The effect of insulin glargine and fish oil supplements on atherosclerosis progression

August 27, 2012

A sub-study of the Outcome Reduction with an Initial Glargine Intervention (ORIGIN) trial, designed to investigate the effect of insulin glargine and omega-3 fatty acids on atherosclerosis progression, has found that, compared to standard care, only insulin glargine (a long-acting insulin) had a "modest" statistically non-significant reducing effect on the primary outcome of rate of change in maximum carotid intima media thickness (CIMT) at 12 carotid sites.

However, while glargine did significantly reduce the secondary outcomes of the study (the annualised rates of change in maximum CIMT for the common carotid artery and for the common carotid plus bifurcation sites), there was no differences in either the primary or secondary outcomes between the omega-3 polyunsaturated and placebo groups.

"Our study demonstrates that in high-risk people with established cardiovascular disease or with plus type 2 diabetes or pre-diabetes, insulin glargine modestly retards the progression of atherosclerosis," said first investigator Professor Eva Lonn, Professor of Medicine and Population Health Research Scientist at McMaster University, Hamilton, Ontario, Canada.

As background to the trial, known as the Glucose Reduction and Atherosclerosis Continuing Evaluation Study (GRACE) study, Professor Lonn explained that the effects of treatment with insulin titrated to normalise fasting and with omega-3 polyunsaturated fatty acid supplements () on atherosclerosis progression in people with type 2 diabetes or pre-diabetes are unknown.

The GRACE study assessed the effects of insulin glargine and omega-3 by performing yearly high-resolution carotid ultrasound examinations for five years and detailed of CIMT. Patients were recruited from 32 centers in seven countries. At baseline patients' mean age was 63 years, over 50% had a history of prior heart attack, stroke or revascularisation, 80% had hypertension, 60% abnormal cholesterol and 10% were current smokers. About 90% had type 2 diabetes and 10% had pre-diabetes.

Most patients were receiving several therapies aimed at reducing their risk for atherosclerosis and its complications. Use of these drugs increased over the duration of the study, so that at study end 52% were on statins, 75% on ACE inhibitors or ARBs, 55% on beta-blockers and 70% on aspirin. Patients received open label insulin glargine targeting normal glucose levels or standard glycemic care, and double-blind therapy with a 1 gram per day supplement of or placebo. Median follow-up was five years.

Insulin glargine significantly lowered fasting plasma glucose, glycated hemoglobin and triglyceride levels and provided overall "excellent" glycemic control, said Professor Lonn, while omega-3 fatty acid supplements had no significant effect on glycemia or on lipid levels. Both interventions were safe.

Compared with the standard glycemic care, insulin glargine reduced the primary CIMT outcome, but the difference was not statistically significant (difference = 0.0030 ±0.0021 mm/year; p=0.145) and significantly reduced the secondary outcomes (difference = 0.0033 ±0.0017 mm/year; p=0.049 and 0.0045 ±0.0021 mm/year; p=0.032). There was no beneficial effect of omega-3 polyunsaturated fatty acid supplements on either outcome.

"These findings support the cardiovascular safety of this intervention," said Professor Lonn, "and suggest that longer term treatment with insulin glargine might prevent cardiovascular events. In the parent ORIGIN trial had a neutral effect on cardiovascular events over 6.2 years. Whether longer-term therapy may result in clinical event reduction remains currently unproven."

"The neutral effect of omega-3 polyunsaturated fatty acid supplements on atherosclerotic vascular disease is also concordant with the neutral effect on clinical cardiovascular effects in the parent ORIGIN trial. Some, but not all, previous studies reported beneficial effects of omega-3 polyunsaturated fatty acid supplements in cardiovascular event prevention and several large ongoing trials are still evaluating this question. Our study does not address the current recommendations to consume more fish, which may have health benefits not conferred by fish oil supplements."

Explore further: Study debunks belief insulin puts people with diabetes at risk of heart disease

Related Stories

Study debunks belief insulin puts people with diabetes at risk of heart disease

June 11, 2012
Researchers at McMaster University have discovered that long-term insulin use does not harm people with diabetes or pre-diabetes or put them at risk of heart attacks, strokes or cancer.

Fish oil won't save diabetics' hearts, research suggests

June 11, 2012
(HealthDay) -- People with type 2 diabetes who take omega-3 fatty acid supplements are neither helping nor harming their heart, a new study finds.

Omega-3 supplements no help against repeat heart trouble: review

April 9, 2012
(HealthDay) -- Taking omega-3 fatty acid supplements won't protect against repeat heart attacks, strokes or other cardiovascular problems, a new analysis indicates.

Vitamin B and omega-3 supplementation and cancer: new data

February 17, 2012
Researchers from the Nutritional Epidemiology Joint Research Unit have just published a study showing that, in men with a previous history of cardiovascular pathologies, supplementation with B vitamins and omega-3 polyunsaturated ...

Omega-3 fatty acids not associated with beneficial effects in multiple sclerosis: study

April 23, 2012
Omega-3 fatty acid supplements were not associated with beneficial effects on disease activity in patients with relapsing-remitting multiple sclerosis, according to a report of a randomized controlled trial published Online ...

Recommended for you

Laser device placed on the heart identifies insufficient oxygenation better than other measures

September 20, 2017
A new device can assess in real time whether the body's tissues are receiving enough oxygen and, placed on the heart, can predict cardiac arrest in critically ill heart patients, report researchers at Boston Children's Hospital ...

Metabolism switch signals end for healing hearts

September 19, 2017
Researchers have identified the process that shuts down the human heart's ability to heal itself, and are now searching for a drug to reverse it.

Beta blockers not needed after heart attack if other medications taken

September 18, 2017
A new study from the University of North Carolina at Chapel Hill finds beta blockers are not needed after a heart attack if heart-attack survivors are taking ACE inhibitors and statins. The study is the first to challenge ...

Which single behavior best prevents high blood pressure?

September 15, 2017
(HealthDay)—You probably already know that certain healthy lifestyle behaviors can reduce your risk of developing high blood pressure, but is any one behavior more important than the others?

RESPECT trial shows closing a small hole in heart may protect against recurrent stroke

September 13, 2017
A device used to close a small hole in the heart may benefit certain stroke patients by providing an extra layer of protection for those facing years of ongoing stroke risk, according to the results of a large clinical trial ...

Study shows so-called 'healthy obesity' is harmful to cardiovascular health

September 11, 2017
Clinicians are being warned not to ignore the increased cardiovascular health risks of those who are classed as either 'healthy obese' or deemed to be 'normal weight' but have metabolic abnormalities such as diabetes.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.