Cardiovascular Diabetology - Latest Articles

Divergent fifteen-year trends in traditional and cardiometabolic risk factors of cardiovascular diseases in the Seychelles

Pascal Bovet — 2009-06-26T00:00:00Z

ObjectiveFew studies have assessed secular changes in the levels of cardiovascular risk factors (CV-RF) in populations of low or middle income countries. The systematic collection of a broad set of both traditional and metabolic CV-RF in 1989 and 2004 in the population of the Seychelles islands provides a unique opportunity to examine trends at a fairly early stage of the "diabesity" era in a country in the African region. Methods: Two examination surveys were conducted in independent random samples of the population aged 25-64 years in 1989 and 2004, attended by respectively 1081 and 1255 participants (participation rates >80%). All results are standardized for age. Results: In 2004 vs. 1989, the levels of the main traditional CV-RF have either decreased, e.g. smoking (17% vs. 30%, p<0.001), mean blood pressure (127.8/84.8 vs. 130.0/83.4 mmHg, p<0.05), or only moderately increased, e.g. median LDL-cholesterol (3.58 vs. 3.36 mmol/l, p<0.01). In contrast, marked detrimental trends were found for obesity (37% vs. 21%) and several cardiometabolic CVD-RF, e.g. mean HDL-cholesterol (1.36 vs. 1.40 mmol/l, p<0.05), median triglycerides (0.80 vs. 0.78 mmol/l, p<0.01), mean blood glucose (5.89 vs. 5.22 mmol/l, p<0.001), median insulin (11.6 vs. 8.3 micromol/l, p<0.001), median HOMA-IR (2.9 vs. 1.8, p<0.001) and diabetes (9.4% vs. 6.2%, p<0.001). At age 40-64, the prevalence of elevated total cardiovascular risk tended to decrease (e.g. WHO-ISH risk score >10; 11% vs. 13%, ns), whereas the prevalence of the metabolic syndrome (which integrates several cardiometabolic CVD-RF) nearly doubled (36% vs. 20%, p<0.001). Data on physical activity and on intake of alcohol, fruit and vegetables are also provided. Awareness and treatment rates improved substantially for hypertension and diabetes, but control rates improved for the former only. Median levels of the cardiometabolic CVD-RF increased between 1989 and 2004 within all BMI strata, suggesting that the worsening levels of cardiometabolic CVD-RF in the population were not only related to increasing BMI levels in the interval. Conclusion: The levels of several traditional CVD-RF improved over time, while marked detrimental trends were observed for obesity, diabetes and several cardiometabolic factors. Thus, in this population, the rapid health transition was characterized by substantial changes in the patterns of CVD-RF. More generally, this analysis suggests the importance of surveillance systems to identify risk factor trends and the need for preventive strategies to promote healthy lifestyles and nutrition.

Combined effects of obesity and type 2 diabetes contribute to increased breast cancer risk in premenopausal women

Majed Alokail — 2009-06-23T00:00:00Z

Background: Both obesity and type 2 diabetes are among the risk factors for breast cancer development. Combined effect of these metabolic abnormalities on breast cancer risk however, has not been examined in premenopausal women. We tested this association in type 2 diabetic women, categorized as obese, overweight and normal body weight groups based on BMI.Design and methods: A total of 101 subjects were included in this study. Serum levels of IL-6, TNF-alpha, C reactive protein, leptin, TGF- alpha, adiponectin and insulin were measured by ELISA. Data were logarithmically transformed for variables not normally distributed. Analysis of variance with post-hoc Bonferroni was applied to compare the data between the groups. Simple and partial correlation coefficients between the variables were determined and a stepwise multiple linear regression analysis was performed to determine the relationships between the variables of interest. Results: Significantly increased levels of IL-6, C reactive protein, leptin and significantly decreased levels of adiponectin were found in obese group, while the levels of TNF-alpha and TGF-alpha were unaltered. A positive correlation between waist circumference and IL-6 was found in obese group. Similarly, C reactive protein, waist and hip circumferences were linearly correlated with BMI in obese group. Stepwise multiple linear regression analysis revealed several significant predictors for breast cancer risk. Conclusions: Obesity and type 2 diabetes, owing to their effects on adipocytokines and inflammatory mediators, contribute to increased breast cancer risk in premenopausal women. This study emphasizes healthy life style and better management of these metabolic disorders to avoid the pathogenesis of breast cancer and of other chronic diseases.

Losartan counteracts the hyper-reactivity to angiotensin II and ROCK1 over-activation in aortas isolated from streptozotocin-injected diabetic rats

Paola Failli — 2009-06-22T00:00:00Z

Background: In streptozotocin-injected rats (STZ-rats), we previously demonstrated a role for angiotensin II (AT-II) in cardiac remodelling and insulin resistance partially counteracted by in vivo treatment with losartan, an AT-II receptor antagonist.We now aimed to investigate the effect of treating diabetic STZ-rats with losartan on diabetes vascular response to vasoconstrictors.Methods Male Wistar rats were randomly divided in four groups, two of them were assigned to receive losartan in the drinking water (20 mg/kg/day) until the experiment ending (3 weeks afterward). After 1 week, two groups, one of which receiving losartan, were injected in the tail vein with citrate buffer (normoglycemic, N and normoglycemic, losartan-treated, NL). The remaining received a single injection of streptozotocin (50 mg/kg in citrate i.v.) thus becoming diabetic (D) and diabetic losartan-treated (DL). Plasma glycaemia and blood pressure were measured in all animals before the sacrifice (15 days after diabetes induction).In aortic strips isolated from N, NL, D and DL rats we evaluated i) the isometric concentration-dependent contractile response to phenylephrine (Phe) and to AT-II; ii) the RhoA-kinase (ROCK1) activity and expression by enzyme-immunoassay and Western blot respectively.Key results: The concentration-dependent contractile effect of Phe was similar in aortas from all groups, whereas at all concentrations tested, AT-II contraction efficacy was 2 and half and 1 and half times higher in D and DL respectively in comparison with N and NL. AT-II contracture was similarly reduced in all groups by AT-II receptor antagonists, irbesartan or irbesartan plus PD123319. HA-1077 (10 microM), an inhibitor of ROCK1 activity, reduced AT-II efficacy (delta mg/mg tissue w.w.) by -3.5 +/-1.0, -4.6+/-1.9, -22.1+/-2.2 and -11.4+/-1.3 in N, NL, D and DL respectively). ROCK1 activity and expression were higher in D than in N/NL and DL aortas.Conclusions and implicationsAortas isolated from STZ-rats present hyper-contracture to AT-II mainly dependent on the up-regulation of ROCK1 expression/activity. In vivo losartan treatment partially corrects AT-II hyper-contracture, limiting the increase in ROCK1 expression/activity. These data offer a new molecular mechanism supporting the rationale for using losartan in the prevention of diabetic vascular complications.

The common G-866A polymorphism of the UCP2 gene and survival in diabetic patients following myocardial infarction

Barry Palmer — 2009-06-15T00:00:00Z

Background: A variant in the promoter of the human uncoupling protein 2 (UCP2) gene, the G-866A polymorphism, has been associated with future risk of coronary heart disease events, in those devoid of traditional risk factors and in those suffering from diabetes. We thus examined the impact of the G-866A polymorphism on 5-year survival in a cohort of 901 post-myocardial infarction patients, and the impact of type-2 diabetes on this relationship. The association of UCP2 with baseline biochemical and hormonal measurements, including levels of the inflammatory marker myeloperoxidase, was also examined. Methods: UCP2 G-866A genotypes were determined using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) protocol. Myeloperoxidase levels were measured in plasma samples taken from 419 cohort patients 24–96 hours after admission. Results: Genotypes were obtained for 901 patients with genotype frequencies AA 15.5%, GA 45.5%, and GG 39.0%. Genotype was not associated with survival in the overall cohort (mortality: AA 15.6%, GA 16.8%, GG 19.4%, p = 0.541). However, amongst diabetics, AA and GA genotype groups had significantly worse survival than GG diabetic patients (p < 0.05) with an attributable risk of 23.3% and 18.7% for those of AA and GA genotype respectively. Multivariate analysis using a Cox proportional hazards model confirmed that the interaction of diabetes with genotype was significantly predictive of survival (p = 0.031). In the cohort's diabetic subgroup AA/GA patients had higher myeloperoxidase levels than their GG counterparts (GA/AA, n = 51, 63.9 ± 5.23; GG, n = 34, 49.1 ± 3.72 ng/ml, p = 0.041). Further analysis showed that this phenomenon was confined to male patients (GA/AA, n = 36, 64.3 ± 6.23; GG, n = 29, 44.9 ± 3.72 ng/ml, p = 0.015). Conclusion: Diabetic patients in this post-myocardial infarction cohort with UCP2 -866 AA/GA genotype have poorer survival and higher myeloperoxidase levels than their GG counterparts.

Changes in body mass index, leptin and adiponectin in Japanese children during a three-year follow-up period: a population-based cohort study

Rimei Nishimura — 2009-06-03T00:00:00Z

ObjectiveThe study examined changes in and relationship between body mass index (BMI), leptin and adiponectin levels over a 3-year period in a pediatric population-based cohort.Study designA 3-year prospective cohort study of 268 boys and 251 girls aged 9–10 in Ina, Saitama, Japan. Results: Median body mass index (BMI) significantly increased from baseline (age 9–10) to follow up (age 12–13) in boys from 17.1 to 18.3 kg/m2 (P < 0.001) and in girls from 16.5 to 18.5 kg/m2 (P < 0.001), respectively. Adiponectin values significantly decreased from baseline to follow up in boys (13.5 to 8.9 μg/ml, respectively) (P < 0.001) and in girls (12.4 to 9.5 μg/ml, respectively) (P < 0.001). Leptin values at follow up significantly decreased from baseline in boys (4.9 to 2.3 ng/dl, respectively) (P < 0.001) and also in girls (5.3 to 5.1 ng/dl, respectively) (P = 0.049).A relatively strong correlation was seen in BMI (Spearman's correlation coefficient, r = 0.864, P < 0.001 in boys; r = 0.873, P < 0.001 in girls), adiponectin (r = 0.705, P < 0.001 in boys; r = 0.695, P < 0.001 in girls), and leptin (r = 0.449, P < 0.001 in boys; r = 0.610, P < 0.001 in girls) before and after the three-year period.The ratio of follow up to baseline BMI was negatively correlated with that for adiponectin (r = -0.224, P < 0.001 in boys; r = -0.165, P = 0.001 in girls) and positively correlated with that for leptin (r = 0.518, P < 0.001 in boys; r = 0.609, P < 0.001 in girls). Conclusion: This study demonstrated that baseline adiponectin, leptin and BMI values measured at ages 9–10 correlated with those measured three years later. However, adiponectin values decreased and leptin values increased in those subjects whose BMI increased during over this period.

Haptoglobin genotype is a determinant of survival and cardiac remodeling after myocardial infarction in diabetic mice

Roy Asaf — 2009-06-02T00:00:00Z

Background: We have recently demonstrated in man that a functional allelic polymorphism in the Haptoglobin (Hp) gene plays a major role in determining survival and congestive heart failure after myocardial infarction (MI). We sought to recapitulate the effect of Hp type on outcomes and cardiac remodeling after MI in transgenic mice. Methods: The Hp 2 allele exists only in man. Wild type C57Bl/6 mice carry the Hp 1 allele with high homology to the human Hp 1 allele. We genetically engineered a murine Hp 2 allele and targeted its insertion by homologous recombination to the murine Hp locus to create Hp 2 mice. Diabetes Mellitus (DM) was induced with streptozotocin. MI was produced by occlusion of the left anterior descending artery in DM C57Bl/6 mice carrying the Hp 1 or Hp 2 allele. MI size was determined with TTC staining. Left ventricular (LV) function and dimensions were assessed by 2-dimensional echocardiography. Results: In the absence of DM, Hp 1-1 and Hp 2-2 mice had similar LV dimensions and LV function. MI size was similar in DM Hp 1-1 and 2-2 mice 24 hours after MI (50.2 ± 2.1%and 46.9 ± 5.5%, respectively, p = 0.6). However, DM Hp 1-1 mice had a significantly lower mortality rate than DM Hp 2-2 mice 30 days after MI (HR 0.41, 95% CI (0.19–0.95), p = 0.037 by log rank). LV chamber dimensions were significantly increased in DM Hp 2-2 mice compared to DM Hp 1-1 mice 30 days after MI (0.196 ± 0.01 cm2 vs. 0.163 ± 0.01 cm2, respectively; p = 0.029). Conclusion: In DM mice the Hp 2-2 genotype is associated with increased mortality and more severe cardiac remodeling 30 days after MI.

HNF1A gene variants and cardiovascular risk factors in individuals with late-onset autosomal dominant diabetes: a cross-sectional study

Fernando Giuffrida — 2009-06-02T00:00:00Z

Background: Type 2 diabetes mellitus (T2DM) is a genetically heterogeneous disease, hepatocyte nuclear factor-1 homeobox A (HNF1A) single-nucleotide polymorphisms (SNPs) playing a minor role in its pathogenesis. HNF1A is a frequent cause of monogenic diabetes, albeit with early-onset. Some uncommon subgroups like late-onset autosomal dominant diabetes mellitus (LOADDM) may present peculiar inheritance patterns with a stronger familial component. This study aims to investigate the relationship of HNF1A SNPs with cardiovascular risk factors in this group, as well as to characterize them in contrast with classical T2DM (CT2DM). Methods: eighteen LOADDM (age at onset > 40 y.o.; diabetes in 3 contiguous generations, uniparental lineage) along with 48 CT2DM patients and 42 normoglycemic controls (N group) have been evaluated for cardiovascular risk factors and SNPs of HNF1A. Results: LOADDM showed significantly higher frequencies of SNPs A98V (22.2% vs 2.1%, p = 0.02) and S487N (72.2% vs 43.8%, p = 0.049) of HNF1A compared to CT2DM. I27L did not show significant difference (66.7% vs 45.8%), but associated with lower risk of hypertriglyceridemia (OR 0.16, 95% CI 0.04–0.65, p = 0.01). "Protective effect" was independent from other well-known predictive risk factors for hypertriglyceridemia, such as waist circumference (OR 1.09 per 1 cm increase, p = 0.01) and HDL (OR 0.01 per 1 mmol/l, p = 0.005), after logistic regression. Conclusion: Late onset autosomal dominant diabetes mellitus is clinically indistinguishable from classical type 2 diabetes individuals. However, LOADDM group is enriched for common HNF1A polymorphisms A98V and S487N. I27L showed "protective effect" upon hypertriglyceridemia in this sample of individuals, suggesting a role for HNF1A on diabetic individuals' lipid profile. These data contribute to the understanding of the complex interactions between genes, hyperglycemia and cardiovascular risk factors development in type 2 diabetes mellitus.

A study of endothelial function and circulating asymmetric dimethylarginine levels in people with Type 1 diabetes without macrovascular disease or microalbuminuria

Latika Sibal — 2009-06-01T00:00:00Z

Background: Asymmetric dimethylarginine (ADMA) is a competitive inhibitor of endothelial nitric oxide synthase (eNOS) that is associated with endothelial dysfunction, and is a risk marker for cardiovascular disease, a significant problem in Type 1 diabetes. The aim of the present study was to measure circulating ADMA, and define its association with endothelial dysfunction and endothelial markers in people with Type 1 diabetes with low likelihood of macrovascular disease. Methods: Sixty-one young people with Type 1 diabetes without macrovascular disease or nephropathy and 62 healthy volunteers underwent brachial artery flow-mediated dilatation (FMD) and assay of plasma ADMA and adhesion molecules. Results: Age, gender, BMI, lipid profile and renal function were similar in the two groups. People with Type 1 diabetes had impaired FMD compared to healthy controls (5.0 ± 0.4 vs 8.9 ± 0.4%; p < 0.001). Plasma ADMA levels were significantly lower in the people with diabetes compared to healthy controls (0.52 ± 0.12 vs 0.66 ± 0.20 μmol/l, p < 0.001). Plasma ICAM-1, E-selectin and PAI-1 levels were significantly higher in people with diabetes compared to healthy controls (median 201 (IQR 172–226) vs 180 (156–216) μg/l, p = 0.027; 44.2 (32.6–60.9) vs. 33.1 (22.4–51.0) μg/l; p = 0.003 and 70.8 (33.3–85.5) vs 46.3 (23.9–76.8) μg/l, p = 0.035). Plasma ADMA and VCAM-1 levels were positively correlated (r = 0.37, p = 0.003) in people with diabetes. There was no correlation between the plasma ADMA and FMD. Conclusion: ADMA levels are not associated with endothelial dysfunction in young adults with Type 1 diabetes without microalbuminuria or known macrovascular disease. This suggests that the impaired endothelial function in these individuals is not a result of eNOS inhibition by ADMA.

Dyslipidemia treatment of patients with diabetes mellitus in a US managed care plan: a retrospective database analysis

Peter Toth — 2009-05-18T00:00:00Z

Background: To evaluate real-world pharmacologic treatment of mixed dyslipidemia in patients with diabetes mellitus (DM). Methods: All commercial health plan members in a large US managed care database with complete lipid panel results (HDL-C, LDL-C, TG) between 1/1/2006 and 12/31/2006 were identified (N = 529,236). DM patients (N = 53,679) with mixed dyslipidemia were defined as having any 2 suboptimal lipid parameters (N = 28,728). Lipid treatment status 6 months pre- and post-index date was determined using pharmacy claims for any lipid therapy. Results: Post-index, 41.1% of DM patients with 2 abnormal lipid parameters and 45.1% with 3 abnormal lipid parameters did not receive lipid-modifying treatment. Post-index treatment rates were 57.4%, 63.6%, and 66.4% for patients with LDL-C, HDL-C, and TG in the most severe quartiles, respectively. Statin monotherapy was the primary lipid-modifying regimen prescribed (54.8% and 47.8% of patients with any 2 and all 3 lipids not at goal, respectively). Less than 30% of treated patients received combination therapy. Conclusion: Over 40% of DM patients with mixed dyslipidemia received no lipid-modifying therapy during the follow-up period. Those who were treated were primarily prescribed statin monotherapy. This study suggests that DM patients are not being treated to ADA-suggested targets.

Patterns and predictors of statin prescription in patients with type 2 diabetes

Heiner Berthold — 2009-05-13T00:00:00Z

Background: The benefit of statins for prevention of cardiovascular events in type 2 diabetes is established, but a gap exists between guideline recommendations and clinical practice. The aim of the study was to identify patient-related factors predicting statin prescription. Methods: We assessed the quality of care in 51,640 patients with type 2 diabetes in a German diabetes registry. Patients were stratified according to primary and secondary prevention. Five-year risk for cardiovascular events was calculated in primary prevention patients. A multivariate adjusted logistic regression model was constructed to determine which parameters influenced statin prescription. Results: 34% had established atherosclerotic disease and 25.5% received a statin. Prescription was significantly higher in the secondary compared to the primary prevention group (38.1% [95% CI 37.4–38.9%] vs. 18.5% [95% CI 18.0–19.0%], respectively). In primary prevention the odds for statin prescription increased with estimated cardiovascular risk (OR 1.17 per 5% increase in 5-year risk, 95% CI 1.11–1.22). Positive predictors for statin prescription were secondary prevention, hypertension, former smoking, baseline LDL-cholesterol, and microalbuminuria. The odds of receiving a statin had an inverted U-shaped relation with age (nadir, 66 years), age at first diagnosis of diabetes (nadir, 56 years), and body mass index (nadir, 32 kg/m2). The model predicted prescription in 70% of the patients correctly. Conclusion: The majority of patients with type 2 diabetes are not receiving statins. The predominant factors determining statin prescription are the patient's prevention status and, in primary prevention, estimated cardiovascular risk. The results suggest that although physicians are aware of the general concept of cardiovascular risk, they fail to consistently implement guidelines.