MedWire News: Results from a meta-analysis published in the BMJ suggest that intensive glucose lowering in patients with Type 2 diabetes has limited cardiovascular (CV) benefits and may actually increase the risk for congestive heart failure (HF).
The team also points out that the harm sustained from a significantly increased risk for severe hypoglycemia in these patients may outweigh any minor reductions in CV risk gained from intensive glucose reduction.
Catherine Cornu (Université Claude Bernard Lyon, France) and colleagues included 13 studies - covering 34,533 patients with Type 2 diabetes - in their analysis. Of these patients, 18,315 received intensive (glycated hemoglobin [HbA1c] target of 6.5% or less) and 16,218 standard treatment (HbA1c target of 7%) for Type 2 diabetes.
The patients were followed-up for incident CV events (myocardial infarction [MI], stroke, congestive heart failure, retinopathy, neuropathy, microalbuminuria, renal failure, and peripheral vascular disease), hypoglycemia, and death for a mean period of 5 years.
The researchers report that in the pooled analysis, intensive glucose therapy did not significantly affect all-cause mortality or CV death.
Intensive glucose lowering did result in significant 15% and 10% reductions in nonfatal MI and microalbuminuria, respectively, compared with standard treatment. However, this was somewhat outweighed by a more than two-fold increased risk for severe hypoglycemia in the intensively treated group.
Cornu and team calculated that 117-150 patients would need to be treated intensively to avoid one MI and 32-142 to avoid one episode of microalbuminuria, but this would, in turn, result in one severe hypoglycemia episode for every 15-52 patients treated.
In a sub-analysis based only on high quality studies (Jadad score of higher than 3), intensive treatment did not significantly lower the risk for any CV events and increased the risk for congestive HF by 47%.
In an accompanying editorial, David Preiss (University of Glasgow, UK) and Kausik Ray (St George's University of London, UK) suggested: "Clinicians should consider these benefits and risks carefully because the most sensible treatment strategy will vary substantially between patients.
"Further studies are needed to determine whether an absolute HbA1c target should be established for everyone or whether HbA1c should be reduced by a target percentage from baseline, so that benefits and harms can be balanced."
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