Subclinical states of glucose intolerance and risk of death in the U.S

Cost-consequence analysis in a French setting of screening and optimal treatment of nephropathy in hypertensive patients with type 2 diabetes

AIM

Forty percent of hypertensive type 2 diabetes patients develop nephropathy (microalbuminuria/overt nephropathy), indicating end organ damage, increased risk of cardiovascular disease (CVD), and death. In France, screening rates and nephropathy treatment are suboptimal. We assessed the health economic impact of nephropathy screening in hypertensive patients with type 2 diabetes followed by optimal antihypertensive/nephroprotective therapy in those who have nephropathy in France.

METHODS

A Markov/Monte Carlo model simulated lifetime impacts of screening for albuminuria (microalbuminuria/overt nephropathy) using semi-quantitative urine dipsticks in a primary care setting, and subsequent addition of irbesartan 300 mg to conventional therapy in hypertensive type 2 diabetes patients identified as having nephropathy. Progression from no renal disease to end-stage renal disease (ESRD) was simulated. Probabilities, utilities and costs of CVD events, medications and ESRD treatment came from published sources. Cumulative incidence of ESRD, life expectancy, quality-adjusted life years (QALYs) and direct costs were projected. Second-order Monte Carlo simulation accounted for uncertainty in multiple parameters. Costs and QALYs were discounted at 3% annually.

RESULTS

Screening and optimized treatment led to a 42% reduction in the cumulative incidence of ESRD from 10.1 +/- 9.9% without screening to 5.8 +/- 5.7%, improvements in life expectancy of 0.38 +/- 0.59 years, improvements of 0.29 +/- 0.32 QALYs, and decreased costs of Euro 4,812 +/- 7,882/patient over 25 years. Sensitivity analysis showed that the results were robust. Screening was most beneficial when performed in younger patients.

CONCLUSION

In hypertensive patients with type 2 diabetes, screening for albuminuria followed by optimal antihypertensive/nephroprotective treatment improves patient outcomes and leads to cost savings in France.

Therapy insight: Influence of type 2 diabetes on the development, treatment and outcomes of cancer

Although type 2 diabetes and cancer are major health concerns among the adult population, few studies have directly addressed the relationship between the two, or the impact of diabetes on cancer outcomes. Diabetes and hyperglycemia are associated with an elevated risk of developing pancreatic, liver, colon, breast, and endometrial cancer. When treating cancer patients who have diabetes, clinicians must consider the cardiac, renal, and neurologic complications commonly associated with diabetes. Chemotherapeutic choices and, ultimately, the outcome for cancers may be affected by the avoidance of agents that have been shown to provide the best clinical response and survival in cancer patients without other disease complications. Evidence from population-based studies and clinical trials indicate that hyperglycemic and diabetic patients experience higher mortality and recurrence rates after diagnosis with, and treatment for, cancer. Evidence from the intensive care literature indicates that achieving glucose control leads to better clinical outcomes. If so, continued improvement of cancer outcomes may depend upon improved diabetes control. The association between diabetes and cancer is complex and warrants further study as the general population ages and the magnitude of both health problems continues to grow. Here we consider the influence of diabetes and hyperglycemia on the development, treatment, and long-term outcomes of cancer.

Should an oral glucose tolerance test be performed routinely in all renal transplant recipients?

Posttransplantation diabetes (PTD) contributes to cardiovascular disease and graft loss in renal transplant recipients (RTR). Current recommendations advise fasting blood glucose (FBG) as the screening and diagnostic test of choice for PTD. This study sought to determine (1) the predictive power of FBG with respect to 2-h blood glucose (2HBG) and (2) the prevalence of PTD using FBG and 2HBG compared with that using FBG alone, in prevalent RTR. A total of 200 RTR (mean age 52 yr; 59% male; median transplant duration 6.6 yr) who were > 6 mo posttransplantation and had no known history of diabetes were studied. Patients with FBG < 126 mg/dl (7.0 mmol/L; n = 188) underwent an oral glucose tolerance test (OGTT). Receiver operating characteristic analyses evaluated the optimal level of FBG predictive of PTD (2HBG > or = 200 mg/dl [11.1 mmol/L]) and impaired glucose tolerance (IGT; 2HBG 140 to 200 mg/dl [7.8 to 11.0 mmol/L]). An abnormal OGTT was reported in 79 (42%) nondiabetic RTR: PTD (n = 22) and IGT (n = 57). The optimal FBG that was predictive of PTD was 101 mg/dl (5.6 mmol/L; area under the curve 0.70; sensitivity 64%, specificity 67%, positive predictive value 20%, negative predictive value 93%). The optimal FBG that was predictive of IGT was less well defined (area under the curve 0.54). The prevalence of PTD was higher by OGTT than by FBG alone (17 versus 6%; P < 0.001). FBG may not be the optimal screening or diagnostic tool for PTD or IGT in RTR. Consideration should be given to introducing the OGTT as a routine posttransplantation investigation, although the implications of a pathologic OGTT are still to be determined in this population.

The importance of tight glycemic control

Macrovascular complications of diabetes are the leading cause of morbidity and mortality in patients with diabetes and may begin well before diabetes is diagnosed. The precise mechanism of how postprandial hyperglycemia contributes to the pathogenesis of cardiovascular disease is not fully known but may be a result of direct effects on the vasculature. Several epidemiologic studies have suggested that increased glycemic exposure, especially postchallenge or postprandial hyperglycemia, is an independent risk factor for macrovascular disease with no apparent upper or lower threshold. Evidence is emerging that this association is also present in the prediabetic and nondiabetic states. In fact, therapies targeting postprandial hyperglycemia have shown reductions in cardiovascular events in patients with impaired glucose tolerance. Meal-related self-monitoring of blood glucose can inform patients and their healthcare providers about postprandial glycemic excursions so that diet, exercise, or medications can be adjusted.

Metabolic Syndrome and Risk of Cardiovascular Events After Myocardial Infarction

OBJECTIVES

We aimed to assess the prevalence and prognostic role of metabolic syndrome (METS) and diabetes in post-myocardial infarction (MI) patients.

BACKGROUND

Diabetes is a well known risk factor for patients with previous MI, but glycemic dysmetabolism develops over a protracted period of time. Scanty data are available on the role of METS in patients with previous MI.

METHODS

Adjusted Cox's regression models, having diabetes, death, major cardiovascular events (CVE), and hospitalization for congestive heart failure (CHF) during follow-up as outcome events, were fitted on 11,323 patients with prior MI enrolled in the GISSI-Prevenzione Trial.

RESULTS

At baseline, 21% and 29% of patients had diabetes mellitus and METS, respectively. The METS patients had a significant (93%) increased risk of diabetes during follow-up. As compared with control subjects, the probability of death and CVE were higher in both METS (+29%, p = 0.002; +23%, p = 0.005) and diabetic patients (+68%, p <0.0001; +47%, p <0.0001), although diabetic but not METS patients were more likely to be hospitalized for CHF (+89%, p <0.0003 and +24%, p = 0.241). Moderate (-6% to -10%) and substantial (>-10%) weight reduction were associated with a significant (18% and 41%, respectively) decreased risk of diabetes. Weight gain was significantly associated with increased risk of diabetes. The risk conferred by METS and diabetes tended to be higher among women.

CONCLUSIONS

In patients with MI, METS and diabetes were highly prevalent and are associated with increased risk of death and CVE. Diabetes is also associated with increased risk of hospitalization for CHF. Weight reduction significantly decreased the risk of becoming diabetic in patients with METS.

Glucose intolerance and all-cause mortality in Japanese migrants

OBJECTIVE

To assess all-cause mortality in a Japanese-Brazilian community according to the categories of glucose tolerance.

STUDY DESIGN AND SETTING

The cohort consisted of participants examined in two phases of a follow-up study started in 1993 (n=647). They were interviewed and submitted to an oral glucose tolerance test. Student's t-test was used to compare baseline parameters between alive and dead subjects. Cox proportional hazards model was used to estimate crude and adjusted hazard ratios (HR).

RESULTS

Seventy-one deaths occurred during the study period and a higher proportion of men (62%) was detected. Crude all-cause mortality rate was 16.2/1000 person-year. Vascular disease and cancer were the most frequent causes of deaths (77.3%). A higher mortality rate was observed in subjects with diabetes when compared with the normal glucose tolerant ones (HR: 2.0; 95% CI: 1.1-3.6), independently of age, systolic blood pressure, smoking and history of myocardial infarction.

CONCLUSION

Also among Japanese living in the Western world, a deleterious role of fasting and 2-h plasma glucose was found on mortality especially among younger subjects.

Factors predicting the development of metabolic syndrome and type II diabetes against a background of hypertension

BACKGROUND

The metabolic syndrome (MetS), predicting coronary heart disease (CHD), is a compound of risk factors including diabetes, obesity and hypertension. The relationship between the development of MetS, diabetes and CHD in patients with established hypertension is unclear. We hypothesized that patients with hypertension developing MetS are at increased risk of type II diabetes and CHD compared with patients who do not develop MetS.

MATERIALS AND METHODS

We prospectively studied 284 patients (100 with existing/established MetS) with hypertension but without diabetes and CHD over 4 years. MetS and diabetes were diagnosed by the modified NCEP and ADA criteria, and CHD risk by the Framingham risk equation; all patients had annual fasting blood sampling.

RESULTS

Over 4 years of follow up, 75 of the 184 patients (41%) initially free of MetS at baseline subsequently fulfilled the criteria for MetS. These patients (i.e. 'developing MetS') had higher baseline BMI, triglycerides and lower HDL cholesterol, with a higher calculated CHD risk (all P <or= 0.001) than those who did not develop MetS. The 4-year odds ratios of developing diabetes in the patients with established MetS (23%) and the patients developing MetS (13.3%) vs. the patients not developing MetS (3.7%, P < 0.001) were 7.8 (95% CI: 2.6-23.5) and 4.0 (95% CI: 1.2-13.4), respectively.

CONCLUSIONS

Patients with hypertension developing MetS have an increased CHD risk and risk of developing type II diabetes even before fulfilling the criteria for MetS, and the former is comparable to patients with established MetS. These data suggest a high-risk phase not adequately identified by current diagnostic thresholds for MetS.

Cross-sectional evaluation of the Finnish Diabetes Risk Score: a tool to identify undetected type 2 diabetes, abnormal glucose tolerance and metabolic syndrome

The aim of this study was to assess the performance of the Finnish Diabetes Risk Score as a screening tool for undetected type 2 diabetes (T2D), abnormal glucose tolerance (AGT) and metabolic syndrome in the general population. In a cross-sectional, population-based survey, a total of 4,622 subjects aged 45-74 years were invited to a health examination that included an oral glucose tolerance test. Full data with risk score estimate and glucose tolerance status were available for 2,966 subjects without a prior history of diabetes. The risk score was associated with the presence of previously undiagnosed T2D, AGT, metabolic syndrome and cardiovascular risk factors. The area under the receiver operating curve for the prevalence of undiagnosed diabetes was 0.72 in men and 0.73 in women. The sensitivity using a cutoff risk score of 11 to identify undiagnosed diabetes was 66% in men and 70% in women; the corresponding false-positive rates were 31% and 39%, respectively. The area under the receiver operating curve for detecting the metabolic syndrome was 0.72 in men and 0.75 in women. The Finnish Diabetes Risk Score can be used as a self-administered test to screen subjects at high risk for T2D. It can also be used in the general population and clinical practice to identify undetected T2D, AGT and the metabolic syndrome.

n-3 long-chain polyunsaturated fatty acids in type 2 diabetes: a review

Historically, epidemiologic studies have reported a lower prevalence of impaired glucose tolerance and type 2 diabetes in populations consuming large amounts of the n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) found mainly in fish. Controlled clinical studies have shown that consumption of n-3 LC-PUFAs has cardioprotective effects in persons with type 2 diabetes without adverse effects on glucose control and insulin activity. Benefits include lower risk of primary cardiac arrest; reduced cardiovascular mortality, particularly sudden cardiac death; reduced triglyceride levels; increased high-density lipoprotein levels; improved endothelial function; reduced platelet aggregability; and lower blood pressure. These favorable effects outweigh the modest increase in low-density lipoprotein levels that may result from increased n-3 LC-PUFA intake. Preliminary evidence suggests increased consumption of n-3 LC-PUFAs with reduced intake of saturated fat may reduce the risk of conversion from impaired glucose tolerance to type 2 diabetes in overweight persons. Reported improvements in hemostasis, slower progression of artery narrowing, albuminuria, subclinical inflammation, oxidative stress, and obesity require additional confirmation. Expected health benefits and public health implications of consuming 1 to 2 g/day n-3 LC-PUFA as part of lifestyle modification in insulin resistance and type 2 diabetes are discussed.

Impact of intensive lifestyle and metformin therapy on cardiovascular disease risk factors in the diabetes prevention program

OBJECTIVE

The Diabetes Prevention Program demonstrated the ability to delay or prevent type 2 diabetes in participants with impaired glucose tolerance (IGT). Participants with IGT are at high risk for cardiovascular disease (CVD), with a marked increase in the number and severity of CVD risk factors. We prospectively assessed the impact of our interventions on hypertension, dyslipidemia, and CVD events.

RESEARCH DESIGN AND METHODS

The study group consisted of 3,234 individuals with IGT randomly assigned to receive intensive lifestyle intervention, metformin, or placebo. Annual assessment of blood pressure, lipids, electrocardiogram, and CVD events was undertaken.

RESULTS

Hypertension was present in 30% of participants at study entry and then increased in the placebo and metformin groups, although it significantly decreased with intensive lifestyle intervention. Triglyceride levels fell in all treatment groups, but fell significantly more with intensive lifestyle intervention. Total cholesterol and LDL cholesterol levels were similar among treatment groups. Intensive lifestyle intervention significantly increased the HDL cholesterol level and reduced the cumulative incidence of the proatherogenic LDL phenotype B. At 3 years of follow-up, the use for pharmacologic therapy to achieve established goals in the intensive lifestyle group was 27-28% less for hypertension and 25% less for hyperlipidemia compared with placebo and metformin groups. Over an average of 3 years, 89 CVD events from 64 participants were positively adjudicated studywide, with no differences among treatment groups.

CONCLUSIONS

Lifestyle intervention improves CVD risk factor status compared with placebo and metformin therapy. Although no differences in CVD events were noted after 3 years, achieved risk factor modifications suggest that longer intervention may reduce CVD event rates.

The cost-effectiveness of lifestyle modification or metformin in preventing type 2 diabetes in adults with impaired glucose tolerance

BACKGROUND

The Diabetes Prevention Program (DPP) demonstrated that interventions can delay or prevent the development of type 2 diabetes.

OBJECTIVE

To estimate the lifetime cost-utility of the DPP interventions.

DESIGN

Markov simulation model to estimate progression of disease, costs, and quality of life.

DATA SOURCES

The DPP and published reports.

TARGET POPULATION

Members of the DPP cohort 25 years of age or older with impaired glucose tolerance.

TIME HORIZON

Lifetime.

PERSPECTIVES

Health system and societal.

INTERVENTIONS

Intensive lifestyle, metformin, and placebo interventions as implemented in the DPP.

OUTCOME MEASURES

Cumulative incidence of diabetes, microvascular and neuropathic complications, cardiovascular complications, survival, direct medical and direct nonmedical costs, quality-adjusted life-years (QALYs), and cost per QALY.

RESULTS OF BASE-CASE ANALYSIS

Compared with the placebo intervention, the lifestyle and metformin interventions were estimated to delay the development of type 2 diabetes by 11 and 3 years, respectively, and to reduce the absolute incidence of diabetes by 20% and 8%, respectively. The cumulative incidence of microvascular, neuropathic, and cardiovascular complications were reduced and survival was improved by 0.5 and 0.2 years. Compared with the placebo intervention, the cost per QALY was approximately 1100 dollars for the lifestyle intervention and $31 300 for the metformin intervention. From a societal perspective, the interventions cost approximately 8800 dollars and 29,900 dollars per QALY, respectively. From both perspectives, the lifestyle intervention dominated the metformin intervention.

RESULTS OF SENSITIVITY ANALYSIS

Cost-effectiveness improved when the interventions were implemented as they might be in routine clinical practice. The lifestyle intervention was cost-effective in all age groups. The metformin intervention did not represent good use of resources for persons older than 65 years of age.

LIMITATIONS

Simulation results depend on the accuracy of the underlying assumptions, including participant adherence.

CONCLUSIONS

Health policy should promote diabetes prevention in high-risk individuals.

Blood glucose and heart failure in nondiabetic patients

OBJECTIVE

Nondiabetic patients were studied to determine whether increasing blood glucose is associated with subsequent incidence of heart failure.

RESEARCH DESIGN AND METHODS

Baseline morning blood glucose determinations were evaluated with respect to subsequent heart failure using records from 20,810 nondiabetic patients. The onset of heart failure >1 year after initial glucose determinations was evaluated for patients who had 2-12 years of care. Patients were excluded if they had ever had the diagnosis of diabetes, had a diagnosis of heart failure <1 year after initial blood glucose determinations, had a blood glucose determination >125 mg/dl, or used corticosteroids, loop diuretics, insulin, or oral hypoglycemics.

RESULTS

Of the 20,810 patients studied, 916 patients developed heart failure over a total analysis time of 71,890 years at risk. Higher baseline morning glucose levels were associated with increased heart failure from 3.5% (glucose <90 mg/dl) to 3.8% (90-99 mg/dl) to 4.8% (100-109 mg/dl) to 6% (110-125 mg/dl) over a mean 4- to 5-year evaluation period. The incidence rate increased from 7.5 cases per 1,000 person-years (glucose <90 mg/dl) to 8.4 (90-99 mg/dl, NS) to 11.1 (100-109 mg/dl, P < 0.001) to 13.7 (110-125 mg/dl, P < 0.0001), an 83% increase in heart failure if baseline glucose was >109 mg/dl compared with <90 mg/dl. A Cox proportionate hazards model including age, sex, BMI, creatinine, hypertension, lipids, smoking, medications, and coronary disease showed a progressive increase in hazard ratio from 1.25 (glucose 90-99 mg/dl, P < 0.05) to 1.46 (100-109 mg/dl, P < 0.001) to 1.55 (110-125 mg/dl, P < 0.001) compared with glucose <90 mg/dl. Kaplan-Meier analysis showed increased glucose- associated risk with time.

CONCLUSIONS

Patients with higher baseline blood glucose levels in the absence of diabetes and after adjustment for covariants have a significantly increased risk of heart failure.

Role of exercise training on cardiovascular disease in persons who have type 2 diabetes and hypertension

Exercise training is an essential component in the medical management of patients who have type 2 diabetes and hypertension. Regular exercise improves the cardiovascular health of individuals who have these conditions through multiple mechanisms (Fig. 1). These mechanisms include improvements in endothelial vasodilator function,left ventricular diastolic function, arterial stiffness.systematic inflammation, and reducing left ventricular mass. Exercise training also reduces total and abdominal fat, which mediate improvements in insulin sensitivity and blood pressure, and possibly, endothelial function. Persons who are in a prediabetic stage or those who have the metabolic syndrome may be able to prevent or delay the progression to overt diabetes by adopting a healthier lifestyle, of which increasing habitual levels of physical activity isa vital component. Most persons who have diabetes and hypertension or are at risk for these conditions should be able to initiate an exercise program safely after appropriate medical screen-ing and the establishment of an individualized exercise prescription. Despite the increasing amount of evidence that shows the benefits of exercise training, this modality of prevention and treatment continues to be underused. Although patients' lack of knowledge of the benefits of exercise or lack of motivation contributes to this underuse, a lack of clear and specific guidelines from health care professionals also is an important factor. Clinicians need to educate patients about the benefits of exercise for managing their type 2 diabetes and assist in formulating specific advice for increasing physical activity. Specific instructions should be given to patients, rather than general advice, such as "you should exercise more often." Many cardiac re-habilitation and clinical exercise programs can accommodate patients who have type 2 diabetes and hypertension. Such programs can establish individualized exercise prescriptions and provide an environment that is conducive for "lifestyle change" that underlies long-term compliance to exercise and risk factor modification.

Glycaemic control is essential for effective cardiovascular risk reduction across the type 2 diabetes continuum

The growing prevalence of diabetes, an established risk factor for cardiovascular disease, threatens to significantly increase the global burden of cardiovascular morbidity and mortality. The risk of cardiovascular mortality is substantially higher in individuals with early glucose intolerance than in those with normal glucose levels and the pathological changes in vascular function begin many years before the diagnosis of overt type 2 diabetes. Postprandial hyperglycaemia is particularly deleterious to vascular function, and impaired glucose tolerance (IGT) - but not impaired fasting glucose - and may be an independent risk factor for cardiovascular disease throughout the glucose intolerance continuum. Evidence that molecular mechanisms induced by postprandial hyperglycaemia contribute to vascular damage has further highlighted the importance of targeting this component of the metabolic syndrome. Indeed, clinical trials have failed to convincingly show that interventions targeting fasting hyperglycaemia significantly reduce diabetes-associated cardiovascular risk. It may be necessary to refocus therapy to target postprandial hyperglycaemia to effectively reduce cardiovascular risk in the diabetic population. There is now direct evidence that pharmacological intervention, in the form of acarbose, to reduce postprandial hyperglycaemia, can significantly decrease the risk of cardiovascular events in individuals with IGT or type 2 diabetes.

Economic evaluation of therapeutic interventions to prevent Type 2 diabetes in Canada

AIMS

To compare the health and economic outcomes of using acarbose, an intensive lifestyle modification programme, metformin or no intervention to prevent progression to diabetes in Canadian individuals with impaired glucose tolerance (IGT).

METHODS

A model was developed to simulate the course of individuals with IGT under each treatment strategy. Patients remain in the IGT state or transition from IGT to diabetes, to normal glucose tolerance (NGT) or to death. Effectiveness and resource use data were derived from published intervention trials. A comprehensive health-care payer perspective incorporating all major direct costs, reported in 2000 Canadian dollars, was adopted.

RESULTS

Over a decade, 70 of the 1000 untreated patients are expected to die and 542 develop diabetes. Intensive lifestyle modification is estimated to prevent 117 cases of diabetes, while metformin would prevent 52 and acarbose 74 cases. The proportion of those who return to NGT also increases with any treatment. While lifestyle modification is more effective, it can increase overall costs depending on how it is implemented, whereas acarbose and metformin reduce costs by nearly $1000 per patient. Lifestyle modification was cost effective, varying from CAD $10 000/LYG vs. acarbose. Acarbose costs somewhat more than metformin, but is more effective: CAD $1798/LYG.

CONCLUSION

The results of this model suggest that the treatment of IGT in Canada is a cost-effective way to prevent diabetes and may generate savings. While pharmacological treatments tended to be less costly, intensive lifestyle modification, if maintained, led to the greatest health benefits at reasonable incremental costs.

Prevalence of non-traditional cardiovascular disease risk factors among persons with impaired fasting glucose, impaired glucose tolerance, diabetes, and the metabolic syndrome: analysis of the Third National Health and Nutrition Examination Survey (NHANES III)

PURPOSE

To calculate the prevalence of non-traditional cardiovascular disease (CVD) risk factors across diabetes status and for persons with and without the metabolic syndrome.

METHODS

Data were analyzed from the Third National Health and Nutrition Examination Survey for normal plasma glucose [<100 mg/dl, n=4589]; impaired fasting glucose [IFG, 100-125 mg/dl, n=2008], diabetes [fasting glucose #10878; 126 mg/dl or diabetes medication, n=750]; and participants with and without the metabolic syndrome, n=1938 and n=5409, respectively.

RESULTS

After adjustment for age, race, sex, body mass index, physical inactivity, cigarette smoking and alcohol consumption, a higher odds (p-trend < 0.01) of the metabolic syndrome, an elevated HOMA-insulin resistance index, chronic kidney disease, elevated C-reactive protein, high fibrinogen, and high white blood cell count was observed across diabetes status. After similar adjustment, the metabolic syndrome was associated with (odds ratio; 95% confidence interval) low apolipoprotein A1 (2.27: 1.30,3.96), high apolipoprotein-B (2.97: 2.03,4.34), a higher HOMA insulin resistance index (5.25: 4.16, 6.63), chronic kidney disease (2.27: 1.42, 3.63), and elevated markers of inflammation [high white blood cell count (1.55: 1.14, 2.10), and elevated C-reactive protein (1.46: 1.06, 2.00)]. Among participants with IFG, the presence of impaired glucose tolerance (IGT) was associated with a higher prevalence of the HOMA insulin reistance index, 32.3%, high fibrinogen, 18.5%, and elevated C-reactive protein, 13.2%, compared to persons with IFG alone, 19.7%, 13.3% and 5.7%, respectively (each p <== 0.05).

CONCLUSIONS

In this representative of the US population, an increased prevalence of non-traditional CVD risk factors was present among persons with diabetes, IGT and IFG compared to IFG alone, and the metabolic syndrome.

Abnormal glucose tolerance--a common risk factor in patients with acute myocardial infarction in comparison with population-based controls

BACKGROUND

A high prevalence of newly detected diabetes and impaired glucose tolerance (abnormal glucose tolerance) was recently reported in patients with acute myocardial infarction. It is important to verify whether this finding is specific for the patients or attributable to the population, from which they were recruited.

OBJECTIVE

To verify whether abnormal glucose tolerance is more prevalent in patients than in controls chosen from the same population and to compare metabolic characteristics between the two groups.

DESIGN AND SUBJECTS

The metabolic state was assessed in patients (n = 181) admitted with acute myocardial infarction and no history of diabetes before discharge and after 3 months. Sex- and age-matched controls (n = 185) without previously known diabetes or cardiovascular disease except hypertension were recruited from the general population.

MAIN OUTCOME MEASURES

Oral glucose tolerance test, glucosylated haemoglobin A1c (HbA1c), insulin, proinsulin, lipid profile, fibrinolytic function and inflammatory markers.

RESULTS

Abnormal glucose tolerance was more common (number/all classified) in patients at discharge 113/168 (67%) and after 3 months 95/145 (66%) than in controls 65/185 (35%) (P < 0.001). Dyslipidaemia (70% vs. 29%; P < 0.001) and previously treated hypertension (32% vs. 18%; P = 0.028) were more frequent amongst patients whilst obesity (18% vs. 24%) did not differ significantly. Blood glucose, HbA1c, proinsulin, proinsulin/insulin ratio, triglycerides, insulin resistance (by HOMA) and fibrinogen were consistently higher in patients than controls (P < 0.01).

CONCLUSIONS

Abnormal glucose tolerance was almost twice as common amongst patients with acute myocardial infarction as in matched controls. Impaired glycaemic control accompanied by insulin resistance, dyslipidaemia, hypertension, together with increased plasma fibrinogen and proinsulin levels were main features characterizing patients.

Newly Diagnosed and Previously Known Diabetes Mellitus and 1-Year Outcomes of Acute Myocardial Infarction

BACKGROUND

A prior diagnosis of diabetes mellitus is associated with adverse outcomes after acute myocardial infarction (MI), but the risk associated with a new diagnosis of diabetes in this setting has not been well defined.

METHODS AND RESULTS

We assessed the risk of death and major cardiovascular events associated with previously known and newly diagnosed diabetes by studying 14,703 patients with acute MI enrolled in the VALsartan In Acute myocardial iNfarcTion (VALIANT) trial. Patients were grouped by diabetic status: previously known diabetes (insulin use or diagnosis of diabetes before MI, n=3400, 23%); newly diagnosed diabetes (use of diabetic therapy or diabetes diagnosed at randomization [median 4.9 d after infarction], but no known diabetes at presentation, n=580, 4%); or no diabetes (n=10,719). Patients with newly diagnosed diabetes were younger and had fewer comorbid conditions than did patients with previously known diabetes. At 1 year after enrollment, patients with previously known and newly diagnosed diabetes had similarly increased adjusted risks of mortality (hazard ratio [HR] 1.43; 95% confidence interval [CI], 1.29 to 1.59 and HR, 1.50; 95% CI, 1.21 to 1.85, respectively) and cardiovascular events (HR, 1.37; 95% CI, 1.27 to 1.48 and HR, 1.34; 95% CI, 1.14 to 1.56).

CONCLUSIONS

Diabetes mellitus, whether newly diagnosed or previously known, is associated with poorer long-term outcomes after MI in high-risk patients. The poor prognosis of patients with newly diagnosed diabetes, despite having baseline characteristics similar to those of patients without diabetes, supports the idea that metabolic abnormalities contribute to their adverse outcomes.

Regeneration of the heart in diabetes by selective copper chelation

Heart disease is the major cause of death in diabetes, a disorder characterized by chronic hyperglycemia and cardiovascular complications. Although altered systemic regulation of transition metals in diabetes has been the subject of previous investigation, it is not known whether changed transition metal metabolism results in heart disease in common forms of diabetes and whether metal chelation can reverse the condition. We found that administration of the Cu-selective transition metal chelator trientine to rats with streptozotocin-induced diabetes caused increased urinary Cu excretion compared with matched controls. A Cu(II)-trientine complex was demonstrated in the urine of treated rats. In diabetic animals with established heart failure, we show here for the first time that 7 weeks of oral trientine therapy significantly alleviated heart failure without lowering blood glucose, substantially improved cardiomyocyte structure, and reversed elevations in left ventricular collagen and beta(1) integrin. Oral trientine treatment also caused elevated Cu excretion in humans with type 2 diabetes, in whom 6 months of treatment caused elevated left ventricular mass to decline significantly toward normal. These data implicate accumulation of elevated loosely bound Cu in the mechanism of cardiac damage in diabetes and support the use of selective Cu chelation in the treatment of this condition.

Diabetic keto-acidotic (DKA) coma following olanzapine initiation in a previously euglycaemic woman and successful continued therapy with olanzapine

We report the case of a euglycaemic woman whose glucose control rapidly decompensated following olanzapine initiation leading to diabetic coma. Hyperglycaemia has been associated with chronic psychotic disorders and antipsychotics for many years. However, it is unusual to see such rapid and life-threatening changes associated with treatment. The case highlights that changes in antipsychotic treatment may be associated with large changes in glucose tolerance, and that it is possible to continue antipsychotic treatment with appropriate diabetic care.

Preventing type II diabetes mellitus

Burgeoning obesity is increasing the prevalence of type II diabetes mellitus. As a consequence, there will be an even greater burden of cardiovascular disease, end-stage renal disease, blindness, and lower extremity amputations. If diagnosed, impaired glucose tolerance presents an opportunity for intervention that potentially could delay or prevent the development of diabetes. Recent prospective studies document the effectiveness of exercise and weight reduction in preventing diabetes. Metformin is less effective than intense lifestyle interventions. Acarbose, losartan, orlistat, pravastatin, ramipril, and hormone replacement therapy are associated with lower rates of the development of diabetes. The Diabetes Reduction Assessment with Ramipril and Rosiglitazone Medication (DREAM) trial and the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial were designed to assess not only the prevention of diabetes but also the impact on cardiovascular morbidity and mortality.

Intensive lifestyle changes or metformin in patients with impaired glucose tolerance: Modeling the long-term health economic implications of the diabetes prevention program in Australia, France, Germany, Switzerland, and the United Kingdom

BACKGROUND

In the Diabetes Prevention Program (DPP), interventions with metformin (plus standard lifestyle advice) or intensive lifestyle changes (ILC) reduced the risk of developing type 2 diabetes mellitus (DM) by 31% and 58%, respectively, versus control (standard lifestyle advice only) in patients with impaired glucose tolerance (IGT).

OBJECTIVE

The goal of this study was to establish whether implementing the active treatments used in the DPP would be cost-effective in Australia, France, Germany, Switzerland, and the United Kingdom.

METHODS

A Markov model simulated 3 states-IGT, type 2 DM, and deceased-using probabilities from the DPP and published data. Country-specific direct costs were used throughout.

RESULTS

Assuming only within-trial effects and costs of interventions, both metformin and ILC improved life expectancy versus control. Mean improvements in nondiscounted life expectancy were 0.11 and 0.22 years for metformin and ILC, respectively. Both interventions were associated with cost savings versus control in all countries except the United Kingdom, where a small increase in costs was observed in both intervention arms. When a lifetime effect of interventions was assumed, incremental improvements in life expectancy were 0.35 and 0.90 years for metformin and ILC, respectively. Results were sensitive to probabilities of developing type 2 DM, the projected long-term duration of effect of interventions after the 3-year trial period, the relative risk of mortality for type 2 DM compared with IGT, and the costs of implementing the interventions.

CONCLUSIONS

Based on probabilities from the DPP and published data, in this model analysis, incorporation of the DPP interventions into clinical practice in 5 developed countries was projected to lead to an increase in DM-free years of life, improvements in life expectancy, and either cost savings or minor increases in costs compared with standard lifestyle advice in a population with IGT. Thus, financial constraints should not prevent the implementation of DM prevention programs.

The metabolic syndrome in children and adolescents

The metabolic syndrome was recently defined by the Adult Treatment Panel III. Despite a lack of uniform definition of the syndrome in pediatrics, recent studies have shown that the syndrome develops during childhood and is highly prevalent among overweight children and adolescents. The hypothesized central role of insulin resistance and obesity as a common underlying feature of the metabolic syndrome also appears to be already manifested in childhood. In view of the current obesity epidemic in children and adolescents, there is a vital need to provide adequate guidelines for the definition of the metabolic syndrome in pediatrics and for the development of screening and treatment strategies. This article focuses on the above issues, as well as on the impact of the syndrome on two major disease outcomes, type 2 diabetes and cardiovascular disease.

Fortschritte in der Prävention des Typ-2-Diabetes

Type 2 diabetes mellitus is a major health problem associated with excess morbidity and mortality. 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. The natural history of type 2 diabetes includes a preceding period of impaired glucose tolerance (IGT)/impaired fasting glucose (IFG) which provides an opportunity for targeted intervention within large communities. 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. Lifestyle intervention studies have consistently shown that quite modest changes can reduce the progression from IGT to diabetes by 50-60%. The Diabetes Prevention Program (DPP) randomised trial has shown that a combined program of weight loss, improvement of diet and increase of physical exercise lowers the risk for development of type 2 diabetes by 58% compared with placebo. It may, however, not be possible to translate these successful findings to larger cohorts or maintain the lifestyle changes longer term. This has lead to consideration of pharmacotherapy. Benefits have been found for metformin, acarbose and troglitazone. Treatment with metformin was less effective than lifestyle modifications, resulting in an average reduction of risk for development of type 2 diabetes by 31% compared with placebo. Similarly, acarbose in the STOP-NIDDM trial reduced the risk of developing type 2 diabetes in patients with IGT by 25%. Remarkably, cardiovascular event rates, in particular myocardial infarction, were significantly reduced when acarbose was used instead of placebo in subjects with glucose intolerance. The ACE inhibitors captopril (CAPPP) or ramipril (HOPE) and the Angiotensin-II receptor antagonist losartan (LIFE) have been shown to reduce the appearance of diabetes by one third when given to patients with hypertension. Since many hypertensive patients are insulin-resistant and have an increased risk in developing type 2 diabetes, the protective effect of these classes of antihypertensive drugs might be explained by their antiinsulin-resistance effects.

The potential of metformin for diabetes prevention

Well designed intervention trials, such as the Diabetes Prevention Program (DPP), have demonstrated the potential of lifestyle interventions or pharmacologic treatments for the prevention or delay of type 2 diabetes in subjects with impaired glucose tolerance (IGT). Lifestyle interventions are likely to form the cornerstone of the management of IGT in the future, as they do in the management of type 2 diabetes today. However, it remains to be seen whether the intensive lifestyle interventions employed in trials such as the DPP can be transferred successfully from the highly structured environment of a randomised trial to routine, day-to-day management within the primary care sector. Thus, pharmacologic treatment may provide an important additional option where subjects are unwilling or unable to improve their diet and levels of physical activity. Treatment with metformin significantly reduced the incidence of diabetes in subjects with IGT and high-normal fasting plasma glucose in the DPP. Moreover, metformin was well tolerated, and health economic analyses suggest that metformin treatment is cost-effective in the US and Europe. The DPP investigators found that the protective effect of metformin persisted beyond the end of the study, and estimated that only one quarter of the protection arose from a short-lived pharmacological effect. The results of the DPP identify metformin as an effective option for the prevention of diabetes in subjects with IGT and impaired fasting glucose.

Treatment for patients with the metabolic syndrome

The metabolic syndrome, or insulin resistance syndrome, is associated with increased risk for cardiovascular disease and related mortality and has an estimated age-adjusted US prevalence of 23.7%. Dyslipidemia in the syndrome is characterized by hypertriglyceridemia, low high-density lipoprotein cholesterol, and small, dense low-density lipoprotein (LDL) particles in the context of normal/slightly elevated LDL cholesterol. Outcomes in treatment studies in or including diabetic patients suggest that a variety of therapies may be of benefit in reducing cardiovascular risk in patients with the metabolic syndrome, including physiologic therapies and pharmacologic treatments, such as aspirin, antihypertensive therapy, anti-ischemic therapy, and lipid-modifying therapies. The recently updated National Cholesterol Education Program Adult Treatment Panel III guidelines identify the metabolic syndrome as a secondary target of lipid-lowering therapy after LDL cholesterol reduction and recommend use of weight reduction and increased physical activity to address underlying risk factors as well as therapies to address specific lipid and nonlipid risk factors.

Contributions of insulin-resistance and insulin-secretory defects to the pathogenesis of type 2 diabetes mellitus

Controlled clinical trials have shown that optimal glycemic control can prevent the microvascular complications of type 2 diabetes mellitus; considerable epidemiological data suggest that this may also be true for macrovascular complications. However, this is frequently not achieved. Consequently, research efforts have been undertaken to better understand the pathophysiology of this disorder. It is now well recognized that 2 factors are involved: impaired beta-cell function and insulin resistance. Prospective studies of high-risk populations have shown insulin-resistance and/ or insulin-secretory defects before the onset of impaired glucose tolerance. Thus, there has been a long-standing debate whether an alteration in insulin sensitivity or in insulin secretion is the primary genetic factor. Most of the available evidence favors the view that type 2 diabetes is a heterogeneous disorder in which the major genetic factor is impaired beta-cell function and insulin resistance is the major acquired factor. Superimposition of insulin resistance on a beta cell that cannot appropriately compensate leads to deterioration in glucose tolerance. Therefore, clinicians managing type 2 diabetes must reduce insulin resistance and augment and/or replace beta-cell function.

Early and more vigorous detection of diabetes

Currently 17 million Americans have diabetes mellitus (DM); 90% of these have type 2 DM. Of these 17 million, 5.9 million remain undiagnosed. The undiagnosed patient with type 2 DM may be asymptomatic for years, while hyperglycemic injury to target organs occurs long before the development of frank diabetes. The prevalence of diabetes among adults is estimated to increase to almost double the present number by 2025. People with diabetes and at risk for diabetes are also at risk for cardiovascular disease. Several investigators have now demonstrated the benefit of controlling blood glucose levels as well as other risk factors in this population to decrease the incidence of microvascular and macrovascular disease. Prevention or delaying the onset of type 2 DM can be accomplished with a program of diet, weight loss, and exercise.

Impact of incident diabetes and incident nonfatal cardiovascular disease on 18-year mortality: the multiple risk factor intervention trial experience

OBJECTIVE

To report long-term risks for total, cardiovascular disease (CVD), and coronary heart disease (CHD) mortality associated with incident diabetes (using current diagnostic criteria) and with incident nonfatal CVD (NF-CVD).

RESEARCH DESIGN AND METHODS

A total of 11645 participants without diabetes or CVD at baseline from the Multiple Risk Factor Intervention Trial who survived to the end of the trial were grouped by during-trial incident diabetes and/or NF-CVD events: neither diabetes nor NF-CVD, diabetes only, NF-CVD only, or both diabetes and NF-CVD. Incident diabetes was defined by use of hypoglycemic agents or fasting glucose >or=126 mg/dl at any time over the 6 trial years. Proportional hazards models tested group differences in mortality over 18 post-trial years.

RESULTS

Among 3859 total deaths were 1846 from CVD and 1277 from CHD, with death rates per 10000 person-years of 203, 97, and 67, respectively. Multivariate-adjusted hazard ratios (HRs) for total mortality were 2.75 (P < 0.0001) for those with NF-CVD and diabetes both, 1.92 (P < 0.0001) for those with NF-CVD only, and 1.49 (P < 0.0001) for those with diabetes only, relative to neither diabetes nor NF-CVD. NF-CVD was associated with a higher hazard of death than diabetes for total (HR 1.29, P = 0.0004), CVD (HR 1.76, P < 0.0001), and CHD (HR 1.88, P < 0.0001) mortality. Only the subgroup of participants on hypoglycemic agents showed an equivalent risk of total mortality relative to participants with NF-CVD (HR 0.93, P = 0.54).

CONCLUSIONS

Current diabetes diagnostic criteria conferred significantly increased total, CVD, and CHD mortality risks independent of the impact of NF-CVD. NF-CVD was more strongly predictive of mortality.

Growth hormone therapy and its relationship to insulin resistance, glucose intolerance and diabetes mellitus: a review of recent evidence

It is widely recommended that consideration should be given to the therapeutic use of growth hormone (GH) in adults with GH deficiency, whether the condition is of childhood or adult onset. One reason for this recommendation is the possibility that such treatment may reduce the excess cardiovascular risk which is associated with hypopituitarism. This excess risk has been well documented, with mortality ratios of 1.7 to 2.2 being quoted in different studies, and may be a result of the insulin resistance which occurs in hypopituitarism. However, it has also been suggested that this insulin resistance may itself be the result of GH deficiency, especially as GH deficiency is accompanied by suggestive morphological features such as central adiposity. There is, however, no direct evidence that the increase in cardiovascular risk in hypopituitarism is the result of GH deficiency, and the only prospective study designed to examine the relationship failed to find a statistically significant correlation between the two. Since GH administration may also have an independent adverse effect on insulin sensitivity and could thus cause a theoretical worsening of cardiovascular risk, it is important to review the observed effects of GH administration on carbohydrate metabolism in practice. Interpretation of the literature is made difficult by many confounding factors, including differences in study duration, biochemical tools adopted, the use of selected populations and the dose-dependent effect of GH on synthesis of insulin- like growth factor-1. One of the most sensitive markers of a deterioration in insulin sensitivity is the serum insulin level. A rise in serum insulin (fasting, or post-glucose load) was reported in all studies in which it was measured. The majority of studies have also reported a rise in fasting blood glucose. A smaller proportion of reports noted an associated increase in postprandial glucose and in glycosylated haemoglobin (HbA(1c)) while a few reported new cases of either impaired glucose tolerance or frank diabetes mellitus. In general, however, the observed deterioration in insulin sensitivity was small and increases which occurred in blood glucose were small. Nevertheless, these data indicate that rather than lead to an improvement in insulin resistance in hypopituitarism, GH treatment may actually make it worse. As it is also known that even minor reductions in insulin sensitivity may be associated with a clinically significant increase in cardiovascular risk, further large-scale controlled trials are required before the efficacy and safety of GH treatment of adults can be established.

Diabetes-related morbidity and mortality in a national sample of U.S. elders

OBJECTIVE

Although the number of elders with diabetes has increased dramatically, there are few data on rates of mortality and serious complications in older populations with diabetes. To determine such rates, we conducted a population-based, nonconcurrent cohort study using claims data from the 1994-1996 Medicare 5% Standard Analytical File.

RESEARCH DESIGN AND METHODS

Codes from the ICD-9 were used to identify diabetes and the following complications: amputation, lower extremity infection, gangrene, blindness, acute myocardial infarction, ischemic heart disease, stroke, and metabolic disorders. Using these codes, we assembled a cohort of 148,562 Medicare Part A and B beneficiaries who were > or = 65 years of age, who were alive on 1 January 1995, who were not in managed care in 1994, and who had a diabetes-related claim in 1994. Age-specific rates of death and complications were then calculated.

RESULTS

During 24 months of follow-up, 22,044 (14.8%) elders with diabetes died. Death rates in men and women increased significantly with age. Compared with their counterparts in the general U.S. population, elders with diabetes suffered excess mortality at every age group, corresponding to an overall standardized mortality ratio of 1.41 (95% CI 1.39,1.43). The incidence of ischemic heart disease and stroke was 181.5 and 126.2 per 1,000 person-years, respectively, which was higher than the incidence of all other diabetes-related complications.

CONCLUSIONS

In every age group, elders with diabetes have significantly higher all-cause mortality rates than the general population. Medicare data may be useful in monitoring trends in diabetes-related morbidity and total mortality in U.S. elders with diabetes.

Endothelial dysfunction in human diabetes

In nondiabetic individuals, a poor response to an endothelium-dependent vasodilator in coronary vessels has been shown to increase the likelihood of a future cardiovascular event. Such prospective data are not as yet available in patients with type 1 or type 2 diabetes. However, consistent with the greatly increased cardiovascular risk in these patients, endothelial dysfunction has been almost universally found to characterize patients with type 2 diabetes particularly. Endothelial dysfunction frequently coexists with features of insulin resistance, such as the presence of small dense low-density lipoprotein (LDL) particles even in nondiabetic individuals. This association is independent of obesity and other causes of endothelial dysfunction, such as LDL cholesterol, hypertension, and smoking. In patients with type 1 diabetes, endothelial dysfunction has been found in approximately half of the studies. In some but not all studies, endothelial dysfunction has been especially severe in patients with poor glycemic control. Reversal or amelioration of endothelial dysfunction has been documented by many commonly used therapeutic agents such as successful insulin therapy, fibrates, and angiotensin-converting enzyme inhibitors, but also with some but not all agents that act as antioxidants. Long-term studies addressing the prognostic significance of endothelial dysfunction and its reversal are urgently needed to determine whether measurement of endothelial function could be used to identify individuals at risk better than can be done at present using classic risk factor assessment among patients with type 2 diabetes especially.

Hyperglycemia and cardiovascular disease

Diabetes is associated with many microvascular and macrovascular complications. Hyperglycemia plays a pivotal role in the development of microvascular complications, but the actual effect of hyperglycemia on the development and progression of macrovascular complications remains unclear and even somewhat controversial, particularly in type 2 diabetes. Macrovascular complications are increased in individuals with type 2 diabetes long before there is significant hyperglycemia, and in many, but not all, studies a clear association of glucose elevations and macrovascular complications cannot be shown. The complicated nature of metabolic abnormalities in type 2 diabetes and the relative role of these associated conditions in the development of macrovascular disease make definitive conclusions somewhat difficult. In spite of these considerations, there are certain aspects of hyperglycemia associated with macrovascular disease, particularly elevations of postprandial glucoses, and a number of basic mechanisms to explain these associations that could lead to the development of cardiovascular disease. Some of these basic abnormalities include activation of the sorbital pathway, oxidative stress, advanced glycation endproducts (AGE), and AGE precursors. These changes can result in many abnormalities, such as endothelial dysfunction, alteration of protein function, increased cytokine production, and glycosylation of structural proteins. These considerations suggest that hyperglycemia may play an important, but as yet not clearly defined, role in clinical macrovascular disease. Pursuant to this, several major multisite studies are currently underway to clarify the role of hyperglycemia in cardiovascular disease in type 2 diabetes.