Cardiovascular Diabetology - Most viewed articles

First-line antihypertensive treatment in patients with pre-diabetes: Rationale, design and baseline results of the ADaPT investigation

2008-07-24

Background: Recent clinical trials reported conflicting results on the reduction of new-onset diabetes using RAS blocking agents. Therefore the role of these agents in preventing diabetes is still not well defined. Ramipril is an ACE inhibitor (ACEi), that has been shown to reduce cardiovascular events in high risk patients and post-hoc analyses of the HOPE trial have provided evidence for its beneficial action in the prevention of diabetes. Methods: The ADaPT investigation ("ACE inhibitor-based versus diuretic-based antihypertensive primary treatment in patients with pre-diabetes") is a 4-year open, prospective, parallel group phase IV study. It compares an antihypertensive treatment regimen based on ramipril versus a treatment based on diuretics or betablockers. The primary evaluation criterion is the first manifestation of type 2 diabetes. The study is conducted in primary care to allow the broadest possible application of its results. The present article provides an outline of the rationale, the design and baseline characteristics of AdaPT and compares these to previous studies including ASCOT-BLPA, VALUE and DREAM. Results: Until March 2006 a total of 2,015 patients in 150 general practices (general physicians and internists) throughout Germany were enrolled. The average age of patients enrolled was 67.1 +/- 10.3 years, with 47% being male and a BMI of 29.9 +/- 5.0 kg/m2. Dyslipidemia was present in 56.5%. 37.8% reported a family history of diabetes, 57.8% were previously diagnosed with hypertension (usually long standing). The HbA1c value at baseline was 5.6 %. Compared to the DREAM study patients were older, had more frequently hypertension and patients with cardiovascular disease were not exlcuded. Conclusions: Comparing the ADaPT design and baseline data to previous randomized controlled trial it can be acknowledged that AdaPT included patients with a high risk for diabetes development. Results are expected to be available in 2010. Data will be highly valuable for clinical practice due to the observational study design.

Endothelial dysfunction: a comprehensive appraisal

2006-02-23

The endothelium is a thin monocelular layer that covers all the inner surface of the blood vessels, separating the circulating blood from the tissues. It is not an inactive organ, quite the opposite. It works as a receptor-efector organ and responds to each physical or chemical stimulus with the release of the correct substance with which it may maintain vasomotor balance and vascular-tissue homeostasis. It has the property of producing, independently, both agonistic and antagonistic substances that help to keep homeostasis and its function is not only autocrine, but also paracrine and endocrine. In this way it modulates the vascular smooth muscle cells producing relaxation or contraction, and therefore vasodilatation or vasoconstriction. The endothelium regulating homeostasis by controlling the production of prothrombotic and antithrombotic components, and fibrynolitics and antifibrynolitics. Also intervenes in cell proliferation and migration, in leukocyte adhesion and activation and in immunological and inflammatory processes. Cardiovascular risk factors cause oxidative stress that alters the endothelial cells capacity and leads to the so called endothelial "dysfunction" reducing its capacity to maintain homeostasis and leads to the development of pathological inflammatory processes and vascular disease.There are different techniques to evaluate the endothelium functional capacity, that depend on the amount of NO produced and the vasodilatation effect. The percentage of vasodilatation with respect to the basal value represents the endothelial functional capacity. Taking into account that shear stress is one of the most important stimulants for the synthesis and release of NO, the non-invasive technique most often used is the transient flow-modulate "endothelium-dependent" post-ischemic vasodilatation, performed on conductance arteries such as the brachial, radial or femoral arteries. This vasodilatation is compared with the vasodilatation produced by drugs that are NO donors, such as nitroglycerine, called "endothelium independent". The vasodilatation is quantified by measuring the arterial diameter with high resolution ultrasonography. Laser-Doppler techniques are now starting to be used that also consider tissue perfusion.There is so much proof about endothelial dysfunction that it is reasonable to believe that there is diagnostic and prognostic value in its evaluation for the late outcome. There is no doubt that endothelial dysfunction contributes to the initiation and progression of atherosclerotic disease and could be considered an independent vascular risk factor. Although prolonged randomized clinical trials are needed for unequivocal evidence, the data already obtained allows the methods of evaluation of endothelial dysfunction to be considered useful in clinical practice and have overcome the experimental step, being non-invasive increases its value making it use full for follow-up of the progression of the disease and the effects of different treatments.

The impact of individualised cardiovascular disease (CVD) risk estimates and lifestyle advice on physical activity in individuals at high risk of CVD: a pilot 2 × 2 factorial understanding risk trial

Hermione C Price, Lynne Tucker, Simon J Griffin and Rury R Holman — 2008-07-17

Background: There is currently much interest in encouraging individuals to increase physical activity in order to reduce CVD risk. This study has been designed to determine if personalised CVD risk appreciation can increase physical activity in adults at high risk of CVD.Methods/DesignIn a 2 × 2 factorial design participants are allocated at random to a personalised 10-year CVD risk estimate or numerical CVD risk factor values (systolic blood pressure, LDL cholesterol and fasting glucose) and, simultaneously, to receive a brief lifestyle advice intervention targeting physical activity, diet and smoking cessation or not. We aim to recruit 200 participants from Oxfordshire primary care practices. Eligibility criteria include adults age 40–70 years, estimated 10-year CVD risk ≥20%, ability to read and write English, no known CVD and no physical disability or other condition reducing the ability to walk. Primary outcome is physical activity measured by ActiGraph accelerometer with biochemical, anthropometrical and psychological measures as additional outcomes. Primary analysis is between group physical activity differences at one month powered to detect a difference of 30,000 total counts per day of physical activity between the groups. Additional analyses will seek to further elucidate the relationship between the provision of risk information, and intention to change behaviour and to determine the impact of both interventions on clinical and anthropometrical measures including fasting and 2 hour plasma glucose, fructosamine, serum cotinine, plasma vitamin C, body fat percentage and blood pressure.DiscussionThis is a pilot trial seeking to demonstrate in a real world setting, proof of principal that provision of personalised risk information can contribute to behaviour changes aimed at reducing CVD risk. This study will increase our understanding of the links between the provision of risk information and behaviour change and if successful, could be used in clinical practice with little or no modification.

Vascular ossification – calcification in metabolic syndrome, type 2 diabetes mellitus, chronic kidney disease, and calciphylaxis – calcific uremic arteriolopathy: the emerging role of sodium thiosulfate

Melvin R Hayden, Suresh C Tyagi, Lisa Kolb, James R Sowers and Ramesh Khanna — 2005-03-18

Background: Vascular calcification is associated with metabolic syndrome, diabetes, hypertension, atherosclerosis, chronic kidney disease, and end stage renal disease. Each of the above contributes to an accelerated and premature demise primarily due to cardiovascular disease. The above conditions are associated with multiple metabolic toxicities resulting in an increase in reactive oxygen species to the arterial vessel wall, which results in a response to injury wound healing (remodeling). The endothelium seems to be at the very center of these disease processes, acting as the first line of defense against these multiple metabolic toxicities and the first to encounter their damaging effects to the arterial vessel wall. Results: The pathobiomolecular mechanisms of vascular calcification are presented in order to provide the clinician – researcher a database of knowledge to assist in the clinical management of these high-risk patients and examine newer therapies. Calciphylaxis is associated with medial arteriolar vascular calcification and results in ischemic subcutaneous necrosis with vulnerable skin ulcerations and high mortality. Recently, this clinical syndrome (once thought to be rare) is presenting with increasing frequency. Consequently, newer therapeutic modalities need to be explored. Intravenous sodium thiosulfate is currently used as an antidote for the treatment of cyanide poisioning and prevention of toxicities of cisplatin cancer therapies. It is used as a food and medicinal preservative and topically used as an antifungal medication. Conclusion: A discussion of sodium thiosulfate's dual role as a potent antioxidant and chelator of calcium is presented in order to better understand its role as an emerging novel therapy for the clinical syndrome of calciphylaxis and its complications.

Evaluation of the cost effectiveness of exenatide versus insulin glargine in patients with sub-optimally controlled Type 2 diabetes in the United Kingdom

Anette Woehl, Marc Evans, Anthony P Tetlow and Philip McEwan — 2008-08-11

ObjectiveExenatide belongs to a new therapeutic class in the treatment of diabetes (incretin mimetics), allowing glucose-dependent glycaemic control in Type 2 diabetes. Randomised-controlled trial data suggest that exenatide is as effective as insulin glargine at reducing HbA1c in combination therapy with metformin and sulphonylureas; with reduced weight but higher incidence of gastro-intestinal adverse events. The objective of this study is to evaluate the cost effectiveness of exenatide versus insulin glargine using RCT data and a previously published model of Type 2 diabetes disease progression that is based on the United Kingdom Prospective Diabetes Study; the perspective of the health-payer of the United Kingdom National Health Service. Methods: The study used a discrete event simulation model designed to forecast the costs and health outcome of a cohort of 1,000 subjects aged over 40 years with sub-optimally-controlled Type 2 diabetes, following initiation of either exenatide, or insulin glargine, in addition to oral hypoglycaemic agents. Sensitivity analysis for a higher treatment discontinuation rate in exenatide patients was applied to the cohort in three different scenarios; (1) either ignored or (2) exenatide-failures excluded or (3) exenatide-failures switched to insulin glargine. Analyses were undertaken to evaluate the price sensitivity of exenatide in terms of relative cost effectiveness. Baseline cohort profiles and effectiveness data were taken from a published randomised controlled trial. Results: The relative cost-effectiveness of exenatide and insulin glargine was tested under a variety of conditions, in which insulin glargine was dominant in the all cases. Using the most conservative of assumptions, the cost-effectiveness ratio of exenatide vs. insulin glargine at the current UK NHS price was -GBP29,149/QALY (insulin glargine dominant) and thus exenatide is not cost-effective when compared with insulin glargine, at the current UK NHS price. Conclusion: This study evaluated the relative cost effectiveness of insulin glargine versus exenatide in the management of Type 2 diabetes using a published model. Given no significant difference in glycaemic control and applying the additional effectiveness of exenatide over insulin glargine, with respect to weight loss, and using the current UK NHS prices, insulin glargine was found to be dominant over exenatide in all modelled scenarios. With current clinical evidence, exenatide does not appear to represent a cost-effective treatment option for patients with Type 2 diabetes when compared to insulin glargine.

Effect of the addition of rosiglitazone to metformin or sulfonylureas versus metformin/sulfonylurea combination therapy on ambulatory blood pressure in people with type 2 diabetes: A randomized controlled trial (the RECORD study)

2008-04-24

Background: Hypertension and type 2 diabetes are common co-morbidities. Preliminary studies suggest that thiazolidinediones reduce blood pressure (BP). We therefore used ambulatory BP to quantify BP lowering at 6–12 months with rosiglitazone used in combination with metformin or sulfonylureas compared to metformin and sulfonylureas in people with type 2 diabetes. Methods: Participants (n = 759) in the multicentre RECORD study were studied. Those taking metformin were randomized (open label) to add-on rosiglitazone or sulfonylureas, and those on sulfonylurea to add-on rosiglitazone or metformin. Results: 24-Hour ambulatory BP was measured at baseline, 6 months and 12 months. At 6 and 12 months, reductions in 24-hour ambulatory systolic BP (sBP) were greater with rosiglitazone versus metformin (difference at 6 months 2.7 [95% CI 0.5–4.9] mmHg, p = 0.015; 12 months 2.5 [95% CI 0.2–4.8] mmHg, p = 0.031). Corresponding changes for ambulatory diastolic BP (dBP) were comparable (6 months 2.7 [95% CI 1.4–4.0] mmHg, p < 0.001; 12 months 3.1 [95% CI 1.8–4.5] mmHg, p < 0.001). Similar differences were observed for rosiglitazone versus sulfonylureas at 12 months (sBP 2.7 [95% CI 0.5–4.9] mmHg, p = 0.016; dBP 2.1 [95% CI 0.7–3.4] mmHg, p = 0.003), but differences were smaller and/or not statistically significant at 6 months (sBP 1.5 [95% CI -0.6 to 3.6] mmHg, p = NS; dBP 1.3 [95% CI 0.0–2.5] mmHg, p = 0.049). Changes in BP were not accompanied by compensatory increases in heart rate, did not correlate with basal insulin sensitivity estimates and were not explained by changes in antihypertensive therapy between the various strata. Conclusion: When added to metformin or a sulfonylurea, 12-month treatment with rosiglitazone reduces ambulatory BP to a greater extent than when metformin and a sulfonylurea are combined.Trial registrationNCT00379769 http://clinicaltrials.gov/

Interaction between Calpain-5, Peroxisome proliferator-activated receptor-gamma and Peroxisome proliferator-activated receptor-delta genes: a polygenic approach to obesity.

2008-07-25

Background: Obesity is a multifactorial disorder, that is, a disease determined by the combined effect of genes and environment. In this context, polygenic approaches are needed. Our objective was to investigate the possibility of the existence of a crosstalk between the Calpain-10 homologue Calpain-5 and nuclear receptors of the peroxisome proliferator-activated receptors family. Methods: The study sample comprise 1953 individuals, 725 obese (defined as body mass index [greater than or equal to] 30) and 1228 non obese subjects. We performed cross-sectional, genetic association study and gene-gene interaction analysis. Results: In the monogenic analysis, only the peroxisome proliferator-activated receptor delta (PPARD) gene was associated with obesity (OR=1.43[1.04-1.97], p=0.027). In addition, we have found a significant interaction between CAPN5 and PPARD genes (p=0.038) that reduces the risk for obesity in a 55%. Conclusions: Our results suggest that CAPN5 and PPARD gene products may also interact in vivo.

Intensification of oxidative stress and inflammation in type 2 diabetes despite antihyperglycemic treatment

Raymond Farah, Revital Shurtz-Swirski and Olga Lapin — 2008-06-22

IntroductionThe metabolic deregulation associated with diabetes mellitus (DM) causes secondary pathophysiologic changes in multiple organ systems. Endothelial injury is induced by oxidative stress (OS) and inflammation. We have previously shown that DM type 2 patients are exposed to increased OS and inflammation contributed in part by primed peripheral polymorphonuclear leukocytes (PMNLs).AimsTo characterize the effect of oral medication on PMNL priming, on PMNL-related and on systemic inflammation, in correlation to changed diabetes parameters in patient with newly diagnosed type 2 DM. Methods: PMNLs were separated from DM patient's prior and following treatment with either metformin (Glucophage), or Thiazolidinedione (rosiglitazone) and from healthy control subjects (HC). Rate of superoxide release from phorbol ester-stimulated PMNLs and CD11b on PMNLs assessed PMNL priming. White blood cells (WBC) and PMNL counts and apoptosis reflected PMNL-related inflammation. CRP, fibrinogen, transferrin and albumin blood levels reflected systemic inflammation. Results: Both metformin and rosiglitazone treatments reduced significantly the high levels of glucose and HbA1c, and slightly improved lipid profile during 2 months. PMNL priming parameters, higher compared to HC, increased after 2 months of metformin treatment. Rosiglitazone treatment decreased PMNL priming. ALP, higher in DM, significantly decreased following 2 months of both treatments. Systemic inflammation markers (fibrinogen, CRP), higher in DM, decreased following both treatments. Transferrin and albumin were similar to HC. PMNL-related inflammation markers were higher in DM; however, only PMNL apoptosis decreased after both treatments. Monocyte counts, higher in DM compared to HC, decreased following both treatments. Serum insulin levels, higher in DM compared to HC, decreased following both treatments. PMNL-related priming and inflammation parameters positively correlated with HbA1c. Conclusion: The present research adds new facet in evaluating anti-hyperglycemic treatment in type 2 DM patients. Despite sufficient glycemic control using both treatments, some PMNL-related parameters deteriorated. Thus, anti hyperglycemic treatment should be favored due to its combined anti-PMNL priming and anti-inflammatory effect, in addition to its anti-hyperglycemic characteristics, according to the correlation among these parameters. Such combined treatment may reduce morbidity and mortality common in DM patients.

Diabetic retinopathy is associated with pulse wave velocity, not with the augmentation index of pulse waveform

2008-04-25

Background: To investigate the clinical differences between pulse wave velocity and augmentation index in diabetic retinopathy. Methods: The subjects were 201 patients with type 2 diabetes. These subjects were measured for both augmentation index (AI) and brachial-ankle pulse wave velocity (baPWV) by a pulse wave analyzer. The relationships between AI, baPWV, and diabetic retinopathy were examined. Results: BaPWV was significantly higher in patients with diabetic retinopathy than in individuals without the disease. (20.13 ± 3.66 vs.17.14 ± 3.60 m/s p < 0.001) AI was higher in patients with diabetic retinopathy, but not significantly. (19.5 ± 15.2 vs. 14.8 ± 20.5% p = 0.14) The association between baPWV and diabetic retinopathy remained statistically significant after adjustment. (Odds ratio: 1.21 Per m/s, 95% confidence interval: 1.07–1.37) On the other hand, the association between AI and diabetic retinopathy was not statistically significant. (Odds ratio: 1.01 Per %, 95% confidence interval: 0.98–1.03) Conclusion: BaPWV is associated with diabetic retinopathy, but AI is not. The clinical significance appears to be different between PWV and AI in patients with diabetes.

Telmisartan/hydrochlorothiazide versus valsartan/hydrochlorothiazide in obese hypertensive patients with type 2 diabetes: the SMOOTH study

Arya M Sharma, Jaime Davidson, Stephen Koval and Yves Lacourcière — 2007-10-02

Background: The Study of Micardis (telmisartan) in Overweight/Obese patients with Type 2 diabetes and Hypertension (SMOOTH) compared hydrochlorothiazide (HCTZ) plus telmisartan or valsartan fixed-dose combination therapies on early morning blood pressure (BP), using ambulatory BP monitoring (ABPM). Methods: SMOOTH was a prospective, randomized, open-label, blinded-endpoint, multicentre trial. After a 2- to 4-week, single-blind, placebo run-in period, patients received once-daily telmisartan 80 mg or valsartan 160 mg for 4 weeks, with add-on HCTZ 12.5 mg for 6 weeks (T/HCTZ or V/HCTZ, respectively). At baseline and week 10, ambulatory blood pressure (ABP) was measured every 20 min and hourly means were calculated. The primary endpoint was change from baseline in mean ambulatory systolic and diastolic blood pressure (SBP; DBP) during the last 6 hours of the 24-hour dosing interval. Results: In total, 840 patients were randomized. At week 10, T/HCTZ provided significantly greater reductions versus V/HCTZ in the last 6 hours mean ABP (differences in favour of T/HCTZ: SBP 3.9 mm Hg, p < 0.0001; DBP 2.0 mm Hg, p = 0.0007). T/HCTZ also produced significantly greater reductions than V/HCTZ in 24-hour mean ABP (differences in favour of T/HCTZ: SBP 3.0 mm Hg, p = 0.0002; DBP 1.6 mm Hg, p = 0.0006) and during the morning, daytime and night-time periods (p < 0.003). Both treatments were well tolerated. Conclusion: In high-risk, overweight/obese patients with hypertension and type 2 diabetes, T/HCTZ provides significantly greater BP lowering versus V/HCTZ throughout the 24-hour dosing interval, particularly during the hazardous early morning hours.