Thiazolidinedione use in patients with Type 2 diabetes may increase risk for diabetic macular edema

June 11, 2012

Treatment with glucose-lowering thiazolidinedione drugs in patients with Type 2 diabetes appears to be associated with an increased risk of diabetic macular edema (a complication that may affect vision) at 1-year and 10-year follow-up evaluations, according to a report published Online First by Archives of Internal Medicine.

The risk-benefit ratio for , which are often used as a second- or third-line therapy in conjunction with oral agents or insulin, has been discussed after a series of metabolic and cardiovascular outcome studies. Several analyses have highlighted adverse effects, including increased incidence of bone fractures, fluid retention and a potentially increased risk of . Some small clinical studies have suggested an association between the medication and (swelling involving an area of the retina), which can affect up to 20 percent of patients with (T2D), according to the study background.

Iskandar Idris, M.D., F.R.C.P., F.R.C.P.(Edin), of the Sherwood Forest Hospitals Foundation Trust, Nottinghamshire, England, and colleagues conducted a of 103,368 patients with T2D and no diabetic macular edema (DME) at baseline using The Network (THIN) database, which collects electronic data from a volunteer sample of United Kingdom general practices.

At one year, the incidence of DME was 1.3 percent (41 cases) among thiazolidinedione users (n=3,227 patients) and was 0.2 percent (227 cases) among nonusers of these drugs.

"This large retrospective cohort study analyzed the primary care of more than 100,000 patients with type 2 diabetes and showed that, even after adjustment for various confounding factors known to influence diabetic retinopathy, exposure to a thiazolidinedione is associated with an increased risk of developing DME. The association was evident with both and rosiglitazone," the authors comment.

The authors suggest that the patients at greatest risk of developing DME were those taking thiazolidinediones in combination with insulin.

"A larger and more detailed meta-analysis of randomized controlled trials (ideally in high-risk patients) will be needed to clearly establish the risk-benefit profile of thiazolidinediones in patients with, or at risk of, DME," the authors conclude. "Clinicians should be vigilant in the clinical screening for DME among those patients taking thiazolidinediones."

In a commentary, Sonal Singh, M.D., M.P.H., and Jodi B. Segal, M.D., M.P.H., of The Johns Hopkins University School of Medicine, Baltimore, write: "…several limitations preclude definitive conclusions. First, the authors did not have information on the duration of thiazolidinedione exposure or duration of diabetes in the THIN data."

"In contrast, other observational studies have reported no elevated risk," the authors continue. "In conclusion, we can neither be certain that thiazolidinediones cause macular edema nor be reassured that such a risk does not exist. Future studies using new-user incipient cohort designs with validated exposure and outcome definitions and appropriate adjustment for diabetes severity may provide additional information on this potential association."

"What should clinicians do when faced with imperfect evidence? Despite the uncertainty regarding the risk of macular edema and thiazolidinediones, the occurrence of characteristic visual symptoms among patients taking thiazolidinediones or any other diabetic medication should prompt evaluation and ophthalmologic referral for DME evaluation, as noted in the current drug labels," they conclude.

Explore further: Thiazolidinediones tied to lower cancer risk in diabetes patients

More information: Arch Intern Med. Published online June 11, 2012. doi:10.1001/archinternmed.2012.1938
Arch Intern Med. Published online June 11, 2012. doi:10.1001/archinternmed.2012.2461

Related Stories

Thiazolidinediones tied to lower cancer risk in diabetes patients

April 27, 2012
(HealthDay) -- Thiazolidinediones are associated with a lower risk of liver and colorectal cancer in patients with type 2 diabetes, according to a study published in the May issue of Hepatology.

Study reports two-year outcomes of diabetic macular edema treatment

April 9, 2012
A randomized controlled trial involving patients with persistent clinically significant diabetic macular edema (swelling of the retina) suggests the greater efficacy of bevacizumab compared with macular laser therapy that ...

Diabetes drug linked to increased risk of bladder cancer

May 31, 2012
a drug used to treat type 2 diabetes - is associated with an increased risk of bladder cancer, finds a study published on BMJ today.

Recommended for you

Smart mat detects early warning signs of foot ulcers

August 16, 2017
While completing his residency in anesthesiology at Massachusetts General Hospital in the mid-2000s, Jon Bloom saw his fair share of foot amputations among patients with diabetes. The culprit: infected foot ulcers.

The best place to treat type 1 diabetes might be just under your skin

August 14, 2017
A group of U of T researchers have demonstrated that the space under our skin might be an optimal location to treat type 1 diabetes (T1D).

New measure of insulin-making cells could gauge diabetes progression, treatment

August 10, 2017
Researchers at the University of Wisconsin-Madison have developed a new measurement for the volume and activity of beta cells, the source of the sugar-regulating hormone insulin.

Pioneering immunotherapy shows promise in type 1 diabetes

August 9, 2017
It may be possible to 'retrain' the immune system to slow the progression of type 1 diabetes, according to results of a clinical trial published today in the journal Science Translational Medicine.

Online team-based game helps patients with diabetes lower blood glucose

August 8, 2017
Researchers from Brigham and Women's Hospital and the Veterans Affairs Boston Healthcare System have found that an online, team-based game designed to teach patients about diabetes self-management had a sustained and meaningful ...

Oxidative stress biomarkers don't always signal diabetes risk

August 7, 2017
High levels of compounds found in the body that are commonly associated with oxidative damage may actually be a good sign for some people, according to a recent review of multiple human studies led by an epidemiologist at ...

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.