Patients with Type 2 diabetes have a significantly lower 10-year incidence of coronary heart disease (CHD) and cardiovascular mortality than nondiabetic patients with a first acute myocardial infarction (AMI).

There has been great debate about whether having Type 2 diabetes is a cardiovascular disease equivalent, with some studies arguing for and some against.

Writing in the journal Diabetes Care, Jaume Marrugat (IMIM, Barcelona, Spain) and colleagues report the long-term results of a population-based cohort study in Spain that included 4410 patients aged 30-74 years. Of these, 2260 had Type 2 diabetes but no CHD at baseline, and 2150 were nondiabetic patients with a first AMI.

Men and women with diabetes had a significant 46% and 72% lower relative risk for developing CHD, respectively, over the 10-year study period than those with AMI. Cardiovascular mortality was also a respective 74% and 84% lower in men and women with diabetes compared with those with AMI.

When the participants were stratified according to individual cardiovascular event type, eg, MI, stroke, unstable angina, all-cause death, coronary death, and stroke death, diabetic patients had significantly lower event rates for all outcomes than AMI patients, with hazard ratios ranging from 0.15 to 0.66.

“The results of our study indicate that Type 2 diabetic patients without previous CHD not only have lower 10-year cardiovascular mortality but also have lower CHD incidence than first AMI patients without diabetes,” summarize Marrugat et al.

The authors concede that geographical variation may partly explain differences between the results of this study and others in the literature, but conclude that their results “do not support equivalence in coronary disease risk for diabetic and MI patients.”

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

Free abstract

Results from a proof-of-concept study show that ghrelin reduces glucose-stimulated insulin secretion and subsequently lowers plasma glucose in healthy nondiabetic individuals.

“Our findings raise the possibility that endogenous ghrelin has a role in physiologic insulin secretion, and that ghrelin antagonists could improve ?-cell function,” say Jenny Tong (University of Cincinnati, Ohio, USA) and colleagues.

For their study, the researchers recruited 12 healthy, nondiabetic volunteers (eight men, four women) aged 18-55 years and with a body mass index (BMI) between 18 and 29 kg/m².

The participants were given an infusion of saline, or ghrelin 0.3, 0.9, or 1.5 nmol/kg/hour for more than 65 minutes on four separate occasions separated by at least 5 days. The team then measured fasting insulin and glucose, and intravenous glucose tolerance (glucose disappearance constant; Kg) and the acute insulin response to intravenous glucose (AIRg).

Tong and co-workers found that, compared with saline, the three ghrelin infusions did not significantly change fasting plasma insulin or glucose levels.

However, AIRg was significantly decreased by the three concentrations of ghrelin to 1478, 1419, and 1120 pmol/l after the ghrelin 0.3, 0.9, and 1.5 nmol/kg/hour infusions, respectively, compared with 2152 pmol/l with saline.

C-peptide concentration was also suppressed in the three ghrelin groups versus saline, at a respective 4.1, 4.2, and 3.6 nmol/l versus 5.8 nmol/l. Kg was significantly reduced after ghrelin 0.3 and 1.5 nmol/kg/hour infusions to 1.00 and 1.05 %change/min, respectively, compared with 1.40 %change/min with saline.

“Preclinical studies support a role for ghrelin to regulate glucose metabolism as well as energy balance and growth hormone secretion,” write the authors in the journal Diabetes.

“However, the effect of ghrelin on insulin secretion and glucose tolerance in humans has not been clearly established in the limited number of studies reported previously.”

Tong et al conclude: “Our study demonstrates that exogenous ghrelin markedly reduces the first-phase insulin and C-peptide responses to intravenous glucose in healthy humans.”

They add that ghrelin antagonists have the potential to improve ?-cell function and say they could provide a novel drug target for the treatment of Type 2 diabetes.

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

Free abstract

Researchers report that restrictive impairment of lung function, as indicated by low forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV₁), is associated with increased risk for incident Type 2 diabetes and fatal coronary heart disease (CHD) in middle-aged men.

“The finding from this and other studies suggest that reduced lung function not only preceded the onset of diabetes but also continued at an accelerated pace after the onset of diabetes,” say study author Sasiwarang Goya Wannamethee (University College London, UK) and team.

“The increased risk of fatal events and increased case fatality associated with poor lung function suggest that reduced lung function may be another potential factor linking diabetes to increased risk of CHD and increased susceptibility to a fatal episode in the event of a cardiac event,” they add.

Wannamethee and colleagues followed-up a group of 4434 British men aged 40-59 years with no prior history of diabetes, CHD, or stroke for 20 years. During this time, there were 256 cases of incident Type 2 diabetes, 276 fatal CHD events, and 404 nonfatal CHD events.

The researchers found that both FVC and FEV₁, but not the FEV₁/FVC ratio, were significantly and inversely related to both incident Type 2 diabetes and fatal CHD events.

Patients in quartile one for FVC and FEV₁ (<3.97 l FVC; <2.95 l FEV₁) were 59% and 74%, respectively, more likely to develop Type 2 diabetes than those in quartile four (over 4.87 l FVC; over 3.81 l FEV₁), both statistically significant trends.

Similarly, the risk for fatal CHD was increased 48% and 81% among patients in quartile one for FVC and FEV₁ respectively, compared with those in quartile four, also statistically significant trends.

However, following adjustment for the inflammatory factors C-reactive protein and interleukin-6, both these associations were somewhat weakened.

“Further studies are now needed to extend such novel observations,” say the investigators.

They conclude in the journal Diabetes Care: “The association between reduced lung function and development of Type 2 diabetes and fatal CHD events may provide another possible explanation for the increased risk of fatal CHD in individuals with Type 2 diabetes.”

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

Free abstract