Oral therapies for diabetic hyperglycemia

Selection and Warning of Evidence-Based Antidiabetic Medications for Patients With Chronic Liver Disease

The global prevalence of chronic liver disease and diabetes mellitus (DM) has gradually increased potentially due to changes in diet and lifestyle. The choice of antidiabetic medications for patients with coexisting DM and chronic liver disease is complicated. Severe liver injury may decrease the metabolism of antidiabetic medications, resulting in elevated drug concentrations and adverse effects. The choice of antidiabetic medications in patients with chronic liver disease has not been well studied. The long-term outcomes of antidiabetic medications in patients with chronic liver disease have gained attention recently. Herein, we reviewed relevant articles to extend our understanding on the selection and warning of antidiabetic medications for patients with chronic liver disease.

The Role of Bioactive Peptides in Diabetes and Obesity

Bioactive peptides are present in most soy products and eggs and have essential protective functions. Infection is a core feature of innate immunity that affects blood pressure and the glucose level, and ageing can be delayed by killing senescent cells. Food also encrypts bioactive peptides and protein sequences produced through proteolysis or food processing. Unique food protein fragments can improve human health and avoid metabolic diseases, inflammation, hypertension, obesity, and diabetes mellitus. This review focuses on drug targets and fundamental mechanisms of bioactive peptides on metabolic syndromes, namely obesity and type 2 diabetes, to provide new ideas and knowledge on the ability of bioactive peptide to control metabolic syndromes.

The Role of Bioactive Peptides in Diabetes and Obesity

Bioactive peptides are present in most soy products and eggs and have essential protective functions. Infection is a core feature of innate immunity that affects blood pressure and the glucose level, and ageing can be delayed by killing senescent cells. Food also encrypts bioactive peptides and protein sequences produced through proteolysis or food processing. Unique food protein fragments can improve human health and avoid metabolic diseases, inflammation, hypertension, obesity, and diabetes mellitus. This review focuses on drug targets and fundamental mechanisms of bioactive peptides on metabolic syndromes, namely obesity and type 2 diabetes, to provide new ideas and knowledge on the ability of bioactive peptide to control metabolic syndromes.

Toxicity of Metformin and Hypoglycemic Therapies

Metformin along with other antidiabetic medications provide benefit to patients in the treatment of type 2 diabetes mellitus, but caution is advised in certain scenarios to avoid toxicity in kidney disease. Renal dosing, monitoring of kidney function, and evaluating the risk of developing serious side effects are warranted with some agents. The available literature with regard to incidence of adverse events and toxicity of hypoglycemic therapies is reviewed.

Can Antidiabetic Drugs Improve Male Reproductive (Dys)Function Associated with Diabetes?

The alarming increase in the number of diabetic patients worldwide raises concerns regarding the impact of the disease on global health, not to mention on social and economic aspects. Furthermore, the association of this complex metabolic disorder with male reproductive impairment is worrying, mainly due to the increasing chances that young individuals, at the apex of their reproductive window, could be affected by the disease, further contributing to the disturbing decline in male fertility worldwide. The cornerstone of diabetes management is glycemic control, proven to be effective in avoiding, minimizing or preventing the appearance or development of disease-related complications. Nonetheless, the possible impact of these therapeutic interventions on male reproductive function is essentially unexplored. To address this issue, we have made a critical assessment of the literature on the effects of several antidiabetic drugs on male reproductive function. While the crucial role of insulin is clear, as shown by the recovery of reproductive impairments in insulin-deficient individuals after treatment, the same clearly does not apply to other antidiabetic strategies. In fact, there is an abundance of controversial reports, possibly related to the various study designs, experimental models and compounds used, which include biguanides, sulfonylureas, meglitinides, thiazolidinediones/glitazones, bile acid sequestrants, amylin mimetics, as well as sodiumglucose co-transporter 2 (SGLT2) inhibitors, glucagon-like peptide 1 (GLP1), α-glucosidase inhibitors and dipeptidyl peptidase 4 (DPP4) inhibitors. These aspects constitute the focus of the current review.

Antidiabetic therapies and male reproductive function: where do we stand?

Diabetes mellitus has been increasing at alarming rates in recent years, thus jeopardizing human health worldwide. Several antidiabetic drugs have been introduced in the market to manage glycemic levels, and proven effective in avoiding, minimizing or preventing the appearance or development of diabetes mellitus-related complications. However, and despite the established association between such pathology and male reproductive dysfunction, the influence of these therapeutic interventions on such topics have been scarcely explored. Importantly, this pathology may contribute toward the global decline in male fertility, giving the increasing preponderance of diabetes mellitus in young men at their reproductive age. Therefore, it is mandatory that the reproductive health of diabetic individuals is maintained during the antidiabetic treatment. With this in mind, we have gathered the available information and made a critical analysis regarding the effects of several antidiabetic drugs on male reproductive function. Unlike insulin, which has a clear and fundamental role on male reproductive function, the other antidiabetic therapies' effects at this level seem incoherent. In fact, studies are highly controversial possibly due to the different experimental study approaches, which, in our opinion, suggests caution when it comes to prescribing such drugs to young diabetic patients. Overall, much is still to be determined and further studies are needed to clarify the safety of these antidiabetic strategies on male reproductive system. Aspects such as the effects of insulin levels variations, consequent of insulin therapy, as well as what will be the impact of the side effect hypoglycemia, common to several therapeutic strategies discussed, on the male reproductive system are still to be addressed.

Synthesis and in vitro evaluation of zerumbone pendant derivatives: potent candidates for anti-diabetic and anti-proliferative activities

A series of zerumbone pendant derivatives were synthesized and evaluated for their α-glucosidase, α-amylase and glycation inhibition activities.

Reported Benefits of Insulin Therapy for Better Glycemic Control in Type 2 Diabetic Patients-Is This Applicable in Saudi Patients?

AIM

To compare the effect of different treatment regimens (oral hypoglycemic agents [OHGs], insulin therapy, and combination of both) on glycemic control and other cardiometabolic risk factors in type 2 diabetes mellitus (T2DM) patients in Saudi.

SUBJECTS AND METHODS

Patients with T2DM, but no serious diabetic complications, were randomly recruited from the diabetes clinics at two large hospitals in Jeddah, Saudi Arabia, during June 2013 to July 2014. Only those without change in treatment modality for the last 18 months were included. Blood pressure and anthropometric measurements were measured. Treatment plan was recorded from the patients’ files. Fasting blood sample was obtained to measure glucose, HbA1c, and lipid profile.

RESULTS

A total of 197 patients were recruited; 41.1% were men and 58.9% were women. The mean (±SD) age was 58.5 ± 10.5 years. Most patients (60.7%) were on OHGs, 11.5% on insulin therapy, and 27.7% were using a combination of insulin and OHGs. The mean HbA1c was lower in patients using OHGs only, compared with means in those using insulin, or combined therapy in patients with disease duration of ≤10 years (P = 0.001) and also in those with a longer duration of the disease (P < 0.001). A lower mean diastolic and systolic blood pressure was found among patients on insulin alone (P < 0.01). No significant differences were found in lipid profiles among the groups.

CONCLUSION

Insulin therapy, without adequate diabetes education, fails to control hyperglycemia adequately in Saudi T2DM patients. There is a challenge to find out reasons for poor control and the ways as to how to improve glycemic control in T2DM.

Sulfonylureas: a new look at old therapy

Sulfonylurea compounds were the first available oral antidiabetic agents and they remain an important tool in our quest for optimal glucose control. The sulfonylureas stimulate the release of insulin from pancreatic β-cells and have a number of extrapancreatic effects, including decreasing hepatic insulin clearance and reducing glucagon secretion in patients with type 2 diabetes. Although these agents have been the mainstay of pharmacotherapy for patients with type 2 diabetes mellitus (T2DM), their safety and clinical utility has been a matter of active debate in recent years, as their use is associated with risks of hypoglycemia and weight gain. We review the discovery and mechanisms of action of sulfonylureas, and the results of clinical trials to provide practical information on the pros and cons of their use in clinical practice. This review addresses advances in our understanding of mechanisms of action of sulfonylurea agents, their efficacy in T2DM, side effects, and impact on cardiovascular disease outcomes.

Overview of food products and dietary constituents with antidiabetic properties and their putative mechanisms of action: a natural approach to complement pharmacotherapy in the management of diabetes

Diabetes is one of the fastest growing chronic, noncommunicable diseases worldwide. Currently, 11 major classes of pharmacotherapy are available for the management of this metabolic disorder. However, the usage of these drugs is often associated with undesirable side effects, including weight gain and hypoglycemia. There is thus a need for new, safe and effective treatment strategies. Diet is known to play a major role in the prevention and management of diabetes. Numerous studies have reported the putative association of the consumption of specific food products, or their constituents, with the incidence of diabetes, and mounting evidence now suggests that some dietary factors can improve glycemic regulation. Foods and dietary constituents, similar to synthetic drugs, have been shown to modulate hormones, enzymes, and organ systems involved in carbohydrate metabolism. The present article reviews the major classes and modes of action of antidiabetic drugs, and examines the evidence on food products and dietary factors with antidiabetic properties as well as their plausible mechanisms of action. The findings suggest potential use of dietary constituents as a complementary approach to pharmacotherapy in the prevention and/or management of diabetes, but further research is necessary to identify the active components and evaluate their efficacy and safety.

GPR40-induced insulin secretion by the novel agonist TAK-875: first clinical findings in patients with type 2 diabetes

AIM

Free fatty acids act as signalling molecules for modulating insulin secretion, and their insulinotropic effects are glucose-dependent and mediated through G protein-coupled receptor 40 (GPR40). This mechanism is a potential target for new treatments for managing diabetes. In this study, we present the first clinical data for TAK-875, a novel highly selective, orally bioavailable GPR40 agonist, in Japanese patients with type 2 diabetes insufficiently controlled by diet or exercise therapy.

METHODS

This was an exploratory phase II, multicentre, randomized, double-blind, parallel group study comparing the efficacy and tolerability of TAK-875 100 and 400 mg, and placebo, all administered once daily for 2 weeks.

RESULTS

After 2 weeks of treatment, TAK-875 produced marked glucose lowering effects in a 75 g oral glucose tolerance test (OGTT) as evidenced by mean ± SE intergroup differences in plasma glucose AUC(0-3 h) of -12.98 ± 1.48 (p < 0.0001) and -8.12 ± 1.49 mmol·h/l (p < 0.0001), for TAK-875 400 mg vs. placebo and TAK-875 100 mg vs. placebo, respectively, and 2 h plasma glucose [-4.95 ± 0.71 (p < 0.0001) and -3.21 ± 0.71 mmol/l (p < 0.0001), respectively]. This was accompanied by a significant increase in insulin AUC(0-3 h) [34.68 ± 12.16 (p < 0.01) and 31.49 ± 12.20 (p < 0 · 05) µIU·h/ml, respectively]. Improvement in glycaemic profile was mirrored by a significant change in fasting plasma glucose [-2.37 ± 0·27 (p < 0.0001) and -1.88 ± 0.27 mmol/l (p < 0.0001), respectively]. No cases of hypoglycaemia were observed despite the significant reduction in plasma glucose.

CONCLUSIONS

These exploratory findings provide evidence of the glucose-dependent insulinotropic potential of the GPR40 agonist TAK-875, and the promising clinical changes support future longer term clinical investigation.

Comparison of metformin, gliclazide MR and rosiglitazone in monotherapy and in combination for type 2 diabetes

OBJECTIVE

To compare the efficacy and tolerability of metformin, rosiglitazone and gliclazide MR as monotherapy and in combination in the treatment of type 2 diabetes.

SUBJECTS AND METHODS

250 patients treated with oral antidiabetic agents for at least 24 weeks in monotherapy or in combination therapy were included in this retrospective study.

RESULTS

As monotherapy the reduction of fasting plasma glucose (FPG), postprandial glycemia (PPG) and HbA1c was similar with the three drugs after 24 weeks. Among patients on combination therapy, the reduction in HbA1c, FPG and PPG was significantly lower with rosiglitazone plus metformin, as compared to metformin plus gliclazide MR or gliclazide MR plus rosiglitazone. Patients treated with rosiglitazone achieved less favorable changes in lipid profile.

CONCLUSION

In monotherapy all drugs were equally effective in improving glycemic control, whereas the combination of metformin plus gliclazide MR provided the best results concerning the improvement of both, glycemic control and lipid profile.

[Childhood-onset diabetes treated with sulphonylureas]

MODY 3 type diabetes belongs to the group of monogenic diabetes and is caused by mutations in the gene for hepatocyte nuclear factor 1-alpha (HNF1-alpha). Although MODY 2 type diabetes is the most frequent form of MODY diabetes in childhood, type 3 is the most frequent in the general population. We report the case of a 12 year old child with basal and post-prandrial hyperglycaemia. No cardinal symptoms of type 1 diabetes mellitus were present. There are numerous cases of diabetes in his family. C-Peptide was 1.13 ng/ml and pancreatic autoimmunity markers were negative. HNF-1alpha gene mutation was found in the patient as well as in his father and sister. Treatment with glibenclamide was started at a dose of 2.5 mg/day in order to reduce the risk of microvascular disease, as this as high in MODY 3 type diabetes as in type 1 diabetes mellitus. Blood glucose returned to normal and glycosylated haemoglobin was maintained between 4.9 and 5.6 %. Side-effects were not observed except some mild hypoglycaemias.

Treating type 2 diabetes: how safe are current therapeutic agents?

Sulphonylureas (SUs) and biguanides (metformin) are the current mainstays in the treatment of type 2 diabetes (T2DM) and represent the most commonly used oral hypoglycaemic agents (OHAs). In recent years, a variety of new OHAs have become available, including thiazolidinediones, glinides, alpha-glucosidase inhibitors, glucagon-like peptide-1 agonists, amylin analogues and dipeptidyl peptidase-IV inhibitors, providing physicians with a larger therapeutic catalogue than ever before. The traditional drugs metformin and SUs have an established safety profile through long-term use. However, long-term clinical trials and routine use are lacking for many of the new agents, and some potentially serious side effects have been reported with several of these compounds. Until adequate data is obtained, it is difficult to assess the risk-benefit ratio of these agents in relation to the traditional drugs. Until that becomes fully documented, it may be wise to start pharmacologic treatment of patients on an individual basis, weighing the benefits and costs of each medication. Thus, there remains a place for well-established drugs that have a proven safety record and are supported by years of clinical use for the treatment of T2DM.

Update on diabetes diagnosis and management

BACKGROUND

The American Diabetes Association has established recommendations for the testing of undiagnosed people. Once diagnosed, those with diabetes must strive to maintain a level of glucose control that results in a metabolism that approaches that of people without diabetes. The dentist also can provide risk-reduction strategies for people prone to develop diabetes, and refer patients with signs and symptoms suggestive of diabetes to physicians.

METHODS

The authors describe criteria for establishing a diagnosis of diabetes and for identifying people at high risk of developing the disease. A combination of approaches in the medical management of type 1 and type 2 diabetes mellitus is presented, along with target outcomes.

RESULTS

Patients with diabetes maintain a glycosylated hemoglobin value of no higher than 7 percent. New therapeutic research includes early clinical trials of islet cell transplantation and therapeutic cloning from human stem cells, which may provide an alternate source of insulin-producing islet cells and, thus, may offer a potential cure for diabetes.

CONCLUSIONS

Rigorous metabolic control of diabetes can be achieved through a combination of therapeutic modalities and the establishment and maintenance of target outcomes. The dentist can implement preventive strategies and refer patients with signs and symptoms suggestive of diabetes to physicians.

CLINICAL IMPLICATIONS

The dentist and physician must work together as a team to achieve rigorous metabolic control of diabetes in their patients.

Pioglitazone and sulfonylureas: effectively treating type 2 diabetes

Type 2 diabetes is characterised by a gradual decline in glycaemic control and progression from oral glucose-lowering monotherapy to combination therapy and exogenous insulin therapy. Functional decline of the insulin-secreting beta-cells is largely responsible for the deterioration in glycaemic control. Preservation of beta-cell functionality, in addition to maintaining glycaemic control and reducing insulin resistance, is now regarded as a key target for long-term management strategies. Early, aggressive intervention with combination therapy is emerging as a valid approach to optimise long-term outcomes and combining agents with differing modes of action and secondary effect profiles should prove valuable. Sulfonylureas and thiazolidinediones exert their glucose-lowering effect through differing mechanisms of action - the sulfonylureas by stimulating insulin secretion, whereas the thiazolidinediones are insulin sensitisers. Both agents offer excellent improvements in glycaemic control when given as monotherapy or in combination. The thiazolidinediones protect beta-cell structural and functional integrity and functionality and complement the sulfonylureas by inducing and maintaining improvements in insulin resistance, the abnormal lipid profile associated with type 2 diabetes and other cardiovascular risk factors. Thus, there is a strong rationale to support the addition of thiazolidinediones to sulfonylureas as a treatment option for type 2 diabetes. This combination may be particularly effective in the early stages of the disease when beta-cell function is at its highest, allowing maximal benefit to be obtained from the insulin secretion-promoting abilities of the sulfonylureas and the beta-cell-protective effects of the thiazolidinediones.

[Treatment of type 2 diabetes: revision of current therapeutical options and priorities]

The paradigm of type 2 diabetes mellitus treatment is based in an adequate meal plan and the regular practice of physical exercise. The benefits of these measures are of evident as it is the perseverance in their compliance. In the daily practice, this reality favours the early implementation of a pharmacological therapy that, in the opinion of different experts, would be simultaneous to the introduction of life style changes. In the last years, new drugs have been developed. On the one hand, there are agents with beneficial effects not only on blood glucose control but also on the components of metabolic syndrome. Other drugs, according to different experts, have doubtful therapeutical contribution. The appearance of new drugs to treat obesity, associated with diabetes or not, extends other possibilities of choice to take into account. The great variety of options makes the decision of the adequate therapy more difficult. In the last decade, many therapeutic guidelines have been developed, with convergences and divergences that may mislead the inexpert practitioners. In this review we propose some practical advise in diet and exercise, and an evaluation of the different drugs and rules of intervention proposed in the different therapeutic guidelines. The ultimate goal is to facilitate and direct type 2 diabetes management.

Pharmacokinetic interactions with thiazolidinediones

Type 2 diabetes mellitus is a complex disease combining defects in insulin secretion and insulin action. New compounds called thiazolidinediones or glitazones have been developed for reducing insulin resistance. After the withdrawal of troglitazone because of liver toxicity, two compounds are currently used in clinical practice, rosiglitazone and pioglitazone. These compounds are generally used in combination with other pharmacological agents. Because they are metabolised via cytochrome P450 (CYP), glitazones are exposed to numerous pharmacokinetic interactions. CYP2C8 and CYP3A4 are the main isoenzymes catalysing biotransformation of pioglitazone (as with troglitazone), whereas rosiglitazone is metabolised by CYP2C9 and CYP2C8. For both rosiglitazone and pioglitazone, the most relevant interactions have been described in healthy volunteers with rifampicin (rifampin), which results in a significant decrease of area under the plasma concentration-time curve [AUC] (54-65% for rosiglitazone, p<0.001; 54% for pioglitazone, p<0.001), and with gemfibrozil, which results in a significant increase of AUC (130% for rosiglitazone, p<0.001; 220-240% for pioglitazone, p<0.001). The relevance of such drug-drug interactions in patients with type 2 diabetes remains to be evaluated. However, in the absence of clinical data, it is prudent to reduce the dosage of each glitazone by half in patients treated with gemfibrozil. Conversely, rosiglitazone and pioglitazone do not seem to significantly affect the pharmacokinetics of other compounds. Although some food components have also been shown to potentially interfere with drugs metabolised with the CYP system, no published study deals specifically with these possible CYP-mediated food-drug interactions with glitazones.

Is daytime insulin more physiologic and less atherogenic than bedtime insulin?

The question is whether bedtime insulin, one of the standard therapy regimens of type 2 diabetes, can be more atherogenic than daytime insulin. There is no study to answer this question. However, pharmacokinetics of drugs and physiopathology of type 2 diabetes are considered, we can assume that daytime OAD plus bedtime insulin therapy might be more atherogenic than daytime insulin plus bedtime OAD therapy. The rationale for combination therapy is based on the assumption that, if evening insulin lowers the fasting glucose concentration to normal, then daytime oral agents will be more effective in controlling postprandial hyperglycemia. However, exogenous insulin administration is not a convenient way to inhibit hepatic glucose production which determines fasting plasma glucose because in post absorptive period, hepatic glucose production is determined by high glucagon and low insulin levels. In postprandial period, beta cell-originated insulin inhibits glucagon synthesis by paracrine effect and also inhibits hepatic glucose production by using half of its concentration that administered to portal system. Since half of insulin that found in portal system is exposed to hepatic clearance to inhibit hepatic glucose production, portal insulin concentration is 2-4-folds higher than peripheral insulin concentration. But, exogenous insulin neither inhibits glucagon synthesis via paracrine effect, nor reaches desired portal concentrations because it has a short half-life and in opposition to physiologic states it is not administered to the portal system. On the contrary, its peripheral concentration is higher than portal one. Thus, exogenous insulin that is used to inhibit hepatic glucose production requires higher concentrations than physiologic values. Eventually, peripheral hyperinsulinemic state which is a risk factor of CVD is created iatrogenically. Bearing in mind that PI3K pathway, working synchronously with the diurnal rhythm of other metabolic hormones, is more active during daytime especially in postprandial period when aminoacids and glucose exist in the environment, and that decreased insulin response in PI3K pathway in diabetics, we may propose iatrogenically created hyperinsulinemia can cause more atherogenic effects via MAPK pathway. For that reason, using OAD instead of bedtime insulin may be a more convenient way to inhibit hepatic glucose production. Thus, glucagon synthesis inhibition can be achieved via paracrine effect of OAD-induced insulin secretion, as well as required portal insulin concentration can be reached by the direct secretion of insulin to the portal system. Moreover, lower peripheral hyperinsulinemia state can be provided.

The incremental costs of recommended therapy versus real world therapy in type 2 diabetes patients

BACKGROUND

The goals of diabetes management have evolved over the past decade to become the attainment of near-normal glucose and cardiovascular risk factor levels. Improved metabolic control is achieved through optimized medication regimens, but costs specifically associated with such optimization have not been examined.

OBJECTIVE

To estimate the incremental medication cost of providing optimal therapy to reach recommended goals versus actual therapy in patients with type 2 diabetes.

METHODS

We randomly selected the charts of 601 type 2 diabetes patients receiving care from the outpatient clinics of Massachusetts General Hospital March 1, 1996-August 31, 1997 and abstracted clinical and medication data. We applied treatment algorithms based on 2004 clinical practice guidelines for hyperglycemia, hyperlipidemia, and hypertension to patients' current medication therapy to determine how current medication regimens could be improved to attain recommended treatment goals. Four clinicians and three pharmacists independently applied the algorithms and reached consensus on recommended therapies. Mean incremental medication costs, the cost differences between current and recommended therapies, per patient (expressed in 2004 dollars) were calculated with 95% bootstrap confidence intervals (CIs).

RESULTS

Mean patient age was 65 years old, mean duration of diabetes was 7.7 years, 32% had ideal glucose control, 25% had ideal systolic blood pressure, and 24% had ideal low-density lipoprotein cholesterol. Care for these diabetes patients was similar to that observed in recent national studies. If treatment algorithm recommendations were applied, the average annual medication cost/patient would increase from 1525 to 2164 dollars. Annual incremental costs/patient increased by 168 dollars (95% CI 133-206 dollars) for antihyperglycemic medications, 75 dollars (57-93 dollars) for antihypertensive medications, 392 dollars (354-434 dollars) for antihyperlipidemic medications, and 3 dollars (3-4 dollars) for aspirin prophylaxis. Yearly incremental cost of recommended laboratory testing ranged from 77-189 dollars/patient.

LIMITATIONS

Although baseline data come from the clinics of a single academic institution, collected in 1997, the care of these diabetes patients was remarkably similar to care recently observed nationally. In addition, the data are dependent on the medical record and may not accurately reflect patients' actual experiences.

CONCLUSION

Average yearly incremental cost of optimizing drug regimens to achieve recommended treatment goals for type 2 diabetes was approximately 600 dollars/patient. These results provide valuable input for assessing the cost-effectiveness of improving comprehensive diabetes care.

Succinic acid monoethyl ester, a novel insulinotropic agent: effect on lipid composition and lipid peroxidation in streptozotocin-nicotin-amide induced type 2 diabetic rats

Succinic acid monoethyl ester (EMS) is recently proposed as an insulinotropic agent for the treatment of non-insulin dependent diabetes mellitus. Oxidative stress has been suggested to be a contributory factor in the development and complications of diabetes. In the present study the effect of EMS and Metformin on plasma glucose, insulin, serum and tissue lipid profile, lipoproteins and lipid peroxidation in streptozotocin-nicotinamide induced type 2 diabetic model was investigated. The carboxylic nutrient EMS was administered intraperitonially (8 micromol/g body weight) to streptozotocin diabetic rats for 30 days. The levels of thiobarbituric acid reactive substances (TBARS) and hydroperoxides in liver and kidney and serum and tissue lipids [cholesterol, triglycerides, phospholipids and free fatty acids] and very low density lipoprotein-cholesterol (VLDL-C) and low density lipoprotein-cholesterol (LDL-C), were significantly increased in diabetic rats, whereas the levels of high-density lipoprotein-cholesterol (HDL-C) and antiatherogenic index (AAI) (ratio of HDL to total cholesterol) were significantly decreased. The effect of EMS was compared with metformin, a reference drug. Treatment with EMS and metformin resulted in a significant reduction of plasma glucose with increase plasma insulin in diabetic rats. EMS also resulted in a significant decrease in serum and tissue lipids and lipid peroxidation products. These biochemical observations were supplemented by histopathological examination of liver and kidney section. Our results suggest the possible antihyperlipidemic and antiperoxidative effect of EMS apart from its antidiabetic effect.

Drug interactions of clinical importance with antihyperglycaemic agents: an update

Because management of type 2 diabetes mellitus usually involves combined pharmacological therapy to obtain adequate glucose control and treatment of concurrent pathologies (especially dyslipidaemia and arterial hypertension), drug-drug interactions must be carefully considered with antihyperglycaemic drugs. Additive glucose-lowering effects have been extensively reported when combining sulphonylureas (or the new insulin secretagogues, meglitinide derivatives, i.e. nateglinide and repaglinide) with metformin, sulphonylureas (or meglitinide derivatives) with thiazolidinediones (also called glitazones) and the biguanide compound metformin with thiazolidinediones. Interest in combining alpha-glucosidase inhibitors with either sulphonylureas (or meglitinide derivatives), metformin or thiazolidinediones has also been demonstrated. These combinations result in lower glycosylated haemoglobin (HbA(1c)), fasting glucose and postprandial glucose levels than with either monotherapy. Even if modest pharmacokinetic interferences have been reported with some combinations, they do not appear to have important clinical consequences. No significant adverse effects, except a higher risk of hypoglycaemic episodes that may be attributed to better glycaemic control, occur with any combination. Challenging the classical dual therapy with sulphonylurea plus metformin, there is a recent trend to use alternative dual combinations (sulphonylurea plus thiazolidinedione or metformin plus thiazolidinedione). In addition, triple therapy with the addition of a thiazolidinedione to the metformin-sulphonylurea combination has been recently evaluated and allows glucose targets to be reached before insulin therapy is considered. This triple therapy appears to be safe, with no deleterious drug-drug interactions being reported so far.Potential interferences may also occur between glucose-lowering agents and other drugs, and such drug-drug interactions may have important clinical implications. Relevant pharmacological agents are those that are widely coadministered in diabetic patients (e.g. lipid-lowering agents, antihypertensive agents); those that have a narrow efficacy/toxicity ratio (e.g. digoxin, warfarin); or those that are known to induce (rifampicin [rifampin]) or inhibit (fluconazole) the cytochrome P450 (CYP) system. Metformin is currently a key compound in the pharmacological management of type 2 diabetes, used either alone or in combination with other antihyperglycaemics. There are no clinically relevant metabolic interactions with metformin, because this compound is not metabolised and does not inhibit the metabolism of other drugs. In contrast, sulphonylureas, meglitinide derivatives and thiazolidinediones are extensively metabolised in the liver via the CYP system and thus, may be subject to drug-drug metabolic interactions. Many HMG-CoA reductase inhibitors (statins) are also metabolised via the CYP system. Even if modest pharmacokinetic interactions may occur, it is not clear whether drug-drug interactions between oral antihyperglycaemic agents and statins may have clinical consequences regarding both efficacy and safety. In contrast, a marked pharmacokinetic interference has been reported between gemfibrozil and repaglinide and, to a lesser extent, between gemfibrozil and rosiglitazone. This leads to a drastic increase in plasma concentrations of each antihyperglycaemic agent when they are coadministered with the fibric acid derivative, and an increased risk of adverse effects. Some antihypertensive agents may favour hypoglycaemic episodes when co-prescribed with sulphonylureas or meglitinide derivatives, especially ACE inhibitors, but this effect seems to result from a pharmacodynamic drug-drug interaction rather than from a pharmacokinetic drug-drug interaction. No, or only modest, interferences have been described with glucose-lowering agents and other pharmacological compounds such as digoxin or warfarin. The effects of inducers or inhibitors of CYP isoenzymes on the metabolism and pharmacokinetics of the glucose-lowering agents of each pharmacological class has been tested. Significantly increased (with CYP inhibitors) or decreased (with CYP inducers) plasma levels of sulphonylureas, meglitinide derivatives and thiazolidinediones have been reported in healthy volunteers, and these pharmacokinetic changes may lead to enhanced or reduced glucose-lowering action, and thus hypoglycaemia or worsening of metabolic control, respectively. In addition, some case reports have evidenced potential drug-drug interactions with various antihyperglycaemic agents that are usually associated with a higher risk of hypoglycaemia.

Disorders of glucose metabolism in the context of human immunodeficiency virus infection

PURPOSE

To discuss the pathophysiology and the current treatment approaches for the dysregulation of glucose metabolism in the context of human immunodeficiency virus (HIV) infection.

DATA SOURCES

Selected research, clinical studies, clinical guidelines, and review articles.

CONCLUSIONS

In HIV infection, multiple factors are associated with the pathogenesis of glucose dysregulation. Studies suggest that protease inhibitors, a class of antiretroviral agent, as well as viral factors, lipodystrophy, hepatitis C infection, injection drug use, and second-generation antipsychotics have been implicated in the development of glucose disorders and diabetes. Current treatment recommendations are based on extrapolated data from non-HIV diabetic patients. More research is needed to establish the most appropriate management for the disorders of glucose metabolism in the context of HIV infection.

IMPLICATIONS FOR PRACTICE

If left untreated, patients are at increased risk for cardiovascular disease and complications associated with untreated diabetes.

Effect of inhibition of alpha-glucosidase on age-related glucose intolerance and pancreatic atrophy in rats

Oral administration of alpha-glucosidase inhibitor reduces postprandial serum glucose and insulin concentrations; thus, alpha-glucosidase inhibitor is used for the treatment of diabetes mellitus worldwide. In our study, we have evaluated the effect of alpha-glucosidase inhibitor, acarbose, on age-related glucose intolerance and pancreatic atrophy in the Long-Evans Tokushima Otsuka (LETO) rat. The first group of rats received a standard rat diet (control). The second group received a diet containing acarbose (150 mg/100 g food) from 12 to 28 weeks and then switched to a standard rat diet until 72 weeks of age (A12-28W). The third group was administered the same diet containing acarbose from 12 to 72 weeks of age (A12-72W). Fasting serum glucose and insulin concentrations gradually increased with increasing age in the control group, but these increases were completely prevented (A12-72W) or delayed (A12-28W) by acarbose treatment. In addition, acarbose treatment prevented the deterioration in insulin resistance with increasing age. At 72 weeks of age, pancreatic wet weight and DNA content in the A12-72W group were significantly higher than those in the control group. Although most islets were enlarged, and some portions of pancreatic tissue contained fatty and connective tissue in the control group, these alterations were mild in the A12-28W group and remained minimal in the A12-72W group. Our study suggests that acarbose is useful in the prevention of age-related glucose intolerance and pancreatic atrophy.

Prevalencia y consumo de medicación antidiabética en la Comunidad de Madrid (1996-2002)

OBJECTIVES/AIMS

To determine the prevalence of diabetes mellitus treated with drugs and the prescription of drugs in diabetes (oral anti-diabetics and insulin) in the Community of Madrid between 1996-2002.

METHODS

We used the indirect method for estimating the rate of prevalence of diabetes based on antidiabetic drug in the Madrid Community. We studied the consumption or oral antidiabetics (OH) and insulin (IN) in all the Madrid Community Area from 1996 to 2002. To make consumption uniform we used the daily doses/1,000 inhabitants/day (DHD). The total consumption was obtained using the official billing data and the annual population data provided by the "Institute Madrileño de Salud".

RESULTS

The prevalence of diabetes mellitus increased 62.5% in the period studied, ranging from 1.6% in 1996 up to 2.6% in 2002. The DHD of oral drugs increased 87.8% from 12.2 in 1996 to 23.07 in 2002. The DHD of insulin decreased 28.2% from 3.99 in 1996 down to 3.11 in 2002. The OH/IN ratio increased 138%, from 3.11 to 7.42 in 2002. There is a tendency to increase biguanide and sulfonilureas with low risk of hypoglycemia. The total cost of insulin and oral medication increase every year, the increase of diabetic patients and the cost/DDD of the new drugs are factors that increase the total cost of diabetes.

CONCLUSIONS

The prevalence of diabetes mellitus treated with drugs increased in the Community of Madrid. There is a progressive use of oral drugs versus insulin, and a tendency to prescribe biguanide, sulfonylureas, especially gliclazide and glimepiride. A tendency to substitute insulin with insulin analogues is also seen in the use of insulin. The cost of diabetes increases yearly.

Improving glucose management: ten steps to get more patients with type 2 diabetes to glycaemic goal

Despite increasingly stringent clinical practice guidelines for glycaemic control, the implementation of recommendations has been disappointing, with over 60% of patients not reaching recommended glycaemic goals. As a result, current management of glycaemia falls significantly short of accepted treatment goals. The Global Partnership for Effective Diabetes Management has identified a number of major barriers that can prevent individuals from achieving their glycaemic targets. This article proposes 10 key practical recommendations to aid healthcare providers in overcoming these barriers and to enable a greater proportion of patients to achieve glycaemic goals. These include advice on targeting the underlying pathophysiology of type 2 diabetes, treating early and effectively with combination therapies, adopting a holistic, multidisciplinary approach and improving patient understanding of type 2 diabetes. Implementation of these recommendations should reduce the risk of diabetes-related complications, improve patient quality of life and impact more effectively on the increasing healthcare cost related to diabetes.

Glycemic management of type 2 diabetes: an emerging strategy with oral agents, insulins, and combinations

The many antihyperglycemic preparations are best used for type 2 diabetes in a logical sequence, using combinations of agents, with clear targets for glycemic control. On the basis of long familiarity, proven benefit and known side effects, and low cost, the sulfonylureas, metformin, and insulin still deserve to be the standard treatments. As shown in the central shaded area of Fig. 4, standard treatment begins with monotherapy and progresses to oral combination therapy and then to two oral agents plus basal insulin. Several triggers for deviation from the standard methods are identified (see Fig. 4). The incidence of each of the conditions that require early individualized treatment has not been studied, but it seems reasonable to estimate no more than 10% each for a strongly symptomatic presentation, inability to use a sulfonylurea or metformin, inability to use insulin, or an early need for prandial therapy. If this estimate is correct, approximately two thirds of patients who are diagnosed with type 2 diabetes should do well with standard therapy for up to 10 years using the standard methods shown. Eventually, many more will need individualized treatment to maintain glycemic control. This scheme is certain to evolve as further information on the nonglycemic benefits (or hazards) of the various therapies appears and as new treatments are released. Notably, agents that mimic or potentiate the effects of gastrointestinal peptides, such as amylin and GLP- 1 analogues and dipeptidyl peptidase IV inhibitors, are likely to alter the current algorithm. For now, systematic application of the scheme (see Fig. 4) should improve the success of treatment greatly from its currently disappointing level.

Oral antihyperglycemic therapy for type 2 diabetes mellitus

Diabetes mellitus is a chronic disease that is growing in prevalence worldwide. Pharmacologic therapy is often necessary to achieve optimal glycemic control in the management of diabetes. Orally administered antihyperglycemic agents (OHAs) can be used either alone or in combination with other OHAs or insulin. The number of available OHAs has increased significantly in the last decade, which translates into more therapeutic options and complex decision-making for physicians. This review article is designed to help with these decisions. We review the mechanism of action, efficacy and side effects of the different classes of OHAs (alpha-glucosidase inhibitors, biguanides, insulin secretagogues, insulin sensitizers and intestinal lipase inhibitor) and discuss the current recommendations for their use.

Treatment of insulin resistance in diabetes mellitus

Insulin resistance is a condition in which the glycemic response to insulin is less than normal. The change in insulin sensitivity leads to several sets of responses. One set effects the beta cell and leads to its accelerated destruction and the development of diabetes mellitus. The other set generates a series of nontraditional cardiovascular risk factors that result in accelerated atherosclerosis. Both of these sets of responses may have impacts on other tissues such as the nervous system. Insulin resistance is probably the result of increased visceral adiposity with increased release of free fatty acids and cytokines and a decreased release of adiponectin. Treatment of insulin resistance and its associated abnormalities can be achieved by lifestyle modification which results in weight loss, by drugs that reverse the abnormal adipocyte effects, by drugs that improve insulin sensitivity at the level of the liver and by anti-inflammatory agents that block activation of the nuclear factor kappa B cascade.

Achieving Glycemic Control in Type 2 Diabetes: A Practical Guide for Clinicians on Oral Hypoglycemics

Type 2 diabetes mellitus has reached epidemic proportions in the United States. Cardiovascular morbidity and mortality are particularly high in this patient population. Improved glucose control, especially early in the course of diabetes, can slow or prevent complications, preserve beta-cell function, and improve long-term outcomes. Within the last decade, new treatments and glycemic goals have created an opportunity to better manage this prevalent, chronic disease. Defects of insulin resistance and deficiency leading to type 2 diabetes can now be directly targeted with available therapies. In addition to diet and exercise, oral treatment options have been broadened, with both insulin secretagogues and insulin sensitizers. These advances in treatment options make glycemic control an obtainable target, and therefore should improve overall morbidity and mortality for patients. This paper will review currently available oral therapies, with a focus on the unique attributes of the insulin sensitizers for patients with type 2 diabetes.

Sulfonylurea treatment of type 2 diabetes mellitus: focus on glimepiride

Sulfonylureas, which have evolved through two generations since their introduction nearly 50 years ago, remain the most frequently prescribed oral agents for treatment of patients with type 2 diabetes mellitus. Glyburide, glipizide, and glimepiride, the newest sulfonylureas, are as effective at lowering plasma glucose concentrations as first-generation agents but are more potent, better tolerated, and associated with a lower risk of adverse effects. Differences in their binding affinity to the beta-cell sulfonylurea receptor have been described, with preservation of cardioprotective responses to ischemia with glimepiride. Clinical studies have shown glimepiride to be safe and effective in reducing fasting and postprandial glucose levels, as well as glycosylated hemoglobin concentrations, with dosages of 1-8 mg/day. In comparative trials, glimepiride was as effective in lowering glucose levels as glyburide and glipizide, but glimepiride was associated with a reduced likelihood of hypoglycemia and a smaller increase in fasting insulin and C-peptide levels than glyburide, and a more rapid lowering of fasting plasma glucose levels than glipizide. Glimepiride also improves first-phase insulin secretion, which plays an important role in reducing postprandial hyperglycemia. Insulin secretagogues, specifically glimepiride, merit consideration as first-line therapy for patients with type 2 diabetes.

Metformin, pre-eclampsia, and pregnancy outcomes in women with polycystic ovary syndrome

AIMS

Was metformin during pregnancy in women with polycystic ovary syndrome (PCOS) associated with pre-eclampsia, and was it safe for mother and neonate?

METHODS

In the current study, pre-eclampsia and other pregnancy outcomes were prospectively studied in 90 women with PCOS who conceived on metformin 1.5-2.55 g/day, and had > or = 1 live birth (97 pregnancies, 100 live births) compared with 252 healthy women (not known to have PCOS) with > or = 1 live birth, consecutively delivered in a community obstetrics practice.

RESULTS

Women with PCOS were older than controls (33 +/- 5 vs. 29 +/- 6 years, P < 0.0001), more likely to be > 35 years old at conception (23 vs. 13%, P = 0.028), much heavier (93 +/- 23 vs. 72 +/- 18 kg, P < 0.0001, BMI 33.8 +/- 7.8 kg/m2 vs. 25.6 +/- 5.9, P < 0.0001), and more likely to be Caucasian (97 vs. 90%, P = 0.05), but there were similar numbers with preconception Type 2 diabetes mellitus [2/90 (2.2%) vs. 1/252 (0.4%), P = 0.17]. Pre-eclampsia in PCOS (5/97 pregnancies, 5.2%), did not differ (P = 0.5) from controls (9/252, 3.6%), nor did it differ (P = 1.0) in PCOS vs. control primigravidas [2/45 (4.4%) vs. 4/91 (4.4%)]. Development of gestational diabetes in PCOS did not differ from controls [9/95 pregnancies (9.5%) vs. 40/251 (15.9%), P = 0.12]. Of the 100 live births to 90 women with PCOS, there were no major birth defects. Mean +/- sd birth weight of the 80 live births > or = 37 weeks gestation in women with PCOS (3414 +/- 486 g) did not differ from controls' 206 live births > or = 37 weeks (3481 +/- 555 g), P = 0.34, nor did the percentage of > or = 37 week gestation neonates > or = 4000 g (12.5 vs. 17.5%, P = 0.3) or > or = 4500 g (1.3 vs. 2.9%, P = 0.7).

CONCLUSIONS

Metformin is not associated with pre-eclampsia in pregnancy in women with PCOS, and appears to be safe for mother and fetus.

Treatment of the metabolic disturbances caused by antipsychotic drugs: focus on potential drug interactions

The risk of excessive bodyweight gain, glucose dysregulation and hyperlipidaemia is differentially increased by conventional and atypical antipsychotic drugs. Switching or combining agents may be sufficient in some cases, but in many instances additional drug treatment will be required. This includes oral antidiabetics, insulin and agents to treat hyperlipidaemia, hypertension and platelet dysfunction, among others. Numerous pharmacokinetic and pharmacodynamic interactions with the antipsychotics are possible, although few have been tested in formal studies. After reviewing the literature, the authors provide preliminary guidelines to assist clinicians in drug selection for this complex and fragile clinical population.

Oral antidiabetic agents: 2004

The appropriate management of patients with type 2 diabetes presents many challenges to health care providers. The first several years of type 2 diabetes are likely to be unrecognized and untreated. The pathophysiology of type 2 diabetes dictates that treatment of insulin resistance should be an early and central focus for every therapeutic program. The pharmacologic tools currently available are capable of allowing most patients with type 2 diabetes to achieve good metabolic control. Implementation of early combination therapy is essential if glycemic targets are to be met.

Drug Therapy in Transplant Recipients

Elderly patients with end-stage organ failure are now more frequently undergoing transplantation. Medication management in this population is challenging because of the combination of multiple comorbidities, polypharmacy, and immunological, pharmacokinetic and pharmacodynamic changes attributable to the aging process. Immunosuppressive medications can exacerbate pre-existing medical conditions and promote the development of disease processes. Cardiovascular disorders, such as hypertension, coronary artery disease, congestive heart failure and arrhythmias are common in elderly transplant recipients, and account for most of the deaths in this population. Blood pressure, blood glucose and cholesterol control is of particular concern because elderly transplant recipients frequently have or develop these complications. Elderly transplant recipients are commonly receiving anticoagulation therapy with warfarin and are at a higher risk of bleeding, especially if they have renal dysfunction. Infectious complications occur frequently in the transplanted population, with pneumonia being the most common infection seen in hospitalised patients. Attention to vaccination for the prevention of influenza and pneumococcal infections is important because of the increased risk of these diseases in this population. Depression itself has been associated with decreased survival in older individuals, and depression in elderly transplant recipients may be reversible with the administration of pharmacological agents. Effective long-term care of transplant recipients demands an understanding of how particular medications affect clinical evaluation and treatment. This article addresses some of the practical issues surrounding medication management and prevention of these particular problems in elderly transplant recipients.

Current management strategies for coexisting diabetes mellitus and obesity

Besides genetic predisposition, obesity is the most important risk factor for the development of diabetes mellitus. Weight reduction has been shown to markedly improve blood glucose control and vascular risk factors associated with insulin resistance in obese individuals with type 2 diabetes. Therapeutic strategies for the obese diabetic patient include: (i) promoting weight loss, through lifestyle modifications (low-calorie diet and exercise) and antiobesity drugs (orlistat, sibutramine, etc.); (ii) improving blood glucose control, through agents decreasing insulin resistance (metformin or thiazolidinediones, e.g. pioglitazone and rosiglitazone) or insulin needs (alpha-glucosidase inhibitors, e.g. acarbose) in preference to agents stimulating defective insulin secretion (sulphonylureas, meglitinide analogues); and (iii) treating common associated risk factors, such as arterial hypertension and dyslipidaemias, to improve cardiovascular prognosis. Whenever insulin is required by the obese diabetic patient after failure to respond to oral drugs, it should be preferably prescribed in combination with an oral agent, more particularly metformin or acarbose, or possibly a thiazolidinedione. When morbid obesity is present, both restoring a good glycaemic control and correcting associated risk factors can only be obtained through a marked and sustained weight loss. This objective justifies more aggressive weight reduction programmes, including very-low-calorie diets and bariatric surgery, but only within a multidisciplinary approach and long-term strategy.

Is there a role for alpha-glucosidase inhibitors in the prevention of type 2 diabetes mellitus?

Type 2 diabetes mellitus is a major health problem associated with excess morbidity and mortality. As the prevalence of this metabolic disorder is rapidly increasing and current treatment fails to stabilise the disease in most patients, prevention should be considered as a key objective in the near future. People who develop type 2 diabetes pass through a phase of impaired glucose tolerance (IGT). Defects in the action and/or secretion of insulin are the two major abnormalities leading to development of glucose intolerance. Any intervention in the impaired glucose tolerance phase that reduces resistance to insulin or protects the beta-cells, or both, should prevent or delay progression to diabetes.Acarbose, miglitol and voglibose act by competitively inhibiting the alpha-glucosidases, a group of key intestinal enzymes involved in the digestion of carbohydrates. They decrease both postprandial hyperglycaemia and hyperinsulinaemia, and thereby may improve sensitivity to insulin and release the stress on beta-cells. These compounds do not induce hypoglycaemia and have a good safety profile, although gastrointestinal adverse effects may limit long-term compliance to therapy. The recent placebo-controlled prospective STOP-noninsulin-dependent diabetes mellitus (STOP-NIDDM) trial demonstrated that acarbose 100mg three times daily reduces the risk of developing type 2 diabetes in patients with IGT (relative risk reduction of 25% after a mean follow-up of 3.3 years). The 6-year Early Diabetes Intervention Trial (EDIT), comparing the effect of acarbose 50mg three times daily to that of metformin, showed a trend to a positive effect of acarbose compared with placebo, in a mid-term 3-year analysis, which should be confirmed in the final analysis. To our knowledge, no such prevention intervention trials have been or are currently being performed with miglitol or voglibose. In conclusion, because of its absence of toxicity and its particular mechanism of action on gastrointestinal tract and indirect consequences on both insulin action and beta-cell function, acarbose may be used to prevent type 2 diabetes. If the ongoing EDIT trial confirms the positive results of the recent STOP-NIDDM trial, acarbose could be used, either as an alternative or in addition to changes in lifestyle, to delay development of diabetes in patients with IGT. However, the best dosage of acarbose for this specific indication remains to be specified, especially when all three important parameters, efficacy, tolerance and cost, are taken into consideration.

New developments in type 2 diabetes mellitus: combination therapy with a thiazolidinedione

BACKGROUND

Diabetes mellitus (DM) is a serious, chronic metabolic disease affecting approximately 17 million Americans. The microvascular and macrovascular complications of DM are associated with considerable morbidity and mortality.

OBJECTIVES

This article reviews the importance of normalizing blood glucose values to reduce the risk of microvascular and macrovascular complications, discusses available treatment options for type 2 DM, and explores the rationale for combination therapy that includes a thiazolidinedione.

METHODS

Relevant articles were selected from published reports and conference presentations from the last 10 years on oral agents for monotherapy and combination therapy for type 2 DM. Other sources were identified from the reference lists of selected articles.

RESULTS

Choices for the pharmacologic treatment of hyperglycemia in patients with type 2 DM include thiazolidinediones, insulin secretagogues, biguanides, and alpha-glucosidase inhibitors. Each of these drug classes is effective in lowering blood glucose concentrations; however, they have distinctly different mechanisms of action that target various pathophysiologic causes of type 2 DM and have different adverse-event profiles. in addition, several of these agents provide unique benefits unrelated to their hypoglycemic effects. Thiazolidinediones offer the therapeutic benefits of increasing insulin sensitivity and perhaps preserving beta-cell function. Use of a thiazolidinedione from the time type 2 DM is diagnosed improves insulin sensitivity, thereby improving glycemic control and minimizing complications. Over time, however, many patients with type 2 DM are unable to maintain adequate glycemic control (ie, glycosylated hemoglobin [HbA(1c)] <7%) with monotherapy. Combination therapy with agents from different classes may be necessary to achieve blood glucose control through an additive reduction in HbA(1c). The combination of a thiazolidinedione and a biguanide reduces hyperglycemia, hyperinsulinemia, and insulin resistance and improves factors that have been implicated in the pathogenesis of cardiovascular complications.

CONCLUSIONS

Patients with type 2 DM who are not able to maintain their HbA(1c). <7% with monotherapy should be considered candidates for combination therapy. Appropriate combination therapy includes treatment with 2 or more agents with different, complementary mechanisms of action. For example, the combination of a thiazolidinedione and a biguanide improves insulin sensitivity and lowers blood glucose through complementary pathways, and therefore produces an additive effect.

Current therapeutic options in type 2 diabetes mellitus: a practical approach

The incidence of type 2 diabetes mellitus (DM) in the United States continues to grow rapidly, paralleling the overweight and obesity epidemic. For many years the only therapeutic options for type 2 DM were sulfonylureas and insulin. However, over the last 9 years there has been an explosion of new and exciting agents approved for the treatment of type 2 DM. Some of the treatments target insulin deficiency and others insulin resistance, the hallmarks of the disease. Other drugs delay the intestinal absorption of carbohydrate. Recently several combination agents have been released. With these new drugs has come an overwhelming mountain of information, making it difficult for the busy clinician to know how best to manage the ever-increasing portion of patients with type 2 DM. New questions have arisen: Which agent to start as first line? How much of this drug to use before adding something else? How long for this drug to reach full effect? Which agent to add second? Should a patient uncontrolled on dual therapy begin insulin or start a third oral agent? If insulin therapy is started, what should become of the patient's oral agents? How best to explain the patient's weight gain on therapy? These are not easy questions and no review can fully detail all the therapeutic combinations possible. Instead, the practical approach of reviewing the agents in terms of their mechanism of action and critically comparing their dosing, effect and cost, is undertaken herein. Also addressed is the possible niche some newer classes of agents and combination drugs may or may not hold in the management of type 2 DM. The decision of using insulin versus a third oral agent will be looked at from the standpoint of where the patient is on dual therapy in relation to the hemoglobin A1c goal. In this way it is hoped that some clarity will be brought to the dizzying array of information that both the physician and patient have to deal with in regard to the management of this prevalent and serious disease.

Current trends in preoperative patient evaluation and management for podiatric surgeons

In preparation for elective foot and ankle surgery, the podiatric surgeon often will refer the patient for a preoperative evaluation. Surgeons rely on the input of that consultant to provide a determination as to the operative risk for the patient. This article reviews the fundamental parts of the preoperative evaluation, perioperative patient management, and recent changes and trends within this arena.

Clinical significance of targeting postprandial and fasting hyperglycemia in managing type 2 diabetes mellitus

Measurement of glycosylated hemoglobin (HbA1c) remains the gold standard for the assessment of glycemic control in patients with type 2 diabetes. Recent investigations have studied the correlations between HbA1c levels and other aspects of glucose metabolism, specifically, postprandial glucose (PPG) and fasting plasma glucose (FPG). The results suggest that PPG is also important to overall glycemic control and may be a better index of glucose regulation than FPG. Further, elevated PPG values have been associated with cardiovascular complications and cardiovascular mortality. Such evidence has led to recommendations that PPG levels be monitored as part of type 2 diabetes management, in addition to HbA1c and FPG. These glycemic parameters are differentially affected by the various classes of oral antidiabetic agents used in the treatment of type 2 diabetes--sulfonylureas, meglitinides, insulin sensitizers and alpha-glucosidase inhibitors. The sulfonylureas, for example, lower HbA1c, PPG and FPG, while the meglitinides have virtually no effect on FPG. The insulin sensitizer metformin, on the other hand, does not affect PPG levels, whereas the alpha-glucosidase inhibitors, in the presence of a high-carbohydrate diet, can effectively lower PPG. Many patients receive combination therapy, thereby benefiting from multiple mechanisms of glucose control, although in most cases insulin must later be added to the regimen in order to effectively suppress FPG. Thus, all aspects of glucose metabolism appear to be clinically relevant and should be monitored for effective diabetes management. Further study will more precisely define the clinical significance of PPG.

Rationale for and role of thiazolidinediones in type 2 diabetes mellitus

Several classes of antihyperglycemic agents are available for the treatment of patients with type 2 diabetes. These agents, including thiazolidinediones, biguanides, insulin secretagogues, alpha-glucosidase inhibitors, and insulin, offer differing mechanisms of actions and can be used either alone or in combination. The thiazolidinediones are a newer class of oral antidiabetic agents that improve glycemic control and may preserve beta-cell function. Clinical trial data suggest that patients with type 2 diabetes experience progressive deterioration of beta-cell function. By decreasing insulin resistance, thiazolidinediones may preserve beta-cell function, and patients may experience prolonged glycemic control. The thiazolidinediones also exert beneficial effects on dyslipidemia, endothelial function, coagulation, and blood pressure. By improving these components of the metabolic syndrome, thiazolidinediones may reduce the incidence of both microvascular and macrovascular complications. This article provides an overview of the role of thiazolidinediones in the treatment of type 2 diabetes.

Combination therapy with nateglinide and a thiazolidinedione improves glycemic control in type 2 diabetes

OBJECTIVE

To compare the effects of monotherapy using nateglinide and the thiazolidinedione troglitazone with initial combination of the two agents on glycated hemoglobin (HbA(1c)) in patients with type 2 diabetes inadequately controlled by diet alone.

RESEARCH DESIGN AND METHODS

This study consisted of a 28-week, double-blind, randomized, multicenter study that included a 4-week, single-blind, placebo, run-in period and a 24-week (shortened to 16 weeks), double-blind, active treatment period.

RESULTS

At the 16-week end point, nateglinide 120 mg, troglitazone 600 mg, and the combination of the agents achieved statistically significant decreases in HbA(1c) in comparison with placebo and a baseline HbA(1c) of 8.1-8.4% (P < 0.001). The reductions in HbA(1c) were similar in the nateglinide (0.6%) and troglitazone (0.8%) monotherapy groups. The reduction in HbA(1c) (1.7%) was greatest in the combination group; 79% of patients in the combination group achieved HbA(1c) levels of <7%. The combination group had a higher number of adverse events, primarily due to an increased incidence of mild hypoglycemia in this treatment group.

CONCLUSIONS

Nateglinide and troglitazone are equally effective in decreasing HbA(1c) levels. However, these reductions from baseline HbA(1c) values of >8% are not adequate to achieve HbA(1c) levels of <7%. In contrast, the combination of nateglinide and of a thiazolidinedione shows an additive effect that is highly effective in reducing HbA(1c) levels to the target of <7% in 66% of patients, from a baseline HbA(1c) that is just above 8%.

Genetically defined pancreatic beta cell failure

The major subtypes of diabetes mellitus (DM) are complex diseases in which the interactions between genetic susceptibility and metabolic, immunologic and environmental factors ultimately lead to the clinical phenotype. The unraveling of these factors and the study of their contribution to the pathogenesis of DM is a process of unimaginable complexity. As a result, despite the individual differences in DM phenotype, most patients with DM receive treatment according to generalized treatment protocols, only discriminating between Type 1 and Type 2 DM and not related to the individual genetic background of the patients. Nevertheless, in recent years, much progress has been made in the search for genetic factors in DM. As an example, the recognition of monogenetic defects in beta cell function has lead to the definition of novel DM subtypes, which have important implications for the individual therapeutic approach for these patients and the understanding of the etiology of DM.