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Showing posts with label Michael O'Riordan. Show all posts
Showing posts with label Michael O'Riordan. Show all posts

Saturday, October 20, 2012

Look AHEAD halted: Lifestyle management fails to reduce hard CV outcomes in diabetics - O'Riordan

Look AHEAD halted: Lifestyle management fails to reduce hard CV outcomes in diabetics


October 19, 2012
A large cardiovascular-outcomes study funded by the National Institutes of Health that included 5145 adults with diabetes and a body mass index >25 kg/m2, Look AHEAD failed to show a difference in the rate of nonfatal MI, nonfatal stroke, death, or hospitalization for angina among patients randomized to an intensive lifestyle intervention and those randomized to a control arm consisting of education alone.
 
Despite significant reductions in weight and improvements in physical-fitness levels among patients with diabetes, investigators concluded that the intervention arm, which included individual sessions with a nutritionist and/or personal trainer, as well as group sessions and refresher courses, failed to provide any benefit in terms of cardiovascular outcomes.
 
Dr Anne Peters (University of Southern California, Los Angeles), one of the study investigators, said in an interview that the trial was successful on one level—namely, that patients lost weight and improved their fitness. Data published at four years showed that the intensive intervention led to weight loss of up to 10% in the first year and that patients maintained a 6.5% reduction in body weight in the following three years. Over an 11-year follow-up period, the patients reported a 5% reduction in body weight from baseline, said Peters.
 
In addition, early data showed that treadmill fitness levels, hemoglobin A1c levels, systolic and diastolic blood pressure, HDL-cholesterol levels, and triglyceride levels were all significantly improved among patients in the lifestyle-intervention arm when compared with the control group. The only cardiovascular risk factor that remained unchanged with treatment was LDL-cholesterol levels.
 
Despite the lack of cardiovascular benefit observed in Look AHEAD, Peters stressed that diabetic patients should not stop exercising or begin eating anything they wish.
 
"We do know that weight loss and exercise can prevent diabetes," said Peters. "I am a big advocate of prevention, both early prevention of obesity altogether, as well as prevention of diabetes in individuals who have become overweight. Lifestyle changes can help prevent diabetes. Once you have diabetes, I think weight loss and exercise can have benefits, but they are not going to reduce the risk for the primary outcome that we set for Look AHEAD, which was a risk for macrovascular events or death."
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Read the full article here.
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Here is the official stated purpose of the Look AHEAD trial.

The primary objective of Look AHEAD is to examine, in overweight volunteers with type 2 diabetes, the long-term effects of an intensive lifestyle intervention program designed to achieve and maintain weight loss by decreased caloric intake and increased physical activity. This program will be compared to a control condition involving a program of diabetes support and education.
The primary hypothesis is that the incidence rate of the first post-randomization occurrence of a composite outcome, which includes
  • cardiovascular death (including fatal myocardial infarction and stroke),
  • non-fatal myocardial infarction,
  • hospitalized angina, and
  • non-fatal stroke,
over a planned follow-up period of up to 13.5 years will be reduced among participants assigned to the Lifestyle Intervention compared to those assigned to the control condition, Diabetes Support and Education.

 
Look AHEAD will also test for reductions in the incidence of three secondary composite outcomes and examine the effect of the intervention on cardiovascular disease risk factors, diabetes control and complications, general health, and quality of life, and psychological outcomes. The cost and cost-effectiveness of the Lifestyle Intervention relative to Diabetes Support and Education will be assessed.
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from https://www.lookaheadtrial.org/public/home.cfm

A comment by Dr. Jack Kruse had this to say about the trial...


Jack Kruse said...

You said, you could not find all cause mortality data for the stop. Not surprising to some of us. The trial was stopped because their hypothesis was being demolished. You and I both know it. But this post further supports my concerns with RCT and so called evidence based medicine. The modern health care complex trump this brand of medicine. I loathe it. There is nothing more dangerous to modern humans than evidence based medicine and we all remain unaware of those pitfalls. Peter has touched on just that here.

I wrote very recently in my Brain Gut 14 blog this: The manner in which we ask questions is deeply flawed in medicine. Here is where the major causative factor lies in medicine that too few are talking about in research literature. You need to know it. Positive findings, whether they are good or bad for our biology, are twice as likely to be published as negative findings.

This dramatically skews the meaning of what the evidence is really showing us in medicine. It is at the core why people do not get better with evidence based practices and remain a medical annuity for the system. This is a cancer at the core evidence-based medicine today. When you become aware of what you do not know, it becomes easier to get to optimal. They key is for you to avoid those pitfalls before you access the healthcare system. Unfortunately, physicians are paid on this data and that is why it appears to many people that doctors just don’t get it. Many of us do get it, but if we step out of line we get punished by the system. That is how I feel about this Look Ahead nonsense. I am more cynical than Peter. I think the trial was ended because a current growth industry in healthcare might have been placed in peril if the trial continued.
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from HyperLipid.

Monday, September 3, 2012

Statins linked with development of cataracts - O'Riordan

Statins linked with development of cataracts
Waterloo, ON - Statin users are more than 50% likelier to develop age-related cataracts, according to the results of a new study. And type 2 diabetics who use statins are at even greater risk of cataracts, report investigators.
 
"The bioplausibility of these results lies in the fact that the crystalline lens membrane requires high cholesterol for proper epithelial cell development and lens transparency," write Dr Carolyn Machan (University of Waterloo, ON) and colleagues in the August 2012 issue of Optometry and Vision Science. "Increased cataract formation has been seen in both animals and humans with hereditary cholesterol deficiency, and the risk exists that statins can inhibit cholesterol biosynthesis in the human lens."
 
Asked to comment on the paper for heartwire, Dr Richard Karas (Tufts University School of Medicine, Boston, MA), called the findings "an interesting observation [that] isn't alarmist." There is, he says, a "suggestion" here that statins may increase the risk of cataracts, but this visual problem eventually afflicts everyone of a certain age anyhow, he says, adding that further study of this association will be required.
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Read complete article here.

Wednesday, August 22, 2012

Coronary artery calcium bests other risk markers.. - O'Riordan

Coronary artery calcium bests other risk markers for CVD risk assessment

August 22, 2012 Michael O'Riordan


Winston-Salem, NC - A comparison of multiple risk markers suggests that coronary artery calcium (CAC) provides the most improvement in the assessment of cardiovascular disease risk in patients at intermediate risk for future events [1]. Ankle-brachial index, high-sensitivity C-reactive protein (CRP), family history, and CAC were all independent risk predictors for incident coronary heart disease and cardiovascular disease, but CAC provided superior discrimination and risk reclassification compared with the other risk markers.
 
"If you go to any cardiologist, all that they're doing while you're sitting in front of them is trying to put you into one of three risk categories," lead investigator Dr Joseph Yeboah (Wake Forest University School of Medicine, Winston-Salem, NC) told heartwire. "We know what we should do for low-risk people. We just emphasize lifestyle changes, and most of the time over 10 years nothing happens to them. We know that in high-risk patients, in addition to lifestyle, certain medications work. What we don't know how to do is treat people who fall into the intermediate group. They're in no-man's land. Yet we know a chunk of the people who have heart attacks are within this group. This tells us that there are people who are wrongly put into this category based on current risk tools."
 
In an editorial accompanying the study [2], Dr J Michael Gaziano (Brigham and Women's Hospital, Boston, MA) and Dr Peter Wilson (Atlanta Veteran Affairs Medical Center, GA) agree that a CAC scan might help guide clinical decisions, but radiation exposure and costs remain important considerations. "Coronary artery calcium findings also are somewhat resistant to change even in the face of improvement in risk factors and may be useful as a single measure for assessment, especially when refinement of a risk estimate is important, but might not be useful for tracking risk over time," according to the editorialists.
 
The study and editorial are published in the August 22, 2012 issue of the Journal of the American Medical Association.

Data from the MESA study
Using data from the Multiethnic Study of Atherosclerosis (MESA), the researchers identified 1330 intermediate-risk patients without diabetes mellitus who had data available for all six of the following cardiovascular risk markers: CAC, carotid intima-media thickness (CIMT), ankle-brachial index (ABI), brachial flow-mediated dilation (FMD), and CRP, as well as family history of coronary heart disease. The purpose of the study, explained Yeboah, was to test the effectiveness of these "top-tier" risk markers for cardiovascular risk stratification when added to conventional risk scores in the same group of patients.
 
After a median follow-up of 7.6 years, there were 123 cardiovascular events. CAC, ABI, high-sensitivity CRP, and family history of coronary heart disease were independently associated with incident coronary heart disease, defined as a composite of MI, angina followed by revascularization, resuscitated cardiac arrest, and coronary heart disease death.
Association of risk markers with incident coronary heart disease*

Risk markerHazard ratio (95% CI)
Ankle-brachial index0.79 (0.66-0.96)
Brachial flow-mediated dilation0.93 (0.74-1.16)
Coronary artery calcium 2.60 (1.94-3.50)
Carotid intima-media thickness1.17 (0.96-1.45)
Family history2.18 (1.38-3.42)
High-sensitivity CRP1.28 (1.00-1.64)

*Adjusted for age, sex, race/ethnicity, systolic blood pressure, total cholesterol, HDL cholesterol, smoking status, body-mass index, use of blood-pressure medication, and use of statins

For coronary and cardiovascular disease events, which included stroke and cardiovascular death, the addition of each of the six markers to the Framingham risk score significantly improved the discrimination of clinical events compared with the Framingham score alone. The area under the curve (AUC) improved for all the risk markers but improved the most with CAC scoring. With the addition of CAC, the AUC improved from 0.623 to 0.784.
 
Similarly, CAC fared best when assessed by net reclassification improvement (NRI), a measure of the relative improvement in the classification of risk with the additional variable. The researchers note that 25.5% of the events were reclassified correctly to the high-risk category, while 40.4% of nonevents were reclassified into the low-risk group. The NRI for the addition of CAC to the Framingham risk score, plus race/ethnicity, was 0.659, the highest reported NRI of the six risk markers.

CAC fares best, but there are caveats
While CAC performed the best of the six markers, Yeboah said that there are important caveats to the results. Echoing the editorialists, he told heartwire that only CAC scoring exposes patients to a small, but not trivial, amount of radiation. He said the long-term effects of radiation on patients remain unknown and will need to be determined before widespread screening using CAC can be used to help the decision-making process.
 
There would be no benefit to society if we drastically reduce the number of heart attacks only to find out that everybody is developing cancer.
 
"There would be no benefit to society if we drastically reduce the number of heart attacks only to find out that everybody is developing cancer," said Yeboah.
 
In addition, there are no outcome studies showing that adding CAC screening to traditional risk scoring systems in intermediate-risk patients reduces the risk of cardiovascular events. If these caveats are addressed, said Yeboah, then CAC screening should be used for the 28 million US adults who fall within the intermediate-risk category. Currently, the American Heart Association and the European Society of Cardiology say it is "reasonable" to use CAC as a screening method for intermediate-risk patients.
 
In their editorial, Gaziano and Wilson note that research into general cardiovascular disease prevention is timely, given that the National Cholesterol Education Program (NCEP) Adult Treatment Panel 4 treatment guidelines are expected this year, and the addition of novel risk markers to Framingham or the Reynolds risk score might help physicians make a decision about whether or not to start a patient on lifelong statin therapy.
 
They note, however, that if a patient is near a boundary for lipid-lowering therapy, the doctor can simply choose to see the patient again in a few months rather than order a costly CAC imaging test. Reassessing vascular risk with a patient visit to repeat tests might improve accuracy and reveal trends that could help guide treatment decisions, according to Gaziano and Wilson. While CAC scores can help augment the risk-assessment process, they have limited utility in tracking a patient's progress, as the test is not likely to be repeated over time.
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Read the full article here.

Wednesday, April 18, 2012

Risk of high-dose simvastatin


Risk of high-dose simvastatin

April 17, 2012 Michael O'Riordan
 
Seattle, WA - Statins were responsible for rhabdomyolysis in 7.5% of patients diagnosed with the skeletal muscle condition, according to a review of International Classification of Disease, Ninth Edition (ICD-9) codes from a large nonprofit healthcare system in Seattle, WA.

Publishing their findings as a letter to the editor in the Journal of the American Medical Association, Dr James Floyd (University of Washington, Seattle) and colleagues also confirmed a significantly higher risk of rhabdomyolysis in patients treated with high doses of simvastatin.

Incidence rates of statin-related rhabdomyolysis
StatinPerson-years of useValidated rhabdomyolysis cases, nIncidence rates per 100 000 person-years
Simvastatin <20 mg/d21 83200
Simvastatin 20-39 mg/d75 08245.3
Simvastatin 40-79 mg/d56 703814.1
Simvastatin >80 mg/d16 876164.8
All doses170 6052313.5
Other statins116 5465.2
All statins286 7562910.1

In total, 22 cases of statin-related rhabdomyolysis were validated among 292 statin users with an ICD-9 code for rhabdomyolysis (positive predictive value 7.5%). Seven other patients were confirmed as having statin-related rhabdomyolysis using other criteria. Overall, the risk of rhabdomyolysis was significantly elevated among patients treated with simvastatin. The incidence rate ratio (IRR) for simvastatin compared with other statins was 2.61 (95% 1.03-7.84) using all validated cases of rhabdomyolysis.

"These results confirm in a community setting findings from a recent clinical trial that prompted the US Food and Drug Administration to issue a warning about the use of high-dose simvastatin," write the researchers.

Source
  1. Floyd JS, Keckbert SR, Weiss SR, Carrel DS, Psaty BM. Use of administrative data to estimate the incidence of statin-related rhabdomyolysis. JAMA 2012; 307:1580-1583.
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