Follow-up report on the diagnosis of diabetes mellitus

Practice Changes in Glycemic Management and Outcomes in Coronary Artery Bypass Surgery Patients

This study aims to evaluate whether a quality improvement initiative in hyperglycemia management could result in substantiated practice changes and improved outcomes for coronary artery bypass surgery patients. Retrospective chart review and analysis of 103 randomly selected patients hospitalized for coronary artery bypass surgery was used. After the glycemia awareness initiative, the perioperative use of intravenous insulin infusion therapy increased in the total population (P = .01) as well as in the diabetes population (P = .03). Frequency of blood glucose level tests ordered for nondiabetic patients increased from 2.8 per day to 4.3 per day (P = .38). Blood glucose values improved in the diabetic population (Ps = .02, .048). The average length of stay improved in all nondiabetic patients (10.7-8.1 days, P = .07) including those who had coronary artery bypass graft surgery with cardiac catheterization (7.8-6.2 days, P = .09) and coronary artery bypass graft surgery with catheterization with complications (15.0-9.0 days, P = .12). The glycemia awareness initiative resulted in a positive impact on practice patterns. Undiagnosed diabetes and impaired fasting glucose are important and unrecognized issues within this hospital population. It is recommended that healthcare practitioners assume that cardiac patients have an increased likelihood of impaired fasting glucose and hyperglycemia. Advanced practice nurses can improve patient outcomes by ordering glucose testing and glycemic management as a routine practice for all cardiac surgery patients, regardless of diabetes diagnosis. Cardiac staff nurses can recommend glucose testing and screening for prediabetes and diabetes as a routine part of all nursing assessment.

Relevance of post-methionine homocysteine and lipoprotein (a) in evaluating the cardiovascular risk in young CAD patients

BACKGROUND

Aims of our study were to evaluate the prevalence of high lipoprotein (a) [Lp(a)] and homocysteine levels - both in the fasting state (FHcy) and post-methionine (PMHcy) - in young coronary artery disease (CAD) patients, and to investigate the role of genetic and environmental factors for hyperhomocysteinaemia.

MATERIALS AND METHODS

We studied 140 patients with angiographically documented CAD (24 women </= 55 years and 116 men </= 50 years) and 140 healthy subjects as controls.

RESULTS

Both FHcy [13.2 (5.4-45.8) vs. 9.0 (5.1-24) micromol L(-1)); P < 0.0001] and PMHcy [(39.4 (9.0-66.4) vs. 25.2 (16.4-33.9); P < 0.0001] were significantly higher in patients than in controls. Lp(a) levels were significantly higher in patients than in controls (200 (3-1486) mg L(-1) vs. 97 (10-412) mg L(-1); P < 0.0001). At the multivariate analysis, adjusted for the classical cardiovascular risk factors and creatinine levels, the OR (95% CI) for CAD at young age significantly increased in the fourth quartile of the distribution of FHcy, PMHcy and Lp(a) levels [FHcy: 14.9 (4.1-58), P < 0.0001; PMHcy: 19.2 (4.0-86.3); P < 0.0001; Lp(a): 19.6 (4.7-78.6): < 0.0001]. Vitamin deficiencies were detected in 28/140 (20%) patients. The prevalence of the homozygous C677T (+/+) methylenetetrahydrofolatereductase genotype was higher, but not significantly different, in patients (22.8%) than in controls (18.6%). The allele frequency of the 844ins68 insertion variant in the cystathionine beta-synthase gene was 0.08 in the control group and 0.06 in the patient group.

CONCLUSIONS

Results of the present study indicate the usefulness of including fasting and post-methionine Hcy, and Lp(a) determination in the diagnostic panels of young CAD patients, in order to obtain a better assessment of their cardiovascular risk profile.

Is atherosclerosis in diabetes and impaired fasting glucose driven by elevated LDL cholesterol or by decreased HDL cholesterol?

OBJECTIVE

To evaluate the atherogenicity of lipids in coronary patients with normal fasting glucose (NFG), impaired fasting glucose (IFG), and type 2 diabetes.

RESEARCH DESIGN AND METHODS

Serum lipid values, the presence of angiographic coronary artery disease (CAD) at baseline, and the incidence of vascular events over 2.3 years were recorded in 750 consecutive patients undergoing coronary angiography.

RESULTS

Triglycerides significantly (P < 0.001) increased and HDL cholesterol (P < 0.001) as well as LDL particle diameter (P < 0.001) significantly decreased from subjects with NFG <5.6 mmol/l (n = 272) over patients with IFG > or =5.6 mmol/l (n = 314) to patients with type 2 diabetes (n = 164). Factor analysis revealed two factors in the lipid profiles of our patients: triglycerides, HDL cholesterol, apolipoprotein A1, and LDL particle diameter loaded high on an HDL-related factor, and total cholesterol, LDL cholesterol, and apolipoprotein B loaded high on an LDL-related factor. In patients with type 2 diabetes, the HDL-related factor (odds ratio 0.648 [95% CI 0.464-0.904]; P = 0.011), but not the LDL-related factor (0.921 [0.677-1.251]; P = 0.597), was associated with significant coronary stenoses > or =50%. Consistently, in the prospective study, the HDL-related factor (0.708 [0.506-0.990]; P = 0.044), but not the LDL-related factor (1.362 [0.985-1.883]; P = 0.061), proved significantly predictive for vascular events in patients with type 2 diabetes.

CONCLUSIONS

The low HDL cholesterol/high triglyceride pattern is associated with the degree of hyperglycemia. In coronary patients with type 2 diabetes, this pattern correlates with the prevalence of CAD and significantly predicts the incidence of vascular events.

Phenotypic heterogeneity in biochemical parameters correlates with mutations in AGPAT2 or Seipin genes among Berardinelli-Seip congenital lipodystrophy patients

The Berardinelli-Seip congenital lipodystrophy (BSCL) syndrome is characterized by a near-total congenital absence of fat and predisposition to develop diabetes mellitus. We have previously reported that 22 patients from 16 consanguineous pedigrees living in the northeastern region of Brazil had a homozygous 669insA mutation in the Seipin gene (BSCL2 locus), while all of the 10 investigated subjects from the southeastern region were homozygous for a 1036 bp deletion in the AGPAT2 gene (BSCL1 locus). In this study, we compared the serum insulin and insulin resistance (HOMA), leptin, triglyceride and fasting glucose levels in individuals of these two genetically distinct clusters of BSCL subjects. The onset of diabetes was also estimated. The fasting glucose and triglyceride levels were not significantly different in these groups. Significant differences were detected for leptin, insulin and insulin resistance. BSCL1 patients presented lower serum leptin levels compared to BSCL2 patients. BSCL2 subjects had earlier onset of diabetes and higher insulin levels. In agreement, BSCL2 patients were more insulin resistant, as detected by HOMA. These results indicate phenotypic heterogeneity between BSCL1 and BSCL2 Brazilian subjects.

ORIGINAL RESEARCH—EPIDEMIOLOGY: Erectile Dysfunction Is a Marker for Cardiovascular Disease: Results of the Minority Health Institute Expert Advisory Panel

INTRODUCTION

Cardiovascular disease and its related comorbidities are associated with significant morbidity and mortality and affect a disproportionately large number of African Americans and Hispanics. The prevalence of cardiovascular disease is increasing worldwide, which underscores the urgency to improve methods of prevention and early detection.

AIM

To develop a risk assessment and management algorithm for primary care patients with erectile dysfunction (ED) that facilitates diagnosis, early intervention, and prevention of cardiovascular disease.

METHODS

The Minority Health Institute (MHI) convened an Expert Advisory Panel of cardiologists and urologists to design a new practice model algorithm that uses ED as a clinical tool for early identification of men with systemic vascular disease. A draft of the algorithm was presented at a national symposium and comments from symposium participants were considered in the development of the final algorithm.

MAIN OUTCOME MEASURES AND RESULTS

Erectile dysfunction is common and has long been considered a secondary complication of cardiovascular disease, diabetes, hypertension, and dyslipidemia. However, a growing body of evidence challenges this view, suggesting instead that ED is an early manifestation of atherosclerosis and a precursor to systemic vascular disease. Endothelial dysfunction is the etiologic factor linking ED and cardiovascular disease.

CONCLUSIONS

The recognition of ED as an early sign of systemic cardiovascular disease offers an opportunity for prevention, particularly in high-risk and underserved minority populations. The MHI algorithm stipulates that all men 25 years old and older regardless of sexual dysfunction complaints should be asked about ED. The presence of ED should prompt an aggressive assessment for cardiovascular risk and occult systemic vascular disease.

Insulin sensitivity and coronary vasoreactivity: insulin sensitivity relates to adenosine-stimulated coronary flow response in human subjects

OBJECTIVE

Diabetes is associated with coronary microvasculature abnormalities and impaired coronary flow reserve (CFR). CFR is the ratio of coronary flow under maximal vasodilation to basal flow and is a measure for coronary vasoreactivity. Insulin resistance is the central defect in the development of type 2 diabetes, preceding its onset by 10-20 years. Thus, the relationship between insulin sensitivity and CFR in nondiabetic subjects is particularly interesting. The aim of the study was to investigate this relationship.

DESIGN

Cross-sectional study.

PATIENTS

The study population consisted of 18 nondiabetic subjects without coronary artery stenosis on coronary angiography. We excluded patients with structural heart disease or with conditions affecting CFR or insulin sensitivity such as low density lipoprotein (LDL)-cholesterol > or = 4.14 mmol/l, smoking, hypertension or obesity with a body mass index (BMI) > 28 kg/m(2).

MEASUREMENTS AND RESULTS

CFR was 3.1 +/- 0.8 (range 1.7-4.8), as assessed by intracoronary Doppler measurements in the left anterior descending coronary arteries after adenosine stimulation. Intravascular ultrasound revealed zero to moderate coronary atherosclerotic changes. Whole-body insulin sensitivity (M-value) was 7.5 +/- 2.9 mg/kg/min (range 2.2-12.6), as assessed by the hyperinsulinaemic-euglycaemic clamp test. Subjects with low CFR (< 3.0) had a significantly lower M-value than subjects with normal CFR (> 3.0) (6.0 +/- 2.5 vs. 9.0 +/- 2.5 mg/kg/min, P = 0.021). Univariate linear regression demonstrated a strong correlation between CFR and M-value (r = 0.76, P < 0.001). In multiple regression analysis, the significant association of CFR with M-value was independent of potential confounders (sex, age, BMI, LDL-cholesterol and plaque burden on intravascular ultrasound). Bootstrap analysis corroborated this finding.

CONCLUSIONS

Whole-body insulin sensitivity relates to coronary vasoreactivity. Across a wide range of both insulin sensitivity and coronary flow reserve from markedly abnormal to normal values, an increase in insulin sensitivity appears to be associated with an increase in coronary flow reserve. Insulin resistance is therefore associated with coronary microvasculature abnormalities in nondiabetics.

Prevention of type 2 diabetes: issues and strategies for identifying persons for interventions

Because of the ongoing worldwide diabetes epidemic and new evidence that type 2 diabetes can be prevented or delayed, we are compelled to implement prevention efforts. Health policy makers need to bridge the evidence gap left by prevention trials that did not include all groups at risk for developing diabetes. Intensive interventions may be appropriate for groups with similar risk as those studied in clinical trials, while less intense efforts may be considered for those groups that have not been studied. Factors such as structure of the health care system and individual social and economic situations may influence the implementation of prevention efforts. Currently, no universally validated and well-tested method exists to identify all people at high risk for developing diabetes. However, groups that will be targeted for prevention efforts can be identified through several reasonable strategies.

Effects of impaired fasting glucose and impaired glucose tolerance on predicting incident type 2 diabetes in a Chinese population with high post-prandial glucose

AIMS

To ascertain which impaired glucose homeostasis at baseline is predictive of conversion to type 2 diabetes in both men and women in a high-risk non-diabetic population.

METHODS

The screening survey for type 2 diabetes was conducted in 1994, and a follow-up study of 627 high-risk non-diabetic individuals at baseline was carried out in 1999 in Beijing area. A total of 70 men and 76 women developed diabetes during the 5-year follow-up.

RESULTS

After adjustment for age, body mass index, smoking, systolic blood pressure, family history of diabetes, total cholesterol, triglycerides, antihypertensive medication, occupation, education, urine albumin excretion rate, and fasting insulin, the odds ratios for incidence of diabetes were 1.00, 2.04 (95% CI 0.84-4.97), 7.82 (2.66-23.00), 9.38 (3.30-26.69) in men with normal glucose, isolated IFG, isolated IGT, and both IFG and IGT, respectively. In women, the corresponding odds ratios were 1.00, 2.19 (0.91-5.30), 1.62 (0.72-3.67), and 8.79 (2.98-25.93), respectively.

CONCLUSIONS

This study shows that combined IFG and IGT at baseline is a strong risk predictor for the development of diabetes in both men and women. Isolated IGT is also a predictor of diabetes in Chinese men.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Increasing prevalence of the metabolic syndrome among u.s. Adults

OBJECTIVE

The prevalence of the metabolic syndrome is high among U.S. adults. Our purpose was to determine whether the prevalence of this syndrome has changed since 1988-1994.

RESEARCH DESIGN AND METHODS

A total of 6,436 men and women aged > or = 20 years from the National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and 1,677 participants from NHANES 1999-2000 were included in the analyses. We used the definition of the metabolic syndrome developed by the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults.

RESULTS

The unadjusted prevalence of the metabolic syndrome was 23.1% in NHANES III and 26.7% in NHANES 1999-2000 (P = 0.043), and the age-adjusted prevalences were 24.1 and 27.0% (P = 0.088), respectively. The age-adjusted prevalence increased by 23.5% among women (P = 0.021) and 2.2% among men (P = 0.831). Increases in high blood pressure, waist circumference, and hypertriglyceridemia accounted for much of the increase in the prevalence of the metabolic syndrome, particularly among women.

CONCLUSIONS

The increased prevalence of the metabolic syndrome is likely to lead to future increases in diabetes and cardiovascular disease.

Lack of agreement between the revised criteria of impaired fasting glucose and impaired glucose tolerance in children with excess body weight

OBJECTIVE

The aim of this study was to describe the agreement between impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) in children with excess body weight using the original and the revised definitions of IFG.

RESEARCH DESIGN AND METHODS

Obese and overweight children aged 4-17 years were included (n = 533). Anthropometric parameters and biochemical tests (fasting and 2-h glucose tests after an oral glucose load [1.75 g/kg]) were performed. Case subjects with a fasting plasma glucose >/=126 mg/dl were excluded. The diagnostic parameters of the original and the revised definitions of IFG for detecting IGT were estimated. The analysis of agreement between these categories was made using the kappa test.

RESULTS

The prevalence of IFG increased from 6.2 to 13.3% using the new criteria. The prevalence of IFG became closer to the prevalence of IGT (14.8%). The revised criteria increased the sensitivity from 26.6 to 36.7%. However, the new IFG definition was not useful for identifying IGT cases. Of the 71 case subjects with IFG, only 29 (40.8%) had IGT. In addition, 50 case subjects with IGT (9.4%) and 13 with diabetes (2.4%) had a fasting glycemia <100 mg/dl. A poor agreement was found between the 2003 IFG definition and abnormal 2-h postchallenge plasma glucose (kappa = 0.359). The proportion of false-positive cases increased (36.3-59.1%) under the new definition.

CONCLUSIONS

The new definition modestly increases the sensitivity of IFG for detecting IGT in children with excess body weight. Despite this, more than one-half of these cases are not detected. In addition, the false-positive rate was increased by 61%.

Fasting plasma glucose and risk of incident ischemic stroke or transient ischemic attacks: a prospective cohort study

BACKGROUND AND PURPOSE

Diabetes and impaired fasting glucose are diagnosed based on an elevated plasma glucose level after an overnight fast. The diagnostic cutpoint of diabetes arises from the threshold for development of microvascular complications. Our aim was to examine the associations between clinical relevant categories of fasting glucose levels and the risk of incident ischemic stroke.

METHODS

Patients with documented coronary heart disease who were screened for inclusion in a secondary prevention clinical trial (n=13,999) were followed-up. At baseline, medical histories were obtained and plasma glucose and lipids assessed at a central study laboratory. During a 6- to 8-year follow-up period 1037 cases were identified with ischemic cerebrovascular disease, of which, after reviewing hospital records with diagnoses of cerebrovascular disease, 576 cases were verified to have had ischemic stroke or transient ischemic attacks.

RESULTS

Increasing fasting glucose level categories were positively associated with increasing age, male gender, body mass index, hypertension, total cholesterol, and triglycerides, and were inversely associated with high-density lipoprotein cholesterol and percent high-density lipoprotein of total cholesterol. In comparison with patients with fasting glucose levels of 90 to 99 mg/dL (n=3706) who constitute the largest category, the odds ratios of ischemic cerebrovascular disease, adjusting for potential confounders, were 1.47 (95% CI, 1.07 to 2.02) for fasting glucose <80, 1.22 (0.98 to 1.52) for 80 to 89, 1.27 (1.02 to 1.60) for 100 to 109, 1.60 (1.26 to 2.03) for 110 to 125, 1.82 (1.33 to 2.49) for 126 to 140, and 2.82 (2.32 to 3.43) for >140 mg/dL. Similar J-shaped associations were observed in analysis excluding patients with known diagnosis of diabetes mellitus.

CONCLUSIONS

The association between fasting plasma glucose and incident ischemic cerebrovascular events in patients with pre-existing atherothrombotic disease is J-shaped. Rates increase for fasting plasma glucose levels >100 mg/dL and also for those with low fasting glucose levels. These findings may carry important implications for prevention strategies.

Creating a pandemic of prediabetes: the proposed new diagnostic criteria for impaired fasting glycaemia

AIMS/HYPOTHESIS

In November 2003 the American Diabetes Association expert committee on the diagnosis and classification of diabetes mellitus suggested a revision of the diagnostic criteria for IFG, lowering the diagnostic threshold from 6.1 to 5.6 mmol/l. The aim of the present study was to evaluate the consequences of this change with respect to: (i) the prevalence of IFG in five different countries; (ii) the concordance between IFG and IGT (classification of individuals); and (iii) the cardiovascular risk profile of these groups. Finally we discuss the likelihood that intervention for cardiovascular risk and prevention strategies developed for individuals with IGT are applicable to subjects with IFG.

METHODS

The first part of the study is based on the population-based Danish Inter99 study, where 6265 individuals, aged 30 to 60 years and without previously diagnosed diabetes, underwent an oral glucose tolerance test. The second part is based on the DETECT-2 project, in which studies from China, India, France and USA were used to analyse the impact of the proposed revision of the diagnostic criteria in different ethnic groups.

RESULTS

The proposed change in diagnostic criteria would increase the prevalence of IFG in Denmark from 11.8 to 37.6%. The proposed IFG category would identify 60.0% of all subjects with IGT compared to 29.2% with the old criteria, but among individuals with the new IFG category only 18.5% would also have IGT. Individuals with isolated IFG had lower insulin levels and a lower cardiovascular risk profile with the proposed criteria compared with the current WHO criteria. Data from the DETECT-2 study confirmed the marked increase in the prevalence of IFG, and the estimated number of individuals in the age range 40 to 64 years with IFG in urban India, urban China and the USA would increase by 78%, 135% and 193% respectively.

CONCLUSIONS/INTERPRETATION

The proposed revised diagnostic criteria will lead to a dramatic increase in the prevalence of IFG, but the concordance rate between IFG and IGT remains low. This new IFG group will have a more favourable cardiovascular risk profile than the current IFG group as defined by the WHO. This seriously questions whether the existing intervention strategies are applicable to the new category of individuals with IFG.

Primacy of beta-cell dysfunction in the development of hyperglycemia: a study in the Japanese general population

To elucidate the hierarchy in the evolution of glucose intolerance in the general population, the relationship between plasma glucose (PG), beta-cell function (insulinogenic index [II] = DeltaIRI(0-30)/DeltaPG(0-30) on 75 g oral glucose tolerance test [OGTT], where IRI is immunoreactive insulin), insulin sensitivity (Si; determined by quantitative insulin sensitivity check index [QUICKI]), age, and body mass index (BMI) were analyzed in 504 Japanese health examinees (men/women: 347/157). The mean (+/-SD) age was 53 (+/-11) years, BMI 23.6 (+/-3.2) kg/m2, fasting PG (FPG) 5.61 (+/-0.97) mmol/L, 2-hour PG 7.42 (+/-3.1) mmol/L, II 74.2 (+/-169.3) [pmol/L]. [mmol/l](-1), and QUICKI 0.385 (+/-0.057) [log (microU/mL) + log (mg/100 mL)](-1). Higher FPG and 2-hour PG, respectively, were independently correlated with lower II, lower QUICKI, higher age, and higher BMI; the standardized correlation coefficient was largest for the correlation between PG and II. Based on the multiple linear regression, FPG = 8.565 - 1.201. log [II] - 5.374. QUICKI + 0.007. age + 0.030. BMI (r2 = 0.442), and 2-hour PG = 14.239 - 4.206. log [II] - 0.141. QUICKI + 0.034 - age + 0.141. BMI (r2 = 0.493). Thus, elevation of PG correlated most prominently with beta-cell dysfunction and less prominently with decreased Si, higher age, and BMI (especially so in the case of 2-hour PG). In conclusion, the primacy of beta-cell dysfunction in the process of developing glucose intolerance was strongly suggested in the Japanese general population.

Evaluation of a type 2 diabetes screening protocol in an urban pediatric clinic

BACKGROUND

In 2000, the American Diabetes Association issued recommendations for type 2 diabetes mellitus screening among children. They recommended testing children > or =10 years of age who have a body mass index (BMI) of >85th percentile for age and at least 2 other risk factors (family history of type 2 diabetes, high-risk race/ethnicity, or evidence of insulin resistance, such as acanthosis nigricans).

OBJECTIVE

To describe the application of a type 2 diabetes mellitus screening protocol in an urban pediatric clinic. Design/Methods. Medical records for patients 10 to 18 years of age who were examined in health maintenance visits during a 13-month period were reviewed; 997 subjects were included in the analyses. Data collected included demographic features, medical history, family history, physical examination findings, dietary and physical activity counseling, and results of laboratory tests. BMI percentiles for age were determined from national references.

RESULTS

Subjects were 50% male (median age: 13.2 years), 96% Hispanic, and 48% (n = 477) had a >85th percentile BMI (including 26% with a > or=95th percentile BMI). Of the 477 subjects, 100% were in high-risk racial/ethnic groups, 29% had a family history of diabetes, and 20% demonstrated evidence of insulin resistance; 194 (41%) met the criteria for screening. Of those who met the criteria, 38% (n = 73) had screening ordered and 65 of those subjects (89%) completed screening. Acanthosis nigricans was more common among subjects for whom screening was ordered (69%), compared with subjects who were not screened (3%). Three screened subjects exhibited impaired glucose tolerance; none had overt diabetes. Subjects for whom screening was ordered were more likely to have received counseling than were subjects not recognized as qualifying for screening (84% vs 52%).

CONCLUSIONS

At this high-risk clinical site, the American Diabetes Association type 2 diabetes screening protocol was inconsistently applied. Acanthosis nigricans was a driving factor in identification and screening. Recognition of the need for screening was associated with a higher rate of documentation of nutritional counseling. Additional evaluation of the effectiveness of screening protocols in the early identification of diabetes and the effects of screening protocols on long-term morbidity is needed.

Lowering the criterion for impaired fasting glucose: impact on disease prevalence and associated risk of diabetes and ischemic heart disease

OBJECTIVE

To determine the effect of lowering the fasting plasma glucose (FPG) criterion for impaired fasting glucose (IFG) on the prevalence of IFG, the risks of diabetes, and cardiovascular disease (CVD) associated with IFG.

RESEARCH DESIGN AND METHODS

Three studies were used: 1). the 1998 National Health Survey (NHS98), a randomly selected cross-sectional sample of 4723 subjects; 2). the Singapore Impaired Glucose Tolerance (IGT) Follow-up Study, a cohort study comprising 295 IGT and 292 normal glucose tolerance subjects (frequency matched for age, sex, and ethnic group) followed up from 1992 to 2000; and 3). the Singapore CVD Cohort Study, comprising 5920 subjects from three cross-sectional studies in whom the first ischemic heart disease (IHD) event was identified through linkage to registry databases. Risk of diabetes (Singapore IGT Follow-up study) was estimated using logistic regression adjusted for age, sex, and ethnicity. Risk of IHD (Singapore CVD cohort) was estimated using stratified (by study, from which data were derived) Cox's proportional hazards models adjusted for age, sex, and ethnicity.

RESULTS

Lowering the criterion for diagnosing IFG to 5.6 mmol/l increased the prevalence of IFG from 9.5 to 32.3% in the NHS98. The lower cutoff identified more subjects at risk of diabetes and IHD, but the relative risk was lower than that for IGT.

CONCLUSIONS

Greater efforts to identify those with IGT, or a group at similar risk of diabetes and CVD, may be a more efficient public health measure than lowering the FPG criterion for diagnosing IFG.

Sensory function and albumin excretion according to diagnostic criteria for diabetes

OBJECTIVE

The purpose of this study was to examine sensory function and albumin excretion according to categories of glucose tolerance in individuals undergoing screening for diabetes.

RESEARCH DESIGN AND METHODS

Sensory function and albumin excretion measurements were obtained in 636 individuals at the time of screening for diabetes according to American Diabetes Association glucose tolerance criteria. Sensory thresholds were measured by forced-choice techniques. Albumin-to-creatinine ratios were calculated from spot urine samples.

RESULTS

Of 90 individuals whose glucose levels were in the range for diabetes, 65 had fasting glucose values >or=126 mg/dl, whereas 25 had 2-h glucose values >or=200 mg/dl, with fasting glucose values <126 mg/dl. In covariance analyses, those with fasting glucose levels >or=126 mg/dl had higher vibration (P < 0.01) and thermal (P < 0.05 for cool and warm) thresholds than those with normal glucose tolerance. This pattern was also evident for albumin-to-creatinine ratios (P < 0.001). In contrast, those with 2-h glucose values >or=200 mg/dl and fasting glucose values <126 mg/dl had sensory threshold and albumin-to-creatinine ratio values similar to those of the normal group. Individuals with fasting glucose levels >or=126 mg/dl had higher vibration threshold and albumin-to-creatinine ratio values (<0.05 and <0.01, respectively) than those with levels <126 mg/dl.

CONCLUSIONS

Sensory threshold and albumin excretion values already tend to be greater than normal at screening in individuals with fasting glucose levels >or=126 mg/dl, but not in those with levels <126 mg/dl. A reliance on fasting glucose levels >or=126 mg/dl for screening might not be sufficient for early intervention and the optimal prevention of diabetes complications.

Prior gestational hyperglycemia: a long-term predictor of the metabolic syndrome

Little is known about the association between prior gestational hyperglycemia of different severity and the subsequent risk for the metabolic syndrome. Eighty-one women with prior gestational diabetes mellitus (GDM), 25 with one abnormal value at the oral glucose tolerance test (OGTT), and 65 with normal OGTT were studied after a mean of 8.5 yr from the index pregnancy. Patients with prior gestational hyperglycemia (both one abnormal value at the OGTT and GDM) showed a worse metabolic pattern than subjects with gestational normoglycemia [respectively higher values of body mass index (BMI), waist, blood pressure, serum glucose, insulin, C-peptide, homeostatic model assessment (HOMA), fibrinogen and lower levels of HDL-cholesterol]. Prevalence of the metabolic syndrome and its components was 2-4-fold higher in women with prior gestational hyperglycemia (and 10-fold higher if pre-pregnancy obesity coexisted) when compared to normoglycemic controls; in a Cox proportional hazard model, after adjustments for age and pre-pregnancy BMI, gestational hyperglycemia and pre-pregnancy BMI predicted subsequent metabolic syndrome [respectively: hazard ratio (HR)=4.26 and HR=1.21] and most of its components. In the same model, the highest quartile of fasting serum glucose at the OGTT of the index pregnancy was significantly associated to the metabolic syndrome and its components. Gestational hyperglycemia and fasting glucose values were also associated to subsequent fibrinogen values, but not to albumin excretion rates. In young adult women, prior gestational hyperglycemia (particularly abnormal fasting glucose values), above all in combination with pre-pregnancy obesity, anticipates a subsequent syndrome at high cardiovascular risk and, possibly, a mild chronic inflammatory response.

Diabetes in African Americans: unique pathophysiologic features

Type 2 diabetes is an increasing public health problem among African Americans, especially children. Several features make type 2 diabetes among African Americans unique. First, African-American adults with type 2 diabetes, or Flatbush diabetes, present with diabetic ketoacidosis. Patients are insulin resistant with acute, severe defects in insulin secretion and no islet cell autoantibodies. Following treatment, some insulin secretory capacity is recovered and ketoacidosis generally does not recur. The second is remission in African Americans with type 2 diabetes. Recovery of glucose homeostasis, accompanied by recovery of beta-cell function, follows intensive glycemic regulation. Finally, among African Americans with diabetes who are not obese, normal insulin sensitivity is not uncommon. Such individuals do not have the increased cardiovascular risk of insulin-resistant individuals. Differences in visceral, not subcutaneous, adipose tissue volume appear to determine insulin sensitivity. Understanding the unique physiologic and clinical features of African Americans is critical in designing appropriate treatment strategies.

Using metabolic syndrome traits for efficient detection of impaired glucose tolerance

OBJECTIVE

Efficient detection of impaired glucose tolerance (IGT) is needed to implement type 2 diabetes prevention interventions.

RESEARCH DESIGN AND METHODS

We assessed the capacity of the metabolic syndrome (MetS) to identify IGT in a cross-sectional analysis of 3,326 Caucasian Framingham Offspring Study (FOS), 1,168 Caucasian and 1,812 Mexican-American San Antonio Heart Study (SAHS), 1,983 Mexico City Diabetes Study (MCDS), and 452 Caucasian, 407 Mexican-American, and 290 African-American Insulin Resistance Atherosclerosis Study (IRAS) men and women aged 30-79 years who had a clinical examination and an oral glucose tolerance test (OGTT) during 1987-1996. Those with diabetes treatment or fasting plasma glucose > or =7.0 mmol/l were excluded (MetS was defined by Third Report of the National Cholesterol Education Program's Adult Treatment Panel criteria and IGT as 2-h postchallenge glucose [2hPG] > or =7.8 mmol/l). We calculated positive (PPV) and negative predictive values (NPV), population attributable risk percentages (PAR%), age- and sex-adjusted odds ratios (ORs), and areas under the receiver operating characteristic curve (AROCs) associated with MetS traits.

RESULTS

Among FOS, SAHS, and MCDS subjects, 24-43% had MetS and 15-23% had IGT (including 2-5% with 2hPG > or =11.1 mmol/l). Among those with MetS, OR for IGT were 3-4, PPV were 0.24-0.41, NPV were 0.84-0.91, and PAR% were 30-40%. Among subjects with MetS defined by impaired fasting glucose (IFG) and any two other traits, OR for IGT were 9-24, PPV were 0.62-0.89, NPV were 0.78-0.87, and PAR% were 3-12%. Among IRAS subjects, 24-34% had MetS and 37-41% had IGT. Among those with MetS, ORs for IGT were 3-6, PPVs were 0.57-0.73, and NPVs were 0.67-0.72. In logistic regression models, IFG, large waist, and high triglycerides were independently associated with IGT (AROC 0.71-0.83) in all study populations.

CONCLUSIONS

The MetS, especially defined by IFG, large waist, and high triglycerides, efficiently identifies subjects likely to have IGT on OGTT and thus be eligible for diabetes prevention interventions.

What is the contribution of obesity to the metabolic syndrome?

Many prospective studies show that obesity is accompanied by increased risk for cardiovascular disease. Obesity affects metabolism of lipids and glucose, regulation of blood pressure, thrombotic and fibrinolytic processes, and inflammatory reactions. Multiple aberrations exist in each of these systems; obesity acting alone probably is not sufficient to produce full-blown metabolic syndrome. There must be other factors, including genetic and aging factors. It is difficult to sort out all pathogenic factors that link obesity to cardiovascular disease risk. It is worthwhile to investigate individually the components of the obesity-induced metabolic syndrome for their atherogenic potential, because out of that investigation likely will come new targets for clinical or public health intervention to reduce the risk for cardiovascular disease.

Evaluation of insulin sensitivity and beta-cell function indexes obtained from minimal model analysis of a meal tolerance test

Modeling analysis of glucose, insulin, and C-peptide following a meal has been proposed as a means to estimate insulin sensitivity (S(i)) and beta-cell function from a single test. We compared the model-derived meal indexes with analogous indexes obtained from an intravenous glucose tolerance test (IVGTT) and hyperglycemic clamp (HGC) in 17 nondiabetic subjects (14 men, 3 women, aged 50 +/- 2 years [mean +/- SE], BMI 25.0 +/- 0.7 kg/m(2)). S(i) estimated from the meal was correlated with S(i) estimated from the IVGTT and the HGC (r = 0.59 and 0.76, respectively; P < 0.01 for both) but was approximately 2.3 and 1.4 times higher (P < 0.05 for both). The meal-derived estimate of the beta-cell's response to a steady-state change in glucose (static secretion index) was correlated with the HGC second-phase insulin response (r = 0.69; P = 0.002), but the estimated rate-of-change component (dynamic secretion index) was not correlated with first-phase insulin release from either the HGC or IVGTT. Indexes of beta-cell function obtained from the meal were significantly higher than those obtained from the HGC. In conclusion, insulin sensitivity and beta-cell indexes derived from a meal are not analogous to those from the clamp or IVGTT. Further work is needed before these indexes can be routinely used in clinical and epidemiological studies.

Relationship to insulin resistance of the adult treatment panel III diagnostic criteria for identification of the metabolic syndrome

The Adult Treatment Panel III (ATP III) has published criteria for diagnosing the metabolic syndrome, a cluster of closely related abnormalities related to insulin resistance that increase cardiovascular disease risk. The present analysis was performed to evaluate the ability of these criteria to identify insulin-resistant individuals. The population consisted of 443 healthy volunteers, with measurements of BMI, blood pressure, fasting plasma glucose, triglycerides, HDL cholesterol concentrations, and steady-state plasma glucose (SSPG) concentration. Insulin resistance was defined as being in the top tertile of SSPG concentrations. Of the population, 20% satisfied ATP III criteria for the metabolic syndrome. Although insulin resistance and the presence of the metabolic syndrome were significantly associated (P < 0.001), the sensitivity and positive predictive value equaled 46% (69 of 149) and 76% (69 of 91), respectively. Being overweight, with high triglycerides, low HDL cholesterol, or elevated blood pressure, most often resulted in a diagnosis of the metabolic syndrome. Thus, the ATP III criteria do not provide a sensitive approach to identifying insulin-resistant individuals. The individual components vary both in terms of their utility in making a diagnosis of the metabolic syndrome and their relationship to insulin resistance, with the obesity and lipid criteria being most useful.

Adverse Prognostic Significance of New Diabetes in Treated Hypertensive Subjects

Diabetes may develop in nondiabetic hypertensive subjects during treatment, but the long-term cardiovascular implications of this phenomenon are not clear. We determined the prognostic value of new diabetes in hypertensive subjects. In a long-term cohort study, 795 initially untreated hypertensive subjects, 6.5% of whom with type 2 diabetes, underwent diagnostic procedures including 24-hour ambulatory blood pressure (BP) monitoring and electrocardiography (ECG). Procedures were repeated after a median of 3.1 years in the absence of cardiovascular events. Follow-up duration was 1 to 16 years (median 6.0). New diabetes occurred in 5.8% of subjects initially without diabetes. Antihypertensive treatment included a diuretic in 53.5% of these subjects, versus 30.4% of those in whom diabetes did not develop (P=0.002). Plasma glucose at entry (P=0.0001) and diuretic treatment on follow-up (P=0.004) were independent predictors of new diabetes. Subsequent to the follow-up visit, a first cardiovascular event occurred in 63 subjects. Event rate in nondiabetic subjects at both visits, new diabetes, and diabetes at entry were 0.97, 3.90, and 4.70x100 person-years, respectively (P=0.0001). After adjustment for several confounders, including 24-hour ambulatory BP, the relative risk of events was 2.92 (95% CI: 1.33 to 6.41; P=0.007) in the group with new diabetes and 3.57 (95% CI: 1.65 to 7.73; P=0.001) in the group with previous diabetes, when compared with the group persistently free of diabetes. In treated hypertensive subjects, occurrence of new diabetes portends a risk for subsequent cardiovascular disease that is not dissimilar from that of previously known diabetes.

The metabolic syndrome in children and adolescents

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

Assessment of glucose intolerance and insulin sensitivity in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is associated with increased risk of impaired glucose tolerance and type 2 diabetes. PCOS has been considered as a major risk factor for the development of diabetes, and screening of women with PCOS for glucose intolerance is suggested. Detection of glucose intolerance in PCOS is best performed via 2-h oral glucose tolerance test rather than fasting plasma glucose alone, since it enables diagnosis of both impaired glucose tolerance and diabetes. Insulin resistance is a prominent feature of PCOS, although not all women with PCOS have insulin resistance. Measurement of insulin resistance is not included in the diagnostic criteria of the syndrome, and not required for the selection of treatments in current clinical practice. However, this measurement is undoubtedly of great interest for clinical research studies of PCOS. Several methods are available to the clinical investigator for the measurement of insulin resistance, yet there is no universally accepted and clinically useful definition, and no specific guidelines about how to measure it. While hyperinsulinaemic glucose clamp is considered to be the 'gold standard' for the measurement of insulin resistance, several alternative methods have been validated against the gold standard. Each method has its own merits and disadvantages. The choice of method for a particular study should be based on the specific aims, size, and type of that study. Variability in measurement of insulin resistance due to physiological factors, assay-related problems, and protocol differences in dynamic function tests deserves much more emphasis when interpreting the results of a study, or making comparisons between studies.