An update on the etiology and epidemiology of diabetes mellitus

miRNAs and diabetes mellitus

Diabetes is a chronic disease that manifests when insulin production by the pancreas is insufficient or when the body cannot effectively utilize the secreted insulin. The onset of diabetes often goes undetected until the later stages where subsequent glucose accumulation in the system (hyperglycemia) is observed. Over time, it leads to serious multi-organ damage, especially to the nerves and blood vessels. The WHO reports that approximately 346 million people worldwide are diagnosed with diabetes. With no cure available, long-term medical care for diabetes has become a global economic challenge globally. Hence, there is a need to explore novel early biomarkers and therapeutics for diabetes. One such potential molecule is the miRNAs. miRNAs are endogenous, noncoding RNAs that predominantly inhibit gene expression. Compelling evidence showed that altered miRNA expressions are linked to pathological conditions, including diabetes manifestation. This review focuses on the implications of miRNAs in diabetes and their related complications.

Short sleep duration and poor sleep quality increase the risk of diabetes in Japanese workers with no family history of diabetes

OBJECTIVE

To investigate whether a difference in the risk for diabetes exists in Japanese workers with regard to sleep duration/quality and the presence or absence of a family history of diabetes (FHD).

RESEARCH DESIGN AND METHODS

The researchers conducted a prospective, occupational-based study of local government employees in Sapporo, Japan. Between April 2003 and March 2004, 3,570 nondiabetic participants, aged 35-55 years, underwent annual health checkups and completed a self-administered questionnaire that included information on sleep duration/quality and FHD at baseline. Having diabetes was defined as taking medication for diabetes or a fasting plasma glucose level of ≥126 mg/dL at follow-up (2007-2008).

RESULTS

A total of 121 (3.4%) new cases of diabetes were reported. In multivariate logistic regression models of workers without an FHD, and after adjustment for potential confounding factors, the odds ratio (95% CI) for developing diabetes was 5.37 (1.38-20.91) in those with a sleep duration of ≤5 h compared with those with a sleep duration of >7 h. Other risk factors were awakening during the night (5.03 [1.43-17.64]), self-perceived insufficient sleep duration (6.76 [2.09-21.87]), and unsatisfactory overall quality of sleep (3.71 [1.37-10.07]). In subjects with an FHD, these associations were either absent or weaker.

CONCLUSIONS

The current study shows that poor sleep is associated with a higher risk of developing diabetes in workers without an FHD. Promoting healthy sleeping habits may be effective for preventing the development of diabetes in people without an FHD.

Olmesartan/amlodipine: blood pressure lowering and beyond in special populations

Clinical studies and population-based analyses show that in patients with hypertension, the majority cannot control their blood pressure (BP) by treatment with a single antihypertensive agent. Combining agents from different antihypertensive classes with complementary modes of action significantly increases efficacy and is a treatment strategy recommended by European treatment guidelines, particularly in patients at high cardiovascular risk. The combinations of antihypertensive agents recommended by the European guidelines include an angiotensin receptor blocker (ARB) with a calcium channel blocker (CCB). The single-pill combination formulation of the ARB olmesartan medoxomil plus the CCB amlodipine is an effective and well-tolerated treatment that provides greater blood pressure lowering and control than the component monotherapies and favours compliance by not increasing pill burden. Importantly, the efficacy and tolerability of olmesartan plus amlodipine is not affected by age, gender, hypertension severity, diabetes status, race or body mass index. Additional blood pressure lowering effects are observed with stepwise uptitration of olmesartan plus amlodipine with or without hydrochlorothiazide, with more patients achieving blood pressure goals. In addition, olmesartan plus amlodipine has demonstrated effects beyond BP lowering by showing beneficial effects on markers of inflammation, endothelial dysfunction and oxidative stress, as well as metabolic improvements and a reduction in new-onset diabetes incidence in hypertensive patients with metabolic syndrome.

Electrocardiogram-based sleep spectrogram measures of sleep stability and glucose disposal in sleep disordered breathing

STUDY OBJECTIVES

Sleep disordered breathing (SDB) is independently associated with insulin resistance, glucose intolerance, and type 2 diabetes mellitus. Experimental sleep fragmentation has been shown to impair insulin sensitivity. Conventional electroencephalogram (EEG)-based sleep-quality measures have been inconsistently associated with indices of glucose metabolism. This analysis explored associations between glucose metabolism and an EEG-independent measure of sleep quality, the sleep spectrogram, which maps coupled oscillations of heart-rate variability and electrocardiogram (ECG)-derived respiration. The method allows improved characterization of the quality of stage 2 non-rapid eye movement (NREM) sleep.

DESIGN

Cross-sectional study.

SETTING

N/A.

PARTICIPANTS

Nondiabetic subjects with and without SDB (n = 118) underwent the frequently sampled intravenous glucose tolerance test (FSIVGTT) and a full-montage polysomnogram. The sleep spectrogram was generated from ECG collected during polysomnography.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Standard polysomnographic stages (stages 1, 2, 3+4, and rapid eye movement [REM]) were not associated with the disposition index (D(I)) derived from the FSIVGTT. In contrast, spectrographic high-frequency coupling (a marker of stable or "effective" sleep) duration was associated with increased, and very-low-frequency coupling (a marker of wake/REM/transitions) associated with reduced D(I). This relationship was noted after adjusting for age, sex, body mass index, slow wave sleep, total sleep time, stage 1, the arousal index, and the apnea-hypopnea index.

CONCLUSIONS

ECG-derived sleep-spectrogram measures of sleep quality are associated with alterations in glucose-insulin homeostasis. This alternate mode of estimating sleep quality could improve our understanding of sleep and sleep-breathing effects on glucose metabolism.

Surgical strategies for type II diabetes

Diabetes mellitus type II (or type 2 diabetes; DM2) has multiple definitions but is generally considered to be a disease marked by insulin resistance and loss of β cell function that develops in adulthood. Today, greater than 90% of patients with diabetes have DM2. When uncontrolled, DM2 may result in comorbidities such as cardiovascular disease, retinopathy, neuropathy, immune system dysfunction, and renal failure. Classically, treatment of type 2 diabetes has included dietary and lifestyle changes. Even with behavior modification and oral hypoglycemics, many patients are unable to maintain glycemic control. With a growing understanding of the hormonal signals involved in the pathogenesis of type 2 diabetes, there has been a shift in the therapeutic approach to this growing epidemic. Bariatric surgery has been shown to decrease the progression and potentially reverse the effects of diabetes in 80% to 90% of patients. In addition, bariatric operations are associated with sustained weight loss in contrast to nonsurgical options. The antidiabetic effect of bariatric operations is likely due to the improvement in the hormonal dysregulation associated with the development of diabetes. Many patients with diabetes, however, have irreparably damaged insulin production capabilities as well. In addition, it is well recognized that transplantation may be required for patients with severe loss of islet cell function. Surgery for type 2 diabetes, via bariatric procedures and transplantation, has become an important treatment modality for patients with advanced disease.

The metabolic syndrome in type 2 diabetic patients in Gorgan: According to NCEP ATPIII and IDF definitions

AIMS

People with metabolic syndrome are at increased risk for developing diabetes mellitus and cardiovascular disease. The present study aimed to assess the metabolic syndrome in type 2 diabetes and compare them with two used methods of diagnostic criteria in Gorgan.

METHODS

The study group included 293 type 2 diabetic patients whom referred to the Department of Diabetes Center in Golestan University of Medical Sciences (2011). The metabolic syndrome was determined according to ATPIII and IDF definitions.

RESULTS

According to ATPIII and IDF criteria, the frequency of metabolic syndrome was 75.42% and 76.79%, respectively. According to ATPIII, the mean triglycerides, body mass index, systolic blood pressure and diastolic blood pressure were higher in subjects with metabolic syndrome than subjects without metabolic syndrome. According to IDF, the mean triglycerides, body mass index and males' waist circumferences were higher in subjects with metabolic syndrome.

CONCLUSIONS

This study showed that females were more affected than males. This may be due to the specific characteristics in the lifestyle changes between females and males diabetic patients among Gorgan inhabitants. Females are less educated in comparison with males diabetic. The majority of females with metabolic syndrome were householder. It seems that they do less physical activity at home. In conclusion, it appears that the female need to change their life style in this area to halt the burden of cardiovascular complications in diabetic patients.

Reduced neutrophil apoptosis in diabetic mice during staphylococcal infection leads to prolonged Tnfα production and reduced neutrophil clearance

Diabetes is a frequent underlying medical condition among individuals with Staphylococcus aureus infections, and diabetic patients often suffer from chronic inflammation and prolonged infections. Neutrophils are the most abundant inflammatory cells during the early stages of bacterial diseases, and previous studies have reported deficiencies in neutrophil function in diabetic hosts. We challenged age-matched hyperglycemic and normoglycemic NOD mice intraperitoneally with S. aureus and evaluated the fate of neutrophils recruited to the peritoneal cavity. Neutrophils were more abundant in the peritoneal fluids of infected diabetic mice by 48 h after bacterial inoculation, and they showed prolonged viability ex vivo compared to neutrophils from infected nondiabetic mice. These differences correlated with reduced apoptosis of neutrophils from diabetic mice and were dependent upon the presence of S. aureus and a functional neutrophil respiratory burst. Decreased apoptosis correlated with impaired clearance of neutrophils by macrophages both in vitro and in vivo and prolonged production of proinflammatory tumor necrosis factor alpha by neutrophils from diabetic mice. Our results suggest that defects in neutrophil apoptosis may contribute to the chronic inflammation and the inability to clear staphylococcal infections observed in diabetic patients.

The impact of type 2 diabetes mellitus on cancer-specific survival: a follow-up study in Sweden

BACKGROUND

Earlier studies have suggested that type 2 diabetes mellitus (T2DM) alters the risk of developing a variety of cancers, but little has been known about the impact of T2DM on cancer prognosis. On the basis of nationwide population-based Swedish registries, the authors of this report compared the cause-specific survival among cancer patients with and without T2DM.

METHODS

Patients with T2DM were identified from the nationwide Swedish Hospital Discharge Register, and cancers were recorded from the Swedish Cancer Registry. Hazard ratios (HRs) were calculated using Cox regression models to compare variations in cause-specific survival between cancer patients with and without T2DM.

RESULTS

Of the 1016,105 cancer patients, 16,123 had been hospitalized with T2DM before their diagnosis of cancer. The mortality rate was significantly higher among cancer patients with T2DM than among those without T2DM (cause-specific HR, 1.38; 95% confidence interval, 1.35-1.41). There were no differences in TNM stage distribution among cancer patients with or without T2DM for the main cancers, with an exception of tumor and metastatic classifications for breast cancer and prostate cancer, respectively.

CONCLUSIONS

The current results indicated that patients with T2DM who are diagnosed with a subsequent cancer are at an increased risk for cause-specific mortality compared with patients who have cancer without T2DM.

Association of angiotensin II type 1 receptor gene A1166C polymorphism with the presence of diabetes mellitus and metabolic syndrome in patients with documented coronary artery disease

BACKGROUND

There are relatively limited data available on the genetic susceptibility to diabetes mellitus and metabolic syndrome in the Iranian population. We have therefore investigated the association between the angiotensin II type I receptor gene polymorphism (AT(1)R/A1166C) and the presence of diabetes mellitus and metabolic syndrome in a well defined group of patients.

METHODS

Patients with angiographically defined coronary artery disease (CAD) (n=309) were evaluated for the presence of AT(1)R/A1166C polymorphism. These patients were classified into subgroups with (n=164, M/F: 109/55) and without (n=145, M/F: 84/61) diabetes mellitus. The AT(1)R polymorphism was assessed using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) based method.

RESULTS

There was a higher frequency of polymorphic genotypes (AC+CC) in the diabetic compared with the non-diabetic group (p=0.01). When determined for each gender separately, this difference remained significant in the males (p=0.04) but not in females (p=0.09). With regard to the allele frequencies, the C allele was significantly higher and the A allele frequency was lower in the diabetic group (p=0.01). This remained significant after gender segregation for males (p=0.01) but not females. In the binary logistic regression analysis, only serum fasting glucose was found as the independent predictor for the presence of diabetes in the CAD patients (β=1.16, p<0.001 for total population and β=1.29, p<0.001 for male subjects). There was no significant difference in genotype or allele frequencies between subgroups with and without metabolic syndrome, this being unaffected by gender or the definition of metabolic syndrome used apart from a significantly lower frequency of C allele in male subjects with metabolic syndrome defined by the NCEP ATP III criteria (p=0.04).

CONCLUSION

The AT(1)R/A1166C polymorphism may be associated with the presence of diabetes mellitus in male subjects with documented CAD.

Mapping the brain in type II diabetes: Voxel-based morphometry using DARTEL

PURPOSE

To investigate the pattern of brain volume changes of the brain in patients with type II diabetes mellitus using voxel-based morphometry.

MATERIAL AND METHODS

Institutional ethics approval and informed consent were obtained. VBM based on the high resolution three-dimensional T1-weighted fast spoiled gradient recalled echo MRI images was obtained from 16 type II diabetes patients (mean age 61.2 years) and 16 normal controls (mean age 59.6 years). All images were spatially preprocessed using Diffeomorphic Anatomical Registration using Exponentiated Lie algebra (DARTEL) algorithm, and the DARTEL templates were made from 100 normal subjects. Statistical parametric mapping was generated using analysis of covariance (ANCOVA).

RESULTS

An atrophy pattern of gray matter was seen in type II diabetes patients compared with controls that involved the right superior, middle, and inferior temporal gyri, right precentral gyrus, and left rolandic operculum region. The loss of white matter volume in type II diabetes mellitus was observed in right temporal lobe and left inferior frontal triangle region. ROI analysis revealed that the gray and white matter volume of right temporal lobe were significant lower in type II diabetes mellitus than that in controls (P<0.05).

CONCLUSION

This work demonstrated that type II diabetes mellitus patients mainly exhibited gray and white matter atrophy in right temporal lobe, and this finding supported that type II diabetes mellitus could lead to subtle diabetic brain structural changes in patients without dementia or macrovascular complications.

Remnant B-cell-stimulative and anti-oxidative effects of Persea americana fruit extract studied in rats introduced into streptozotocin - induced hyperglycaemic state

Insulin-stimulative and anti-oxidative effects of Persea americana fruit extract were evaluated using streptozotocin (STZ). Ethanol extract of P. americana in the concentration of 300 mg/kg body weight/rat /day was orally administered to rats introduced into STZ-induced hyperglycaemic state for a period of 30 days. After the treatment with avocado fruit extract, the elevated levels of blood glucose, glycosylated haemoglobin, blood urea and serum creatinine seen in the hyperglycaemic rats, reverted back to near normal. Similarly, significantly decreased plasma insulin and haemoglobin levels went back to near normal after the treatment, suggesting the insulin-stimulative effect of P. americana fruit. Determination of thiobarbituric acid reactive substances (TBARS), hydroperoxides and both enzymatic and non-enzymatic antioxidants, confirmed the anti-oxidative potential of avocado fruit extract which, in turn, might be responsible for its hypoglycaemic potential. Changes in activities of enzymes such as serum aspartate transaminase (AST), serum alanine transaminase (ALT), and serum alkaline phosphatase (ALP) seen in the control and experimental rats, revealed the tissue-protective nature of Persea americana fruits, while all of the analysed biochemical parameters were comparable to those obtained with gliclazide as a standard reference drug.

International noninterventional study of acarbose treatment in patients with type 2 diabetes mellitus

AIM

To obtain data on efficacy, safety and tolerability of acarbose monotherapy or combination therapy during daily-life treatment.

METHODS

This prospective, non-controlled, observational study enrolled patients with type 2 diabetes, whose physician decided that acarbose treatment was appropriate, from China, Middle East, Indonesia, Morocco, Pakistan, Philippines, Poland and Taiwan. The observation period included an initial visit and up to three follow-up visits; an extension of 2 years was realized in Pakistan and Poland.

RESULTS

Of 14,574 patients enrolled, 14,418 comprised the intent-to-treat population. At the initial visit, 74.1% of patients had been treated with a glucose-lowering agent. Fasting blood glucose was reduced from 175.2mg/dL at the initial visit to 133.7 mg/dL at the last visit (mean of 11.3 weeks after initial visit; P<0.0001). Mean 2-h postprandial blood glucose decreased from 244.7 mg/dL to 172.4 mg/dL (P<0.0001). HbA1c reduced from 8.4% to 7.4% (P<0.0001). Glycemic efficacy was maintained over the 2-year extension period. There were 432 adverse events in 293 patients (2.03%), mainly gastrointestinal. Physicians assessed efficacy as "very good"/"good" in 85.1% of patients, and were "very satisfied"/"satisfied" with acarbose therapy in 94.3% of cases.

CONCLUSION

Acarbose therapy was efficacious and well tolerated in daily life in patients with type 2 diabetes.

Matrix type transdermal therapeutic systems of glibenclamide: Formulation, ex vivo and in vivo characterization

Matrix type transdermal therapeutic systems (TTS) of glibenclamide were formulated using polymers Eudragit RL 100, ethyl cellulose, PVP K-30, and polyvinyl acetate, and citral was used as the penetration enhancer. The polymer films were formulated with Eudragit RL 100 and PVP K-30 in different ratios and subsequently subjected to ex vivo studies (drug permeation through rat skin) followed by interaction studies, skin irritation studies, accelerated stability analysis, and in vivo studies (determination of blood glucose level in rabbits). The drug content of the formulations was found to be 99.1-99.2%. The cumulative percentages of drug permeated through rat skin from the three selected formulations in 48 h were 95.3%, 98.8%, and 99%, respectively. A plot between cumulative percent of drug permeated and square root of time exhibited linear curves, which suggests the Higuchian matrix mechanism of drug release. The formulation containing Eudragit RL 100 and PVP K-30 showed better improvement in hypoglycemic activity in rabbits (56.2-60.8% reduction in blood glucose level, p < 0.05). There were fewer fluctuations in blood glucose level as compared to oral therapy due to controlled release of the active pharmaceutical ingredient, and no interaction was found between the drug and excipients of the formulation. Accelerated stability analysis showed that the formulation was stable up to 5.5 years, with negligible skin irritation. The formulation precluded severe hypoglycemic reactions (side effect of sulfonylureas) and was effective for management of diabetes mellitus up to 48 h, with a single TTS.

Prevalence and antifungal resistance profile of Candida spp. oral isolates from patients with type 1 and 2 diabetes mellitus

OBJECTIVE

The goal of the study was to measure the prevalence of Candida spp. in the oral cavity of patients with diabetes types 1 and 2 when compared to healthy individuals and to study antifungal resistance profile of the isolates.

DESIGN

There were 162 subjects in the study: diabetes type 1 (n=39); control group 1 (n=50): healthy individuals matched in gender, age, and oral conditions to diabetes type 1 patients; diabetes type 2 (n=37); control group 2 (n=36) who were matched to each patient of the diabetes type 2 group. Stimulated saliva was collected and isolates were identified with phenotypic tests. The presence of C. dubliniensis was determined by multiplex PCR.

RESULTS

There were no statistically significant differences in Candida spp. frequency between the diabetes 1 group and its control (p=0.443) nor between the diabetes 2 group and its control (p=0.429). C. albicans was the most frequently isolated yeast in all groups. In the diabetes groups, C. stellatoidea, C. parapsilosis, C. tropicalis, C. lipolytica, C. glabrata, and C. krusei were also identified. Additionally, in control groups, C. kefyr was also detected. None of the isolates were resistant to amphotericin B and flucytosine. A low percentage of the isolates were resistant to ketoconazole.

CONCLUSIONS

No differences were detected in colonization of Candida spp. oral isolates from type 1 and type 2 diabetes when compared to matched controls. The antifungal resistance of Candida spp. isolates for ketoconazole from type 1 diabetes patients was significantly higher than that of its matched control.

[Diabetic maculopathy and retinopathy. Functional and sociomedical significance]

OBJECTIVE

The incidence of diabetic microvascular complications is expected to increase by 20-50% in the coming years. Diabetic macular edema (DME) is already a leading cause of blindness in the working-age population in developed countries, and its impact is expected to increase dramatically.

METHODS

Recent literature on the epidemiology and impact of diabetic microangiopathy (maculopathy) on visual function was reviewed to provide a comprehensive overview of the functional and socioeconomic consequences of diabetic retinal microangiopathy and new therapeutic strategies.

RESULTS

The first changes indicating diabetic microangiopathy are detectable shortly after the development of hyperglycemia, and in the long term they induce severe organ damage. More resources are used for this condition's treatment than for the treatment of hyperglycemia, corresponding to an enormous sociomedical burden of disease. Early detection of increased retinal vascular permeability may help control treatment effects. The control of recognized risk factors for the development and progression of DME, namely hyperglycemia and hyperlipidemia, as well as of hypertension has remained the cornerstone of therapy and serves as the basis for preserving visual function.

CONCLUSIONS

Modern treatment options, begun early, may result in a remarkably delayed occurrence of irreversible diabetic microvascular pathologies, particularly diabetic retinopathy and maculopathy. Ophthalmological screening nowadays aims at earlier recognition of at-risk individuals to optimize the therapeutic strategy--that is, before visual impairment is imminent. Close interdisciplinary medical cooperation and implementation of new therapeutic options may provide the foundation for success in terms of maintaining visual function.

Limitations of the db/db mouse in translational wound healing research: Is the NONcNZO10 polygenic mouse model superior?

Murine models have provided valuable insights into the pathogenesis of both diabetes and chronic wounds. However, only a few published reports to date have investigated wound healing differences among the differing diabetic mouse models. The goal of the present study was to further define the wound healing deficiency phenotypes of streptozotocin-induced (STZ-induced), Akita, and db/db diabetic mice in comparison with a promising new polygenic strain of Type 2 diabetes (NONcNZO10) by using three specific wound models that targeted different critical processes in the pathogenesis of chronic wounds. Incisional, excisional, and ischemia/reperfusion wound models were established on mice of each strain. Wound healing parameters including tensile strength, epithelial gap, and wound necrosis were evaluated. In contrast to the other diabetic mice, the NONcNZO10 strain was found to have significant wound healing impairments in all wound healing models. Not only do the NONcNZO10 mice appear to better model human Type 2 diabetes, these provocative findings suggest that the mice may show more clinically relevant wound healing deficiencies than previous diabetic mouse models.

Inhibition of aldehyde dehydrogenase 2 by oxidative stress is associated with cardiac dysfunction in diabetic rats

Left ventricular (LV) dysfunction is a common comorbidity in diabetic patients, although the molecular mechanisms underlying this cardiomyopathic feature are not completely understood. Aldehyde dehydrogenase 2 (ALDH2) has been considered a key cardioprotective enzyme susceptible to oxidative inactivation. We hypothesized that hyperglycemia-induced oxidative stress would influence ALDH2 activity, and ALDH2 inhibition would lead to cardiac functional alterations in diabetic rats. Diabetes was induced by intraperitoneal (i.p.) injection of 60 mg/kg streptozotocin. Rats were divided randomly into four groups: control, untreated diabetic, diabetic treated with N-acetylcysteine (NAC) and diabetic treated with α-lipoic acid (α-LA). Cardiac contractile function, oxidative stress markers and reactive oxygen species (ROS) levels were assessed. ALDH2 activity and expression also were determined. The role of ALDH2 activity in change in hyperglycemia-induced mitochondrial membrane potential (Δψ) was tested in cultured neonatal cardiomyocytes. Myocardial MDA content and ROS were significantly higher in diabetic rats than in controls, whereas GSH content and Mn-SOD activity were decreased in diabetic rats. Compared with controls, diabetic rats exhibited significant reduction in LV ejection fraction and fractional shortening, accompanied by decreases in ALDH2 activity and expression. NAC and α-LA attenuated these changes. Mitochondrial Δψ was decreased greatly with hyperglycemia treatment, and high glucose combined with ALDH2 inhibition with daidzin further decreased Δψ. The ALDH2 activity can be regulated by oxidative stress in the diabetic rat heart. ALDH2 inhibition may be associated with LV reduced contractility, and mitochondrial impairment aggravated by ALDH2 inhibition might reflect an underlying mechanism which causes cardiac dysfunction in diabetic rats.

Meat consumption and risk of type 2 diabetes: the Multiethnic Cohort

OBJECTIVE

To examine the association of meat consumption with diabetes risk in the Hawaii component of the Multiethnic Cohort and to assess effect modification by ethnicity.

DESIGN

A prospective cohort study. Baseline information on diet and lifestyle was assessed by questionnaire. The cohort was followed up for incident cases of diabetes, which were identified through self-reports, medication questionnaires, or health plan linkages. Cox regression was used to calculate hazard ratios (HR) and 95% confidence intervals for diabetes associated with quintile of meat consumption.

SETTING

Hawaii, USA.

SUBJECTS

A total of 29,759 Caucasian, 35,244 Japanese-American and 10,509 Native Hawaiian men and women, aged 45-75 years at baseline.

RESULTS

During a mean follow-up time of 14 years, 8587 incident diabetes cases were identified. Intake of red meat was positively associated with diabetes risk in men (fifth v. first quintile: HR=1.43; 95% CI 1.29, 1.59) and women (fifth v. first quintile: HR=1.30; 95% CI 1.17, 1.45) in adjusted models. The respective HR for processed red meat intake were 1.57 (95% CI 1.42, 1.75) and 1.45 (95% CI 1.30, 1.62). The association for processed poultry was weaker than for processed red meat, and fresh poultry intake was not associated with diabetes risk. For men only, we observed significant interactions of ethnicity with the red and processed red meat associations, with Caucasians experiencing slightly higher risks than Japanese-Americans.

CONCLUSIONS

Our findings support the growing evidence that red and processed meat intake increase risk for diabetes irrespective of ethnicity and level of BMI.

Risk of cancer following hospitalization for type 2 diabetes

The present study assessed subsequent cancer risks in type 2 diabetes patients first hospitalized for this disease at age >39 years. Twenty-four cancer types showed an elevated risk when follow-up was started after the last hospitalization for type 2 diabetes. No additional risk was found in familial diabetics.

Objectives.

Cancer and type 2 diabetes (T2D) are two common diseases that may share risk factors. We aimed at determining subsequent cancer risks in patients hospitalized for T2D in Sweden.

Methods.

T2D patients were obtained from the nationwide Hospital Discharge Register; cancers were recorded from the Swedish Cancer Registry. Standardized incidence ratios (SIRs) were calculated for cancer following last hospitalization for T2D. The comparison group was the general Swedish population.

Results.

The number of hospitalized T2D patients from 1964 to 2007 was 125,126, of whom 26,641 had an affected family member. Altogether 24 cancers showed an elevated risk when follow-up was started after the last hospitalization. The highest SIRs were for pancreatic (6.08) and liver (4.25) cancers. The incidences of these cancers were even elevated when follow-up was started 5 years after the last hospitalization for T2D, with primary liver cancer showing the highest SIR of 4.66. Also increased were the incidences of upper aerodigestive tract, esophageal, colon, rectal, pancreatic, lung, cervical, endometrial, ovarian, and kidney cancers. Prostate cancer showed a lower risk. Familial T2D patients showed no exceptional elevated cancer risks but their prostate cancer and melanoma risks were lower.

Conclusions.

This study, covering approximately one half of Swedish T2D patients, showed an elevated risk for several cancers after hospitalization for T2D, probably indicating the profound metabolic disturbances of the underlying disease. The highest risks were found for liver and pancreatic cancers. No excess cancer risks were observed in familial diabetics. The lower risk for prostate cancer remains intriguing.

Nuts, metabolic syndrome and diabetes

The ability of nuts to improve the blood lipid profile and reduce the risk of CHD is now well established. The interest that health effects of nuts have gained recently has brought the possible benefits of consuming nuts, such as improvement in the conditions of the metabolic syndrome, and their potential to prevent and control diabetes into focus. Results from cohort studies have associated nut consumption with a reduced risk of developing diabetes and CVD. However, few randomised controlled trials have assessed the effect of nuts on diabetes control, and those that have been undertaken have shown improvements in blood lipids but not in the glycaemic control. Diabetes agencies are increasingly recognising the importance of controlling postprandial glycaemia fluctuations. Acute feeding studies indicate that nuts have minimal effects on rising postprandial blood glucose levels when eaten alone, and diminish the postprandial glycaemic response when consumed with high-glycaemic index carbohydrate foods in both normoglycaemic and type 2 diabetic individuals. Nuts have a healthy nutritional profile, high in MUFA and PUFA, are a good source of vegetable protein and are rich in fibre, vitamins and minerals. Incorporation of nuts in the diet may therefore improve the overall nutritional quality of the diet. While more research is required to establish the ability of nuts to improve glycaemic control in the long run, early data indicate that the inclusion of nuts in the diets of individuals with diabetes and the metabolic syndrome is warranted, in view of their potential to reduce CHD risk.

Stopping the cardiovascular disease continuum: Focus on prevention

The cardiovascular disease continuum (CVDC) is a sequence of events, which begins from a host of cardiovascular risk factors that consists of diabetes mellitus, dyslipidemia, hypertension, smoking and visceral obesity. If it is not intervened with early, it inexorably progresses to atherosclerosis, coronary artery disease, myocardial infarction, left ventricular hypertrophy, and left ventricular dilatation, which lead to left ventricular diastolic or systolic dysfunction and eventually end-stage heart failure and death. Treatment intervention at any stage during its course will either arrest or delay its progress. In this editorial, the cardiovascular risk factors that initiate and perpetuate the CVDC are briefly discussed, with an emphasis on their early prevention or aggressive treatment.

Metabolic syndrome components in murine models

Animal models have enriched understanding of the physiological basis of metabolic disorders and advanced identification of genetic risk factors underlying the metabolic syndrome (MetS). Murine models are especially appropriate for this type of research, and are an excellent resource not only for identifying candidate genomic regions, but also for illuminating the possible molecular mechanisms or pathways affected in individual components of MetS. In this review, we briefly discuss findings from mouse models of metabolic disorders, particularly in light of issues raised by the recent flood of human genome-wide association studies (GWAS) results. We describe how mouse models are revealing that genotype interacts with environment in important ways, indicating that the underlying genetics of MetS is highly context dependant. Further we show that epistasis, imprinting and maternal effects each contribute to the genetic architecture underlying variation in metabolic traits, and mouse models provide an opportunity to dissect these aspects of the genetic architecture that are difficult if not impossible to ascertain in humans. Finally we discuss how knowledge gained from mouse models can be used in conjunction with comparative genomic methods and bioinformatic resources to inform human MetS research.

Profile of patients with diabetes in Eritrea: results of first phase registry analyses

A cross-sectional descriptive study was done on patients recently entered into the National Diabetes Registry in Eritrea where the prevalence was estimated to be 2.2% based on patient information in 2004. Of the 627 patients with diabetes, two thirds were type 2. Although type 1 had poorer control (42.9%) than type 2 (29.9%), some of the risk factors such as cholesterol (43.4 vs. 28.2%), triglyceride (23.4 vs. 12.8%), hypertension (55.2 vs. 12.7%) as well as BMI and waist/hip ratio were higher in type 2 than type 1. More than one-third (41.2%) of patients with type 2 compared to type 1 (19.5%) had complications, the commonest being retinopathy (33%) followed by foot ulcers (14%) and neuropathy (4%). Many of the diabetic patients demonstrated the presence of the metabolic syndrome components such as hypertension, obesity and dyslipidemia. The authors conclude that diabetes registry is invaluable in providing evidence-based prevention and control of the disease.

Familial risks for type 2 diabetes in Sweden

OBJECTIVE

Our aim was to characterize familial risks for type 2 diabetes by the type and number of affected family members, including half-siblings, adoptees, and spouses, to quantify risks and estimate the contribution of environmental effect.

RESEARCH DESIGN AND METHODS

Families were identified from the Multigeneration Register, and type 2 diabetic patients were obtained from the Hospital Discharge Register. Standardized incidence ratios were calculated for offspring with type 2 diabetes whose family members were hospitalized for type 2 diabetes at ages >39 years compared with those lacking affected family members.

RESULTS

The number of hospitalized type 2 diabetic patients was 157,549. Among 27,895 offspring, 27.9% had a parent or sibling also hospitalized for type 2 diabetes. The familial relative risk (RR) ranged from 2.0 to >30, depending on the number and type of probands. The highest RRs of type 2 diabetes were found in individuals who had at least two siblings affected by type 2 diabetes, irrespective of the parental disease. Adoptees showed no risk from adopted parents.

CONCLUSIONS

The study, the largest yet published, showed that familial RRs varied by the number and type of affected family member. However, much of the familial clustering remains yet to be genetically explained. The high risk should be recognized in clinical genetic counseling. The data from adoptees confirmed the genetic basis of the familial associations, but those from half siblings and spouses suggested that a smaller part of familial clustering may be accounted for by environmental factors.

Critical role of IFN-gamma in CFA-mediated protection of NOD mice from diabetes development

IFN-gamma signaling-deficient non-obese diabetic (NOD) mice develop diabetes with similar kinetics to those of wild-type NOD mice. However, the immunization of IFN-gamma signaling-deficient NOD mice with CFA failed to induce long-term protection, whereas wild-type NOD mice receiving CFA remained diabetes-free. CFA also failed to protect IFN-gamma receptor-deficient (IFN-gammaR(-/-)) NOD mice from the autoimmune rejection of transplanted islets, as it does in diabetic NOD mice, and from disease transfer by spleen cells from diabetic NOD mice. These data clearly show that the pro-inflammatory cytokine IFN-gamma is necessary for the CFA-mediated protection of NOD mice from diabetes. There is no difference in the T(h)1/T(h)17 balance between IFN-gammaR(-/-) NOD and wild-type NOD mice. There is also no difference in the total numbers and percentages of regulatory T (Treg) cells in the lymph node CD4(+) T-cell populations between IFN-gammaR(-/-) NOD and wild-type NOD mice. However, pathogenic T cells lacking IFN-gammaR are resistant to the suppressive effect of Treg cells, both in vivo and in vitro. Therefore, it is likely that CFA-mediated protection against diabetes development depends on a change in the balance between Treg cells and pathogenic T cells, and IFN-gamma signaling seems to control the susceptibility of pathogenic T cells to the inhibitory activity of Treg cells.

Anti-infectious antibodies and autoimmune-associated autoantibodies in patients with type I diabetes mellitus and their close family members

Type 1 diabetes mellitus (T1DM) is an autoimmune disease with complex interactions between genetic and environmental factors. We compared antibody levels to various infectious agents and of autoimmune-associated autoantibodies between Colombian T1DM patients, their close family members and healthy controls. Significantly lower levels of antibodies against several infectious agents were detected in the T1DM patients. These included Helicobacter pylori (P = 0.01), cytomegalovirus (P = 0.001), Epstein-Barr virus (P = 0.02) and Toxoplasma (P = 0.001). T1DM patients had significantly higher levels of IgG-anti-gliadin antibodies (P = 0.001) and IgG-antitissue transglutaminase antibodies (P = 0.03), and a borderline association with anticentromere antibodies (P = 0.06). The lower level of antibodies against infectious agents in T1DM patients may be related to their younger ages, but may also point to a protective role of those infections in T1DM development in susceptible individuals. Our results confirm the association between T1DM and celiac disease. A possible association with anticentromere antibody needs further studies.

Menopausal hormone therapy and new-onset diabetes in the French Etude Epidemiologique de Femmes de la Mutuelle Générale de l'Education Nationale (E3N) cohort

AIMS/HYPOTHESIS

Two US randomised trials found a lower incidence of type 2 diabetes in women treated by menopausal hormone therapy (MHT) with oral conjugated equine oestrogen combined with medroxyprogesterone acetate. The purpose of this study was to evaluate the influence of various MHTs, according to their formulation and route of administration, on new-onset diabetes in a cohort of postmenopausal French women.

METHODS

The association between MHT use and new-onset diabetes was investigated by Cox regression analysis in 63,624 postmenopausal women in the prospective French cohort of the Etude Epidemiologique de Femmes de la Mutuelle Générale de l'Education Nationale (E3N). Cases of diabetes were identified through self-reporting or drug-reimbursement record linkage, and further validated.

RESULTS

1,220 new-onset diabetes cases were validated. We observed a lower risk of new-onset diabetes among women who had ever used MHT (HR 0.82 [95% CI 0.72-0.93]), compared with those who had never used MHT. Adjustment for BMI during follow-up (rather than according to baseline BMI) did not substantially modify this association. An oral route of oestrogen administration was associated with a greater decrease in diabetes risk than a cutaneous route (HR 0.68 [95% CI 0.55-0.85] vs 0.87 [95% CI 0.75-1.00], p for homogeneity = 0.028). We were not able to show significant differences between the progestagens used in combined MHT.

CONCLUSIONS/INTERPRETATION

Use of MHT appeared to be associated with a lower risk of new-onset diabetes. This relationship was not mediated by changes in BMI. Further studies are needed to confirm the stronger effect of oral administration of oestrogen compared with cutaneous administration.

Medical and endovascular management of critical limb ischemia

Critical limb ischemia (CLI) is the term used to designate the condition in which peripheral artery disease has resulted in resting leg or foot pain or in a breakdown of the skin of the leg or foot, causing ulcers or tissue loss. If not revascularized, CLI patients are at risk for limb loss and for potentially fatal complications from the progression of gangrene and the development of sepsis. The management of CLI requires a multidisciplinary team of experts in different areas of vascular disease, from atherosclerotic risk factor management to imaging, from intervention to wound care and physical therapy. In the past decade, the most significant change in the treatment of CLI has been the increasing tendency to shift from bypass surgery to less invasive endovascular procedures as first-choice revascularization techniques, with bypass surgery then reserved as backup if appropriate. The goals of intervention for CLI include the restoration of pulsatile, inline flow to the foot to assist wound healing, the relief of rest pain, the avoidance of major amputation, preservation of mobility, and improvement of patient function and quality of life. The evaluating physician should be fully aware of all revascularization options in order to select the most appropriate intervention or combination of interventions, while taking into consideration the goals of therapy, risk-benefit ratios, patient comorbidities, and life expectancy. We discuss the incidence, risk factors, and prognosis of CLI and the clinical presentation, diagnosis, available imaging modalities, and medical management (including pain and ulcer care, pharmaceutical options, and molecular therapies targeting angiogenesis). The endovascular approaches that we review include percutaneous transluminal angioplasty (with or without adjunctive stenting); subintimal angioplasty; primary femoropopliteal and infrapopliteal deployment of bare nitinol, covered, drug-eluting, or bioabsorbable stents; cryoplasty; excimer laser-assisted angioplasty; excisional atherectomy; and cutting balloon angioplasty.

Management of hypertension in patients with diabetes: the place of angiotensin-II receptor blockers

Hypertension is an important cardiovascular (CV) risk factor in patients with diabetes mellitus. In this setting, tight control of blood pressure (BP) significantly reduces CV morbidity and mortality. In the UK Prospective Diabetes Study, a 10 mmHg reduction in systolic blood pressure (SBP) was superior to a 0.7% decrease in glycosylated haemoglobin A1c (HbA1c) as far as reducing morbidity and mortality was concerned. In the Hypertension Optimal Treatment study, the risk of CV events decreased by 51% among patients with type 2 diabetes randomized to the lower BP level. Based on these findings, contemporary treatment guidelines recommend a target SBP/diastolic blood pressure of <130/80 mmHg for patients with diabetes.

Human cerebral neuropathology of Type 2 diabetes mellitus

The cerebral neuropathology of Type 2 diabetes (CNDM2) has not been positively defined. This review includes a description of CNDM2 research from before the 'Pubmed Era'. Recent neuroimaging studies have focused on cerebrovascular and white matter pathology. These and prior studies about cerebrovascular histopathology in diabetes are reviewed. Evidence is also described for and against the link between CNDM2 and Alzheimer's disease pathogenesis. To study this matter directly, we evaluated data from University of Kentucky Alzheimer's Disease Center (UK ADC) patients recruited while non-demented and followed longitudinally. Of patients who had come to autopsy (N = 234), 139 met inclusion criteria. These patients provided the basis for comparing the prevalence of pathological and clinical indices between well-characterized cases with (N = 50) or without (N = 89) the premortem diagnosis of diabetes. In diabetics, cerebrovascular pathology was more frequent and Alzheimer-type pathology was less frequent than in non-diabetics. Finally, a series of photomicrographs demonstrates histopathological features (including clinical-radiographical correlation) observed in brains of persons that died after a history of diabetes. These preliminary, correlative, and descriptive studies may help develop new hypotheses about CNDM2. We conclude that more work should be performed on human material in the context of CNDM2.

Effects of acute intermittent hypoxia on glucose metabolism in awake healthy volunteers

Accumulating evidence suggests that obstructive sleep apnea is associated with alterations in glucose metabolism. Although the pathophysiology of metabolic dysfunction in obstructive sleep apnea is not well understood, studies of murine models indicate that intermittent hypoxemia has an important contribution. However, corroborating data on the metabolic effects of intermittent hypoxia on glucose metabolism in humans are not available. Thus the primary aim of this study was to characterize the acute effects of intermittent hypoxia on glucose metabolism. Thirteen healthy volunteers were subjected to 5 h of intermittent hypoxia or normoxia during wakefulness in a randomized order on two separate days. The intravenous glucose tolerance test (IVGTT) was used to assess insulin-dependent and insulin-independent measures of glucose disposal. The IVGTT data were analyzed using the minimal model to determine insulin sensitivity (S(I)) and glucose effectiveness (S(G)). Drops in oxyhemoglobin saturation were induced during wakefulness at an average rate of 24.3 events/h. Compared with the normoxia condition, intermittent hypoxia was associated with a decrease in S(I) [4.1 vs. 3.4 (mU/l)(-1).min(-1); P = 0.0179] and S(G) (1.9 vs. 1.3 min(-1)x10(-2), P = 0.0065). Despite worsening insulin sensitivity with intermittent hypoxia, pancreatic insulin secretion was comparable between the two conditions. Heart rate variability analysis showed the intermittent hypoxia was associated with a shift in sympathovagal balance toward an increase in sympathetic nervous system activity. The average R-R interval on the electrocardiogram was 919.0 ms during the normoxia condition and 874.4 ms during the intermittent hypoxia condition (P < 0.04). Serum cortisol levels after intermittent hypoxia and normoxia were similar. Hypoxic stress in obstructive sleep apnea may increase the predisposition for metabolic dysfunction by impairing insulin sensitivity, glucose effectiveness, and insulin secretion.

Effects of acute intermittent hypoxia on glucose metabolism in awake healthy volunteers

Accumulating evidence suggests that obstructive sleep apnea is associated with alterations in glucose metabolism. Although the pathophysiology of metabolic dysfunction in obstructive sleep apnea is not well understood, studies of murine models indicate that intermittent hypoxemia has an important contribution. However, corroborating data on the metabolic effects of intermittent hypoxia on glucose metabolism in humans are not available. Thus the primary aim of this study was to characterize the acute effects of intermittent hypoxia on glucose metabolism. Thirteen healthy volunteers were subjected to 5 h of intermittent hypoxia or normoxia during wakefulness in a randomized order on two separate days. The intravenous glucose tolerance test (IVGTT) was used to assess insulin-dependent and insulin-independent measures of glucose disposal. The IVGTT data were analyzed using the minimal model to determine insulin sensitivity (S(I)) and glucose effectiveness (S(G)). Drops in oxyhemoglobin saturation were induced during wakefulness at an average rate of 24.3 events/h. Compared with the normoxia condition, intermittent hypoxia was associated with a decrease in S(I) [4.1 vs. 3.4 (mU/l)(-1).min(-1); P = 0.0179] and S(G) (1.9 vs. 1.3 min(-1)x10(-2), P = 0.0065). Despite worsening insulin sensitivity with intermittent hypoxia, pancreatic insulin secretion was comparable between the two conditions. Heart rate variability analysis showed the intermittent hypoxia was associated with a shift in sympathovagal balance toward an increase in sympathetic nervous system activity. The average R-R interval on the electrocardiogram was 919.0 ms during the normoxia condition and 874.4 ms during the intermittent hypoxia condition (P < 0.04). Serum cortisol levels after intermittent hypoxia and normoxia were similar. Hypoxic stress in obstructive sleep apnea may increase the predisposition for metabolic dysfunction by impairing insulin sensitivity, glucose effectiveness, and insulin secretion.

Changes of some Health Indicators in Patients with Type 2 Diabetes: A Prospective Study in three Community Pharmacies in Sharjah, United Arab Emirates

Aim: The study aimed to examine changes in some health indicators in people with type 2 diabetes mellitus, namely: reported self-care activity, health related quality of life, and patient opinion of the services provided by three community pharmacies in Sharjah, UAE. Method: A group of patients was followed over 24 months. Patients under investigation received reminders packages during the first three months of the study. No reminders were sent after 3 months after the study was underway. Repeated measures ANOVA were used to test differences between means over different periods. Results: All patients included in this study were found to have poor diet and exercise behavior at baseline. Three months into the study, more than 27% of the patients had acceptable diet, exercise, foot care and self-testing behavior. However, evaluation at six months and 24-months show that mean scores had almost returned to baseline levels. There were significant differences between the mean values of initial (baseline data) and final (at the end of the study) scores for general health (5.86, p = 0.001), vitality (5.25, p < 0.001), and role physical scales (3.81, p = 0.02). There was a significant (p < 0.001) 25% increase in the patients' perception of the ability of the pharmacist to assist in decreasing blood glucose level. Conclusion: Ongoing reminder packages are needed for continued progress in self-care activities and for achieving lasting changes in the behavior. Implementation of such a strategy through community pharmacies could help to improve patients' views of the quality of services received from these pharmacies and patient's quality of life, which should improve patient's drug therapy and reduce complications of diabetes.

Functional foods for health: focus on diabetes

Type 2 diabetes is one of the fastest growing public health problems worldwide. Menopause may present additional challenges for women who have diabetes by increasing the risk for cardiovascular disease (CVD) and making blood glucose control more difficult. Functional foods may have the potential to improve glycemic control, but little evidence is known about the efficacy of these foods. The purpose of this literature review is to establish a recommendation for the intake of functional foods in a healthy diet - such as nuts, omega-3 fatty acids (FAs) and cinnamon - for the glycemic control in type 2 diabetes. Nuts and omega-3 FAs appear to have an overall beneficial effect on CVD; however, their effect on glucose homeostasis is uncertain. In addition, cinnamon appears to inconsistently improve glycemic parameters in diabetic patients. Overall, more research on the potential effect of all of these functional foods on patients with type 2 diabetes is needed to able to make specific recommendations. In conclusion, there is reason to consider the inclusion of nuts and fish, as a source of omega-3 FAs, in the diets of individuals with diabetes in view of their potential to reduce CVD risk, even though their ability to influence overall glycemic control remains to be established.

Analysis of maternal-offspring HLA compatibility, parent-of-origin and non-inherited maternal effects for the classical HLA loci in type 1 diabetes

AIM

Type 1 diabetes (T1D) is a complex trait for which variation in the classical human leucocyte antigen (HLA) loci within the Major Histocompatibility Complex (MHC) significantly influences disease risk. To date, HLA class II DR-DQ genes confer the strongest known genetic effect in T1D. HLA loci may also influence T1D through additional inherited or non-inherited effects. Evidence for the role of increased maternal-offspring HLA compatibility, and both parent-of-origin (POO) and non-inherited maternal HLA (NIMA) effects in autoimmune disease has been previously established. The current study tested hypotheses that classical HLA loci influence T1D through these mechanisms, in addition to genetic transmission of particular risk alleles.

METHODS

The Type 1 Diabetes Genetics Consortium (T1DGC) cohort was of European descent and consisted of 2271 affected sib-pair families (total n = 11 023 individuals). Class I genes HLA-A, Cw and B, and class II genes HLA-DRB1, DQA1, DQB1, DPA1 and DPB1 were studied. The pedigree disequilibrium test was used to examine transmission of HLA alleles to individuals with T1D. Conditional logistic regression was used to model compatibility relationships between mother-offspring and father-offspring for all HLA loci. POO and NIMA effects were investigated by comparing frequencies of maternal and paternal transmitted and non-transmitted HLA alleles for each locus. Analyses were also stratified by gender of T1D-affected offspring.

RESULTS

Strong associations were observed for all classical HLA loci except for DPA1, as expected. Compatibility differences between mother-offspring and father-offspring were not observed for any HLA loci. Furthermore, POO and NIMA HLA effects influencing T1D were not present.

CONCLUSIONS

Maternal-offspring HLA compatibility, POO and NIMA effects for eight classical HLA loci were investigated. Results suggest that these HLA-related effects are unlikely to play a major role in the development of T1D.

The phosphotyrosine interactome of the insulin receptor family and its substrates IRS-1 and IRS-2

The insulin signaling pathway is critical in regulating glucose levels and is associated with diabetes, obesity, and longevity. A tyrosine phosphorylation cascade creates docking sites for protein interactions, initiating subsequent propagation of the signal throughout the cell. The phosphotyrosine interactome of this medically important pathway has not yet been studied comprehensively. We therefore applied quantitative interaction proteomics to exhaustively profile all potential phosphotyrosine-dependent interaction sites in its key players. We targeted and compared insulin receptor substrates 1 and 2 (IRS-1 and IRS-2) as central distributors of the insulin signal, the insulin receptor, the insulin-like growth factor 1 receptor, and the insulin receptor-related receptor. Using the stable isotope labeling by amino acids in cell culture (SILAC) approach with phosphorylated versus non-phosphorylated bait peptides, we found phosphorylation-specific interaction partners for 52 out of 109 investigated sites. In addition, doubly and triply phosphorylated motifs provided insight into the combinatorial effects of phosphorylation events in close proximity to each other. Our results retrieve known interactions and substantially broaden the spectrum of potential interaction partners of IRS-1 and IRS-2. A large number of common interactors rationalize their extensive functional redundancy. However, several proteins involved in signaling and metabolism interact differentially with IRS-1 and IRS-2 and thus provide leads into their different physiological roles. Differences in interactions at the receptor level are reflected in multisite recruitment of SHP2 by the insulin-like growth factor 1 receptor and limited but exclusive interactions with the IRR. In common with other recent reports, our data furthermore hint at non-SH2 or phosphotyrosine-binding domain-mediated phosphotyrosine binding.

Effects of treadmill exercise on cell proliferation and differentiation in the subgranular zone of the dentate gyrus in a rat model of type II diabetes

In the present study, we investigated the effects of a treadmill exercise on serum glucose levels and Ki67 and doublecortin (DCX) immunoreactivity, which is a marker of cell proliferation expressed during cell cycles except G0 and early G1 and a marker of progenitors differentiating into neurons, respectively, in the subgranular zone of the dentate gyrus (SZDG) using a type II diabetic model. At 6 weeks of age, Zucker lean control (ZLC) and Zucker diabetic fatty (ZDF) rats were put on a treadmill with or without running for 1 h/day/5 consecutive days at 22 m/min for 5 weeks. Body weight was significantly increased in the control (without running)-ZDF rats compared to that in the other groups. In the control groups blood glucose levels were increased by 392.7 mg/dl in the control-ZDF rats and by 143.3 mg/dl in the control-ZLC rats. However, in the exercise groups, blood glucose levels were similar between the exercise-ZLC and ZDF rats: The blood glucose levels were 110.0 and 118.2 mg/dl, respectively. Ki67 positive nuclei were detected in the SZDG in control and exercise groups. The number of Ki67 positive nuclei was significantly high in exercise groups compared to that in the control groups. In addition, Ki67 positive cells were abundant in ZLC groups compared to those in ZDF groups. DCX-immunoreactive structures in the control-ZDF rats were lower than that in the control-ZLC rats. In the exercise groups, DCX-immunoreactive structures (somata and processes with tertiary dendrites) and DCX protein levels were markedly increased in both the exercise-ZLC and ZDF rats compared to that in the control groups. These results suggest that a treadmill exercise reduces blood glucose levels in ZDF rats and increases cell proliferation and differentiation in the SZDG in ZLC and ZDF rats compared to those in control groups.