Calcium antagonists in patients with type 2 diabetes and hypertension

A retrospective longitudinal cohort study of antihypertensive drug use and new-onset diabetes in Taiwanese patients

Antihypertensive drugs have been linked to new-onset diabetes (NOD); however, data on the effect of these drugs on the development of NOD in hypertensive patients has not been well determined in a clinical setting. The aim was to investigate the association between antihypertensive drugs and NOD in Taiwan. We conducted a retrospective study of hypertensive Taiwanese patients receiving antihypertensive drugs treatment between January 2006 and December 2011. Clinical information and laboratory parameters were collected by reviewing the medical records. We estimated the odds ratios (ORs) of NOD associated with antihypertensive drug use; nondiabetic subjects served as the reference group. A total of 120 NOD cases were identified in 1001 hypertensive patients during the study period. The risk of NOD after adjusting sex, age, baseline characteristics, and lipid profiles was higher among users of thiazide diuretics (OR, 1.65; 95% confidence interval (CI), 1.12–2.45) and nondihydropyridine (non-DHP) calcium channel blockers (CCBs) (OR, 1.96; 95% CI, 1.01–3.75) than among nonusers. Other antihypertensive drug classes were not associated with risk of NOD. Our results show that patients with hypertension who take thiazide diuretics and non-DHP CCBs are at higher risk of developing NOD than those who take other classes of antihypertensive drugs in Taiwan.

Zinc signalling and subcellular distribution: emerging targets in type 2 diabetes

A finely tuned subcellular distribution of zinc (Zn), through the coordinated action of Zn transporters (ZnTs) and metallothioneins (MTs), is crucial for optimal cell function. Dysfunctions of these proteins might act as key causative or promoting factors in several chronic pathologies. Evidence of their involvement in the pathogenesis of type 2 diabetes (DM2) is emerging. The association of single nucleotide polymorphisms in genes encoding ZnT-8 and MT with DM2 has drawn attention to the relevance of Zn homeostasis for insulin secretory capacity and responsiveness. Here, we propose that potential mechanisms leading to altered subcellular Zn distribution rather than deficiency might be important in DM2. Increasing knowledge of the mechanisms of Zn homeostasis and signalling should promote the development of targeted interventions with the potential to reduce the burden of disease.

Effective management of hypertension with dihydropyridine calcium channel blocker-based combination therapy in patients at high cardiovascular risk

The increasing prevalence of hypertension, owing to modern lifestyles and the increasing elderly population, is contributing to the global burden of cardiovascular (CV) disease. Although effective antihypertensive therapies are available, blood pressure (BP) is generally poorly controlled. In addition, the full benefits of antihypertensive therapy can only be realised when target BP is achieved. International guidelines and clinical trial evidence support the use of combination therapy to manage hypertension. In high-risk patients, such as those with coronary artery disease, diabetes and renal dysfunction, BP targets are lower and there is a need for intensive management with combination therapy to control BP and provide additional CV risk reduction benefits. Combinations of antihypertensive agents with different but complementary modes of action improve BP control and may also provide vascular-protective effects. Calcium channel blockers (CCBs) have been shown to be effective in combination with a range of antihypertensive drugs and in different patient populations. As part of a first-line combination strategy, CCBs can provide CV benefits beyond BP control, even in patients at increased CV risk. Benefits include protection against end-organ damage and serious CV events. Indeed, in major intervention trials, these benefits have already been clearly demonstrated. Ongoing studies will provide further data to support the clinical benefits of combination therapy as a first-line treatment approach. Implementation of this approach in clinical practice, together with adherence to global hypertension management guidelines will help ensure patients achieve and sustain BP targets, and reduce the risk of CV events.

Effect of antihypertensive agents on the development of type 2 diabetes mellitus

People with hypertension have a high prevalence of insulin resistance and are at relatively high risk of developing type 2 diabetes mellitus. It is becoming increasingly evident that antihypertensive agents have disparate metabolic effects. For example, recent clinical trials indicate that agents that interrupt the renin-angiotensin axis reduce the risk of developing diabetes compared with other classes of antihypertensive agents. Blockade of the effects of angiotensin II might improve blood flow to insulin-sensitive tissues. Furthermore, interruption of the renin-angiotensin system might provide metabolic benefit through such mechanisms as reduced oxidative stress and restored nitric oxide production, which could lead to improved insulin signaling. Alternatively, collective trials suggest that both diuretics and beta-blockers accelerate the appearance of new-onset type 2 diabetes mellitus in patients with hypertension. Therefore, the risk of new-onset diabetes-associated cardiovascular risks should be factored into future treatment recommendations for patients who require antihypertensive therapy. This will become even more important as the number of insulin-resistant patients with hypertension increases in parallel with the steady growth in the number of sedentary, obese, and aged persons in our population.

Challenges in the diagnosis and management of new-onset diabetes after transplantation

With the availability of newer and more potent immunosuppressive agents, post-transplant survival has markedly improved. However, these agents, together with the rising age of transplant recipients, have been associated with a rise in the incidence of new-onset diabetes after transplantation (NODAT). Besides the traditional risk factors for diabetes mellitus, such as age, obesity, hypertension, and family history of diabetes, additional risk factors for NODAT are identified. These include immunosuppressive therapy, hepatitis C infection, acute rejection, and deceased donor kidney transplant. In this article, we discuss the epidemiology, risk factors, pathophysiology, clinical course, and therapeutic and diagnostic challenges of this emerging disease.

Diabetes, hypertension, and cardiovascular derangements: Pathophysiology and management

Hypertension frequently coexists with diabetes mellitus, occurring twice as frequently in diabetic as in nondiabetic persons. It accounts for up to 75% of added cardiovascular disease (CVD) risk in people with diabetes, contributing significantly to the overall morbidity and mortality in this high-risk population. Patients with hypertension are two times more prone to have diabetes than are normotensive persons. Hypertension substantially increases the risk for coronary heart disease (CHD), stroke, retinopathy, and nephropathy. In patients with type 2 diabetes, hypertension usually clusters with the other components of the cardiometabolic syndrome, such as microalbuminuria, central obesity, insulin resistance, dyslipidemia, hypercoagulation, increased inflammation, and left ventricular hypertrophy (LVH). In type 1 diabetes, hypertension often occurs subsequent to the development of diabetic nephropathy. Hypertension in people with diabetes is characterized by volume expansion, increased salt sensitivity, isolated systolic blood pressure (BP) elevation, loss of the nocturnal dipping of BP and pulse, and increased propensity toward orthostatic hypotension and albuminuria. Among the treatment strategies tested in hypertensive diabetic persons, low-density lipoprotein (LDL)-cholesterol lowering to less than 100 mg/dL and aggressive BP control to less than 130/80 mm Hg have proven effective in CVD risk reduction. The combination of two or more drugs is usually necessary to achieve the target BP.