Results from a meta-analysis show that high meat intake may increase the risk for Type 2 diabetes.

“However, the possibility that residual confounding could explain this association cannot be excluded,” caution the researchers.

“A Western dietary pattern has been associated with an increased risk of Type 2 diabetes in cohort studies, but it is not clear which component(s) of this dietary pattern may increase the risk of Type 2 diabetes,” say Dag Aune (University of Oslo, Norway) and colleagues.

“Several subsequent publications have reported an increased risk of diabetes or Type 2 diabetes with a high intake of processed meat, red meat and total meat, but the results have not been consistent.”

To be included in the meta-analysis, studies had to investigate the link between intake of total, red, and/or processed meat and incidence of Type 2 diabetes mellitus. The team found 12 suitable cohort studies in total.

Five cohort studies with 445,323, ten cohort studies with 433,070, and nine cohort studies with 380,606 participants investigated the link between total, red, and processed meat intake, respectively.

In the corresponding groups there were 6525, 12,226, and 9999 cases of Type 2 diabetes over a follow-up period of 4.6??”23.0 years.

Writing in the journal Diabetologia, the researchers report that individuals who consumed the highest amounts of total, red, and processed meat had a 17%, 21%, and 41% increased relative risk for Type 2 diabetes, respectively, compared with those who consumed the lowest amounts.

They conclude: “We cannot completely rule out the possibility of residual confounding or a temporal bias, but if the association is real, meat could be added to the list of behavioral factors which can be modified to decrease type 2 diabetes risk.”

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

Free abstract

Patients with Type 2 diabetes and associated foot ulceration have elevated levels of plasma interleukin (IL)-6 and resistin, coupled with diminished adiponectin relative to their diabetic peers with no foot complications, research shows.

The findings “underline the importance of inflammatory and metabolic milieu such as cytokines and adipose hormones in foot complications in diabetics as already reported for other vascular complications of diabetes,” say Antonio Pinto (The University of Palermo, Italy) and colleagues.

Previous studies of diabetic foot have found an elevated expression of cytokines, including tumor necrosis factor-? and interleukin-1?, suggestive of an inflammatory cascade.

To investigate further, the researchers examined the immune-inflammatory biomarkers IL-6, adiponectin, and resistin in 34 patients with Type 2 diabetes mellitus and foot ulceration, who had been hospitalized for conditions related to diabetic disease, but not for new vascular events.

For a control group they recruited 37 patients with Type 2 diabetes mellitus without foot ulceration hospitalized for conditions related to diabetic disease (excluding new vascular events).

Compared with patients without foot ulceration, those with diabetic foot showed lower median plasma levels of adiponectin (7.7450 µg/ml vs 8.480 µg/ml) and higher median plasma levels of IL-6 (3.21 pg/ml vs 2.73 pg/ml) and resistin (3.860 ng/ml vs 3.690 ng/ml).

In multivariate analysis, older age, diabetes duration, hypercholesterolemia, hypertension, microalbuminuria, retinopathy, IL-6 plasma levels, and resistin plasma levels were significantly associated with diabetic foot, whereas adiponectin plasma levels were negatively associated with diabetic foot.

Discussing the findings, Pinto et al say that lowered adiponectin levels can be viewed as “an early sign of a complex cardiovascular risk factor predisposing to the atherosclerosis process as well as accelerating the progress of the atherosclerotic plaque.”

They comment: “As several cytokines are also produced by adipose tissue it is postulated that an ‘adipovascular’ axis may contribute to the increased risk of cardiovascular events in patients with Type 2 diabetes.

“In patients with diabetic foot this adipo-vascular axis expression in lower plasma levels of adiponectin and higher plasma levels of IL-6 could be linked to foot ulcers pathogenesis by microvascular and inflammatory mechanisms.”

The research is published in the journal Cardiovascular Diabetology.

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

Atherosclerotic plaques are present in the vast majority of patients with Type 2 diabetes mellitus, a state-of-the-art imaging study has found.

The study, which used dual-source computed tomography angiography (DSCTA), also reveals that plaque in these patients is typically noncalcified, nonobstructive, and distributed extensively throughout the carotid and cerebrovascular vasculature.

Zhi-gang Yang (West China Hospital of Sichuan University, China) and co-authors studied the prevalence, distribution, and morphology of atherosclerotic plaque in patients with symptomatic Type 2 diabetes mellitus.

In all, 125 patients were imaged using DSCTA, a recently developed imaging method that is able not only to identify plaque and assess the degree of stenosis but also to predict plaque composition. A total of 4723 carotid and cerebrovascular arterial segments >1.5 mm in diameter were analyzed.

The overall prevalence of atherosclerotic plaque was 91.2%, and the most common location for any plaque was the cavernous segment, report Yang et al in the journal Cardiovascular Diabetology.

The most common type of plaque was noncalcified, which accounted for 45% of all plaque and was found predominantly in the intracranial arteries (81.8%).

Calcified plaque was the second most common type, accounting for 39% of all plaque and being present mainly in the intracranial internal carotid artery (ICA) (65.9%) and extracranial arteries (28.2%).

Finally, mixed plaques accounted for 16% of all plaque and were most commonly found in the intracranial arteries (25.2%) and intracranial ICA (56.1%).

Plaques were typically nonobstructive, with just 9% being classified as obstructive (>70% luminal narrowing).

Discussing their study, Yang and co-authors note that DSCTA has many advantages over conventional CTE, including the ability to discriminate plaque subtypes, lower radiation dose, faster scan acquisition time, and higher resolution.

“DSCTA detected a high prevalence of cerebrovascular disease in patients with symptomatic Type 2 diabetes mellitus,” they conclude.

“A relatively high proportion of plaques was noncalcified and calcified, primarily leading to nonobstructive stenoses. The distributions of plaques were different and extensive, with the most common site being the cavernous segment of ICA.”

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

Diabetic retinopathy is associated with visceral fat accumulation and insulin resistance in patients with Type 2 diabetes, study results show.

Futoshi Anan (Oita Red Cross Hospital, Japan) and co-workers explain that “increased visceral fat accumulation is a risk factor for cardiovascular disease and is associated with insulin resistance in healthy subjects and patients with Type 2 diabetes mellitus.”

Furthermore, the researchers add that “the presence of diabetic retinopathy is reported to be associated with insulin resistance in Type 2 diabetes mellitus patients.”

Based on these observations, Anan and team hypothesized that increased severity of diabetic retinopathy is associated with visceral fat accumulation and insulin resistance in patients with Type 2 diabetes mellitus.

The scientists studied 31 patients with Type 2 diabetes and 71 patients with both Type 2 diabetes and diabetic retinopathy, all of whom were Japanese.

Analysis of visceral fat levels and insulin sensitivity revealed that the risk for diabetic retinopathy was significantly, positively, and independently predicted by visceral fat accumulation and degree of insulin resistance. These associations remained after controlling for potential confounders, including age, gender, body mass index, waist circumference, duration of diabetes, hypertension, dyslipidemia, blood pressure, and lipid concentrations.

The authors concede in the journal Metabolism: Clinical and Experimental that their study is limited because none of the patients underwent coronary angiography and so the potential influence of cardiovascular disease on the relationships between visceral fat accumulation and retinopathy could not be accounted for.

However, despite these and other limitations, they conclude that the findings provide early evidence for links between diabetic retinopathy and elevated levels of visceral fatty acid accumulation and insulin resistance, which deserves further study.

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; 2009

Free abstract