c-peptide and Myocardial-Infarction

Patients with insulin resistance and early type 2 diabetes exhibit an increased propensity to develop a diffuse and extensive pattern of arteriosclerosis. Diabetic subjects show a remarkable increase in vascular complications, including myocardial infarction and strokes. The accelerated atherosclerosis in these patients is likely to be multifactorial. In this review, we focus on the advanced glycation end product (AGE)-receptor for AGE (RAGE) axis and the role of C-peptide as a mediator of lesion development. AGEs are proteins or lipids that become glycated after exposure to sugars. By engaging the RAGEs, AGEs induce the expression of proinflammatory mediators in various vascular cell types and are involved in a variety of microvascular and macrovascular complications. In animal models, interruption of the AGE-RAGE interaction reduces lesion size and plaque development and RAGE deficiency in a RAGE(-/-)/apolipoprotein E(-/-) double knockout mouse attenuates the development of atherosclerosis in diabetes. On the other side, patients with type 2 diabetes show increased levels of C-peptide and over the last years various groups examined the effect of C-peptide in vascular cells as well as its potential role in lesion development. Recent data suggest that the proinsulin cleavage product C-peptide could play a causal role in atherogenesis by promoting monocyte and CD4-positive lymphocyte recruitment in early arteriosclerotic lesions and by inducing the proliferation of vascular smooth muscle cells. The following review will summarize these two pathophysiological aspects and discuss on the one hand the potential role of the activated AGE-RAGE axis in diabetes-accelerated atherogenesis and on the other hand the role of C-peptide as a mediator in lesion development in patients with type 2 diabetes.

Topics: Animals; Apolipoproteins E; Atherosclerosis; C-Peptide; CD4-Positive T-Lymphocytes; Cell Proliferation; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Gene Expression Regulation; Glycation End Products, Advanced; Humans; Inflammation Mediators; Mice; Mice, Knockout; Mitogen-Activated Protein Kinases; Monocytes; Myocardial Infarction; Myocytes, Smooth Muscle; Receptor for Advanced Glycation End Products; Stroke

Topics: Adult; C-Peptide; Diabetes Mellitus, Type 2; Humans; Hypoglycemic Agents; Infections; Insulin; Insulin Resistance; Myocardial Infarction

Insulin resistance early after acute myocardial infarction is associated with increased heart failure and mortality. OMEGA-REMODEL was a prospective double-blind 1:1 randomized control trial of patients with AMI. We reported that 6-month treatment with omega-3 fatty acid (O-3FA) 4 g/day attenuated cardiac remodeling accompanied by reduction in inflammation. We hypothesized that insulin resistance modifies the therapeutic effect of O-3FA on post-MI cardiac remodeling. The OMEGA-REMODEL study group was dichotomized according to cohort- and gender-specific median cutoff value of leptin-to-adiponectin ratio (LAR) at baseline (LAR-Hi vs LAR-Lo). Mixed model regression analyses were used to evaluate effect modification of O-3FA on reduction of left ventricular end-systolic volume index (LVESVI) by LAR status. Baseline LAR was evaluated on 325 patients (59 ± 11 years, 81% male). A total of 168 patients were categorized in LAR-Lo, and 157 in LAR-Hi. O-3FA treatment resulted in significant LVESVI reduction in patients with LAR-Lo but not with LAR-Hi (p = 0.0002 vs 0.66, respectively). Mixed model regression analysis showed significant modification of LAR on O-3FA's treatment effect in attenuating LVESVI (p = 0.021). In conclusion, this post-hoc efficacy analysis suggests that LAR status significantly modified O-3FA's treatment effect in attenuating cardiac remodeling. During the convalescent phase of acute infarct healing, patients with lower insulin resistance estimated by LAR appear to derive more therapeutic response from O-3FA toward improvement of LVESVI.

Topics: Adiponectin; Aged; C-Peptide; Double-Blind Method; Fatty Acids, Omega-3; Female; Humans; Insulin Resistance; Leptin; Male; Middle Aged; Myocardial Infarction; Prognosis; Proinsulin; Stroke Volume; Treatment Outcome; Ventricular Remodeling

Both carvedilol and metoprolol have cardioprotective effects and decrease infarct size in myocardium. We compared effects of carvedilol and metoprolol on insulin resistance and serum lipid levels after myocardial infarction.. Fifty-nine patients aged between 30 and 70 and BMI = 25-30 kg/m2, who were diagnosed with myocardial infarction with ST segment elevation, were considered to be eligible for the study. Patients were randomly allocated to two different therapy protocols. Metoprolol 100 mg bid or carvedilol 25 mg bid was added to their standardized therapy regimen. Baseline to week 4 and 12, fasting blood glucose, serum lipid profile, BMI, C-peptide, insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were measured.. After 12 weeks of metoprolol therapy HOMA-IR, insulin and C-peptide levels were significantly higher (p < 0.05 for all) and total cholesterol and triglyceride levels decreased significantly (p < 0.05 for all) compared to baseline. After 12 weeks of carvedilol therapy HOMA-IR, insulin and C-peptide (p < 0.05 for all), total cholesterol and triglyceride (p = 0.001 for all) decreased significantly compared to baseline. Carvedilol provided more decrease in total cholesterol and LDL levels than metoprolol (p = 0.043 and p = 0.021, respectively).. In patients after myocardial infarction, carvedilol added to background therapy improved insulin resistance and lipid profile.

Topics: Adrenergic alpha-Antagonists; Adrenergic beta-Antagonists; Adult; Aged; C-Peptide; Carbazoles; Carvedilol; Cholesterol, LDL; Female; Glucose Clamp Technique; Humans; Insulin Resistance; Male; Metoprolol; Middle Aged; Myocardial Infarction; Propanolamines; Triglycerides

Glucosamine has a major influence on the impairment of some metabolic mechanisms in the human body. As shown in vitro experiments, it takes part in inducing mechanisms of insulin resistance. Therefore, the purpose of our study was to evaluate glucosamine levels in the serum of patients who suffered myocardial infarction (MI) and who either had or didn't have diagnosed type II diabetes in relation to healthy people. The levels of glucosamine, immunoreactive insulin, C-peptide, glucose and lipid indexes were measured in venous blood in investigated patients. In patients with MI without diabetes the highest concentrations of glucosamine, insulin and C-peptide were noted as compared to the results obtained from other groups of patients. In patients with diabetes, on the other hand, the highest glucose levels were noted as compared to the results of other patients. There were no statistically differences of lipid indexes between two groups of patients following MI. A negative correlation between glucosamine levels and glucose concentrations in patients without diabetes may suggest that glucose does not directly determine glucosamine levels. The returning of insulin levels to normal in patients with hyperinsulinemia (antidiabetic drugs) may play a role in the lowering of glucosamine induced peripheral insulin resistance.

Topics: Adult; C-Peptide; Cholesterol; Diabetes Mellitus, Type 2; Glucosamine; Humans; Insulin; Insulin Resistance; Male; Middle Aged; Myocardial Infarction; Statistics, Nonparametric; Triglycerides

We investigated the relationship between hs-CRP, a marker of low-grade inflammation, alone or in combination with C-peptide, a marker of hyperinsulinemia/insulin resistance, and risk for cardiovascular events (CVEs) and mortality in patients recently diagnosed with type 2 diabetes (T2D).. In patients with recent-onset T2D, we measured serum hs-CRP (n = 7,301) and C-peptide (n = 5,765) in the prospective Danish Centre for Strategic Research in Type 2 Diabetes cohort study. Patients with no prior CVE (n = 6,407) were followed until first myocardial infarction, stroke, coronary revascularization, or cardiovascular death, and all patients (n = 7,301) were followed for all-cause mortality. We computed adjusted hazard ratios (aHRs) by Cox regression and tested for the interaction between hs-CRP and C-peptide.. During follow-up (median 4.8 years), high (>3 mg/L) versus low (<1 mg/L) hs-CRP was associated with increased CVE risk (aHR 1.45 [95% CI 1.07-1.96]) and with even greater risk of all-cause mortality (2.47 [1.88-3.25]). Compared with patients with low hs-CRP (≤3 mg/L) and low C-peptide (<1,470 pmol/L), those with high levels of both biomarkers had the highest CVE (1.61 [1.10-2.34]) and all-cause mortality risk (2.36 [1.73-3.21]). Among patients with high C-peptide, risk of CVEs did not differ by low or high hs-CRP, whereas risk of all-cause mortality did.. The finding of high hs-CRP as a stronger prognostic biomarker of all-cause mortality than of CVEs may facilitate improved early detection and prevention of deadly diseases besides CVEs. Conversely, elevated C-peptide as a strong CVE biomarker supports the need to target hyperinsulinemia/insulin resistance in T2D CVE prevention.

Topics: Biomarkers; C-Peptide; C-Reactive Protein; Cardiovascular Diseases; Cohort Studies; Denmark; Diabetes Mellitus, Type 2; Humans; Insulin Resistance; Myocardial Infarction; Prospective Studies; Risk Factors

Previous studies have confirmed an association between C-peptide levels with the risk of cardiometabolic diseases. However, whether circulating C-peptide was related to subclinical myocardial injury (SC-MI) remains unknown.. A total of 3,752 participants without a history of cardiovascular diseases were included in our study from National Health and Nutrition Examination Survey III (NHANES III). Multivariable linear regression was performed to explore the correlation between C-peptide and cardiac injury score (CIIS). Multivariate logistic regression was used to examine the association between C-peptide quartile and SC-MI.. Circulating C-peptide was significantly associated with CIIS (β:0.09, 95% confidence interval [CI]: 0.00-0.17;. The level of C-peptide was independently associated with CIIS and SC-MI, which could serve as a new risk factor of SC-MI.

Topics: Aged; C-Peptide; Cross-Sectional Studies; Electrocardiography; Female; Humans; Male; Middle Aged; Myocardial Infarction; Nutrition Surveys

To analyse the association between serum C-peptide and coronary artery disease in the general population.. Follow-up study of 6630 adults from the general population. They were stratified into group 1 (no insulin resistance: C-peptide < third tercile and glycaemia < 100 mg/dL), group 2 (initial insulin resistance: C-peptide ⩾ third tercile and glycaemia < 100 mg/dL) and group 3 (advanced insulin resistance: glycaemia ⩾ 100 mg/dL).. After 3.5 years of follow-up, group 2 had a higher incidence of myocardial infarction (relative risk (RR) = 4.2, 95% confidence interval (CI) = 1.7-10.6) and coronary artery disease (RR = 3.5, 95% CI = 1.9-6.6) than group 1. Group 3 also had increased incidences of both diseases. In multivariable analysis of the entire population, groups 2 and 3 showed significant risks of myocardial infarction and coronary artery disease (RR > 3 and RR > 2, respectively). However, when people with diabetes were excluded, the increased risks were corroborated only in group 2 for myocardial infarction (RR = 2.8, 95% CI = 1.1-6.9; p = 0.025) and coronary artery disease (RR = 2.4, 95% CI = 1.3-4.6; p = 0.007).. Elevated C-peptide is associated with the incidence of myocardial infarction and coronary artery disease in the general population. It can be an earlier predictor of coronary events than impaired fasting glucose.

Topics: Adolescent; Adult; Aged; Biomarkers; Blood Glucose; C-Peptide; Chi-Square Distribution; Coronary Artery Disease; Early Diagnosis; Female; Follow-Up Studies; Humans; Incidence; Insulin Resistance; Male; Middle Aged; Myocardial Infarction; Odds Ratio; Predictive Value of Tests; Proportional Hazards Models; Risk Factors; Spain; Up-Regulation; Young Adult

The shortage of data concerning the character of changes of leptin concentration and its role information of insulin resistance under development of acute coronary events determined the appropriateness of the present study. The cardiac infarction patients with and without diabetes type II were examined. The identified hyperleptinemia, its relationship with basal and post-prandial hyperglycemia and with increase of C-peptide concentration and free fatty acids made possible to consider leptin both as one of the important components in the series of carbohydrate and lipid metabolism disorders and the additional marker of development of insulin resistance under cardiac infarction. These study results can be applied to patients with diabetes anamnesis and to patients without this concomitant pathology. The study results can be used as a foundation for new diagnostic and therapy tactics of metabolic disorders correction in patients with acute coronary vascular pathology.

Topics: Aged; Biomarkers; Blood Glucose; Body Mass Index; C-Peptide; Case-Control Studies; Diabetes Mellitus, Type 2; Female; Humans; Insulin; Insulin Resistance; Leptin; Male; Middle Aged; Myocardial Infarction

During myocardial infarction (MI), a transient decrease of both insulin sensitivity and secretion triggers stress hyperglycemia, which is followed by a substantial increase in mortality. Recent findings in cellular models indicate that HDL may act on glucose homeostasis by improving insulin sensitivity and secretion. In this study, we explored this potential effect in patients during the acute phase of MI.. Plasma glucose, insulin and C-peptide were measured at admission in the first 24h and on the fifth day after MI with ST-segment elevation in 183 consecutive non-diabetic patients. Patients were divided into HDL-C quartiles for the analyses (Q1: <31, Q2: 31-38, Q3: 38-47 and Q4: >47mg/dL). The Homeostasis Model Assessment version 2 was used to assess insulin sensitivity (HOMA2S) and beta-cell function (HOMA2B).. On admission, no difference was found between the quartiles in glucose (p=0.6), insulin (p=0.6) or C-peptide (p=0.5) levels, HOMA2S (p=0.9) or HOMA2B (p=1.0). On the fifth day there was a reduction in glucose levels whose intensity was directly proportional to the HDL-C quartile (p<0.001). At the same time, there was a reduction in plasma insulin (p<0.001) and C-peptides (p<0.001) whose magnitude was inversely proportional to the HDL-C quartile. Consistently, the increase of HOMA2S (p<0.001) and HOMA2B (p=0.01) were also positively associated with HDL-C levels. Furthermore, plasma HDL-C levels were inversely and independently associated with blood glucose change during the acute phase.. This study demonstrates the association between low plasma HDL-C levels and increased duration of stress hyperglycemia during MI and suggests in humans the interaction between HDL and insulin secretion and sensitivity.

Topics: Aged; Analysis of Variance; Biomarkers; Blood Glucose; Brazil; C-Peptide; Cholesterol, HDL; Female; Homeostasis; Humans; Hyperglycemia; Insulin; Insulin-Secreting Cells; Logistic Models; Male; Middle Aged; Multivariate Analysis; Myocardial Infarction; Prospective Studies; Stress, Physiological; Time Factors; Up-Regulation

Immunoassays are susceptible to analytical interferences including from endogenous immunoglobulin antibodies at a rate of ∼0.4% to 4%. Hundreds of millions of immunoassay tests (>10 millions in the UK alone) are performed yearly worldwide for measurements of an array of large and small moieties such as proteins, hormones, tumour markers, rheumatoid factor, troponin, small peptides, steroids and drugs.. Interference in these tests can lead to false results which when suspected, or surmised, can be analytically confirmed in most cases. Suspecting false laboratory data in the first place is not difficult when results are gross and without clinical correlates. However, when false results are subtle and/or plausible, it can be difficult to suspect with adverse clinical sequelae. This problem can be ameliorated by using a probabilistic Bayesian reasoning to flag up potentially suspect results even when laboratory data appear "not-unreasonable".. Essentially, in disorders with low prevalence, the majority of positive results caused by analytical interference are likely to be false positives. On the other hand, when the disease prevalence is high, false negative results increase and become more significant. To illustrate the scope and utility of this approach, six different examples covering wide range of analytes are given, each highlighting specific aspect/nature of interference and suggested options to reduce it.. Bayesian reasoning would allow laboratorians and/or clinicians to extract information about potentially false results, thus seeking follow-up confirmatory tests prior to the initiation of more expensive/invasive procedures or concluding a potentially wrong diagnosis.

Topics: Acute Coronary Syndrome; Aged; Bayes Theorem; C-Peptide; Chorionic Gonadotropin; Data Interpretation, Statistical; False Positive Reactions; Female; Humans; Hyperglycemia; Hypothyroidism; Immunoassay; Insulin; Myocardial Infarction; Proinsulin; Prostate-Specific Antigen; Rheumatoid Factor; Thyrotropin; Troponin

Diabetes and prediabetic conditions are growing cardiovascular risk factors. Better understanding and earlier recognition and treatment of dysglycemia-related risk are health priorities. We assessed the predictive value of 3 proposed new markers for diabetes and cardiovascular risk. We tested whether the plasma levels of (1) asymmetric dimethylarginine (ADMA), (2) cortisol/cortisone (Cl/Cn) ratio, and (3) C-peptide predicted glycemic status, coronary artery disease, and death or myocardial infarction (MI) in a nested case-control cohort (N = 850) with normal fasting glucose (< 110 mg/dL), impaired fasting glucose (110-125), or diabetic (> or = 126) status.. High-sensitivity C-reactive protein (hsCRP) served as a control risk marker. Follow-up averaged 2.6 +/- 1.4 years. High-pressure liquid chromatography with pre-column derivitization and fluorescence was used to assay ADMA, liquid chromatography/tandem mass spectrometry for Cl and Cn, and chemiluminescent immunoassay for C-peptide.. Asymmetric dimethylarginine levels were positively associated with glycemic category (P < .001). Quartiles 2 to 4 ADMA also conferred increased risk of death/MI independent of hsCRP and other risk factors (adjusted hazard ratio, 2.1; P = .002). Cortisol/Cortisone ratios (P = .013) and C-peptide (P = .047) were associated with glycemic categories but less strongly than ADMA. Quartiles 2 to 4 Cl/Cn were protective against incident death/MI (adjusted hazard ratio, 0.48; P < .001), whereas C-peptide did not predict outcomes.. Among a high coronary risk case-control cohort, ADMA (strongly), Cl/Cn (moderately), and C-peptide (weakly) predicted glycemic categories. Asymmetric dimethylarginine and Cl/Cn also predicted clinical outcome independent of and more strongly than hsCRP. Asymmetric dimethylarginine and Cl/Cn represent promising new candidate markers of dysglycemia and associated cardiovascular risk.

Topics: Arginine; Biomarkers; Blood Glucose; C-Peptide; Case-Control Studies; Coronary Disease; Cortisone; Diabetes Mellitus; Female; Humans; Hydrocortisone; Hyperinsulinism; Logistic Models; Male; Middle Aged; Myocardial Infarction; Nitric Oxide Synthase; Predictive Value of Tests; Risk Assessment

Insulin resistance is associated with atherosclerosis, and hyperinsulinemia is predictive of coronary heart disease. However, a quantitative estimation of in vivo insulin sensitivity in juvenile myocardial infarction is still lacking and the mechanism of hyperinsulinemia is unknown. We estimated insulin sensitivity, beta-cell secretion, and hepatic insulin extraction using the minimal model analysis of a frequently sampled intravenous glucose tolerance test (FSIGT) in 25 normal-weight subjects without glucose intolerance and hypertension who had an acute myocardial infarction before the age of 40 years, and 10 control subjects comparable for age, sex, body mass index, and blood pressure. All patients underwent a coronary angiography. Insulin sensitivity was significantly lower in patients than in control subjects (mean +/- SEM, 4.6 +/- 0.6 v8.5 +/- 1.2 10(-4). min(-1)(microU/mL), P = .002). The basal C-peptide secretion rate (P = .02), total C-peptide secretion (P = .005), area under the curve (AUC) of insulin (P = .04) and C-peptide (P = .01), and hepatic insulin extraction (P = .04) were higher in patients versus control subjects. In conclusion, insulin resistance is evident in subjects with early myocardial infarction accurately selected to avoid the influence of other factors known to reduce insulin sensitivity, and hyperinsulinemia is due to an increase in beta-cell secretion rather than a decrease in hepatic insulin extraction.

Topics: Adult; Age Factors; Blood Glucose; C-Peptide; Coronary Vessels; Female; Humans; Insulin; Insulin Resistance; Islets of Langerhans; Male; Myocardial Infarction; Time Factors

Insulin resistance is known as an important risk factor for coronary artery disease (CAD). However, CAD-related mortality in Japanese type 2 diabetics is lower than in Caucasians. To investigate whether insulin resistance is related to CAD in Japanese type 2 diabetics, we measured insulin sensitivity and several coronary risk factors in Japanese patients with type 2 diabetes with and without CAD. Thirty-three patients with definite CAD and 33 age- and sex-matched patients without CAD (control) were studied. Insulin sensitivity was assessed by the K index of insulin tolerance test (KITT). Clinical characteristics, classical risk factors, lipoprotein (a), and insulin sensitivity were compared between the two groups. Patients with CAD had a significantly longer duration of diabetes (9.0 +/- 1.4 vs. 5.5 +/- 0.9 years, P < 0.05, respectively), were mostly hypertensive (69.7 vs. 39.4%, P < 0.05), and more likely to be treated with insulin (45.5 vs. 18.2%, P < 0.05) compared with the control. Concerning the metabolic parameters, patients with CAD had a significantly higher insulin resistance than control (2.40 +/- 0.15 vs. 3.23 +/- 0.17%/min, P < 0.01, respectively), higher triglyceride (1.39 +/- 0.10 vs. 1.05 +/- 0.05 mmol/l, P < 0.05), lower HDL cholesterol (1.05 +/- 0.05 vs. 1.28 +/- 0.06 mmol/l, P < 0.05), and higher lipoprotein (a) (27.5 +/- 4.3 vs. 17.4 +/- 2.0 mg/dl, P < 0.05). Multiple logistic regression analysis indicated that hypertension, insulin resistance, high lipoprotein (a) and triglyceride, and low HDL cholesterol were independently related to CAD. Our results suggest that insulin resistance per se is a significant risk factor for CAD in Japanese patients with type 2 diabetes.

Topics: Aged; Asian People; Blood Glucose; Blood Pressure; C-Peptide; Cholesterol; Cholesterol, HDL; Coronary Disease; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Female; Glycated Hemoglobin; Humans; Insulin Resistance; Japan; Lipoprotein(a); Male; Middle Aged; Myocardial Infarction; Risk Factors; Smoking; Triglycerides; White People

Low serum levels of high-density lipoprotein (HDL) cholesterol or apolipoprotein A-I and high serum levels of insulin increase the risk of coronary heart disease (CHD) and can indicate insulin resistance. We tested the strength, independence, and interactions of associations between HDL cholesterol (or apolipoprotein A-I), insulin (or C-peptide), glucose, and CHD in 95 male nondiabetic patients with CHD who were <60 years old, in 92 probands from the PROCAM study, and in 61 non-cardiologic patients; all subjects were matched by age, body mass index, and smoking habits. Systemic hypertension (odds radio [OR] 2.8, 95% confidence intervals [CI] 1.6 to 4.8), high serum levels of glucose (OR 2.3, 95% CI 1.6 to 4.8), insulin (OR 2.1, 95% CI 1.3 to 3.6), and C-peptide (OR 4.1, 95% CI 2.2 to 7.5) as well as low serum levels of HDL cholesterol (OR 2.0, 95% CI 1.1 to 3.5) or apolipoprotein A-I (OR 3.9, 95% CI 2.1 to 7.1) had significant associations with CHD. At multivariate analysis, systolic blood pressure, glucose, apolipoprotein A-I, and C-peptide, but not HDL cholesterol and insulin, had consistent independent associations with CHD. Thus, the combined measurement of apolipoprotein A-I and C-peptide may improve the identification of nondiabetic patients at increased risk for CHD.

Topics: Adult; Apolipoprotein A-I; C-Peptide; Case-Control Studies; Cholesterol, HDL; Coronary Disease; Humans; Insulin; Male; Middle Aged; Myocardial Infarction; Regression Analysis; Risk Factors

To study velocity characteristics of changes in the levels of insulin, glucagon and C-peptide in the course of the intravenous glucose tolerance test (IGTT).. Glucose, insulin, glucagon and peptide levels were measured in the course of IGTT performed in 50 patients with coronary atherosclerosis (CA) who survived transmural myocardial infarction, 32 individuals with hereditary predisposition to CA and 30 controls free of cardiovascular or endocrine pathology. The results were approximated using high-degree polynomes allowing calculation of the first and second derivatives (the velocity and rate of its change).. CA patients showed inhibited changes of blood glucose, immunoreactive insulin. The reduction of the latter lasted longer than that in the control group.. Under urgent mobilization of blood glucose regulation system, CA patients develop retention of immunoreactive insulin.

Topics: C-Peptide; Coronary Artery Disease; Glucagon; Glucose Tolerance Test; Humans; Insulin; Myocardial Infarction

The objective of the study was to determine if male subjects with coronary atherosclerotic heart disease (CHD) without major CHD risk factors have hyperinsulinemia and related metabolic changes. Previous studies suggested that hyperinsulinemia is a CHD risk factor, but they did not entirely exclude concurrent metabolic abnormalities. A prospective, comparative, cross-sectional study in a tertiary care teaching hospital in Mexico City was conducted in 15 men who had suffered myocardial infarction 6 to 24 months before and had significant coronary occlusion on angiography. Control group was formed by 15 age-matched healthy men. None had hypertension, obesity, diabetes, gout, glucose intolerance or hyperlipidemia. Body mass index (BMI), waist/hip ratio (WHR), blood pressure (BP); oral glucose tolerance test (OGTT) with measurement of serum glucose, insulin and C-peptide every 30 min for 2 h, fasting serum cholesterol, triglycerides and uric acid, areas under curve (AUC) of glucose and insulin, insulin/glucose ratio and insulin sensitivity index were calculated. BMI, WHR and BP were similar in both groups. Fasting and post-load serum glucose and insulin concentrations were significantly higher in CHD than in control group (p < 0.01); fasting glucose 5.9 +/- 0.6 vs. 4.8 +/- 0.7 nmol/1, 2-h glucose 8.3 +/- 0.6 vs. 7.3 +/- 0.9 mmol/l, fasting insulin 17.5 +/- 1.2 vs. 15.3 +/- 1.7 pmol/l, 2 h insulin 448 +/- 108 vs. 282 +/- 87 pmol/l in CHD and control group, respectively. AUC of glucose, AUC of insulin, insulin/glucose ratio, post load C-peptide, serum cholesterol, triglycerides and uric acid levels were also significantly higher in CHD than in healthy controls. Insulin sensitivity index was significantly lower in patients with CHD (27.7 +/- 8.3) than in healthy control subjects (73.9 +/- 18) (p < 0.001). Patients with CHD have hyperinsulinemia and subtle metabolic abnormalities related with insulin resistance even in absence of overt risk factors.

Topics: Adult; Aged; Anthropometry; Blood Glucose; Blood Pressure; C-Peptide; Comorbidity; Convalescence; Coronary Artery Disease; Cross-Sectional Studies; Glucose Tolerance Test; Humans; Hyperinsulinism; Insulin Resistance; Lipids; Male; Mexico; Middle Aged; Myocardial Infarction; Prospective Studies; Risk Factors; Uric Acid

In this study, we investigated the influence of glucose administration on binding and degradation of 125I-insulin by receptors on erythrocytes as well as on insulin and C-peptide serum levels in 15 patients after myocardial infarction and in 15 age-matched healthy persons. Venous blood samples were taken directly before and at 30, 60 and 120 minutes after oral administration of 75 g of glucose. In the collected blood samples serum glucose, insulin and C-peptide levels were determined. Binding and degradation of 125I-insulin by specific receptors on red blood cells were evaluated using the method described by Gambhir and modified by the authors. Serum insulin and C-peptide levels were significantly higher while binding of 125I-insulin to erythrocytes was decreased in patients after myocardial infarction. These results seem to support the hypothesis that insulin resistance and hyperinsulinism play a role in the pathogenesis of ischaemic heart disease. Impaired degradation of 125I-insulin during the oral glucose tolerance test in the patients after myocardial infarction indicates that insulin resistance is located at the receptor level.

Topics: Adult; C-Peptide; Erythrocytes; Glucose; Glucose Tolerance Test; Humans; Insulin; Iodine Radioisotopes; Middle Aged; Myocardial Infarction

The majority (> 80%) of patients with non insulin dependent diabetes mellitus (NIDDM) present in Europe and America are obese. In developing countries like India, most NIDDM (> 60%) are non-obese and many are actually lean with a body mass index (BMI) of < 18.5 and are referred to as 'lean NIDDM'. This paper compares the clinical profile of a cohort of 347 lean NIDDM, with a group of 6274 NIDDM of ideal body weight (IBW) and 3252 obese NIDDM attending a diabetes centre at Madras in South India. The lean NIDDM who constituted 3.5% of all NIDDM patients seen at our centre, had more severe diabetes and an increased prevalence of retinopathy (both background and proliferative), nephropathy and neuropathy. Although a larger percentage of the lean NIDDM patients were treated with insulin, 47% of the males and 53% of the females were still on oral hypoglycaemic agents even after a mean duration of diabetes of 9.2 +/- 8.1 years. Studies of GAD antibodies, islet cell antibodies (ICA) and fasting and stimulated C-peptide estimations done in a small subgroup of the lean NIDDM showed that they were distinct from IDDM patients. More studies are needed on metabolic, hormonal and immunological profile of lean NIDDM seen in developing countries like India.

Topics: Adult; Autoantibodies; Blood Glucose; Blood Pressure; Body Mass Index; Body Weight; C-Peptide; Cholesterol; Cohort Studies; Diabetes Mellitus; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Diabetic Neuropathies; Diabetic Retinopathy; Diastole; Dose-Response Relationship, Drug; Fasting; Female; Glutamate Decarboxylase; Glycated Hemoglobin; Humans; Hypoglycemic Agents; India; Insulin; Islets of Langerhans; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Obesity; Postprandial Period; Smoking; Systole; Triglycerides

To study the frequency of antibodies to glutamic acid decarboxylase (GAD) and islet cell antibodies (ICAs) and their predictive value with respect to the development of insulin deficiency in 133 newly diagnosed middle-aged patients with non-insulin-dependent diabetes mellitus (NIDDM) and in 126 control subjects and to study the persistence of GAD antibodies in diabetic patients during the follow-up.. The study participants consisted of a well-characterized group of 133 middle-aged newly diagnosed patients with NIDDM and 126 control subjects. The follow-up examinations were performed 5 and 10 years after the baseline. The development of absolute and relative insulin deficiency was based on a stimulated C-peptide level that was undetectable or < 0.70 nmol/l, respectively. GAD antibodies were measured retrospectively from stored samples.. The overall prevalence of GAD antibody and ICA positivity at the time of diagnosis was 9.0 and 3.8% in diabetic patients and 1.6 and 0% in the control population, respectively. During the 10-year follow-up, 3 (2.3%) and 10 (7.5%) of the diabetic patients developed absolute and relative insulin deficiency, respectively. Of these, two (67%) and six (60%) had been GAD antibody-positive at the time of diagnosis. The sensitivity and specificity of the GAD antibody to predict absolute or relative insulin deficiency were 67 vs. 94% and 60 vs. 95%, while corresponding figures for ICA were 33 vs. 97% and 20 vs. 98%, respectively. The negative predictive value of GAD antibody testing was higher than positive predictive value (97 vs. 50%). During the follow-up, low-grade GAD antibody positivity showed an evanescent nature, whereas the high levels were quite persistent.. In an unselected population of newly diagnosed NIDDM patients, the prevalence of latent autoimmune diabetes in adults was < 10%. While GAD antibody and ICA measured at the time of diagnosis of NIDDM are equally specific predictors of subsequent insulin dependency, the GAD antibody may have a higher sensitivity. Therefore, measurements of GAD antibody may aid the clinician in the choice of treatment of these patients.

Topics: Autoantibodies; Blood Glucose; C-Peptide; Cohort Studies; Diabetes Mellitus, Type 2; Female; Follow-Up Studies; Glucose Tolerance Test; Glutamate Decarboxylase; Glycated Hemoglobin; Humans; Hypertension; Incidence; Insulin; Islets of Langerhans; Male; Middle Aged; Myocardial Infarction; Predictive Value of Tests; Reference Values; Sensitivity and Specificity; Time Factors

To examine the role of insulin as a cardiovascular risk factor in British Asian and white men.. Case-controlled study of survivors of first myocardial infarction.. District general hospital.. Consecutive series of 76 white and 74 Asian men who survived first myocardial infarction compared with 58 white and 61 Asian male controls without coronary artery disease who were randomly sampled from the community.. More Asians than white subjects had impaired glucose tolerance or overt diabetes as measured by the two hour glucose tolerance test (23/74 (32%) v 11/76 (15%) (p less than 0.001) among patients; 17/61 (28%) v 3/58 (6%) (p less than 0.001) among controls). Insulin and C peptide concentrations were higher in both patient groups than in respective controls (p less than 0.001) and higher in Asian than in white subjects, irrespective of their glucose tolerance. Triglyceride concentrations were higher in patients than in controls (1.92 (SD 1.05) v 1.43 (0.82) mmol/l among Asian men; 1.65 (0.83) v 1.3 (0.61) mmol/l among white subjects; p less than 0.001). Total cholesterol concentrations were lower in both groups of Asians than in respective white subjects (5.78 (0.99) v 6.22 (1.04) mmol/l (p less than 0.01) among patients; 5.54 (1.01) v 5.65 (1.11) mmol/l (p less than 0.6) among controls). High density lipoprotein cholesterol concentrations were lower in Asian than in white subjects. The ratio of total cholesterol to high density lipoprotein cholesterol was significantly higher (p less than 0.001) in both patient groups (6.69 (1.81) in Asian patients and 6.31 (1.91) in white patients) than in respective controls (5.24 (1.19) and 4.77 (1.43)). Regression analysis identified C peptide concentration and the ratio of total to high density lipoprotein cholesterol as powerful independent predictors of myocardial infarction in Asian and white men. Total cholesterol concentration predicted infarction in white but not in Asian men.. Secretion and hepatic extraction of insulin are high in survivors of myocardial infarction and especially high in British Asians. Tissue resistance to the action of insulin, giving rise to increased pancreatic secretion, may be an important risk factor for coronary artery disease in both ethnic groups and may be partly responsible for the high incidence of diabetes and coronary artery disease in Asian populations.

Topics: Asia; Body Constitution; C-Peptide; Case-Control Studies; Cholesterol; England; Humans; Insulin; Lipids; Male; Myocardial Infarction; Regression Analysis; Risk Factors