Diabetes guidelines might need revision to include minimum HbA1c value

January 01, 0001

Diabetes guidelines might need revision to include minimum HbA1c value

Results of intervention studies in patients with type 2 diabetes have led to concerns about the safety of aiming for normal blood glucose concentrations. The researchers from the UK and USA assessed survival as a function of HbA1c in people with type 2 diabetes. Two cohorts of patients aged 50 years and older with type 2 diabetes were generated from the UK General Practice Research Database from November 1986 to November 2008. They identified 27,965 patients whose treatment had been intensified from oral monotherapy to combination therapy with oral blood-glucose lowering agents, and 20,005 who had changed to regimens that included insulin.

For combined cohorts, compared with the glycated haemoglobin (HbA1c) decile with the lowest hazard, the adjusted hazard ratio (HR) of all-cause mortality in the lowest HbA1c decile was 1·52, and in the highest HbA1c decile was 1·79. Results showed a general U-shaped association, with the lowest HR at an HbA1c of about 7·5%. HR for all-cause mortality in people given insulin-based regimens (2834 deaths) versus those given combination oral agents (2035) was 1·49.

The researchers concluded: "Low and high mean HbA1c values were associated with increased all-cause mortality and cardiac events. If confirmed, diabetes guidelines might need revision to include a minimum HbA1c value."

A recurring pattern in recent research, but yet to be fully explained.

For the full abstract, click here.

The Lancet 375(9713):481-489, 6 February 2010 © 2010 Elsevier Ltd
Survival as a function of HbA1c in people with type 2 diabetes: a retrospective cohort study. Craig J Currie, John R Peters, Aodán Tynan et al. Correspondence to Craig Currie: [email protected]

Category: T. Endocrine/Metabolic/Nutritional, HSR. Health Services Research. Keywords: survival, HbA1c, type 2 diabetes, retrospective cohort study, journal watch.
Synopsis edited by Dr Stephen Wilkinson, Melbourne, Australia. Posted on Global Family Doctor 25 February 2010

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.