Diabetes duration may modify the association between genetic variation in the glycoprotein Ia subunit of the platelet collagen receptor and risk of severe diabetic retinopathy: a working hypothesis

Genetic factors appear to contribute to the severity and progression of diabetic retinopathy. We assessed the associations of the C807T and Glu505Lys variants of the glycoprotein Ia ( 2 integrin) subunit of the platelet/endothelial collagen receptor and risk of retinopathy in a population-based survey of 288 diabetic patients in one Swedish community. Neither variant was associated with retinopathy risk overall. However, the 807T variant was associated with increased risk of severe retinopathy, and the association was modified by diabetes duration. Among patients with diabetes of longer duration ( 25 years), the 807T variant was strongly associated with risk of severe retinopathy (odds ratio 7.49, 95% confidence interval 1.75 to 32.1). There was no association between the 807T variant and risk of severe retinopathy among patients with diabetes duration <25 years. The Lys505 variant of glycoprotein Ia was associated with an odds ratio for severe retinopathy of 1.88 (95% confidence interval 0.83 to 4.24). Overall, there was a significant interaction between glycoprotein Ia genotype and duration of diabetes on the risk of retinopathy (P-value for interaction = 0.019).These results suggest the hypothesis that genetic variation of platelet glycoprotein Ia may play a particularly important role during the advanced stages of diabetic retinopathy.

Genome-wide analysis of DNA methylation in subjects with type 1 diabetes identifies epigenetic modifications associated with proliferative diabetic retinopathy

BACKGROUND

Epigenetic variation has been linked to several human diseases. Proliferative diabetic retinopathy (PDR) is a major cause of vision loss in subjects with diabetes. However, studies examining the association between PDR and the genome-wide DNA methylation pattern are lacking. Our aim was to identify epigenetic modifications that associate with and predict PDR in subjects with type 1 diabetes (T1D).

METHODS

DNA methylation was analyzed genome-wide in 485,577 sites in blood from cases with PDR (n = 28), controls (n = 30), and in a prospective cohort (n = 7). False discovery rate analysis was used to correct the data for multiple testing. Study participants with T1D diagnosed before 30 years of age and insulin treatment within 1 year from diagnosis were selected based on 1) subjects classified as having PDR (cases) and 2) subjects with T1D who had had diabetes for at least 10 years when blood DNA was sampled and classified as having no/mild diabetic retinopathy also after an 8.7-year follow-up (controls). DNA methylation was also analyzed in a prospective cohort including seven subjects with T1D who had no/mild diabetic retinopathy when blood samples were taken, but who developed PDR within 6.3 years (converters). The retinopathy level was classified by fundus photography.

RESULTS

We identified differential DNA methylation of 349 CpG sites representing 233 unique genes including TNF, CHI3L1 (also known as YKL-40), CHN2, GIPR, GLRA1, GPX1, AHRR, and BCOR in cases with PDR compared with controls. The majority of these sites (79 %) showed decreased DNA methylation in cases with PDR. The Natural Killer cell-mediated cytotoxicity pathway was found to be significantly (P = 0.006) enriched among differentially methylated genes in cases with PDR. We also identified differential DNA methylation of 28 CpG sites representing 17 genes (e.g. AHRR, GIPR, GLRA1, and BCOR) with P <0.05 in the prospective cohort, which is more than expected by chance (P = 0.0096).

CONCLUSIONS

Subjects with T1D and PDR exhibit altered DNA methylation patterns in blood. Some of these epigenetic changes may predict the development of PDR, suggesting that DNA methylation may be used as a prospective marker of PDR.

Photocoagulation of human retinal pigment epithelium in vitro: unravelling the effects on ARPE-19 by transcriptomics and proteomics

PURPOSE

Despite the extensive use of retinal photocoagulation for ischaemia and vascular leakage in retinal vascular disease, the molecular mechanisms behind its clinical beneficial effects are still poorly understood. One important target of laser irradiation is the retinal pigment epithelium (RPE). In this study, we aimed at identifying the isolated effects of photocoagulation of RPE at both the mRNA and protein expression levels.

METHODS

Human ARPE-19 cells were exposed to photocoagulation. Gene expression and protein expression were compared to untreated cells using microarray and liquid chromatography-mass spectrometry analysis. Genes and proteins queried by microarray and mass spectrometry were subjected to the Kyoto Encyclopedia of Genes and Genomes (KEGG) database pathway analyses.

RESULTS

Laser irradiation resulted in an induction of the cytoprotective heat-shock protein subfamily Hsp70 as well as in a suppression of the vascular permeability factor carbonic anhydrase 9 (CA9). These expression patterns were evident at both the mRNA and protein levels. KEGG pathway analyses revealed genes and proteins involved in cellular turnover, repair and inflammation.

CONCLUSIONS

By characterizing the transcriptional and translational effects of laser coagulation on the RPE cells in culture, we have revealed responses, which might contribute to some of the beneficial effects obtained by photocoagulation for ischaemia and vascular leakage in retinal vascular disease.

Ethnicity is an independent risk indicator when estimating diabetes risk with FINDRISC scores: a cross sectional study comparing immigrants from the Middle East and native Swedes

AIMS

This study sought to compare type 2 diabetes (T2D) risk indicators in Iraqi immigrants with those in ethnic Swedes living in southern Sweden.

METHODS

Population-based, cross-sectional cohort study of men and women, aged 30-75 years, born in Iraq or Sweden conducted in 2010-2012 in Malmö, Sweden. A 75g oral glucose tolerance test was performed and sociodemographic and lifestyle data were collected. T2D risk was assessed by the Finnish Diabetes Risk Score (FINDRISC).

RESULTS

In Iraqi versus Swedish participants, T2D was twice as prevalent (11.6 vs. 5.8%, p<0.001). A large proportion of the excess T2D risk was attributable to larger waist circumference and first-degree family history of diabetes. However, Iraqi ethnicity was a risk factor for T2D independently of other FINDRISC factors (odds ratio (OR) 2.5, 95% CI 1.6-3.9). The FINDRISC algorithm predicted that more Iraqis than Swedes (16.2 vs. 12.3%, p<0.001) will develop T2D within the next decade. The total annual costs for excess T2D risk in Iraqis are estimated to exceed 2.3 million euros in 2005, not accounting for worse quality of life.

CONCLUSIONS

Our study suggests that Middle Eastern ethnicity should be considered an independent risk indicator for diabetes. Accordingly, the implementation of culturally tailored prevention programs may be warranted.

GAD autoantibody affinity in adult patients with latent autoimmune diabetes, the study participants of a GAD65 vaccination trial

OBJECTIVE

Patients with latent autoimmune diabetes in adults (LADA) express autoantibodies against the 65-kDa isoform of GAD (GADA). Intervention with recombinant human GAD65 formulated with aluminium hydroxide (GAD-alum) given twice subcutaneously to LADA patients at intervals of 4 weeks was safe and did not compromise β-cell function in a Phase II clinical trial. GADA affinity has been shown to predict progression to type 1 diabetes. Here, we asked whether GADA affinity was affected by the GAD65 antigen-specific vaccination and/or associated with β-cell function in participants of this trial.

RESEARCH DESIGN AND METHODS

GADA affinity was measured in sera of 46 LADA patients obtained prior to the first week and 20 weeks after the second injection with GAD-alum or placebo using competitive binding experiments with [125I]-labeled and unlabeled human GAD65.

RESULTS

At baseline, GADA affinities ranged from 1.9 × 10(7) to 5.0 × 10(12) L/mol (median 2.8 × 10(10) L/mol) and were correlated with GADA titers (r = 0.47; P = 0.0009), fasting (r = -0.37; P = 0.01) and stimulated (r = -0.40; P = 0.006) C-peptide concentrations, and HbA1c (r = 0.39; P = 0.007). No significant changes in affinity were observed from baseline to week 24. Patients with GADA affinities in the lower first quartile (<4 × 10(9) L/mol) had better preserved fasting C-peptide concentrations at baseline than those with higher affinities (mean 1.02 vs. 0.66 nmol/L; P = 0.004) and retained higher concentrations over 30 months of follow-up (mean 1.26 vs. 0.62 nmol/L; P = 0.01).

CONCLUSIONS

Intervention with GAD-alum in LADA patients had no effect on GADA affinity. Our data suggest that patients with low GADA affinity have a prolonged preservation of residual β-cell function.

Cardiovascular disease in relation to diabetes status in immigrants from the Middle East compared to native Swedes: a cross-sectional study

BACKGROUND

Type 2 diabetes is highly prevalent in immigrants to Sweden from Iraq, but the prevalence of cardiovascular disease (CVD) and its risk factors are not known. In this survey we aimed to compare the prevalence of CVD and CVD-associated risk factors between a population born in Iraq and individuals born in Sweden.

METHODS

This population-based, cross-sectional study comprised 1,365 Iraqi immigrants and 739 Swedes (age 30-75 years) residing in the same socioeconomic area in Malmö, Sweden. Blood tests were performed and socio-demography and lifestyles were characterized. To investigate potential differences in CVD, odds ratios (ORs) with 95% confidence intervals (CIs) were estimated by multivariate logistic regression analysis with adjustment for metabolic, lifestyle and psychosocial risk factors for CVD. Outcome measures were odds of CVD.

RESULTS

There were no differences in self-reported prevalence of CVD between Iraqi- and Swedish-born individuals (4.0 vs. 5.5%, OR 0.9, 95% CI 0.4-1.8). However, the prevalence of type 2 diabetes was higher in Iraqi compared to Swedish participants (8.4 vs. 3.3%, OR = 4.2, 95% CI 2.6-6.7). Moreover, among individuals with type 2 diabetes, Iraqis had a higher prevalence of CVD (22.8 vs. 8.0%, OR = 4.2, 95% CI 0.9-20.0), after adjustment for age and sex. By contrast, among those without diabetes, immigrants from Iraq had a lower prevalence of CVD than Swedes (2.2 vs. 5.5%, OR = 0.6, 95% CI 0.3-0.9).Type 2 diabetes was an independent risk factor for CVD in Iraqis only (OR = 6.8, 95% CI 2.8-16.2). This was confirmed by an interaction between country of birth and diabetes (p = 0.010). In addition, in Iraqis, type 2 diabetes contributed to CVD risk to a higher extent than history of hypertension (standardized OR 1.5 vs. 1.4).

CONCLUSIONS

This survey indicates that the odds of CVD in immigrants from Iraq are highly dependent on the presence or absence of type 2 diabetes and that type 2 diabetes contributes with higher odds of CVD in Iraqi immigrants compared to native Swedes. Our study suggests that CVD prevention in immigrants from the Middle East would benefit from prevention of type 2 diabetes.

Photocoagulation of human retinal pigment epithelial cells in vitro: evaluation of necrosis, apoptosis, cell migration, cell proliferation and expression of tissue repairing and cytoprotective genes

Aims

Sight-threatening diabetic retinopathy has been treated with photocoagulation for decades but the mechanisms behind the beneficial clinical effects are poorly understood. One target of irradiation and a potential player in this process is the retinal pigment epithelium (RPE). Here we establish an in vitro model for photocoagulation of human RPE cells.

Methods

ARPE-19 cells were exposed to photocoagulation and studied at various time points up to 168h. Lesion morphology, necrosis and apoptosis were investigated by light microscopy; LIVE/DEAD staining and measurements of lactate dehydrogenase activity; and TUNEL- and ELISA-based quantification of DNA fragments, respectively. Cell migration and proliferation were explored using docetaxel and mitomycin C; temporal and spatial changes in proliferation were assessed by confocal immunofluorescence of proliferating cell nuclear antigen. Gene expression was measured by qPCR.

Results

Photocoagulation of ARPE-19 resulted in denaturation of proteins and reproducible lesion formation. A transient peak in necrosis, followed by a peak in apoptosis was observed in cells within the lesions at 6h and 24h, respectively after photocoagulation. Cell proliferation was depressed during the first hours after photocoagulation, back to control levels at 24h and augmented in the following days. These effects were not limited to cells in the lesions, but also evident in neighbouring cells. Changes in cell proliferation during lesion repair were preceded by changes in cell migration. Altered mRNA expression of genes previously implicated in the regulation of cell proliferation (FOS, IL-1β, IL-8, HMGA2), migration and tissue repairing (TGFBR2, ADAMTS6, TIMP3, CTGF) was observed, as well as increased expression of the alarmin IL33 and the cytoprotective gene HSPA6.

Conclusions

Using a laser system and experimental settings that comply with standards used in clinical practice, we have established a suitable model for in vitro photocoagulation of human RPE cells to isolate their contribution to the beneficial effects of laser treatment.

Profile of intraocular tumour necrosis factor-α and interleukin-6 in diabetic subjects with different degrees of diabetic retinopathy

PURPOSE

To assess and correlate the levels of inflammatory mediators in the eyes from non-diabetic and diabetic subjects without retinopathy (NDR), with non-proliferative diabetic retinopathy (NPDR) or with proliferative diabetic retinopathy (PDR) to corresponding erum levels.

METHODS

The levels of interleukin 1β, interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) were analysed by an ELISA-mimicking technique in the vitreous from 26 diabetic subjects with active PDR and 27 non-diabetic subjects, or by a multiplex bead assay in the aqueous humour from 35 diabetic subjects with NDR/NPDR and 40 non-diabetic subjects. Intraocular protein production was estimated in vitreous specimens by calculating a vitreous/serum ratio.

RESULTS

In the vitreous, IL-6 was higher in diabetic [157.5 (25.0-1401.0) pg/ml; median (min-max)] than in non-diabetic subjects [44.0 (5.0-4425) pg/ml; p = 0.021]. The vitreous/serum ratio was high (55.5:1 and 16:1, respectively), suggesting intraocular production. TNF-α was lower in diabetic [18.0 (8.0-46.0) pg/ml] than in non-diabetic subjects [22.0 (13.0-47.0) pg/ml; p = 0.034], but the vitreous/serum ratio was elevated in both groups (2:1 and 3.4:1, respectively). TNF-α levels were higher in serum from diabetic subjects [9.0 (5.0-53.0) pg/ml versus 6.7 (3.0-11.0) pg/ml; p < 0.001]. Aqueous levels of inflammatory mediators did not differ between diabetic subjects with NDR/NPDR and non-diabetic subjects despite elevated TNF-α in serum [27.8 (6.8-153.7) pg/ml versus 16.4 (4.1-42.4) pg/ml; p = 0.021].

CONCLUSION

Intraocular inflammation seems to be involved in PDR but does not seem to be prominent in early retinopathy stages, i.e. NDR or NPDR. Diabetic subjects have an overall increased inflammatory activity compared to non-diabetic subjects, as demonstrated by increased serum levels of TNF-α.

Association between TNF-α -308G/A polymorphism and diabetic nephropathy risk: a meta-analysis

Background

Several candidate genes on the short arm of chromosome 6 including the HLA locus, TNF, LTA and AGER could be associated with late diabetic complications. The aim of our study was therefore to explore whether polymorphisms (TNF -308 G→A, LTA T60N C→A and AGER -374 T→A) in these genes alone or together (as haplotypes) increased the risk for diabetic complications.

Methodology/Principal Findings

The studied polymorphisms were genotyped in 742 type 1 and 2957 type 2 diabetic patients as well as in 206 non-diabetic control subjects. The Haploview program was used to analyze putative linkage disequilibrium between studied polymorphisms. The TNF, LTA and AGER polymorphisms were associated with the HLA-DQB1 risk genotypes. The AGER -374 A allele was more common in type 1 diabetic patients with than without diabetic nephropathy (31.2 vs. 28.4%, p = 0.007). In a logistic regression analysis, the LTA but not the AGER polymorphism was associated with diabetic nephropathy (OR 2.55[1.11–5.86], p = 0.03). The AGER -374 A allele was associated with increased risk of sight threatening retinopathy in type 2 diabetic patients (1.65[1.11–2.45], p = 0.01) and also with increased risk for macrovascular disease in type 1 diabetic patients (OR 2.05[1.19–3.54], p = 0.01), but with decreased risk for macrovascular disease in type 2 diabetic patients (OR 0.66[0.49–0.90], p = 0.009). The TNF A allele was associated with increased risk for macrovascular complications in type 2 (OR 1.53 [1.04–2.25], p = 0.03, but not in type 1 diabetic patients.

Conclusions/Significance

The association between diabetic complications and LTA, TNF and AGER polymorphisms is complex, with partly different alleles conferring susceptibility in type 1 and type 2 diabetic patients. We can not exclude the possibility that the genes are part of a large haplotype block that also includes HLA-DQB1 risk genotypes.

Switching from high-fat to low-fat diet normalizes glucose metabolism and improves glucose-stimulated insulin secretion and insulin sensitivity but not body weight in C57BL/6J mice

OBJECTIVES

Environmental factors such as a high-fat diet contribute to type 2 diabetes and obesity. This study examined glycemia, insulin sensitivity, and β-cell function after switching from a high-fat diet to a low-fat diet in mice.

METHODS

C57BL/6J mice were fed a high-fat diet or low-fat diet for 18 months, after which mice on the high-fat diet either maintained this diet or switched to a low-fat diet for 4 weeks. Body weight and glucose and insulin responses to intraperitoneal glucose were determined. Insulin secretion (insulinogenic index: the 10-minute insulin response divided by the 10-minute glucose level) and insulin sensitivity (1 divided by basal insulin) were determined.

RESULTS

After 18 months on a high-fat diet, mice had glucose intolerance, marked hyperinsulinemia, and increased body weight compared to mice on a low-fat diet (P < 0.001). Switching from a high-fat diet to low-fat diet normalized glucose tolerance, reduced but not normalized body weight (P < 0.001), increased insulin secretion (248 ± 39 vs 141 ± 46 pmol/mmol; P = 0.028) and improved but not normalized insulin sensitivity (3.2 ± 0.1 vs 1.0 ± 0.1 [pmol/L]; P = 0.012).

CONCLUSION

Switching from a high-fat diet to low-fat diet normalizes glucose tolerance and improves but not normalizes insulin secretion and insulin sensitivity. These effects are more pronounced than the reduced body weight.

HLA-DQB1 genotypes and islet cell autoantibodies against GAD65 and IA-2 in relation to development of diabetes post partum in women with gestational diabetes mellitus

AIMS

To study HLA-DQB1 genes and islet cell autoantibodies against glutamic acid decarboxylase 65 (GADA) and insulinoma antigen-2 (IA-2A) in relation to diabetes post partum in mothers with diagnosed gestational diabetes mellitus (GDM).

METHODS

During 2003-2004, women undergoing a 75 g oral glucose tolerance test (OGTT) during pregnancy were invited to participate in the Mamma Study. Cut-off level defining GDM was a 2-h capillary blood glucose of 7.8 mmol/L. 1-2 years after delivery a 75 g OGTT was performed, GADA and IA-2A were measured and HLA-DQB1 genes analysed. Data were available for 452 mothers with previous GDM and 168 randomly selected control subjects.

RESULTS

HLA-DQB1*0602 was negatively associated with GDM (p=0.033) and with development of diabetes post partum (p=0.017), whereas high risk HLA were not associated with GDM or with diabetes. The presence of GADA post partum was positively associated with diabetes post partum (p=0.0009), but not with impaired glucose tolerance.

CONCLUSIONS

Mothers with GDM and HLA-DQB1*0602 were less likely to develop diabetes after pregnancy, and type 1 diabetes associated high risk HLA genes did not predict type 1 diabetes post partum. Additionally, GADA were positively associated with diabetes development.

Gestational diabetes mellitus is associated with TCF7L2 gene polymorphisms independent of HLA-DQB1*0602 genotypes and islet cell autoantibodies

AIMS

To test whether the TCF7L2 gene was associated with gestational diabetes, whether the association between TCF7L2 and gestational diabetes was independent of HLA-DQB1*0602 and islet cell autoantibodies, as well as maternal age, number of pregnancies, family history of diabetes and the HLA-DQB1 genotypes, and to test whether the distribution of HLA-DQB1 alleles was affected by country of birth.

METHODS

We genotyped the rs7903146, rs12255372 and rs7901695 single nucleotide polymorphisms of the TCF7L2 gene in 826 mothers with gestational diabetes and in 1185 healthy control subjects in the Diabetes Prediction in Skåne Study. The mothers were also typed for HLA-DQB1 genotypes and tested for islet cell autoantibodies against GAD65, insulinoma-associated antigen-2 and insulin.

RESULTS

The heterozygous genotypes CT, GT and TC of the rs7903146 (T is risk for Type 2 diabetes), rs12255372 (T is risk for Type 2 diabetes) and rs7901695 (C is risk for Type 2 diabetes), respectively, as well as the homozygous genotypes TT, TT and CC of the rs7903146, rs12255372 and rs7901695, respectively, were strongly associated with gestational diabetes (P < 0.0001). These associations remained statistically significant after adjusting for maternal age, number of pregnancies, family history of diabetes and HLA-DQ genotypes and were independent of the presence of islet cell autoantibodies. No interaction was observed between TCF7L2 and HLA-DQB1*0602, which was shown to be negatively associated with gestational diabetes in mothers born in Sweden (P = 0.010).

CONCLUSIONS

The TCF7L2 was associated with susceptibility for gestational diabetes independently of the presence of HLA-DQB1*0602 and islet cell autoantibodies and other factors such as maternal age, number of pregnancies, family history of diabetes and other HLA-DQ genotypes. The HLA-DQB1*0602 was negatively associated with gestational diabetes in mothers born in Sweden.

High prevalence of type 2 diabetes in Iraqi and Swedish residents in a deprived Swedish neighbourhood--a population based study

BACKGROUND

Immigrants from the Middle-East are at high risk of developing type 2 diabetes (T2D). The aim of the present survey was to measure, in a single deprived neighbourhood, the prevalence rates of impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and T2D in residents originating from Iraq and to compare them to those in residents born in Sweden. An additional aim was to identify metabolic, lifestyle and socioeconomic risk factors associated with IFG/IGT and T2D in these residents.

METHODS

The study was conducted February 1'st to March 31'st 2010. Men and women aged 45 to 65 years of Swedish or Iraqi origin, living in the neighbourhood of Rosengård, Malmö, Sweden, were randomly selected from the census register. Each participant signed a written informed consent form, underwent a physical examination and an oral glucose tolerance test (OGTT), provided blood samples and filled in a questionnaire. A total of 175 subjects participated (Swedish origin n = 79, Iraqi origin n = 96), reflecting an overall response rate of almost 60%.

RESULTS

In total, 21.9% and 19.0% of the Iraqi and Swedish participants, respectively, suffered from T2D, while 24.0% of the Iraqi participants and 25.3% of the Swedish participants had IFG/IGT. There were no significant differences in prevalence rates relating to country of origin.Obesity (BMI ≥30 kg/m2) and sedentary leisure time physical activity were highly prevalent in both groups, while a family history of diabetes was more prevalent in participants from Iraq (49.2%) than in those from Sweden (22.8%) (p = 0.001).Being obese or having a sedentary leisure time were, independently associated with T2D (OR 5.43 (95% CI 2.10-14.02) and 2.89 (95% CI 1.03-8.10) respectively), while economic difficulties were independently associated with IFG/IGT (OR 2.55 (95% CI 1.06-6.15)) after adjustment for the confounding effects of other common risk factors for T2D.

CONCLUSIONS

This study reveals a high prevalence of T2D, independently of country of origin (Iraq or Sweden), in a socially vulnerable area and additionally presents a risk factor profile that is markedly different from that of Sweden in general.

Evaluation of the aldose reductase inhibitor fidarestat on ischemia-reperfusion injury in rat retina

This study evaluated the effects of retinal ischemia-reperfusion (IR) injury and pre-treatment with the potent and specific aldose reductase inhibitor fidarestat on apoptosis, aldose reductase and sorbitol dehydrogenase expression, sorbitol pathway intermediate concentrations, and oxidative-nitrosative stress. Female Wistar rats were pre-treated with either vehicle (N-methyl-D-glucamine) or fidarestat, 32 mg kg(-1) d(-1) for both, in the right jugular vein, for 3 consecutive days. A group of vehicle- and fidarestat-treated rats were subjected to 45-min retinal ischemia followed by 24-h reperfusion. Ischemia was induced 30 min after the last vehicle or fidarestat administration. Retinal IR resulted in a remarkable increase in retinal cell death. The number of TUNEL-positive nuclei increased 48-fold in the IR group compared with non-ischemic controls (p<0.01), and this increase was partially prevented by fidarestat. AR expression (Western blot analysis) increased by 19% in the IR group (p<0.05), and this increase was prevented by fidarestat. Sorbitol dehydrogenase and nitrated protein expressions were similar among all experimental groups. Retinal sorbitol concentrations tended to increase in the IR group but the difference with non-ischemic controls did not achieve statistical significance (p=0.08). Retinal fructose concentrations were 2.2-fold greater in the IR group than in the non-ischemic controls (p<0.05). Fidarestat pre-treatment of rats subjected to IR reduced retinal sorbitol concentration to the levels in non-ischemic controls. Retinal fructose concentrations were reduced by 41% in fidarestat-pre-treated IR group vs. untreated ischemic controls (p=0.0517), but remained 30% higher than in the non-ischemic control group. In conclusion, IR injury to rat retina is associated with a dramatic increase in cell death, elevated AR expression and sorbitol pathway intermediate accumulation. These changes were prevented or alleviated by the AR inhibitor fidarestat. The results identify AR as an important therapeutic target for diseases involving IR injury, and provide the rationale for development of fidarestat and other AR inhibitors.

Vascular cellular adhesion molecule-1 (VCAM-1) expression in mice retinal vessels is affected by both hyperglycemia and hyperlipidemia

Background

Inflammation has been proposed to be important in the pathogenesis of diabetic retinopathy. An early feature of inflammation is the release of cytokines leading to increased expression of endothelial activation markers such as vascular cellular adhesion molecule-1 (VCAM-1). Here we investigated the impact of diabetes and dyslipidemia on VCAM-1 expression in mouse retinal vessels, as well as the potential role of tumor necrosis factor-α (TNFα).

Methodology/Principal Findings

Expression of VCAM-1 was examined by confocal immunofluorescence microscopy in vessels of wild type (wt), hyperlipidemic (ApoE^−/−) and TNFα deficient (TNFα^−/−, ApoE^−/−/TNFα^−/−) mice. Eight weeks of streptozotocin-induced diabetes resulted in increased VCAM-1 in wt mice, predominantly in small vessels (<10 µm). Diabetic wt mice had higher total retinal TNFα, IL-6 and IL-1β mRNA than controls; as well as higher soluble VCAM-1 (sVCAM-1) in plasma. Lack of TNFα increased higher basal VCAM-1 protein and sVCAM-1, but failed to up-regulate IL-6 and IL-1β mRNA and VCAM-1 protein in response to diabetes. Basal VCAM-1 expression was higher in ApoE^−/− than in wt mice and both VCAM-1 mRNA and protein levels were further increased by high fat diet. These changes correlated to plasma cholesterol, LDL- and HDL-cholesterol, but not to triglycerides levels. Diabetes, despite further increasing plasma cholesterol in ApoE^−/− mice, had no effects on VCAM-1 protein expression or on sVCAM-1. However, it increased ICAM-1 mRNA expression in retinal vessels, which correlated to plasma triglycerides.

Conclusions/Significance

Hyperglycemia triggers an inflammatory response in the retina of normolipidemic mice and up-regulation of VCAM-1 in retinal vessels. Hypercholesterolemia effectively promotes VCAM-1 expression without evident stimulation of inflammation. Diabetes-induced endothelial activation in ApoE^−/− mice seems driven by elevated plasma triglycerides but not by cholesterol. Results also suggest a complex role for TNFα in the regulation of VCAM-1 expression, being protective under basal conditions but pro-inflammatory in response to diabetes.

Inflammatory activity increases with haemoglobin A1c in patients with acute coronary syndrome

OBJECTIVE

To study the relationship between inflammation, diabetes and HbA(1)c levels in patients with acute coronary syndrome (ACS).

DESIGN

Single-centre cross-sectional study comprising 688 consecutive patients with ACS (108 with diabetes) and 341 with stable coronary artery disease (SCAD) (51 with diabetes). High-sensitive C-reactive protein (hsCRP), albumin and fibrinogen concentrations, erythrocyte sedimentation rates (ESR) and leukocyte counts were measured.

RESULTS

hsCRP, fibrinogen and ESR levels were higher and albumin lower in ACS patients. ESR was higher, albumin lower and hsCRP borderline significantly higher (p=0.053) in ACS patient with diabetes compared to those without. All inflammatory markers were associated with HbA(1)c in all 688 ACS patients as well as in 540 non-diabetic ACS patients with normal HbA(1)c. In multivariate analyses, all inflammatory markers were independently associated with HbA(1)c in the entire ACS group, regardless of diabetes being present or not. When non-diabetic ACS patients were analyzed separately, only ESR and leukocyte counts were independently correlated with HbA(1)c.

CONCLUSIONS

Patients with ACS had increased inflammatory activity, which increased with HbA(1)c levels in patients who neither had a history of diabetes nor HbA(1)c above normal, and was further exaggerated in the presence of diabetes.

Nuclear factor of activated T cells regulates osteopontin expression in arterial smooth muscle in response to diabetes-induced hyperglycemia

OBJECTIVE

Hyperglycemia is a recognized risk factor for cardiovascular disease in diabetes. Recently, we reported that high glucose activates the Ca(2+)/calcineurin-dependent transcription factor nuclear factor of activated T cells (NFAT) in arteries ex vivo. Here, we sought to determine whether hyperglycemia activates NFAT in vivo and whether this leads to vascular complications.

METHODS AND RESULTS

An intraperitoneal glucose-tolerance test in mice increased NFATc3 nuclear accumulation in vascular smooth muscle. Streptozotocin-induced diabetes resulted in increased NFATc3 transcriptional activity in arteries of NFAT-luciferase transgenic mice. Two NFAT-responsive sequences in the osteopontin (OPN) promoter were identified. This proinflammatory cytokine has been shown to exacerbate atherosclerosis and restenosis. Activation of NFAT resulted in increased OPN mRNA and protein in native arteries. Glucose-induced OPN expression was prevented by the ectonucleotidase apyrase, suggesting a mechanism involving the release of extracellular nucleotides. The calcineurin inhibitor cyclosporin A or the novel NFAT blocker A-285222 prevented glucose-induced OPN expression. Furthermore, diabetes resulted in higher OPN expression, which was significantly decreased by in vivo treatment with A-285222 for 4 weeks or prevented in arteries from NFATc3(-/-) mice.

CONCLUSIONS

These results identify a glucose-sensitive transcription pathway in vivo, revealing a novel molecular mechanism that may underlie vascular complications of diabetes.

Exposure to p,p'-DDE: a risk factor for type 2 diabetes

Background

Persistent organic pollutants (POPs), such as PCBs, DDT and dioxins have in several cross-sectional studies shown strong associations with type 2 diabetes mellitus. Reversed causality can however not be excluded. The aim of this case-control study was to evaluate whether POPs concentration is a risk factor for type 2 diabetes.

Methodology/Principal Findings

A case-control study was performed within a well-defined cohort of women, age 50–59 years, from the Southern part of Sweden. Biomarkers for POP exposure, 2,2′,4,4′,5,5′-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p′-DDE) were analyzed in stored serum samples, which were collected at the baseline examination when the cohort was established. For 107 out of the 371 cases, serum samples were stored at least three years before their type 2 diabetes was diagnosed. In this data set, CB-153 and p,p′-DDE were not associated with an increased risk to develop type 2 diabetes. However, when only the cases (n = 39) that were diagnosed more than six years after the baseline examination and their controls were studied, the women in the highest exposed quartile showed an increased risk to develop type 2 diabetes (OR of 1.6 [95% 0.61, 4.0] for CB-153 and 5.5 [95% CI 1.2, 25] for p,p′-DDE).

Conclusions/Significance

The results from the present case-control study, including a follow-up design, confirms that p,p′-DDE exposure can be a risk factor for type 2 diabetes.

Tumor necrosis factor-alpha does not mediate diabetes-induced vascular inflammation in mice

OBJECTIVE

Vascular inflammation is a key feature of both micro- and macrovascular complications in diabetes. Several lines of evidence have implicated the cytokine tumor necrosis factor (TNF) alpha as an important mediator of inflammation in diabetes. In the present study we evaluated the role of TNF alpha in streptozotocin (STZ)-induced diabetes on vascular inflammation in C57BL/6 wild-type and apoE-/- mice.

METHODS AND RESULTS

Diabetes increased the expression of vascular cell adhesion molecule (VCAM)-1 in cerebral arteries 150 m in diameter as well as the macrophage accumulation in aortic root atherosclerotic plaques in apoE-/- mice. A more pronounced vascular inflammatory response was observed in diabetic TNF alpha-deficient apoE-/- mice. These mice were also characterized by increased accumulation of IgG and IgM autoantibodies in atherosclerotic lesions. Diabetes also increased VCAM-1 expression and plaque formation in apoE-competent TNF alpha -/- mice, whereas no such effects were observed in C57BL/6 wild-type mice.

CONCLUSIONS

The present findings suggest that TNF alpha does not mediate diabetic-induced vascular inflammation in mice and reveal an unexpected protective role for TNF alpha. These effects are partly attributable to a direct antiinflammatory role of TNF alpha, but may also reflect a defective development of the immune system in these mice.

The aldose reductase inhibitor fidarestat suppresses ischemia-reperfusion-induced inflammatory response in rat retina

Recent studies suggest that increased aldose reductase (AR) activity plays an important role in ischemia-reperfusion injury in the retina. The mechanisms are not completely understood, but may be linked to inflammation. In the present study, we investigated whether the AR inhibitor fidarestat suppressed the retinal inflammatory response induced by ischemia-reperfusion in a rat model. The inflammatory response was manifested by increased gene expression of tumor necrosis factor-alpha and intercellular adhesion molecule-1 (ICAM-1) as well as elevated protein levels of soluble ICAM-1. This response was partially suppressed by the AR inhibitor fidarestat. The findings may reveal beneficial effects of AR inhibition on retinal inflammation associated with ischemia-reperfusion and are in agreement with recent developments in pharmacological research suggesting that pathological conditions other than diabetes may benefit from AR inhibitors.

Increased retinopathy occurrence in type 1 diabetes patients with increased serum levels of the advanced glycation endproduct hydroimidazolone

PURPOSE

We aimed to investigate associations between serum levels of the advanced glycation endproduct methylglyoxal-derived hydroimidazolone (MG-H1) and retinopathy in a sample of patients with type 1 diabetes.

METHODS

We conducted a cross-sectional study in a Scandinavian ophthalmology outpatient clinic on 61 randomly selected patients with type 1 diabetes. Blood samples and retinal photographs were taken at the same visit. Serum levels of hydroimidazolone immunoreactivity were determined using an immunoassay, and levels of retinopathy were determined from seven standard field stereo photographs of each eye according to the ETDRS method. Results were compared between patients with and without retinopathy.

RESULTS

Hydroimidazolone quartiles were significantly associated with retinopathy (p = 0.013). The most profound increase in occurrence of retinopathy was observed from the lowest to the second-lowest hydroimidazolone quartile. Adjusted for duration of diabetes using logistic regression, a significant difference in the presence of retinopathy was found when comparing the lowest quartile with the rest (p = 0.022).

CONCLUSIONS

In our patients with type 1 diabetes, serum levels of hydroimidazolone were found to be associated with retinopathy. This is in keeping with findings in a larger sample of patients with type 2 diabetes.

Coeliac disease-specific tissue transglutaminase autoantibodies are associated with osteoporosis and related fractures in middle-aged women

OBJECTIVE

To investigate whether the serological marker for coeliac disease, tissue transglutaminase autoantibody (tTGAb), is associated with decreased bone mass density (BMD) and increased frequency of fractures in middle-aged women screened for osteoporosis.

MATERIAL AND METHODS

The study comprised 6480 women (mean age 56 years, range 50-64) who answered a number of questionnaires and who underwent dual X-ray absorptiometry of the wrist bone. Serum samples were analysed for tTGAb using radioligand binding assays. A tTGAb level of >4 U/ml was used to determine a positive value and a level of >17 U/ml was used as an alternative discrimination of high levels.

RESULTS

A tTGAb level >4 U/ml was found among 90/6480 (1.4%) women and correlated with lower BMD (multiple linear regression coefficient -382.1; 95% CI = - 673.6-90.7, p=0.011) and with fracture frequency (r=0.18, p=0.023). The 59 women with tTGAb levels >or=17 U/ml had a lower BMD (0.41+/-0.08 g/cm(2) versus 0.44+/-0.08 g/cm(2), p=0.001) and a lower T-score (-1.40+/-1.28 versus -0.90+/-1.40, p=0.003) as well as a higher prevalence of osteoporosis (13.4% versus 6.5%, p=0.008) compared with the remaining 6421 women with tTGAb levels <17 U/ml. Furthermore, fracture frequency was more pronounced in women with tTGAb levels >or=17 U/ml, among whom 19/59 (32.2%) had fractures during the study period compared with 1204/6421 (18.8%) among women with tTGAb levels <17 U/ml (p=0.009).

CONCLUSIONS

High levels of tTGAb indicating coeliac disease are associated with lower BMD and higher fracture frequency in women between 50 and 64 years of age. Osteometry is therefore warranted in middle-aged women detected with tTGAb.

Effect of dietary fibre on blood glucose, plasma immunoreactive insulin, C-peptide and GIP responses in non insulin dependent (type 2) diabetics and controls

A high fibre and a low fibre breakfast meal were given to eight non insulin dependent diabetics ( NIDD ), and eight controls. Blood glucose response was monitored continuously for three hours and characterized using a straight line model. After the high fibre meal the rates of increase and decrease in blood glucose concentration were slower both in diabetics and controls than after the low fibre meal. The delay time, however, i.e. the time from meal intake to the start of glucose increase, hypothetically corresponding to gastric emptying time, was the same after both test meals. The postprandial glucose increment calculated as the area under the 0-120 min curve was lower after the high fibre meal in the NIDD , but not in the controls. The two-hour C-peptide and gastric inhibitory polypeptide values were lower for the diabetics after the high fibre breakfast. The results indicate a prolonged carbohydrate digestion and/or absorption after high fibre breakfast.

Improvement of peripheral nerve function after institution of insulin treatment in diabetes mellitus. A case-control study

The influence of improved diabetic control on peripheral nerve function was studied before and 3-4 months after institution of insulin treatment in 22 diabetics unsatisfactorily controlled by oral hypoglycemic agents. After institution of insulin treatment, diabetic control was improved as demonstrated by decreasing levels of HbA1. There was an overall tendency towards improvement of motor and sensory conduction velocities, however significant only in the upper extremities. There was a tendency towards improved temperature sensitivity in the legs, while no changes occurred in the hands and face. The sensation for vibration did not change. It is concluded that improved diabetic control, even in elderly patients with long-standing diabetes, is followed by neurophysiological signs of improved peripheral nerve function.

Autonomic and peripheral nerve function in early diabetic neuropathy. Possible influence of a novel aldose reductase inhibitor on autonomic function

Autonomic and peripheral nerve functions as well as the possible short-term effect of a novel aldose reductase inhibitor (ARI) on neuropathy were evaluated in 30 male type I diabetics (age 25-44 years, mean 34; duration of diabetes 10-20 years, mean 34) with neurographic signs of peripheral neuropathy (PN). Autonomic neuropathy (AN) was established by the heart rate reactions to deep breathing (E/I ratio = vagal function) and to tilt (acceleration index = sympathetic and vagal functions; the brake index = vagal function). Twenty-nine patients, 13 with AN, completed the study. Among neurographic variables, only sural nerve function tests correlated with autonomic functions. Patients with AN showed significantly lower mean sensory action potential amplitudes (SAPA) sural, indicating axonal losses, than patients without AN (3.58 +/- 0.79 microV v. 7.34 +/- 1.12 microV; p less than 0.01). PN as measured by neurography did not improve during ARI treatment. On the other hand, vagal function (brake indices) improved (p less than 0.05) during ARI in AN patients.

Plasma high density lipoproteins and lipolytic enzyme activities in diabetic patients

Eighty diabetic patients, consecutively selected from an out-patient clinic, were studied with regard to plasma lipoprotein levels, especially HDL. Patients treated with sulphonylureas had 24% lower HDL cholesterol concentrations (p less than 0.01) but only about 7% lower apo AI levels (n.s.) than those on insulin treatment. This difference could at least partly be explained by differences in age and type of diabetes. There was no relationship between the degree of diabetic control, as measured by fasting blood glucose levels, and HDL levels. In two subgroups of insulin-treated diabetics, selected to represent extremely low and high HDL levels (range 0.5-0.8 and 1.8-2.0 mmol/l, respectively) but matched with regard to age, duration of diabetes, insulin dosage and diabetic control, the activities of lipoprotein lipase and hepatic lipase in postheparin plasma were also recorded. The high HDL group had significantly higher lipoprotein lipase activities (p less than 0.01) and significantly lower hepatic lipase activities (p less than 0.05) than the low HDL group, supporting the hypothetical roles of these enzymes in HDL metabolism, and offering a tentative mechanism behind the large variability of HDL levels in diabetics.

Plasma lipids and plasma lipoproteins in diabetics with and without proliferative retinopathy

The single most important factor related to the development of diabetic retinopathy is the duration of diabetes. Little is known about the underlying mechanisms, but many factors have been suggested to be involved, among them derangements in plasma lipids and plasma lipoproteins. In the present study we examined the relation between plasma lipids, plasma lipoproteins, and the duration of diabetes in Type I diabetics with and without proliferative retinopathy. The duration of diabetes in the two groups was 12.2 +/- 2.8 and 21.5 +/- 9.0 years, respectively (mean +/- SD; p less than 0.01). Except for moderately low HDL levels, plasma lipid and lipoprotein concentrations were normal in both groups of patients. The levels of lipids and lipoproteins did not correlate with the duration of diabetes. Furthermore, no differences were seen between patients with and without proliferative retinopathy. Thus, the present study does not indicate that plasma lipids and plasma lipoproteins play any major role in the development of diabetic proliferative retinopathy.

Serum beta-hexosaminidase in diabetes mellitus with reference to the type of treatment

A significantly increased serum level of beta-hexosaminidase was found in an unselected group of 85 diabetics. When the patients were divided into three groups according to type of treatment, increased enzyme levels were found only in patients treated with oral hypoglycemic agents or diet while insulin-treated patients had normal serum levels of beta-hexosaminidase. There was a positive correlation between beta-hexosaminidase and blood glucose concentration for the entire patient series. When grouped according to treatment, a positive correlation was found only in the insulin-treated group despite its normal serum activity of beta-hexosaminidase. Serum beta-hexosaminidase of patients with retinopathy did not differ from the mean value of their group. It is concluded that the activity of beta-hexosaminidase in diabetics can produce different results depending on the type of patients under study.

Dietary fibre in type II diabetes

Recent studies have indicated that diets rich in digestible carbohydrates and dietary fibre might be beneficial in the regulation of type II non insulin dependent diabetes (NIDD). Addition of the gel forming type of dietary fibre such as pectin and guar gum to meals or glucose solutions reduces post-prandial glucose and insulin response. Addition of cereal fibres in the form of bran seems to have long term beneficial effect improving glucose tolerance. Little is known, however, concerning effects of dietary fibre naturally occurring in food on postprandial glucose and hormone response. In the present study we prepared two breakfast meals which were similar regarding digestible carbohydrates but differed in their dietary fibre content. One of the meals, including whole grain bread and whole apples, contained 8.4 g of dietary fibre, and the other one, containing white bread and apple juice, 3.1 g. When given to eight NIDD, the fibre rich breakfast gave significantly lower blood glucose increment during the three hours following ingestion. The results indicate that foods rich in dietary fibre might be useful in the regulation of type II diabetes.

TNF-alpha is an independent serum marker for proliferative retinopathy in type 1 diabetic patients

PURPOSE

This study aimed to determine if there are any associations between serum levels of inflammatory markers and proliferative retinopathy (PDR) in type 1 diabetic patients.

DESIGN

A cross-sectional design was utilized for this study.

METHODS

One hundred twenty-eight type 1 diabetic patients underwent stereo fundus photography according to the Early Treatment Diabetic Retinopathy Study and were divided into two retinopathy groups: no or nonproliferative retinopathy (NDR/NPDR; n=62) and PDR (n=66). Serum levels of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 beta, IL-6, soluble vascular cellular adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), P-selectin, and high-sensitivity C-reactive protein (hsCRP) were analyzed. Statistical analysis was performed using nonparametric Mann-Whitney U test and multivariate logistic regression analysis.

RESULTS

Patients with PDR had higher levels of TNF-alpha [7.0 pg/ml (<4-17) vs. 6.0 pg/ml (<4-25); P=.009], sVCAM-1 [860 ng/ml (360-2120) vs. 700 ng/ml (310-1820); P<.001], and P-selectin [180 ng/ml (39-400) vs. 150 ng/ml (42-440); P=.017; figures are expressed as median (range)]. There were no differences in serum levels of sICAM-1 or hsCRP. IL-1 beta was not detectable in any patient, and IL-6 was detectable in only 22.7% of the patients. In multivariate logistic regression analysis, TNF-alpha was the single, persistent, independent determinant inflammatory marker for PDR.

CONCLUSION

The association between TNF-alpha and PDR in type 1 diabetic patients suggests that inflammation might play a role in the pathogenesis of proliferative diabetic retinopathy.

Blood pressure in middle-aged women: are androgens involved? A population-based study of Swedish women: the Women's Health in the Lund Area study

OBJECTIVE

To assess the prevalence of hypertension and use of antihypertensive drug therapy in relation to menopausal status and to delineate perceived associations between androgens and blood pressure in perimenopausal women.

METHODS

A population-based sample of women aged 50-59 (n = 6893). Women were divided into three groups according to their hormonal status: premenopausal, postmenopausal without hormone therapy, and postmenopausal with hormone therapy.

RESULT

In the premenopausal, postmenopausal without hormone therapy, and postmenopausal with hormone therapy groups, the prevalence of high blood pressure (>/= 140 mmHg systolic or >/= 90 mmHg diastolic) was 43.9, 49.9 and 45.8%, respectively. In women with normal blood pressure, adjusting for age, body mass index and smoking, there were negative associations between serum testosterone and systolic blood pressure in the total sample (P < 0.01) and the postmenopausal without hormone therapy group (P < 0.05). In women using antihypertensive drug therapy with a blood pressure of at least 140/90 mmHg, positive associations were found between serum testosterone and systolic blood pressure in the total series (P < 0.05) and in the postmenopausal without hormone therapy group (P < 0.05).

CONCLUSION

Abnormal blood pressure is common in middle-aged women regardless of hormonal status. Our findings suggest that testosterone could have a dual influence on blood pressure in perimenopausal women.

Insulin resistance and self-rated symptoms of depression in Swedish women with risk factors for diabetes: the Women's Health in the Lund Area study

Previous studies have suggested that depression increases the risk for diabetes and that this may be mediated through insulin resistance. The study aimed to analyze if self-rated symptoms of depression are related to insulin resistance among middle-aged and older Swedish women with features of the metabolic syndrome and being at risk for type 2 diabetes mellitus. We analyzed data from 1047 Swedish women aged 50 to 64 years without a history of diabetes and living in the southern part of Sweden. A variable self-rated symptoms of depression (SRSD) was defined by using the Gothenburg Quality of Life instrument. We estimated odds ratios (ORs) to determine whether or not SRSD was associated with the homeostasis model assessment of insulin resistance. The variable SRSD was not associated with insulin resistance. However, it was positively associated with waist-hip ratio (OR, 1.95; 95% confidence interval, 1.28-3.00) and negatively associated with physical exercise (OR, 1.29; 95% confidence interval, 0.99-1.68) after multivariate adjustment. In conclusion, lifestyle factors such as physical inactivity and abdominal obesity, but not insulin resistance, seem to be related to self-rated symptoms of depression in women with risk factors for diabetes mellitus. The relationship between insulin resistance and major depression needs to be further examined.

Circulating antipericyte autoantibodies: a novel modifier of risk of progression of diabetic retinopathy?

BACKGROUND

Antipericyte autoantibodies (APAAs) are present in high frequency among diabetic subjects with and without nonproliferative retinopathy. This study aimed to determine whether progression of retinopathy in type 2 diabetes was associated with the same medical risk factors in APAA-positive subjects as in APAA-negative subjects.

METHODS

Type 2 diabetic patients with nonproliferative diabetic retinopathy at baseline were followed prospectively for 2 years monitoring progression of retinopathy. Thirty-eight (21.7%) of 175 patients had progression in Early Treatment Diabetic Retinopathy Study grade by > or =2 steps in at least 1 eye. Serum APAAs were detected by immunofluorescence on tissue-cultured bovine retinal pericytes.

RESULTS

Progression of retinopathy was associated with HbA(1c) level (P = 0.002), diabetes duration (P = 0.03), and albumin/creatinine ratio (P = 0.02) in APAA-negative subjects but not in APAA-positive subjects. The association between progression and APAAs was strongest in the upper quartile for HbA(1c) level (>8.0%), where 71.4% of patients negative for APAAs had progression of retinopathy while only 24.1% of patients positive for APAAs had progression (P = 0.007).

CONCLUSION

The results suggest that APAA presence is a modifier of risk of progression of retinopathy due to hyperglycemia and that it could be useful as a biochemical marker of risk of progression of diabetic retinopathy in type 2 diabetic patients with poor metabolic control.

Health Hazards in Middle-Aged Women with Cardiovascular Disease: A Case-Control Study of Swedish Women. The Women's Health in the Lund Area (WHILA) Study

OBJECTIVE

To delineate the health profile in middle-aged women with cardiovascular disease (CVD).

METHODS

The Women's Health in the Lund Area (WHILA) project covered all women born 1935-1945 (n = 10,766) living in the Lund area; 6917 (64.2%) women completed a generic questionnaire and underwent physical and laboratory assessments. Of the 6917 women, 6416 were postmenopausal women, of whom 104 had CVD. For each woman with CVD, two controls were selected and matched for age, smoking habits, body mass index (BMI), waist/hip ratio (WHR), low-density lipoprotein cholesterol (LDL-C), high-density liproprotein cholesterol (HDL-C), diastolic blood pressure and hormonal status.

RESULTS

One hundred four women (1.6%) reported CVD. Forty-nine had a myocardial infarction (MI), 49 had a stroke, and 6 women had both events; 71.4% were postmenopausal, with never use of hormone therapy (HT) (PM0), and 28.6% were postmenopausal with ever use of HT (PMT). Compared with the control group, serum androstendione was lower (p = 0.004) in the case group, and menopausal estradiol (E(2)) values were less frequent (p = 0.037) in cases from the PM0 group. Among psychological and somatic symptoms, nervousness (p < 0.05), difficulty relaxing, crying easily, visual disturbance (p </= 0.01 for all), dizziness, difficulties in voiding urine, shortness of breath, breast tenderness, and constipation (p </= 0.001 for all) were more common among women with CVD. Women with CVD expressed less satisfaction with feeling healthy, body image, memory loss, irritability, and sexuality (p </= 0.05 for all). The case group had more problems with daily activities, more days spent in hospital during the previous 5 years, and more regular medical appointments with healthcare centers, more often had diabetes mellitus (DM) (p < 0.001 for all), and had experienced more falls in the previous year (p < 0.05). Urinary incontinence and decreased body weight were more common among cases (p </= 0.01 for both).

CONCLUSION

Several health hazards as well as somatic and psychological symptoms were more common in subjects with CVD, rendering them more susceptible to future disease.

Do sex hormones influence features of the metabolic syndrome in middle-aged women? A population-based study of Swedish women: the Women's Health in the Lund Area (WHILA) Study

OBJECTIVE

To outline perceived associations between various sex hormones and risk markers for cardiovascular disease in middle-aged women, with an emphasis on features of the metabolic syndrome (MS).

DESIGN

Cross-sectional analysis.

SETTING

Women's Health in the Lund Area Study.

PATIENT(S)

Population-based cohort.

INTERVENTION(S)

A generic questionnaire, physical examinations, and laboratory assessments were completed by 6,917 women aged 50-59 years living in the Lund area of southern Sweden. Women at or above defined cutoff limits for the MS were considered positively screened. After exclusion of women using hormone therapy (HT), 2,038 women with (MS+) and 2,054 women without features of the MS (MS-) were included. The ELISA techniques were used for the determination of serum androstendione (A), E2, T, sex hormone-binding globulin (SHBG), cortisol, insulin, and leptin levels. Serum lipids and lipoproteins were determined by conventional methods. Multiple linear regression analyses were performed, controlling for age, body mass index (BMI), and smoking habits.

MAIN OUTCOME MEASURE(S)

Features of the MS, sex steroids, cardiovascular risk markers.

RESULT(S)

In the MS+ group, a positive association was seen between A and systolic blood pressure. Estradiol was negatively associated with total cholesterol and diastolic blood pressure. The SHBG was negatively associated with triglycerides, blood glucose, and diastolic blood pressure and positively with high-density lipoprotein (HDL). In the MS- group, there were positive associations between A, blood glucose, and systolic blood pressure. Testosterone was positively associated with HDL. Estradiol was negatively associated with total cholesterol and positively with systolic blood pressure. The SHBG was positively associated with HDL and negatively with triglycerides and diastolic blood pressure. There were positive associations between cortisol, low-density lipoprotein (LDL) cholesterol, blood glucose, and systolic blood pressure and a negative association with triglycerides in both MS+ and MS- groups.

CONCLUSION(S)

Androstendione, E2, and T levels were associated with cardiovascular risk factors in middle-aged women. Effects by sex steroids on cardiovascular risk markers seem to be different in women with or without features of the MS.

Polymorphism in the MHC2TA gene is associated with features of the metabolic syndrome and cardiovascular mortality

BACKGROUND

Recently, a -168A-->G polymorphism in the MHC class II transactivator gene (MHC2TA) was shown to be associated with increased susceptibility to myocardial infarction (MI).

AIM

To confirm the association between the MHC2TA -168A-->G polymorphism and MI and to study its putative role for microalbuminuria, the metabolic syndrome (MetS) and cardiovascular mortality.

MATERIALS AND METHODS

Using an allelic discrimination method we genotyped 11,064 individuals from three study populations: 1) 4,432 individuals from the Botnia type 2 diabetes (T2D) study, 2) 1,222 patients with MI and 2,345 control subjects participating in the Malmö Diet and Cancer study and comprising an MI case-control sample, and 3) 3,065 T2D patients from the Local Swedish Diabetes registry.

RESULTS

No association between the -168A-->G polymorphism in MHC2TA and MI was observed. However, in the Botnia cohort the AG/GG genotypes were associated with cardiovascular mortality after MI (1.78 [1.09-2.92], p = 0.02). In addition, the AG/GG genotypes were more common in subjects with MetS (40.1% vs. 36.9%, p = 0.03) and in non-diabetic subjects with microalbuminuria (45.4% vs. 36.5%, p = 0.003) compared to control subjects.

CONCLUSIONS

A polymorphism in MHC2TA was associated with cardiovascular mortality and predictors of cardiovascular mortality, microalbuminuria and MetS.

Obese women and the relation between cardiovascular risk profile and hormone therapy, glucose tolerance, and psychosocial conditions

OBJECTIVE

To evaluate the relation between cardiovascular disease (CVD) risk factors and hormone therapy, serum hormone levels, glucose tolerance, and psychosocial and psychological conditions in subjectively healthy obese female subjects.

RESEARCH DESIGN AND METHODS

The study included 606 women, aged 50-64 years, with BMI 30-40 kg/m(2) and no history of cardiovascular or other severe diseases. One group with a CVD risk profile (n = 473) (i.e., cholesterol >7.0 mmol/l, HDL cholesterol <1.2 mmol/l, triglycerides >2.0 mmol/l, systolic or diastolic blood pressure >140/90 mmHg, or waist-to-hip ratio >0.85) was compared with women without such risk (n = 133). Steroid hormones, leptin, insulin, and oral glucose tolerance tests (OGTTs) were analyzed. A subgroup of women with baseline impaired glucose tolerance (IGT) completed a 2.5-year follow-up OGTT.

RESULTS

Fewer obese postmenopausal women with CVD risk had ever used hormone therapy (odds ratio 0.24 [95% CI 0.07-0.75]), after multivariate adjustments. Furthermore, women with CVD risk had a higher testosterone index (1.07 [1.01-1.13]) and more had insulin resistance (1.04 [1.00-1.08]) and IGT (2.92 [1.50-5.69]), while OGTT was similar at follow-up. No differences were observed regarding family history or lifestyle, except that fewer women with CVD risk consumed fruits, boiled vegetables, or whole-grain cereals. More women with CVD risk lived alone (3.26 [1.28-8.31]) and had more mental problems (1.16 [1.05-1.28]).

CONCLUSIONS

Previously healthy obese women with a CVD risk profile seemed to have a high risk of diabetes, as well as psychosocial or psychological problems. Hormone therapy was associated with reduced CVD risk. Obesity's growing burden on society makes it more important to further target individuals that are at greatest risk of future health hazards.

Colorectal cancer in middle-aged women in relation to hormonal status: a report from the Women's Health in the Lund Area (WHILA) study

OBJECTIVE

To delineate a perceived association of estradiol versus estradiol plus norethisterone hormone therapy on the prevalence of colorectal cancer in postmenopausal women.

METHODS

The Women's Health in the Lund Area (WHILA) project covers 10,766 women aged 50-60 years, living in the Lund area, Sweden. Out of this population, 6908 (64%) women completed questionnaires, underwent physical and laboratory assessments and had self-reported information regarding colorectal cancer. Four hundred and twenty-two (6%) were premenopausal (PM), 3600 (52%) were postmenopausal without hormone therapy (PM0), 2452 (36%) were postmenopausal with combined hormone therapy (PMT-HT) and 364 (5%) were postmenopausal with estrogen monotherapy (PMT-E).

RESULTS

There were 21 cases of colorectal cancer (0.3%), one in the PM group, 16 in the PM0 group, two in the PMT-HT group and another two in the PMT-E group. Colorectal cancer prevalence was lower in the PMT-HT than in the PM0 group (odds ratio (OR) = 0.18, 95% confidence interval (CI) = 0.04-0.80). However, for the PMT-E group, the OR (95% CI) was 1.02 (0.86-1.20). There was a positive association between low physical activity (p = 0.04), low parity (p = 0.02) and risk of colorectal cancer.

CONCLUSION

Combined hormone therapy seemed to be associated with a lower risk of colorectal cancer in postmenopausal women in contrast to estrogen monotherapy. Hence the progestin might have a protective role.

Expression of antioxidant enzymes in rat retinal ischemia followed by reperfusion

To evaluate the expression and protein levels of antioxidant enzymes in the rat retina exposed to oxidative stress induced by ischemia-reperfusion injury. Retinal ischemia was induced in female Wistar rats by ligation of the optic nerve and vessels behind the left eye bulb, and was followed by reperfusion for 0, 3, 6, or 24 hours. The right eye served as control. RNA and protein were extracted simultaneously from each retina. Expressions of the endogenous antioxidant enzymes glutathione peroxidase (GPx1), catalase (CAT), copper/zinc superoxide dismutase, manganese superoxide dismutase, and the catalytic subunit of glutamylcysteine ligase (GCLc) were analyzed with real-time reverse transcription polymerase chain reaction and related to the endogenous control cyclophilin B. Protein levels were measured with Western blot analysis. During the early phase (0 or 3 hours) of reperfusion, no changes were seen in enzyme expression. After 6 hours, GCLc expression increased by a factor of 1.14 (P = .034), followed by a decline of 0.80 after 24 hours (P = .00004), according to the comparative Ct method. After 24 hours of reperfusion, GPx1 expression increased by a factor of 1.14 (P = .028), and CAT had decreased by 0.82 (P = .022). Expressions of copper/zinc superoxide dismutase and manganese superoxide dismutase showed a tendency toward a decrease by factors of 0.86 (P = .055) and 0.88 (P = .053), respectively, after 24 hours. Protein levels did not differ for any of the antioxidants, regardless of reperfusion time. The slightly increased messenger RNA expression of GPx1 after 24 hours of reperfusion with a concomitant very modest decrease in CAT and GCLc expression and no change in protein levels indicate a very modest, if any, response to oxidative stress generated by ischemia followed by reperfusion in rat retina.

Increased serum levels of the specific advanced glycation end product methylglyoxal-derived hydroimidazolone are associated with retinopathy in patients with type 2 diabetes mellitus

Advanced glycation end products (AGEs) are thought to play a major pathogenic role in diabetic retinopathy. The most important AGE is unknown, but as increased serum methylglyoxal-derived hydroimidazolone has been demonstrated in patients with type 2 diabetes mellitus, the aim of the present study was to elucidate possible associations between serum levels of hydroimidazolone and retinopathy in patients with type 2 diabetes mellitus. We recruited 227 patients with type 2 diabetes mellitus and retinopathy ranging from none to proliferative. Level of retinopathy was determined from 7 standard field stereo photographs per eye according to the Early Treatment Diabetic Retinopathy Study. The patients were 66 +/- 11 years old, with a known diabetes duration of 14 +/- 9 years. Serum levels of hydroimidazolone were determined with a competitive immunoassay. Serum levels of hydroimidazolone were increased in nonproliferative (median, 4.50 U/mL; interquartile range, 3.69-5.77 U/mL) and proliferative retinopathy (median, 4.88 U/mL; interquartile range, 3.70-6.52 U/mL) compared with patients without retinopathy (median, 4.02 U/mL; interquartile range, 3.47-4.88 U/mL) (P = .008 and .002, respectively). There was no association between hydroimidazolone and hemoglobin A1c (r = 0.04, P = .57). In addition, patients with proliferative retinopathy and a relatively short known duration of diabetes, that is, less than the median of 14 years, had increased serum levels of hydroimidazolone (median, 6.91 U/mL; interquartile range, 4.70-8.91 U/mL) compared with those with nonproliferative retinopathy (median, 4.34; interquartile range, 3.86-5.53U/mL, P = .015). Serum levels of hydroimidazolone are increased in type 2 diabetic patients with retinopathy. This association is independent of hitherto known associated factors, such as hemoglobin A1c.

Modifying a standard method allows simultaneous extraction of RNA and protein, enabling detection of enzymes in the rat retina with low expressions and protein levels

The aim of the study was to evaluate messenger RNA and protein expression in limited amounts of tissue with low protein content. The Chomczynski method was used for simultaneous extraction of RNA, and protein was modified in the protein isolation step. Template mass and cycling time for the complementary DNA synthesis step of real-time reverse transcription-polymerase chain reaction (RT-PCR) for analysis of catalase, copper/zinc superoxide dismutase, manganese superoxide dismutase, the catalytic subunit of glutamylcysteine ligase, glutathione peroxidase 1, and the endogenous control cyclophilin B (CypB) were optimized before PCR. Polymerase chain reaction accuracy and efficacy were demonstrated by calculating the regression (R2) values of the separate amplification curves. Appropriate antibodies, blocking buffers, and running conditions were established for Western blot, and protein detection and multiplex assays with CypB were performed for each target. During the extraction procedure, the protein phase was dissolved in a modified washing buffer containing 0.1% sodium dodecyl sulfate, followed by ultrafiltration. Enzyme expression on real-time RT-PCR was accomplished with high reliability and reproducibility (R2, 0.990-0.999), and all enzymes except for glutathione peroxidase 1 were detectable in individual retinas on Western blot. Western blot multiplexing with CypB was possible for all targets. In conclusion, connecting gene expression directly to protein levels in the individual rat retina was possible by simultaneous extraction of RNA and protein. Real-time RT-PCR and Western blot allowed accurate detection of retinal protein expressions and levels.

Bovine retinal pericytes are resistant to glucose-induced oxidative stress in vitro

Diabetic retinopathy is a sight-threatening complication of diabetes, and loss of pericytes represents early signs of its development. We tested the hypothesis that high glucose levels may induce signs of oxidative stress in cultured bovine retinal pericytes. Pericytes were exposed to either normal (5.5 mM) or high (22 mM) glucose levels for 1, 3, and 5 days. Signs of oxidative stress were measured by expression of copper/zinc superoxide dismutase, manganese superoxide dismutase, catalase, and glutathione peroxidase using real-time RTPCR. To elucidate the role of oxidative stress, we also measured glutathione (GSH) concentration in the cells and investigated the impact of thiol-reactive metal ions and hydrogen peroxide (H(2)O(2)) on intracellular GSH. Despite the stimulation with high glucose, thiol-reactive metal ions, or H(2)O(2), there was no clear increased expression of antioxidant enzymes or influence of GSH levels. Lipid peroxidation (malondialdehyde level) was increased in bovine aortic smooth muscle cells, but not in bovine retinal pericytes. The data indicate that pericytes do not develop oxidative stress in response to hyperglycemia. However, it is not definitively excluded that oxidative stress may occur after longer time periods of glucose stimulation.

Women living alone have an increased risk to develop diabetes, which is explained mainly by lifestyle factors

OBJECTIVE

The purpose of this study was to assess the role of household conditions for the progression to diabetes in women with impaired glucose tolerance (IGT).

RESEARCH DESIGN AND METHODS

A total of 461 women, aged 50-64 years, with IGT defined by an oral glucose tolerance test, had baseline advice on physical exercise, diet, smoking, and alcohol habits. Physical examination, blood tests, and questionnaires were completed at baseline and after 2.5 years. Household status was categorized into living alone or with a partner, other adults, or children.

RESULTS

Women living alone had a 2.68-fold increased risk (95% CI 1.02-7.05) of developing diabetes after adjustments for biological risk factors. Further stepwise adjustments for education, occupation, subjective mental health, exercise, diet, and alcohol showed remaining significant odds ratios (ORs), decreasing from 3.26 (1.19-8.96) to 3.03 (1.02-8.99). However, when smoking status was added, the OR became nonsignificant, 2.07 (0.62-6.88). More women who lived alone smoked and did not reduce their daily cigarette consumption compared with women in other household conditions. At follow-up, women living alone had reduced their alcohol consumption and were more often abstainers and fewer had healthy dietary habits or had improved their diet. Physical exercise did not differ among the groups. Separate analyses of any other household status did not show any excess risk for development of diabetes.

CONCLUSIONS

Women living alone had a higher risk to progress from IGT to diabetes, mostly explained by smoking, alcohol, and dietary habits. Household conditions should be accounted for when assessing future risk for diabetes.

Immunomodulation with human recombinant autoantigens

The loss of beta cells in type 1 diabetes is the consequence of a T cell-dependent autoimmune attack. Autoantibodies against GAD65 (Mr 65.000 isoform of glutamic acid decarboxylase), IA-2 (insulinoma-associated protein IA-2) or insulin, alone or in combination, predict disease. Preclinical studies in spontaneously diabetic rodents suggest that immunomodulation with autoantigens might alter the course of autoimmune diabetes. Oral insulin reduces the development of diabetes in risk subjects with high insulin autoantibody levels. Giving alum-formulated GAD65 to patients classified with latent autoimmune diabetes of the adult (LADA) is safe and suggests possible immunomodulating effects of GAD65. Future immunomodulation trials might better ascertain subjects based on HLA genetic risk factors, the level of insulin that is still produced or by combining autoantigens with, for example, anti-CD3 antibodies, to induce antigen-specific tolerance and thereby a long-lasting protection for beta cells.

Clinical evidence for the safety of GAD65 immunomodulation in adult-onset autoimmune diabetes

The purpose of this Phase II study was to evaluate if alum-formulated human recombinant GAD65 is safe and does not compromise beta cell function. The study was conducted as a randomized, double blind, placebo-controlled, dose-escalation clinical trial in a total of 47 Latent Autoimmune Diabetes in Adults (LADA) patients who received either placebo or 4, 20, 100, or 500 microg Diamyd subcutaneously at Weeks 1 and 4. Safety evaluations, including neurology, beta cell function tests, diabetes status assessment, hematology, biochemistry, and cellular and humoral immunological markers, were repeatedly assessed over 24 weeks. None of the patients had significant study-related adverse events (AE). Fasting c-peptide levels at 24 weeks were increased compared with placebo (P=.0015) in the 20 microg but not in the other dose groups. In addition, both fasting (P=.0081) and stimulated (P=.0236) c-peptide levels increased from baseline to 24 weeks in the 20 microg dose group. GADA log levels clearly increased (P=.0002) in response to 500 microg Diamyd. The (CD4+)(CD25+)/(CD4+)(CD25-) cell ratio increased (P=.0128) at 24 weeks in the 20 microg group. No sudden increase in HbA1c or plasma glucose or decrease in beta cell function was observed in any of the dose groups. These positive findings for clinical safety further support the clinical development of Diamyd as a therapeutic to prevent autoimmune diabetes.

Markers of inflammation in patients with coronary artery disease are also associated with glycosylated haemoglobin A1c within the normal range

AIMS

Diabetes is a risk factor for atherosclerosis and low-degree inflammation may play a central role in both diseases. Glycosylated haemoglobin A(1c) (HbA(1c)) is an established measure of long-term glycaemic control but data on its correlation with markers of inflammation are limited, especially in patients with atherosclerotic manifestations. The aim of the present study was thus to investigate the associations between HbA(1c) and a panel of inflammation-sensitive parameters in patients with and without diabetes.

METHODS AND RESULTS

This single centre cross-sectional study comprised 314 consecutive subjects who underwent coronary angioplasty for stable coronary artery disease. Sixty-six patients had diabetes mellitus. Haemoglobin A(1c) and markers of inflammation, i.e., plasma levels of CRP, fibrinogen, and albumin, erythrocyte sedimentation rate and white blood cell count were measured. All inflammation markers were altered in a more inflammatory direction in diabetic patients. Furthermore, when non-diabetic patients with HbA(1c) levels within the normal range were studied separately, all inflammation-sensitive parameters except albumin correlated significantly with HbA(1c).

CONCLUSION

In subjects with known coronary atherosclerosis, low-degree inflammatory activity is not only increased in diabetic patients, but also increased with increasing HbA(1c) in non-diabetic individuals with HbA(1c) within the normal range, i.e., at a pre-diabetic level of glucose metabolism derangement.