US researchers report that there is “considerable discordance” between fasting plasma glucose- (FPG) and glycated hemoglobin- (HbA1c) based diagnosis of diabetes and prediabetes in elderly Black and White individuals.

Use of FPG cut points to diagnose diabetes and prediabetes has been the gold standard for many years. Recently HbA1c cut points have been added to the diagnostic criteria for these conditions, but there have been few diagnostic comparisons using the two measures, particularly in elderly individuals.

Kasia Lipska (Yale University School of Medicine, New Haven, Connecticut) and colleagues used the two measures to assess rates of prediabetes and Type 2 diabetes in 3075 people (42% Black) aged 70-79 years..

Diabetes was defined as a FPG of 126 mg/dl or above or a HbA1c of 6.5% or above, and prediabetes as a FPG of 100 mg/dl or above or a HbA1c of 5.7% or above.

As reported in the Journal of Clinical Endocrinology and Metabolism, the team found that 2.7% and 3.1% of the population had undiagnosed Type 2 diabetes according to FPG and HbA1c measurements, respectively.

Of the remaining people in the cohort, 21.1% and 22.2% had prediabetes by FPG and HbA1c measurements, respectively.

In total, 1189 participants were normoglycemic by both FPG and HbA1c, 596 prediabetic by FPG or HbA1c, and 80 diabetic by FPG or HbA1c measurements.

Lipska and co-investigators found that sensitivities and specificities of HbA1c compared with FPG for diabetes were 56.9% and 98.4% and for prediabetes 47.0% and 84.5%, respectively.

Of note, Black people and women were more likely to be identified as having dysglycemia by HbA1c than FPG.

“The optimal screening test for diabetes (and prediabetes) remains uncertain,” write the authors. “A recent report suggests that HbA1c is similarly associated with the risk for diabetes as FPG but outperforms the latter in its prediction of future cardiovascular death.”

They conclude: “To settle this controversy, additional long-term longitudinal studies are needed, especially those that include a large sample of older adults.”

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

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High exposure to bisphenol A (BPA), a chemical used in plastic food containers, is associated with increased risk for coronary heart disease (CHD) and diabetes, confirm study results.

David Melzer (University of Exeter, UK) and co-investigators previously discovered the link between BPA exposure and CHD and diabetes in a smaller study, as reported by MedWire News.

“This is only the second analysis of BPA in a large human population sample. It has allowed us to largely confirm our original analysis and exclude the possibility that our original findings were a statistical ‘blip’,” said Melzer.

The researchers assessed links between BPA exposure, measured from urinary concentrations of BPA, and diagnoses of myocardial infarction, CHD, angina, diabetes and elevated serum liver enzyme levels.

The study cohort comprised 2948 adults aged 18 “74 years who participated in the National Health and Nutrition Examination Survey (NHANES) 2003 “2004 (n=1455) and 2005 “2006 (n=1493) and who were representative of the general US population.

The mean level of urinary BPA was lower in 2005 “2006 than 2003 “2004 at 1.79 versus 2.49 ng/ml.

A per z-score increase in urinary BPA increased the relative risk for CHD by 33% and 42% in the 2005 “2006 cohort and 2003 “2006 pooled cohort, respectively.

A similar increase in urinary BPA did not significantly increase the relative risk for diabetes in 2005 “2006. However, in the 2003 “2006 pooled cohort a per z-score increase in BPA amplified the relative risk for diabetes by 24%.

Of note, the team found no significant association between BPA levels and gamma glutamyl transferase concentrations, but in the pooled cohort associations with alkaline phosphatase and lactate dehydrogenase were significant.

“We now need to investigate what causes these health risk associations in more detail and to clarify whether they are caused by BPA itself or by some other factor linked to BPA exposure,” commented study author Tamara Galloway (University of Exeter).

“The risks associated with exposure to BPA may be small, but they are relevant to very large numbers of people. This information is important since it provides a great opportunity for intervention to reduce the risks.”

The results of this study are published in the journal PLoS ONE.

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

Bisphenol A exposure linked with metabolic disorders

Treatment of patients with Type 2 diabetes without known large-vessel disease with fenofibrate significantly reduces their risk for amputation events, report researchers from the FIELD study.

However, the risk for major amputation among patients with atherosclerotic disease of the major peripheral arteries was not significantly influenced by fenofibrate treatment.

“Amputations in people with Type 2 diabetes mellitus substantially impair their quality of life and impose high costs on health-care systems,” say Kushwin Rajamani (University of Sydney, New South Wales, Australia) and co-investigators.

The researchers tested the effect of fenofibrate on amputation risk in participants of the FIELD (Fenofibrate Intervention and Event Lowering in Diabetes) study, which included 9795 patients with Type 2 diabetes aged 50??”75 years.

Of these, 4895 were randomly assigned to take fenofibrate 200 mg/day and 4900 to take placebo for a period of 5 years. During this time, 115 patients had one or more non-traumatic lower-limb amputations as a result of their diabetes.

Major amputations were defined as those above and minor those below the ankle. The researchers further classified individuals who underwent amputation as having minor amputation without previous large-vessel disease - thought to be due to microvascular disease, or minor or major amputations with documented large-vessel disease ??” thought to be due to atherosclerotic disease of the major peripheral arteries.

Writing in The Lancet, the authors report that fenofibrate treatment significantly reduced the risk for first on-study amputation (all types) and minor amputation without previous large-vessel disease by 36% and 47%, respectively, compared with placebo.

However, the reduction in risk for major amputation events with documented large-vessel disease was non-significantly different between the fenofibrate- and placebo-treated groups (7% reduction).

“These findings could lead to a change in standard treatment for the prevention of diabetes-related lower-limb amputations,” conclude Rajamani et al.

Of note, the reduction in amputation risk observed in this study was not associated with any lipid variables, suggesting “the effects of treatment with fenofibrate on the risk of amputation might go beyond the improvements in controlling the lipid profile,” says the team.

“Because development and care of skin ulcers are formidable predictors of future amputations, one has to wonder whether some of the effects of fenofibrate can be attributed to improvement in wound healing,” commented Sergio Fazio and MacRae Linton (Vanderbilt University Medical Center, Nashville, Tennessee, USA) in an accompanying commentary.

“This effect ??” more so than anti-inflammatory, antioxidant, or endothelium-mediated effects ??” would set fibrates apart from the many agents (statins, antihypertensives, aspirin, and vitamin E) that have so far been unable to reduce amputations in people with diabetes.”

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a part of Springer Science+Business Media. © Current Medicine Group Ltd; 2009

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