockers or any other class of anti-hypertensive. Prescription of beta-blockers also correlated negatively with opioid use
This is a hypothesis-generating rather than hypothesis-testing study based on secondary analysis of data from another study. It is not going to change guidelines, practice, or decision-making.”
many confounders such as concomitant medications and the characteristics of the patients on beta-blockers may have been in play.
He also pointed out that in presenting the ORs the authors did not present the absolute difference –– “so it’s hard to get a handle on the actual magnitude of the difference.”
Many studies only report only on the differences in data, not the absolute numbers (especially when they are trying to mislead).
For example, here are two hypothetical study results:
- Data A = 100 and data B = 150
- data A = 1,000,100. and data B = 1,000,200
The percentage of increase is much greater in the first case:
- In the first case, it is an increase of 50%
- in the second case, it is an increase of 00.01%
However, the amount of increase is far greater in the second case:
- In the first case, it is an increase of 50
- in the second case, it is an increase of 100.
In this way, you can “prove” that A is less than B or that A is greater than B.
You can publish either result because they both are technically correct, but lead to opposite conclusions.
Hadler cautioned that testing the hypothesis would be expensive in terms of money and manpower.
Valdes told MedPage Today, however, that the team is now seeking funding for a study of a large general-practice database to see if the findings from this and other research can be confirmed.
Testing beta-blockers for both blood pressure and analgesia in knee OA and hypertension is challenging, however, since guidelines for first-line treatment for hypertension do not recommend this class of drugs.
Among the several limitations of the study noted was
- its cross-sectional observational nature, which cannot establish causality and may have contained several unknown confounding factors, the researchers noted.
- In addition, the hospital-based case control cohort of large-joint OA included many patients who had undergone arthroplasty at other joint sites, thereby introducing potential selection bias.
- In addition, patients self-reported the duration of antihypertensive use, and there were no data on adherence to medications or other possible indications for beta-blockers
- Moreover, the study did not evaluate which joints were responsible for pain and could not determine whether the pain reported by those with total joint replacement was predominantly persistent post-surgical pain or pain from the non-operated OA joints.
This seems a very weak study with so many weaknesses.
However, another possible conclusion is that beta-blockers are effective pain relievers for just some people and not others.
Source Reference: Valdes AM, et al “Beta-blocker use associates with lower prevalence of joint pain and lower opioid requirement in people with osteoarthritis” Arthritis Care Res 2016; DOI: 10.1002/acr.23091.