Inflammation, insulin resistance, and glucose intolerance in acute myocardial infarction patients without a previous diagnosis of diabetes mellitus

Association of relative hand grip strength with myocardial infarction and angina pectoris in the Korean population: a large-scale cross-sectional study

BACKGROUND

Low hand grip strength (HGS) is associated with the risk of cardiovascular diseases, but the association between HGS and myocardial infarction/angina pectoris (MIAP) is unclear. Furthermore, there have been no studies examining the associations of MIAP with anthropometric indices, absolute HGS indices, and relative HGS indices calculated by dividing absolute HGS values by body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), or weight values. Therefore, the objective of this study was to examine the associations of MIAP with absolute and relative HGS combined with several anthropometric indices.

METHODS

In this large-scale cross-sectional study, a total of 12,963 subjects from the National Health and Nutrition Examination Survey were included. Odds ratios and 95% confidence intervals for the associations of MIAP with anthropometric indices, absolute HGS indices, and relative HGS indices were computed from binary logistic regression models. We built 3 models: a crude model, a model that was adjusted for age (Model 1), and a model that was adjusted for other relevant covariates (Model 2).

RESULTS

For men, the average age was 61.55 ± 0.16 years in the MIAP group and 66.49 ± 0.61 years in the non-MIAP group. For women, the average age was 61.99 ± 0.14 years in the MIAP group and 70.48 ± 0.61 years in the non-MIAP group. For both sexes, the MIAP group had lower diastolic blood pressure, shorter stature, greater WC, and a greater WHtR than did the non-MIAP group, and women tended to have greater systolic blood pressure, weight, and BMI than in men. HGS was strongly associated with the risk of MIAP in the Korean population. In men, relative HGS indices combined with WC and the WHtR had greater associations with MIAP than did the anthropometric indices and absolute HGS indices. However, in women, anthropometric indices, including weight, BMI, WC, and WHtR, were more strongly associated with MIAP than were absolute and relative HGS indices, unlike in men. When comparing absolute and relative HGS indices in women, relative HGS indices combined with BMI and weight was more strongly related to MIAP than was absolute HGS indices.

CONCLUSIONS

MIAP might be better identified by relative HGS than absolute HGS in both sexes. The overall magnitudes of the associations of MIAP with absolute and relative HGS are greater in men than in women.

Modulation of mTOR Signaling in Cardiovascular Disease to Target Acute and Chronic Inflammation

Inflammation is a key component in the pathogenesis of cardiovascular diseases causing a significant burden of morbidity and mortality worldwide. Recent research shows that mammalian target of rapamycin (mTOR) signaling plays an important role in the general and inflammation-driven mechanisms that underpin cardiovascular disease. mTOR kinase acts prominently in signaling pathways that govern essential cellular activities including growth, proliferation, motility, energy consumption, and survival. Since the development of drugs targeting mTOR, there is proven efficacy in terms of survival benefit in cancer and allograft rejection. This review presents current information and concepts of mTOR activity in myocardial infarction and atherosclerosis, two important instances of cardiovascular illness involving acute and chronic inflammation. In experimental models, inhibition of mTOR signaling reduces myocardial infarct size, enhances functional remodeling, and lowers the overall burden of atheroma. Aside from the well-known effects of mTOR inhibition, which are suppression of growth and general metabolic activity, mTOR also impacts on specific leukocyte subpopulations and inflammatory processes. Inflammatory cell abundance is decreased due to lower migratory capacity, decreased production of chemoattractants and cytokines, and attenuated proliferation. In contrast to the generally suppressed growth signals, anti-inflammatory cell types such as regulatory T cells and reparative macrophages are enriched and activated, promoting resolution of inflammation and tissue regeneration. Nonetheless, given its involvement in the control of major cellular pathways and the maintenance of a functional immune response, modification of this system necessitates a balanced and time-limited approach. Overall, this review will focus on the advancements, prospects, and limits of regulating mTOR signaling in cardiovascular disease.

Undiagnosed Impaired Glucose Tolerance and Type-2 Diabetes in Acute Myocardial Infarction Patients: Fequency, Characteristics and Long-Term Mortality

Background

In this study we investigated the prevalence of undiagnosed impaired glucose tolerance and type-2-diabetes (T2D) among patients with acute myocardial infarction (AMI) and prospectively analyzed whether these patients have a higher long-term mortality.

Methods

The analysis was based on 2,317 AMI patients aged 25–84 years from the population-based Myocardial Infarction Registry Augsburg, recruited between 2009 and 2014 and followed-up until 2019 (median follow-up time 6.5 years [IQR: 4.9–8.1]). AMI patients with a diagnosis of diabetes were divided into a high (>7.0%) and a low HbA1c group (≤7.0%) according to HbA1c values at admission. The remaining patients (without known diabetes) were grouped into normal (<5.7%), elevated (5.7–6.4%), and high (≥6.5%) HbA1c groups. In a multivariable-adjusted COX regression analysis, the association between HbA1c groups and long-term mortality was investigated. Linear regression models were used to identify AMI patients with elevated HbA1c values by means of personal characteristics.

Results

At admission, 29.5% of all patients reported a diagnosis of diabetes. Of all patients without known diabetes, 5.4% had HbA1c values of ≥ 6.5 and 37.9% had HbA1c values between 5.7 and 6.4%. The fully adjusted Cox regression model showed a non-significant trend toward higher long-term mortality for AMI patients with increased HbA1c values (HbA1c 5.7–6.4% HR: 1.05 [0.79–1.38], HbA1c > 6.5% HR: 1.34 [0.77–2.31]). A linear regression model including the variables admission serum glucose, BMI, age, sex and type of infarction (STEMI, NSTEMI) showed only poor prediction of HbA1c values (R²: 11.08%).

Conclusion

A fairly high number of AMI patients without known diabetes have elevated HbA1c values. Though we could not prove a higher risk of premature mortality in these patients, early detection and adequate therapy might lead to reduced diabetes-associated complications and improve long-term outcomes.

Insulin resistance and dysglycemia are associated with left ventricular remodeling after myocardial infarction in non-diabetic patients

Background

Adverse cardiac remodeling after ST-segment elevation myocardial infarction (STEMI) is a major cause for poor cardiovascular outcomes such as heart failure. The predisposing factors and underlying mechanisms remain not fully understood. This study investigates the association of insulin resistance and dysglycemia with left ventricular (LV) remodeling after STEMI in non-diabetic patients.

Methods

A total of 485 non-diabetic subjects with STEMI who underwent primary percutaneous coronary intervention were consecutively enrolled and followed up for 12 months. Relation of homeostasis model assessment-estimated insulin resistance (HOMA-IR) and glucose levels to changes in echocardiography parameters was studied.

Results

Left ventricular dilation was detected in 49.1% of subjects at 12-month follow-up after STEMI, and was more severe in subjects with impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and high HOMA-IR levels. HOMA-IR remained correlated to changes in LV dimensions after adjusting for confounding risk factors. Multivariate regression analysis demonstrated that higher HOMA-IR was independently associated with greater LV dilation after STEMI. A significant interaction term was present between HOMA-IR and IGT in the model (P = 0.001).

Conclusions

Our study reveals that insulin resistance and dysglycemia are prevalent in non-diabetic patients with STEMI and are predictors of the post-infarction LV dilation.

Trial registration Trials number, NCT02089360; registered on March 17, 2014

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0904-3) contains supplementary material, which is available to authorized users.

Glycated hemoglobin, admission blood glucose delta, and associated mortality in patients with acute ST-segment elevation myocardial infarction

The importance of glucose metabolism in patients with acute coronary syndrome has been increasingly recognized. We conducted a retrospective study of the associations between prior glycated hemoglobin (HbA1c) levels, admission glucose values, HbA1c-derived estimated average glucose levels (eAG), admission glucose delta (admission glucose - eAG), and mortality in patients presenting with ST-segment elevation myocardial infarction. A total of 676 and 566 patients were included in the in-hospital and 12-month mortality models, respectively. Mean admission blood glucose values were higher in the in-hospital and 12-month mortality groups in patients with no prior diagnosis of diabetes (P < 0.001). Pre, post, and admission HbA1c levels and eAG levels were not associated with in-hospital or 12-month all-cause mortality. The admission glucose delta was higher in patients with in-hospital mortality (87.3 ± 122.7 mg/dL) than in patients who survived (35.88 ± 81.23 mg/dL; P = 0.040). The in-hospital death rate was significantly higher (17% vs 4%, P = 0.017) for patients with admission glucose delta ≥140 mg/dL compared to lower values. In conclusion, HbA1c-derived admission glucose delta is associated with in-hospital mortality in patients with ST-segment elevation myocardial infarction. The mechanisms for the association of acute hyperglycemia with increased acute coronary syndrome mortality are unclear.

Cardiac Outcomes After Ischemic Stroke or Transient Ischemic Attack: Effects of Pioglitazone in Patients With Insulin Resistance Without Diabetes Mellitus

BACKGROUND

Insulin resistance is highly prevalent among patients with atherosclerosis and is associated with an increased risk for myocardial infarction (MI) and stroke. The IRIS trial (Insulin Resistance Intervention after Stroke) demonstrated that pioglitazone decreased the composite risk for fatal or nonfatal stroke and MI in patients with insulin resistance without diabetes mellitus, after a recent ischemic stroke or transient ischemic attack. The type and severity of cardiac events in this population and the impact of pioglitazone on these events have not been described.

METHODS

We performed a secondary analysis of the effects of pioglitazone, in comparison with placebo, on acute coronary syndromes (MI and unstable angina) among IRIS participants. All potential acute coronary syndrome episodes were adjudicated in a blinded fashion by an independent clinical events committee.

RESULTS

The study cohort was composed of 3876 IRIS participants, mean age 63 years, 65% male, 89% white race, and 12% with a history of coronary artery disease. Over a median follow-up of 4.8 years, there were 225 acute coronary syndrome events, including 141 MIs and 84 episodes of unstable angina. The MIs included 28 (19%) with ST-segment elevation. The majority of MIs were type 1 (94, 65%), followed by type 2 (45, 32%). Serum troponin was 10× to 100× upper limit of normal in 49 (35%) and >100× upper limit of normal in 39 (28%). Pioglitazone reduced the risk of acute coronary syndrome (hazard ratio, 0.71; 95% confidence interval, 0.54-0.94; P=0.02). Pioglitazone also reduced the risk of type 1 MI (hazard ratio, 0.62; 95% confidence interval, 0.40-0.96; log-rank P=0.03), but not type 2 MI (hazard ratio, 1.05; 95% confidence interval, 0.58-1.91; P=0.87). Similarly, pioglitazone reduced the risk of large MIs with serum troponin >100× upper limit of normal (hazard ratio, 0.44; 95% confidence interval, 0.22-0.87; P=0.02), but not smaller MIs.

CONCLUSIONS

Among patients with insulin resistance without diabetes mellitus, pioglitazone reduced the risk for acute coronary syndromes after a recent cerebrovascular event. Pioglitazone appeared to have its most prominent effect in preventing spontaneous type 1 MIs.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov. Unique identifier: NCT00091949.

New-Onset Diabetes After Acute and Critical Illness: A Systematic Review

Hyperglycemia is commonly observed during acute and critical illness. Recent studies have investigated the risk of developing diabetes after acute and critical illness, but the relationship between degree of in-hospital hyperglycemia and new-onset diabetes has not been investigated. This study examines the evidence for the relationship between in-hospital hyperglycemia and prevalence of new-onset diabetes after acute and critical illness. A literature search was performed of the MEDLINE, EMBASE, and Scopus databases for relevant studies published from January 1, 2000, through August 4, 2016. Patients with no history of diabetes before hospital discharge were included in the systematic review. In-hospital glucose concentration was classified as normoglycemia, mild hyperglycemia, or severe hyperglycemia for the meta-analysis. Twenty-three studies were included in the systematic review, and 18 of these (111,078 patients) met the eligibility criteria for the meta-analysis. The prevalence of new-onset diabetes was significantly related to in-hospital glucose concentration and was 4% (95% CI, 2%-7%), 12% (95% CI, 9%-15%), and 28% (95% CI, 18%-39%) for patients with normoglycemia, mild hyperglycemia, and severe hyperglycemia, respectively. The prevalence of new-onset diabetes was not influenced by disease setting, follow-up duration, or study design. In summary, this study found stepwise growth in the prevalence of new-onset diabetes with increasing in-hospital glucose concentration. Patients with severe hyperglycemia are at the highest risk, with 28% developing diabetes after hospital discharge.

Effects of prandial challenge on triglyceridemia, glycemia, and pro-inflammatory activity in persons with chronic paraplegia

CONTEXT/OBJECTIVE

Exaggerated postprandial lipemia has been reported after spinal cord injury (SCI). We examined metabolite and accompanying pro-inflammatory biomarker responses to repeat feeding of typical high-fat meals in individuals with chronic paraplegia.

DESIGN

Descriptive trial.

METHODS

Metabolites (triglycerides, glucose, and insulin) and inflammatory biomarkers (interleukin-6 and high-sensitivity C-reactive protein (hsCRP)) were measured under fasting conditions in 11 recreationally active individuals with chronic (>1 year) paraplegia. Subjects received high-fat meals at time point 0 and again at minute 240. Antecubital venous blood was obtained at time points -30 (fasting), 0 (first meal), 30, 60, 90, 120, 240 (second meal), 360, and 480 minutes. Correlations were examined among the study variables. Exploratory subgroup analysis was performed for subjects with levels of postprandial glucose greater than >200 mg/dl.

RESULTS

Triglycerides showed a significant rise 4 hours after eating. Basal inflammatory markers were elevated, and did not undergo additional change during the testing. Additionally, subjects with excessive postprandial glucose responses showed higher hsCRP levels than those having typical glucose responses both for fasting (11.8 ± 6.5 vs. 2.9 ± 2.7 mg/l, P = 0.064) and postprandial (11.1 ± 4.9 vs. 3.7 ± 3.8 mg/l, P = 0.018) values.

CONCLUSIONS

Despite elevations in metabolic response markers, inflammatory markers did not change significantly after consumption of population-representative (i.e. hypercaloric) mixed-nutrient meals. Levels of fasting CRP in the high-risk range are consistent with other reports in persons with SCI and continue to pose concern for their cardiovascular disease risk. The possible association between postprandial metabolic responses and inflammatory states warrants further investigation to identify individual component risks for this secondary health hazard.

Factors associated with untreated diabetes: analysis of data from 20,496 participants in the Japanese National Health and Nutrition Survey

Objective

We aimed to examine factors associated with untreated diabetes in a nationally representative sample of the Japanese population.

Research Design and Methods

We pooled data from the Japanese National Health and Nutrition Survey from 2005 to 2009 (n = 20,496). Individuals aged 20 years and older were included in the analysis. We classified participants as having diabetes if they had HbA1c levels ≥6.5% (≥48 mmol/mol). People with diabetes who self-reported that they were not currently receiving diabetic treatment were considered to be untreated. We conducted a multinomial logistic regression analysis to determine factors associated with untreated diabetes relative to non-diabetic individuals.

Results

Of 20,496 participants who were included in the analysis, untreated diabetes was present in 748 (3.6%). Among participants with untreated diabetes, 48.3% were previously diagnosed with diabetes, and 46.5% had HbA1c levels ≥7.0% (≥53 mmol/mol). Participants with untreated diabetes were significantly more likely than non-diabetic participants to be male, older, and currently smoking, have lower HDL cholesterol levels and higher BMI, non-HDL cholesterol levels, and systolic blood pressure.

Conclusions

A substantial proportion of people in Japan with untreated diabetes have poor glycemic control. Targeting relevant factors for untreated diabetes in screening programs may be effective to enhance the treatment and control of diabetes.

Glycemic Variability Determined by Continuous Glucose Monitoring System Predicts Left Ventricular Remodeling in Patients With a First ST-Segment Elevation Myocardial Infarction

BACKGROUND

Impaired glucose metabolism plays an important role in patients with acute myocardial infarction, but the clinical significance of glycemic variability (GV) early after the onset of ST-segment elevation myocardial infarction (STEMI) remains to be fully elucidated.

METHODS AND RESULTS

We prospectively investigated the clinical impact of GV, as determined by a continuous glucose monitoring system (CGMS), on left ventricular remodeling (LVR) assessed by cardiac magnetic resonance imaging (CMR) in 69 patients (63±13 years, 59 men) with a first reperfused STEMI within 12 h of onset. All patients were equipped with a CGMS when in a stable phase after admission and underwent repeat CMR at baseline and 7 months follow-up. Patients were divided into 2 groups according to the mean amplitude of glycemic excursions (MAGE). Patients in the upper tertile of MAGE were categorized as group High (H) and the other two-thirds as group Low (L). LVR was defined as an absolute increase in left ventricular end-diastolic volume index of ≥20%. LVR more frequently occurred in group H than in group L (56% vs. 11%, P<0.001). Multivariate analysis showed the higher MAGE group was an independent predictor of LVR in the chronic phase (odds ratio, 13.999; 95% confidence interval, 3.059 to 64.056; P=0.001).

CONCLUSIONS

MAGE early after the onset of STEMI identified patients with LVR in the chronic phase.

In-hospital daily insulin dose predicts long-term adverse outcome in patients with diabetes with ST-elevation myocardial infarction treated with successful primary percutaneous angioplasty

INTRODUCTION

Early initiation of reperfusion therapy including primary percutaneous coronary revascularization (PPCI) has been recognized as a crucial factor determining clinical outcomes in the acute phase of myocardial infarction. In unstable patients with type 2 diabetes mellitus (T2D) the clear benefit from PPCI was proven. We aim to evaluate the prognostic value of factors describing glycometabolic state on admission in patients with T2D undergoing PPCI in acute ST-elevation myocardial infarction (STEMI).

MATERIAL AND METHODS

Prospective analysis of clinical and laboratory variables (mean daily short acting exogenous insulin dose (DID), admission blood glucose, glycated hemoglobin (HbA1c), microalbuminuria) was performed in 112 consecutive patients with T2D with STEMI who underwent PPCI. Women comprised 58% of the group.

RESULTS

Insulin dosing was targeted to obtain a mean daily glucose level < 7.8 mmol/l. During 12-month follow-up 33 (29.5%) major adverse cardiac events (major adverse cardiac events (MACE) consisting of death, reinfarction, and repeated target vessel revascularization) were reported. Microalbuminuria was present in 68 (60.5%) patients. The mean HbA1c level was 7.9%. In the multivariate logistic regression model only DID > 44 IU remained an independent risk factor for MACE (p = 0.02, OR = 5.2).

CONCLUSIONS

In patients with diabetes with STEMI treated with PPCI, simple measurement of DID during hospitalization can add valuable prognostic information about the future risk of MACE.

Increased orosomucoid in urine is an independent predictor of cardiovascular and all-cause mortality in patients with type 2 diabetes at 10 years of follow-up

AIMS

To evaluate whether increased urinary orosomucoid excretion rate (UOER) is an independent predictor of cardiovascular and all-cause mortality in type 2 diabetes (T2DM) and type 1 diabetes (T1DM) at 10years of follow-up.

METHOD

We followed 430 patients with T2DM and 148 patients with T1DM until emigration, death or November 2011. We measured UOER levels in overnight urine samples.

RESULTS

Descriptive data are given in the article. In patients with T2DM and T1DM, all-cause mortality (log-rank test, p<0.01 for both types) and cardiovascular mortality (log-rank test, p<0.01 for T2DM and p=0.04 for T1DM) were significantly higher in patients with increased UOER. Normoalbuminuric patients with T2DM and increased UOER levels had higher all-cause and cardiovascular mortality (log-rank test, p<0.01 for both types). UOER was independently predictive of all-cause (HR 1.52; 95% CI 1.10-2.09; p=0.01) and cardiovascular (HR 2.31; 95% CI 1.46-3.66; p<0.01) mortality in patients with T2DM, but not in patients with T1DM.

CONCLUSION

UOER is an independent predictor of all-cause and cardiovascular mortality even in normoalbuminuric patients with T2DM at 10years of follow-up. Further studies are needed in order to evaluate the prognostic and clinical relevance.

The oral glucose tolerance test for the diagnosis of diabetes mellitus in patients during acute coronary syndrome hospitalization: a meta-analysis of diagnostic test accuracy

Background

The appropriateness of the routine performance of an oral glucose tolerance test (OGTT) to screen for diabetes mellitus (DM) during acute coronary syndrome hospitalization is still under debate.

Methods

A systematic search of databases (MEDLINE [1985 to March 2012], EMBASE [1985 to March 2012]) was conducted. All prospective cohort studies assessing the accuracy or reproducibility of an OGTT in ACS or non-ACS individuals were included. A bivariate model was used to calculate the pooled sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). Heterogeneity was explored using subgroup analysis and meta-regression.

Results

Fifteen studies with 8,027 participants were included (10 ACS and 5 non-ACS studies). The pooled results on SEN, SPE, PLR, NLR, and DOR were 0.70 (95% CI, 0.60-0.78), 0.91 (95% CI, 0.86-0.94), 7.6 (95% CI, 4.9-11.7), 0.33 (95% CI, 0.25-0.45), and 23 (95% CI, 12–41), respectively. The OGTT has a slightly lower SPE in diagnosing DM in ACS than in non-ACS patients (0.86 [95% CI 0.81-0.92] versus 0.95 [95% CI 0.93-0.98], p<0.01), while the SEN values are comparable (0.71 [95% CI 0.60-0.82] versus 0.67 [95% CI 0.54-0.81], p=0.43). After adjusting the interval between repeated tests and age, the meta-regression did not show a difference in DOR between ACS and non-ACS studies.

Conclusions

Despite the discrepancy in the interval between the two OGTTs, performing an OGTT in patients with ACS provides accuracy that is similar to that in in non-ACS patients. It is reasonable to screen patients hospitalized for ACS for previously undiagnosed DM using an OGTT.

Adipokines, ghrelin and obesity-associated insulin resistance in nondiabetic patients with acute coronary syndrome

Altered glucose metabolism negatively modulates outcome in acute coronary syndromes (ACS). Insulin resistance is commonly associated with increasing BMI in the general population and these associations may involve obesity-related changes in circulating ghrelin and adipokines. We aimed at investigating interactions between BMI, insulin resistance and ACS and their associations with plasma ghrelin and adipokine concentrations. Homeostasis model assessment of insulin resistance (HOMA(IR))-insulin resistance index, plasma adiponectin, leptin, total (T-Ghrelin), acylated (Acyl-Ghrelin), and desacylated ghrelin (Desacyl-Ghrelin) were measured in 60 nondiabetic ACS patients and 44 subjects without ACS matched for age, sex, and BMI. Compared with non-ACS, ACS patients had similar HOMA(IR) and plasma adipokines, but lower T- and Desacyl-Ghrelin and higher Acyl-Ghrelin. Obesity (BMI > 30) was associated with higher HOMA(IR), lower adiponectin, and higher leptin (P < 0.05) similarly in ACS and non-ACS subjects. In ACS (n = 60) HOMA(IR) remained associated negatively with adiponectin and positively with leptin independently of BMI and c-reactive protein (CRP) (P < 0.05). On the other hand, low T- and Desacyl-Ghrelin with high Acyl-Ghrelin characterized both obese and non-obese ACS patients and were not associated with HOMA(IR). In conclusion, in ACS patients, obesity and obesity-related changes in plasma leptin and adiponectin are associated with and likely contribute to negatively modulate insulin resistance. ACS per se does not however enhance the negative impact of obesity on insulin sensitivity. High acylated and low desacylated ghrelin characterize ACS patients independently of obesity, but are not associated with insulin sensitivity.

Cardiovascular risk factor management of myocardial infarction patients with and without diabetes in the Netherlands between 2002 and 2006: a cross-sectional analysis of baseline data

OBJECTIVE

We examined levels and trends in cardiovascular risk factors and drug treatment in myocardial infarction (MI) patients with and without diabetes.

DESIGN

Cross-sectional analysis of baseline Alpha Omega Trial data, a randomised controlled trial.

SETTING

32 hospitals in the Netherlands.

PARTICIPANTS

In total, we had 1014 MI patients with diabetes (74% men) and 3823 without diabetes (79% men) aged 60-80 years, analysed over the period 2002-2006.

RESULTS

Between 2002 and 2006, a significantly decreasing trend in the prevalence of obesity (-5%, p(trend)=0.02) and in systolic blood pressure (BP) levels (-5 mm Hg, p(trend)<0.0001) was demonstrated in non-diabetic patients, but not in diabetic patients. In 2006, obesity, mean systolic BP and serum triglyceride levels were significantly higher, whereas high-density lipoprotein cholesterol levels were lower in diabetic patients compared to those without. Prescription of antihypertensive drug (diabetic vs non-diabetic patients respectively, 95% vs 93%, p=0.08) and statin treatment were high (86% and 90%, p=0.11).

CONCLUSIONS

A high proportion of MI patients with and without diabetes was similarly treated with cardiovascular drugs. In spite of high drug treatment levels, more adverse risk factors were found in patients with diabetes.

Detection of glucose abnormalities in patients with acute coronary heart disease: study of reliable tools in clinical practice

AIM

To investigate the prevalence of glucose abnormalities in patients with acute coronary syndrome and to assess the reliability of certain clinical or analytical variables to predict a pathologic result of oral glucose tolerance test (OGTT) at 3 months from discharge.

SUBJECTS AND METHODS

Prospective study of 102 patients admitted to the coronary care units. Patients were classified according to the American Diabetes Association criteria. Three months after discharge, an OGTT was performed to non-diabetic patients.

RESULTS

Forty-six (45.1%) patients were identified as diabetic (5 previously undiagnosed) and 56 (54.9%) as non-diabetic. OGTT identified 22% of diabetes, 33% of impaired glucose tolerance, and 45% of normal glucose tolerance. Fasting glucose (r=0.55, p<0.001), glycated hemoglobin (HbA1c) (r=0.46, p<0.001), low HDL cholesterol (HDLc) levels (r=-0.34, p<0.02), waist-hip ratio (r=0.45, p<0.01), high systolic blood pressure (r=0.5, p<0.01), and presence of acute myocardial infarction (r=0.46, p<0.001) at admission resulted significant to predict a pathologic result of OGTT.

CONCLUSIONS

Glucose abnormalities are frequent in acute coronary syndrome patients. Certain clinical and analytical markers at admission such as fasting glucose, HbA1c, HDL-c<40 mg/dl, waist-hip ratio, and systolic blood pressure, are useful to recognize patients with a higher predisposition to present a pathologic result in OGTT at 3 months from discharge.

Management of tight intraoperative glycemic control during off-pump coronary artery bypass surgery in diabetic and nondiabetic patients

OBJECTIVES

To optimize intra- and postoperative insulin management in cardiac surgical patients.

DESIGN

A prospective, randomized, open-label, single-center study.

SETTING

A large nonuniversity hospital.

PARTICIPANTS

Sixty diabetics and 60 nondiabetics undergoing off-pump cardiac bypass surgery.

INTERVENTIONS

Intra- and postoperative tight glycemic control were achieved using different approaches with a modified insulin protocol.

MEASUREMENTS AND MAIN RESULTS

Nondiabetics were divided randomly: in the ND-ind group (n = 30), insulin was started at induction according to preinduction blood glucose (BG) concentrations. In group ND >110 (n = 30), insulin was started when BG concentrations exceeded 110 mg/dL during surgery. Up to 85% of the ND >110 group started on insulin intraoperatively. Intraoperatively, the ND-ind group had more BG within target (80-110 mg/dL) (p = 0.002), less BG >130 mg/dL (p = 0.015), and more BG between 70 and 79 mg/dL (p = 0.002). In diabetics, BG concentration was checked every 30 (DM-30), n = 30) versus 60 minutes (DM-60, n = 30) to improve the protocol's performance. Intraoperatively, there were more BG concentrations within target (80-110 mg/dL) (p = 0.02) and less >130 mg/dL (p = 0.0002) in the DM-30 group. During surgery, the hyperglycemic index and the glycemic penalty index were lower in the ND-ind group (p < 0.05). Postoperatively, the mean BG concentrations, hyperglycemic index, and glycemic penalty index in diabetics and nondiabetics were comparable between groups (p < 0.05). In the overall 2,641 BG samples, the lowest BG concentration in the operating room was 71 and in the intensive care unit (ICU) it was 61 mg/dL.

CONCLUSIONS

In diabetics and nondiabetics undergoing off-pump coronary artery bypass surgery, tight perioperative glycemic control is feasible and efficient, with minimal risks for hypo- and hyperglycemia. In nondiabetics, starting insulin therapy from induction onwards results in more measurements within target, without affecting the mean BG. In diabetics, decreasing the sampling interval from 60 to 30 minutes results in more measurements within target and in a mean blood glucose within target at ICU arrival.

Prevalence, detection, and management of the metabolic syndrome in patients with acute myocardial infarction: role of an obesity-centric definition

Background. We sought to determine and compare the prevalence of the Metabolic Syndrome (MS) in patients with acute myocardial infarction (AMI) utilizing the new International Diabetes Federation (IDF) definition with the older National Cholesterol Education Program (NCEP) definition. We also examined the clinical utility of MS in this context. Methods. A total of 107 consecutive patients with AMI were prospectively evaluated for MS. Fasting lipids obtained at admission and fasting glucose at discharge were used. A postdischarge folder audit verified rates of discharge coding and implementation of specific management strategies for MS. Results. Baseline patient characteristics included: mean age 59 +/- 13 years; males 80%; diabetes 19%; mean BMI 29.7 +/- 8.4 kg/m(2). MS prevalence was 54% by the IDF definition and 49% by the NCEP definition, with good agreement between definitions: kappa = 0.664, P < .001. Factors predictive of MS after multivariate analysis included: hypertension, fasting glucose, waist circumference, and serum HDL (all P < .05). Despite the high prevalence, MS was recognized at discharge in only 1 patient, and referral for exercise and/or weight-loss programs was undertaken in 5 patients. Conclusion. There is a high prevalence of MS utilizing contemporary definitions in patients with AMI: 54% by the IDF definition and 49% by NCEP criteria. Despite the high prevalence, MS was under-recognized and under-treated in this population.

Screening for overt diabetes by oral glucose tolerance test: stratification by fasting blood glucose and patients' age improve practicability of guidelines in cardiological routine

BACKGROUND/OBJECTIVES

Guidelines recommend screening all patients with cardiovascular disease by oral glucose tolerance test (OGTT). Due to its time-consuming protocol, costs and overall inconvenience performance of OGTT is limited in cardiological routine. Thus, we aimed to identify easily available parameters that could help to reduce the numbers of OGTT needed.

METHODS

OGTTs (n=1215) were performed in all patients without known type 2 diabetes mellitus (T2DM) that were submitted to the heart center Wuppertal with known or suspected coronary artery disease for an elective coronary angiography from January to October 2007.

RESULTS

31.4% had normal glucose tolerance; prediabetes was present in 50.7%, whereas 17.9% were newly diagnosed with T2DM. Thus, 998 OGTTs did not result in the new diagnosis of so far undiagnosed T2DM. Multiple logistic regression and receiver operated characteristic analyses demonstrated that fasting blood glucose (FBG)≥ 90 mg/dl and age ≥ 55 years were predictive for so far undiagnosed T2DM. Considering these two parameters 81.1% (=sensitivity) of so far undiagnosed T2DM patients would have been identified (specificity=63.4%) and the number of OGTTs could have been reduced from 1215 to 541.

CONCLUSIONS

About 70% of patients were newly diagnosed with impaired glucose metabolism. FBG ≥ 90 mg/dl and age ≥ 55 years were predictive for so far undiagnosed T2DM and OGTTs could be reduced by 55.5%. This should alleviate the implementation of the current guidelines in daily cardiological practice.

Glucose homeostasis abnormalities in cardiac intensive care unit patients

The aim of this study was to characterize the abnormalities in glucose homeostasis in intensive care unit patients following an acute coronary event. The study population included all non-diabetic patients ages 20-80 years that were admitted to a coronary intensive unit. Glucose, insulin and C-peptide levels during an oral glucose tolerance test (OGTT) were measured during the acute admission. From January to September 2003, 277 patients were admitted to the coronary unit. Of these, 127 patients underwent an OGTT. Of these, only 29 patients (23%) exhibited normal glucose metabolism. The remainder had type 2 diabetes (32%), impaired glucose tolerance (37%) or isolated impaired fasting glucose (8%, 100-125 mg/dl). Based on homeostasis model assessment (HOMA) calculations, diabetic patients had impaired beta-cell function and patients with elevated fasting glucose levels were insulin resistant. Beta-cell dysfunction during the acute stress seems to contribute to the glucose abnormalities. Most patients who experience an acute coronary event demonstrate abnormal glucose metabolism. Post glucose-load abnormalities are more common than abnormal fasting glucose level in this situation. It is postulated that the acute stress of a coronary event may contribute to the dysglycemia.

Intensive perioperative glucose control does not improve outcomes of patients submitted to open-heart surgery: a randomized controlled trial

BACKGROUND

The objective of this study was to investigate the relationship between different target levels of glucose and the clinical outcomes of patients undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

We designed a prospective study in a university hospital where 109 consecutive patients were enrolled during a six-month period. All patients were scheduled for open-heart surgery requiring cardiopulmonary bypass. Patients were randomly allocated into two groups. One group consisted of 55 patients and had a target glucose level of 80-130 mg/dl, while the other contained 54 patients and had a target glucose level of 160-200 mg/dl. These parameters were controlled during surgery and for 36 hours after surgery in the intensive care unit. Primary outcomes were clinical outcomes, including time of mechanical ventilation, length of stay in the intensive care unit, infection, hypoglycemia, renal or neurological dysfunction, blood transfusion and length of stay in the hospital. The secondary outcome was a combined end-point (mortality at 30 days, infection or length of stay in the intensive care unit of more than 3 days). A p-value of <0.05 was considered significant.

RESULTS

The anthropometric and clinical characteristics of the patients from each group were similar, except for weight and body mass index. The mean glucose level during the protocol period was 126.69 mg/dl in the treated group and 168.21 mg/dl in the control group (p<0.0016). There were no differences between groups regarding clinical outcomes, including the duration of mechanical ventilation, length of stay in the intensive care unit, blood transfusion, postoperative infection, hypoglycemic event, neurological dysfunction or 30-day mortality (p>0.05).

CONCLUSIONS

In 109 patients undergoing cardiac surgery with cardiopulmonary bypass, both protocols of glycemic control in an intraoperative setting and in the intensive care unit were found to be safe, easily achieved and not to differentially affect clinical outcomes.

Impaired glucose tolerance and endothelial damage, as assessed by levels of von Willebrand factor and circulating endothelial cells, following acute myocardial infarction

BACKGROUND

Impaired glucose tolerance (IGT) following acute myocardial infarction (AMI) increases the incidence of major adverse cardiac events. We hypothesized that endothelial damage following AMI, as assessed by levels of von Willebrand factor (vWF) and circulating endothelial cells (CECs), would be more pronounced in patients with IGT compared to those with normal glucose tolerance (NGT).

METHODS

We studied non-diabetic patients with AMI (n=125; 107 (86%) male; mean age 59 years (SD 12.5)) who underwent oral glucose tolerance testing 3-5 days after admission. We measured vWF (enzyme-linked immunosorbent assay) and CECs (CD146 immunobead capture) in the fasting state and at 2 h post glucose load.

RESULTS

Base-line vWF and CEC levels were higher in IGT patients versus those with NGT and healthy controls (HC) (P<0.001). The acute increase in vWF and CECs in response to the glucose load was significantly higher in the IGT group compared to those with NGT and HC (P<0.01)-an increase on a par with that seen in newly diagnosed diabetics.

CONCLUSION

The degree of endothelial damage post AMI in patients with IGT is greater than NGT, and comparable to that seen in frank diabetes mellitus. Subjects with IGT therefore need to be as actively sought and managed.

Temporal change in glucose tolerance in non-ST-elevation myocardial infarction

We assessed the prevalence and 3-month change in glucose tolerance status in consecutive non-ST-elevation myocardial infarction (NSTEMI; European Society of Cardiology 2007 definition) patients (N=49; mean (S.D.) age 65 (11) years) admitted to a coronary care unit, without known diabetes. These patients underwent an oral glucose tolerance test (OGTT) 36-hour (median, IQR: 18-72) after admission and at 3 months. Undiagnosed abnormal glucose tolerance (AGT: impaired fasting glucose (IFG), impaired glucose tolerance (IGT) or new diabetes) was common (61% at admission and 41% at 3 months, p<0.05) and the majority (approximately 3/4) had IGT. Glucose tolerance status improved in a higher proportion of patients than it worsened (31% vs. 8%, p=0.04). At 3 months, fasting glucose was unchanged but 2-hour OGTT glucose was lower (mean (S.D.): 8.5 (2.7) mmol/L vs. 7.7 (2.7) mmol/L, p=0.004). 'Stress hyperglycaemia' could explain higher admission glucose levels and this raises the question about the optimal timing of OGTT in relation to myocardial infarction. Newly diagnosed diabetes was present in approximately 10% of patients and this was not reliably detected by fasting plasma glucose. In NSTEMI patients OGTT is the only reliable strategy to identify subjects with IGT and diabetes.

Impaired fasting glucose and outcomes of ST-elevation acute coronary syndrome treated with primary percutaneous intervention among patients without previously known diabetes mellitus

BACKGROUND

Fasting blood glucose levels (FG) are related to adverse outcomes in all patients with acute myocardial infarction (AMI), probably more so than admission glucose (AG) levels. We sought to examine this correlation among patients with ST-elevation AMI treated with primary percutaneous coronary interventions (PPCI).

METHODS

Our cohort included 570 consecutive patients without previously known diabetes mellitus who were treated with PPCI for ST-elevation AMI. The cohort was divided according to FG levels measured on days 2 to 4 of hospitalization, while the patients were clinically stable: FG < or = 100 mg/dL, normal range; FG 100-110 mg/dL, mildly impaired FG; FG 110-126 mg/dL, significantly impaired FG; FG > or = 126 mg/dL, diabetic range.

RESULTS

One third of the cohort had impaired FG, of whom 20% had FG levels in the diabetic range. There was a weak correlation between AG and FG levels (r = 0.38, P = .000). In the multivariate analysis, adjusted for AG quartiles, patients with FG > or = 110 mg/dL were more likely to die within 30 days (odds ratio 1.7, 95% CI 1.03-2.70, P = .04). Admission glucose levels did not independently impact on 30-day mortality (odds ratio 0.99, 95% CI 0.50-1.90, P = .96).

CONCLUSIONS

Fasting blood glucose levels may be routinely assessed among patients with ST-elevation AMI undergoing PPCI, possibly aiding in risk prognostication and the tailoring of therapy.

Oral glucose tolerance test: a reliable tool for early detection of glucose abnormalities in patients with acute myocardial infarction in clinical practice: a report on repeated oral glucose tolerance tests from the GAMI study

OBJECTIVE

Previously undetected glucose abnormalities are common in patients with acute myocardial infarction (AMI). We evaluated long-term reliability of early glucometabolic classification of patients with AMI by repeated oral glucose tolerance tests (OGTTs).

RESEARCH DESIGN AND METHODS

A glucometabolic OGTT-based classification was obtained in 122 patients by measuring capillary whole-blood glucose. The classification was performed on three occasions, before hospital discharge and 3 and 12 months thereafter.

RESULTS

At discharge, 34, 31, and 34% were classified as having normal glucose tolerance, impaired glucose tolerance (IGT), or type 2 diabetes, respectively, and 93% of all patients with type 2 diabetes were still classified with type 2 diabetes (n = 27) or IGT (n = 12) after 12 months. The agreements between the OGTTs at discharge and 3 and 12 months were kappa = 0.35, P < 0.001, and kappa = 0.43, P < 0.001, respectively.

CONCLUSIONS

The outcome of an OGTT performed in AMI patients at hospital discharge reliably informs on long-term glucometabolic state.

Adiponectin and the cardiovascular system: from risk to disease

Adiponectin is known to play a role in fatty acid and glucose metabolism through a change in insulin sensitivity and activation of fuel oxidation by AMP-activated protein kinase. Adiponectin can be considered an important factor able to modulate the adipovascular axis which, through genomic and environmental influences, affects the cardiovascular risk milieu, from the pre-metabolic syndrome-- through the metabolic syndrome--to the overt atherosclerotic process and its clinical manifestations. Hypoadiponectinaemia can be viewed as an early sign of a complex cardiovascular risk factor predisposing to the atherosclerosis process as well as a contributing factor accelerating the progress of the atherosclerotic plaque. In addition, adiponectin per se holds a protective role thanks to its anti-inflammatory and antiatherogenic properties. The early identification of patients "at cardiovascular risk" means in the current practice to search for indexes of metabolic derangements and pro-inflammatory status (adiponectin) from adolescence and childhood.

Causes and consequences of hyperglycemia in critical illness

PURPOSE OF REVIEW

This article reviews recent epidemiologic and intervention studies addressing the impact of hyperglycemia on morbidity and mortality in critically ill patients. It also discusses a growing body of literature examining why elevated blood glucose occurs in hospitalized patients without previously recognized diabetes.

RECENT FINDINGS

Hyperglycemia is highly prevalent in the intensive care unit. Numerous observational studies have demonstrated the association between hyperglycemia and adverse outcomes, independent of pre-existing diabetes. Intervention trials of insulin therapy are limited but overall demonstrate that glucose lowering significantly improves outcomes. The ideal target for blood glucose and the population that would benefit most from intervention remain controversial. Less frequently studied than the consequences, the causes of hyperglycemia occurring during critical illness remain unclear. Although glucose abnormalities in hospitalized patients have traditionally been explained by mediators of stress, a growing body of evidence has examined whether underlying defects in glucose metabolism may also be important contributors.

SUMMARY

In general, evidence suggests that hyperglycemia is a potentially correctable abnormality that has deleterious effects in critically ill individuals. Hyperglycemic patients without previously recognized diabetes appear to be particularly vulnerable, and thus further examination of the mechanisms underlying the development of elevated blood glucose is warranted.

Should oral glucose tolerance testing be mandatory following acute myocardial infarction?

A high prevalence of newly detected diabetes mellitus (DM) and impaired glucose tolerance (IGT) has been reported in patients with acute myocardial infarction (AMI) and no previous diagnosis of DM. However, the prevalence of newly detected DM is grossly underestimated by using fasting plasma glucose (FPG). We determined the prevalence of DM and IGT in patients post-AMI from our local mixed ethnicity population, and evaluated the usefulness of oral glucose tolerance testing in such patients. All non-diabetic subjects admitted with AMI underwent a standardised oral glucose tolerance test (OGTT) with 75 g glucose load predischarge in our institution. Fasting and 2-h postchallenge plasma glucose levels were recorded, in addition to admission plasma glucose, serum cholesterol, triglycerides, HDL cholesterol and haemoglobin A1(C)levels. We studied 61 patients [38 (62%) male; mean (SD) age, 64 (12.5) years], of whom 70% were white European and 30% South Asians. Mean (SD) plasma glucose concentration on admission was 6.9 (1.7; range, 5.8-8.1) mmol/l. Newly diagnosed DM and IGT were detected in 31% (95% CI 10-52) and 33% (95% CI 12-53) of patients respectively. Of those with newly detected diabetes only 32% (95% CI 0-69) had FPG > 6.1 mmol/l. The 12 month major adverse cardiac event rate was 4.5%, 15% and 32% in those with normal glucose tolerance, IGT and DM respectively. Previously undiagnosed DM and IGT in patients with AMI is common. The false reassurance of a normal FPG denies a significant proportion of undiagnosed diabetics the chance of early treatment. The importance of OGTT in the diagnostic work up of this vulnerable high-risk group cannot be over-emphasised.

Cost analysis of intensive glycemic control in critically ill adult patients

STUDY OBJECTIVES

To assess the effect of an intensive glycemia management protocol on the cost of care of a heterogeneous population of critically ill adult patients.

DESIGN

Economic analysis of a 1,600-patient "before-and-after" study of intensive glycemia management.

SETTING

Fourteen-bed mixed medical-surgical adult ICU of a university-affiliated community teaching hospital.

PATIENTS

Eight hundred consecutive admissions to the ICU prior to the institution of an intensive glucose management protocol were compared to the first 800 patients admitted to the ICU following institution of the protocol.

INTERVENTIONS

Cost data were analyzed using the comprehensive database of the ICU as well as other hospital data repositories.

MEASUREMENTS AND RESULTS

The ICU database was used to quantify the major components of the cost of care. The analysis includes costs associated with ICU and non-ICU patient days, ventilator days, and laboratory, pharmacy, and radiology services. Comparing the baseline and treatment periods, there were decreases in patient days in the ICU; ventilator days; total laboratory, pharmacy and radiology costs; and post-ICU hospital length of stay. The net annualized decrease in costs during the treatment period was USD 1,339,500, or USD 1,580 per patient.

CONCLUSIONS

The institution of a program to intensively monitor glucose levels and treat even modest hyperglycemia in the ICU was associated with substantial cost savings. This finding, in conjunction with the previously demonstrated improvement in mortality and morbidity, strongly supports the adoption of this intervention as a standard of care in the ICU.

Perioperative glucose control

PURPOSE OF REVIEW

Hyperglycemia occurs commonly among acutely ill patients owing to a combination of counterregulatory and stress responses, as well as insulin resistance and deficiency, and is associated with increased morbidity and mortality in a variety of different patient populations. This manuscript reviews the adverse consequences of hyperglycemia in these different settings and focuses on perioperative glycemic management.

RECENT FINDINGS

Hyperglycemia has a number of effects on the native immune system that may explain its role in increasing the risk of infection. Insulin may exert its beneficial effects by altering lipid metabolism as well as by modulating endothelial function through several mechanisms. Hyperglycemia during cardiac surgery is associated with increased risk of postoperative complications, including death. Several interventional studies have concluded that intensive glycemic management is beneficial, but there are limited data available from general surgical populations.

SUMMARY

Hyperglycemia is associated with adverse outcomes in acutely ill adult patients and its treatment has been shown to improve mortality and morbidity in a variety of different settings. Additional studies are needed in heterogeneous populations of critically ill patients as well as in other populations of acutely ill patients, especially general surgical patients, to confirm the early studies and define the correct glycemic target.

Adiponectin and the development of diabetes in patients with coronary artery disease and impaired fasting glucose

OBJECTIVES

Adiponectin has insulin-sensitizing properties, and high adiponectin levels have been shown to be associated with reduced risk of developing diabetes. Patients with coronary artery disease (CAD) have relatively low adiponectin levels and high prevalence of glucose intolerance. The role of adiponectin in predicting the development of diabetes in this high-risk group has not been determined. The study aimed to determine whether baseline adiponectin levels predict the development of diabetes in a group of patients with CAD and impaired fasting glucose (IFG).

METHODS

A total of 588 patients who participated in the Bezafibrate Infarction Prevention (BIP) study and who had at baseline fasting glucose of 100-125 mg/dl were included and followed for 6.2+/-1.3 years. Adiponectin was determined in frozen plasma samples taken at baseline.

RESULTS

Of the patients with IFG at baseline, 256 (44%) developed diabetes during follow-up. The patients who developed diabetes had at baseline higher body-mass index, fasting glucose, C-reactive protein, triglycerides, homeostatic assessment of insulin resistance (HOMA-IR) and diastolic blood pressure than patients who did not develop diabetes. Adiponectin levels at baseline were significantly lower in patients who developed diabetes than in patients who did not develop diabetes (P = 0.009, nonparametric Kruskall-Wallis test). An increase of 1 unit of natural logarithm of adiponectin level was associated with a hazard ratio of 0.77 (95% CI, 0.61-0.96) for diabetes development.

CONCLUSION

Patients with CAD and IFG have a very high rate of conversion to type 2 diabetes. Even in this high-risk group, high adiponectin levels are associated with reduced risk of developing diabetes.

Predominance of Small Dense Low-Density Lipoproteins and Abnormal Glucose Regulation in Patients With Acute Coronary Syndrome

BACKGROUND

Although small dense low-density lipoprotein (sd-LDL) has an established association with diabetic dyslipidemia, previous studies have failed to show an association between sd-LDL and diabetes among coronary heart disease patients. This study investigated the prevalence of sd-LDL and abnormal glucose regulation in acute coronary syndrome (ACS).

METHODS AND RESULTS

LDL size at the onset of ACS was measured by nondenatured gradient gel electrophoresis in 314 of 429 consecutive patients. Sd-LDL was prevalent in 54% of the patients, irrespective of the presence of previously known diabetes (50% vs 60% in nondiabetes and diabetes, respectively). Diabetes was present in 122 (28%) of the patients, and 110 patients without diabetes underwent an oral glucose tolerance test. Impaired glucose tolerance (IGT) and newly detected diabetes were found in as many as 44% and 22% of the patients tested, even though their hemoglobinA1c levels were in the normal range (5.3+/-0.5%). The prevalence of sd-LDL was significantly higher in patients with glucose intolerance than in those with normal glucose tolerance (61% vs 42%).

CONCLUSION

IGT and diabetes were far more common than normal glucose regulation in ACS patients, and the abnormal glycometabolism was closely associated with highly atherogenic sd-LDL.

Beta cell dysfunction in patients with acute myocardial infarction but without previously known type 2 diabetes: a report from the GAMI study

AIMS/HYPOTHESIS

Patients with acute myocardial infarction (AMI) but without previously known type 2 diabetes have a high prevalence of undiagnosed IGT and type 2 diabetes. Such perturbations have dismal prognostic implications. The aim of this study was to characterise AMI patients in terms of insulin resistance and beta cell function.

METHODS

A total of 168 consecutive AMI patients were classified by means of an OGTT before hospital discharge as having NGT, IGT or type 2 diabetes. The homeostasis model assessment (HOMA-IR) was used to estimate insulin resistance. Beta cell responsiveness was quantified as insulinogenic index (IGI) at 30 min (DeltaI(30)/DeltaG(30)).

RESULTS

According to the HOMA-IR, patients with type 2 diabetes were more insulin resistant than those with IGT or NGT (p=0.003). Beta cell responsiveness deteriorated with decreasing glucose tolerance as measured by the IGI (median [quartile 1, quartile 3] in pmol/mmol: NGT, 70.1 [42.7, 101.4]; IGT, 48.7 [34.7, 86.8], type 2 diabetes, 38.1 [25.7, 61.6]; p<0.001). The IGI was significantly related to admission capillary blood glucose (r=-0.218, p=0.010) and to the area under the curve for glucose (r=-0.475, p<0.001).

CONCLUSIONS/INTERPRETATION

Glucose abnormalities are very common in patients with AMI but without previously known type 2 diabetes. To a significant extent, this seems to be related to impaired beta cell function and implies that dysglycaemia immediately after an infarction is not a stress epiphenomenon but reflects stable disturbances of glucose regulation preceding the AMI. Early beta cell dysfunction may have important pathophysiological implications and may serve as a future target for treatment strategies.