Is glycosylated hemoglobin A1c a surrogate for metabolic syndrome in nondiabetic, first-degree relatives of African-American patients with type 2 diabetes?

[Risk factors for ketoacidosis in children/adolescents with type 1 diabetes mellitus and establishment of a predictive model]

OBJECTIVES

To investigate the risk factors for diabetic ketoacidosis (DKA) in children/adolescents with type 1 diabetes mellitus (T1DM) and to establish a model for predicting the risk of DKA.

METHODS

A retrospective analysis was performed on 217 children/adolescents with T1DM who were admitted to General Hospital of Ningxia Medical University from January 2018 to December 2021. Among the 217 children/adolescents,169 cases with DKA were included as the DKA group and 48 cases without DKA were included as the non-DKA group. The risk factors for DKA in the children/adolescents with T1DM were analyzed, and a nomogram model was established for predicting the risk of DKA in children/adolescents with T1DM.

RESULTS

For the 217 children/adolescents with T1DM, the incidence rate of DKA was 77.9% (169/217). The multivariate logistic regression analysis showed that high levels of random blood glucose, hemoglobin A1c (HbA1c), blood ketone body, and triglyceride on admission were closely associated with the development of DKA in the children/adolescents with T1DM (OR=1.156, 3.2031015, 20.131, and 9.519 respectively; P<0.05). The nomogram prediction model had a C-statistic of 0.95, with a mean absolute error of 0.004 between the risk of DKA predicted by the nomogram model and the actual risk of DKA, indicating that the model had a good overall prediction ability.

CONCLUSIONS

High levels of random blood glucose, HbA1c, blood ketone body, and triglyceride on admission are closely associated with the development of DKA in children/adolescents with T1DM, and targeted intervention measures should be developed to reduce the risk of DKA.

Plasma neurofilament light and its association with all-cause mortality risk among urban middle-aged men and women

BACKGROUND

Neurofilament light chain (NfL) is released into the blood during neuronal damage. NfL is linked to mortality in neurological disorders, remaining unexplored in population studies. We investigated whether initial (v1) and annualized change (δ) in plasma NfL can predict all-cause mortality in middle-aged dementia-free urban adults.

METHODS

Longitudinal data were from 694 participants in the Healthy Aging in Neighborhoods of Diversity Across the Life Span study (HANDLS, mean agev1: 47.8 years, 42% male, 55.8% African American). Plasma NfL was measured prospectively at three visits. Analyses included Cox proportional hazards models for all-cause mortality risk and 4-way decomposition testing for interaction and mediation.

RESULTS

Unlike men, women exhibited a direct association between δNfL (above vs. below median) and all-cause mortality risk in both the minimally (HR = 3.91, 95% CI 1.10-13.9, p = 0.036) and fully adjusted models (HR = 4.92, 95% CI 1.26-19.2, p = 0.022), and for δNfL (per unit increase) in the full model (HR = 1.65, 95% CI 1.04-2.61, p = 0.034). In both models, and among women, 1 standard deviation of NfLv1 was associated with an increased all-cause mortality risk (reduced model: HR = 2.01, 95% CI 1.24-3.25, p = 0.005; full model: HR = 1.75, 95% CI 1.02-2.98, p = 0.041). Only few interactions were detected for cardio-metabolic risk factors. Notably, NfLv1 was shown to be a better prognostic indicator at normal hsCRP values among women, while HbA1c and δNfL interacted synergistically to determine mortality risk, overall.

CONCLUSIONS

These findings indicate that plasma NfL levels at baseline and over time can predict all-cause mortality in women and interacts with hsCRP and HbA1c to predict that risk.

Mechanism and effects of artesunate on the liver function of rats with type 1 diabetic periodontitis

Periodontitis is an inflammatory disease of the gums. Periodontitis in patients with diabetes can aggravate insulin resistance, but its molecular and biological mechanism remains unclear. This study aimed to explore the effects of diabetic periodontitis on liver function and determine the mechanism by which artesunate improves liver function. Rats with streptozotocin-induced diabetes were divided into five groups, i.e., normal control group (NC group), diabetic periodontitis group (DM+PD group), artesunate intervention group (ART group), insulin intervention group (INS group), and combined medication intervention group (ART+INS group). Drug interventions were then administered to the rats in each group as follows: 50 mg/kg artesunate to the ART group, 6 U/kg insulin to the INS group, and 50 mg/kg artesunate + 6 U/kg insulin to the ART+INS group. Blood samples, liver tissues, and the maxillary alveolar bone were collected post-sacrifice. ART was found to significantly ameliorate hyperglycemia, blood lipid levels, and liver function. The levels of inflammatory factors reduced; the effect was more pronounced in the ART+INS group. Artesunate presumably inhibits the TLR4/NF-κB signaling pathway and expression of downstream inflammatory factors, thereby exerting a protective effect on diabetes-related liver function. This offers a fresh approach to treat diabetes mellitus.

Markers of insulin resistance in Polycystic ovary syndrome women: An update

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders, affecting 5%-10% of women of reproductive age. The importance of this syndrome lies in the magnitude of associated comorbidities: infertility, metabolic dysfunction, cardiovascular disease (CVD), plus psychological and oncological complications. Insulin resistance (IR) is a prominent feature of PCOS with a prevalence of 35%-80%. Without adequate management, IR with compensatory hyperinsulinemia contributes directly to reproductive dysfunction in women with PCOS. Furthermore, epidemiological data shows compelling evidence that PCOS is associated with an increased risk of impaired glucose tolerance, gestational diabetes mellitus and type 2 diabetes. In addition, metabolic dysfunction leads to a risk for CVD that increases with aging in women with PCOS. Indeed, the severity of IR in women with PCOS is associated with the amount of abdominal obesity, even in lean women with PCOS. Given these drastic implications, it is important to diagnose and treat insulin resistance as early as possible. Many markers have been proposed. However, quantitative assessment of IR in clinical practice remains a major challenge. The gold standard method for assessing insulin sensitivity is the hyperinsulinemic euglycemic glucose clamp. However, it is not used routinely because of the complexity of its procedure. Consequently, there has been an urgent need for surrogate markers of IR that are more applicable in large population-based epidemiological investigations. Despite this, many of them are either difficult to apply in routine clinical practice or useless for women with PCOS. Considering this difficulty, there is still a need for an accurate marker for easy, early detection and assessment of IR in women with PCOS. This review highlights markers of IR already used in women with PCOS, including new markers recently reported in literature, and it establishes a new classification for these markers.

Application of a Machine Learning Technology in the Definition of Metabolically Healthy and Unhealthy Status: A Retrospective Study of 2567 Subjects Suffering from Obesity with or without Metabolic Syndrome

The key factors playing a role in the pathogenesis of metabolic alterations observed in many patients with obesity have not been fully characterized. Their identification is crucial, and it would represent a fundamental step towards better management of this urgent public health issue. This aim could be accomplished by exploiting the potential of machine learning (ML) technology. In a single-centre study (n = 2567), we used an ML analysis to cluster patients with metabolically healthy (MHO) or metabolically unhealthy (MUO) obesity, based on several clinical and biochemical variables. The first model provided by ML was able to predict the presence/absence of MHO with an accuracy of 66.67% and 72.15%, respectively, and included the following parameters: HOMA-IR, upper body fat/lower body fat, glycosylated haemoglobin, red blood cells, age, alanine aminotransferase, uric acid, white blood cells, insulin-like growth factor 1 (IGF-1) and gamma-glutamyl transferase. For each of these parameters, ML provided threshold values identifying either MUO or MHO. A second model including IGF-1 zSDS, a surrogate marker of IGF-1 normalized by age and sex, was even more accurate with a 71.84% and 72.3% precision, respectively. Our results demonstrated high IGF-1 levels in MHO patients, thus highlighting a possible role of IGF-1 as a novel metabolic health parameter to effectively predict the development of MUO using ML technology.

Impact of triglycerides and waist circumference on insulin resistance and β-cell function in non-diabetic first-degree relatives of type 2 diabetes

BACKGROUND

Although there is abundant evidence indicating the relative contribution of insulin resistance (HOMA-IR) and β-cell dysfunction (HOMA-β) among first-degree relatives (FDRs) of Type 2 DM patients, few studies reported the association between HOMA-IR and HOMA-β with metabolic syndrome. Our objective was to evaluate the impact of metabolic syndrome factors on HOMA-IR, HOMA-β and glycoproteins in non-diabetic FDRs.

METHODS

In this study, 103 Yemeni male subjects aged 25-42 years, with BMI < 25 kg/m² were examined, 39 of whom were normal subjects with no family history of diabetes served as control and 64 subjects were non-diabetic FDRs of Type 2 DM patients.

RESULTS

Both glycoproteins, glycated haemoglobin (HbA1c) and fructosamine as well as insulin, HOMA-IR and HOMA-β were significantly (p = 4.9 × 10^-9; 6.0 × 10^-8; 6.6 × 10^-12; 1.3 × 10^-7; 5.5 × 10^-12, respectively) higher in non-diabetic FDRs as compared to control group. Fasting plasma glucose, though within normal range, were significantly (p = 0.026) higher in non-diabetic FDRs. Linear regression analysis showed that both TG and WC are the main metabolic syndrome factors that significantly increased HOMA-IR (B = 0.334, p = 1.97 × 10^-6; B = 0.024, p = 1.05 × 10^-5), HOMA-β (B = 16.8, p = 6.8 × 10^-5; B = 0.95, p = 0.004), insulin (B = 16.5, p = 1.2 × 10^-6; B = 1.19, p = 8.3 × 10^-6) and HbA1c (B = 0.001, p = 0.034; B = 0.007, p = 0.037).

CONCLUSION

Triglyceride and WC are the important metabolic syndrome factors associated with insulin resistance, basal β-cell function and insulin levels in non-diabetic FDR men of Type 2 DM patients. Moreover, FDRs showed insulin resistance with compensatory β-cell function (hyperinsulinaemia) suggesting that insulin resistance precede the development of pancreatic β-cell dysfunction in individuals at risk of Type 2 DM.

Association of serum free thyroxine and glucose homeostasis: Korea National Health and Nutrition Examination Survey

BACKGROUND/AIMS

Thyroid hormones are involved in wide range of glucose metabolism functions. Overt thyroid dysfunctions are related to altered glucose homeostasis. However, it is not conclusive as to whether subtle changes in thyroid hormones within normal ranges can induce alterations in glucose homeostasis. The aim of this study was to evaluate the association between thyroid hormone and glucose homeostasis parameters in subjects without overt thyroid dysfunction based on nationwide population data.

METHODS

In the Sixth Korea National Health and Nutrition Examination Survey 2015 (n = 7,380), data were collected from subjects with insulin and thyroid function measurements who were older than 19-years-old. After the exclusion of 5,837 subjects, a total of 1,543 patients were included in the analysis. Subjects were categorized into the quartiles of the free thyroxine (FT4). Fasting glucose, insulin, homeostatic model assessment of insulin resistance and hemoglobin A1c (HbA1c) levels were considered to be glucose homeostasis parameters.

RESULTS

Subjects with the highest FT4 quartile showed significantly lower fasting insulin and HbA1c levels. A significant inverse correlation FT4 and HbA1c levels was observed (β = -0.261, p = 0.025). In the logistic regression analysis, the highest quartile of FT4 was demonstrated to lower the risk of HbA1c to a greater degree than the median by approximately 40%, after adjusting for confounders, compared to the lowest quartile (p = 0.028).

CONCLUSION

We demonstrated subjects with a lower FT4 quartile exhibited high risk of HbA1c levels above the median value in a representative Korean population. Subjects with the lowest FT4 quartile should be cautiously managed in terms of altered glucose homeostasis.

High-sensitivity C-reactive protein, hemoglobin A1c and breast cancer risk: a nested case-control study from Alberta's Tomorrow Project cohort

PURPOSE

Our aim is to examine the associations between high-sensitivity C-reactive protein (hsCRP) and hemoglobin A1c (HbA1c), common biomarkers of inflammation and insulin resistance, respectively, with breast cancer risk, while adjusting for measures of excess body size.

METHODS

We conducted a nested case-control study within the Alberta's Tomorrow Project cohort (Alberta, Canada) including 197 incident breast cancer cases and 394 matched controls. The sample population included both pre- and postmenopausal women. Serum concentrations of hsCRP and HbA1c were measured from blood samples collected at baseline, along with anthropometric measurements, general health and lifestyle data. Conditional logistic regression was used to evaluate associations between hsCRP, HbA1c, and breast cancer risk adjusted for excess body size (body fat percentage) and other risk factors for breast cancer.

RESULTS

Higher concentrations of hsCRP were associated with elevated breast cancer risk (odds ratio [OR] 1.27; 95% confidence interval [95% CI] 1.03-1.55). The observed associations were unchanged with adjustment for body fat percentage. Higher HbA1c concentrations were not significantly associated with an increased breast cancer risk (OR 1.22; 95% CI 0.17-8.75).

CONCLUSION

These data suggest that hsCRP may be associated with elevated breast cancer risk, independent of excess body size. However, elevated concentrations of HbA1c did not appear to increase breast cancer risk in apparently healthy women.

Population-derived cut-off for HbA1c could enhance the identification of metabolic syndrome among non-diabetic population

BACKGROUND

Metabolic syndrome (MetS) is a multifactorial disorder and a predisposing factor for diabetes, heart diseases, and stroke. Glycated haemoglobin (HbA1c) has recently received considerable attention as a potential marker to identify subjects at risk of MetS. This study aimed at assessing the performance of fasting plasma glucose (FPG), the American Diabetes Association (ADA) HbA1c cut-off, and a population-derived HbA1c (pHbA1c) cut-off value as the glycaemic criterion for MetS in a non-diabetic population.

METHODS

In this cross-sectional study, we recruited 728 non-diabetic Ghanaian adults. Venous blood sample was obtained and fasting plasma insulin and glucose, HbA1c, lipid profile, blood pressure and anthropometric measurements were performed for each respondent.

RESULTS

The prevalence of MetS using the FPG, ADA HbA1c and pHbA1c criteria were 35.2%, 38.5% and 41.8%, respectively. The pHbA1c cut-off identified 6.6% and 3.3% more subjects with MetS when compared with FPG and the ADA HbA1c cut-offs, respectively while the ADA HbA1c cut-off identified 3.3% more subjects with MetS compared with the FPG criterion. The ADA HbA1c criterion showed a substantial agreement (ĸ = 0.79) with the FPG criterion while pHbA1c showed an almost perfect concordance (ĸ = 0.82) with the FPG criterion and an excellent sensitivity and specificity for identifying subjects with MetS in the study population.

CONCLUSION

Screening of MetS by introduction of the ADA HbA1c criterion in addition to the traditional FPG criterion enhances the detection of more people with MetS. However, the use of population-derived HbA1c cut-off value could potentially identify even greater number of high risk subjects in that specific population.

Metabolic Syndrome Including Glycated Hemoglobin A1c in Adults: Is It Time to Change?

(1) Background: To assess the suitability of replacing conventional markers used for insulin resistance and dysglycemia by HbA1c in both the quantitative and qualitative metabolic syndrome (MetS) definition criteria; (2) Methods: Confirmatory factorial analysis was used to compare three quantitative definitions of MetS that consisted of many single-factor models, one of which included HbA1c as the dysglycemia indicator. After that, the model with the better goodness-of-fit was selected. Furthermore, a new MetS qualitative definition was proposed by replacing fasting plasma glucose with HbA1c > 5.7% in the International Diabetes Federation (IDF) definition. The clinical performance of these two MetS criteria (IDF and IDF-modified including HbA1c as the dysglycemia indicator) to predict vascular damage (pulse wave velocity [PWv], intima media thickness [IMT] and albumin-to-creatinine ratio [ACR]) was estimated; (3) Results: The single-factor model including HbA1c showed the better goodness-of-fit (χ² = 2.45, df = 2, p = 0.293, CFI = 0.999, SRMR = 0.010). Additionally, the IDF-modified criteria gained in clinical performance to predict vascular damage (diagnostic Odds Ratio: 6.94, 1.34 and 1.90) for pulse wave velocity (PWv), intima media thickness (IMT) and albumin-to-creatinine ratio (ACR), respectively; and (4) Conclusions: These data suggest that HbA1c could be considered as a useful component to be included in the MetS definition.

Comparative Abilities of Fasting Plasma Glucose and Haemoglobin A1c in Predicting Metabolic Syndrome among Apparently Healthy Normoglycemic Ghanaian Adults

There are arguments as to whether haemoglobin A1c (HbA1c) better predicts Metabolic syndrome (MetS) than fasting plasma glucose. The aim of the study was to explore the comparative abilities of HbA1c and Fasting plasma glucose (FPG) in predicting cardiometabolic risk among apparently healthy adults in the Tamale metropolis. This study was a cross-sectional study conducted in the Tamale metropolis from September, 2017, to January, 2018, among one hundred and sixty (160) apparently healthy normoglycemic adults. A self-designed questionnaire was administered to gather sociodemographic data. Anthropometric and haemodynamic data were also taken and blood samples collected for haemoglobin A1c (HbA1c), fasting plasma glucose (FPG), and lipid profile. MetS was classified using the harmonised criteria as indicated in the joint interim statement (JIS). Out of the 160 participants, 42.5% were males and 57.5% were females. FPG associated better with MetS and other cardiovascular risk markers, compared to HbA1c. FPG had the largest area under curve for predicting MetS and its components. This study shows a stronger association between FPG and MetS compared with haemoglobin A1c; it also provides evidence of a superior ability of FPG over HbA1c in predicting MetS and other adverse cardiovascular outcomes in apparently heathy normoglycemic individuals.

Risk Factors for Underdiagnosis of Diabetes Based on the Korean National Health and Nutrition Examination Survey 2013-2015

We included 11 298 subjects aged 30 years or older without diagnosis of diabetes by doctors who had undergone A1C screening. The diagnostic criterion for diabetes was A1C ≥6.5% (48 µmol/mol). This cross-sectional study was performed by reflecting weight of the sample in Korean National Health and Nutrition Examination Survey to represent South Korea. Risk factors were age (odds ratio [OR] = 1.06, 95% confidence interval [CI] = 1.04-1.08), Medicaid beneficiary (OR = 2.77, 95% CI = 1.25-6.14), presence of family history of diabetes (OR = 1.97, 95% CI = 1.36-2.84), serum triglyceride level (OR = 1.01, 95% CI = 1.01-1.03), serum high-density lipoprotein level (OR = 0.96, 95% CI = 0.95-0.98), currently smoking (OR = 1.85, 95% CI = 1.20-2.85), and the presence of regular checkup (OR = 1.41, 95% CI = 1.01-2.00). To prevent diabetes with a healthy life, it is necessary to establish a diabetes prevention program for vulnerable people and implement health-related policies such as smoking cessation and regular checkups.

Association of fasting glucose and glycated hemoglobin with the long-term risk of incident metabolic syndrome: Korean Genome and Epidemiology Study (KoGES)

AIMS

Previous studies have proposed potential benefit of glycated hemoglobin (HbA1c) supplementary to fasting glucose in detecting metabolic syndrome (MetS). This study was to investigate an association of incident MetS with levels of HbA1c and fasting glucose.

METHODS

In a cohort of Korean Genome and Epidemiology Study, 5515 non-diabetic adults were grouped by the levels of baseline fasting glucose and HbA1c, and followed-up for 10 years. Using multivariate Cox proportional hazards assumption, hazards ratios (HRs) and 95% confidence interval (CI) for incident MetS (adjusted HRs [95% CI]) were calculated according to baseline fasting glucose and HbA1c. In individuals with normal fasting glucose, subgroup analysis was conducted to evaluate an association of HbA1c levels with MetS.

RESULTS

The risk for MetS significantly increased proportionally to fasting glucose ≥ 80 mg/dL and HbA1c ≥ 5.5%, compared with fating glucose < 80 mg/dL and HbA1c < 5.3%, respectively. In subgroups of normal fasting glucose, HbA1c ≥ 5.7% had the increased risk of MetS in fasting glucose < 80 mg/dL (5.7-5.9%: 1.41 [1.07-1.86] and 6.0-6.4%: 2.20 [1.40-2.92]), and HbA1c ≥ 5.5% had the increased risk of MetS in fasting glucose of 80-99 mg/dL (5.5-5.6%: 1.33 [1.08-1.64], 5.7-5.9%: 1.57 (1.27-1.93), and 6.0-6.4%: 2.37 [1.87-3.00]).

CONCLUSIONS

Both elevated fasting glucose and HbA1c were significantly associated with the increased risk of MetS even within normal range. HbA1c is effective in identifying high-risk group for MetS in individuals with normal fasting glucose.

Prevalence of metabolic syndrome and the comparison of fasting plasma glucose and HbA1c as the glycemic criterion for MetS definition in non-diabetic population in Ghana

BACKGROUND

Glycated hemoglobin (HbA1c), owing to its ability to reflect glycemia over a relatively longer time span, is still been investigated as an adjunct test for fasting plasma glucose (FPG) to identify subjects at risk of metabolic syndrome (MetS) in some Caucasian populations. However, whether or not HbA1c can serve as an adjunct to FPG in the definition of MetS in the Ghanaian population remains unknown. This study determined the prevalence of MetS and evaluated HbA1c ≥ 5.6% and FPG ≥ 5.6 mmol/l as the glycemic component of MetS among non-diabetic population in Ghana.

METHODS

This was a case-control study conducted at St Francis Xavier Hospital, Assin Fosu, Central Region, Ghana. A total of 264 non-diabetic Ghanaian adults consisting of 158 newly diagnosed hypertensives and 106 normotensives, were recruited for the study. Fasting plasma insulin and glucose, HbA1c, and lipid profile was performed for each respondent.

RESULTS

Using the FPG as glycemic criterion, the overall MetS prevalence was 46.6%, 37.1%, and 12.5% according by the IDF, NCEP ATP III, and WHO criteria, respectively. The prevalence of MetS using the HbA1c criterion was 54.2%, 52.7%, and 42.4% by the IDF, NCEP ATP III and WHO criteria, respectively. The HbA1c criterion identified more participants with MetS compared to the FPG criterion with a good agreement between HbA1c and FPG using the IDF and NCEP ATP III criteria (κ = 0.484 to 0.899) respectively. However, the overlap between HbA1c and FPG based diagnosis of MetS was limited for the WHO criterion.

CONCLUSION

The prevalence of metabolic syndrome is high among non-diabetics in Ghana. Introduction of HbA1c in addition to FPG in the screening of MetS improves identification of more people with MetS who would otherwise have been missed when only FPG-based diagnosis of MetS is used; with a substantial agreement with FPG, except when using the WHO criteria.

Mobile health, physical activity, and obesity: Subanalysis of a randomized controlled trial

BACKGROUND

Recent studies on physical activity were analyzed by randomizing participants into either the intervention or control group. It is necessary to classify each intervention and control groups according to physical activity using the International Physical Activity Questionnaire (IPAQ).

METHODS

This was a pilot project for SmartCare Services. The intervention group received obesity management services using a smartphone for 24 weeks, while the control group did not receive the interventions. Six anthropometric indices were analyzed: weight, body mass index (BMI), waist circumference, body fat, systolic blood pressure (SBP), and diastolic blood pressure (DBP). Five laboratory tests, including fasting blood sugar (FBS), glycosylated hemoglobin (HbA1c), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), and triglycerides (TGs), were also assessed. The final 324 participants were categorized using the IPAQ questionnaire, and anthropometric indices and laboratory tests were analyzed for within-group and between-group changes from baseline to final visit.

RESULTS

Statistically significant decreases in the intervention group compared with the control group were observed in terms of insufficient activity (IA) (-1.6 ± 3.03 vs -0.1 ± 1.94 kg) and moderate activity (MA) (-2.5 ± 3.81 vs -0.3 ± 2.24 kg) for weight, IA (-0.7 ± 1.14 vs -0.2 ± 0.93 kg/m) and MA (-0.9 ± 1.30 vs -0.2 ± 0.86 kg/m) for BMI, and health-enhancing physical activity (HEPA) (-1.6 ± 3.69% vs -0.1 ± 3.15%) for body fat. For HbA1c, HEPA in the intervention group showed significant decreases (-0.2 ± 0.67 vs 0.0 ± 0.34 mg/dL) compared with the control group.

CONCLUSION

Anthropometric indices and laboratory test results were improved in the smartphone-based intervention group. Especially, improvement of metabolic components in the group with more active physical activity was remarkable.

A decrease in serum 1,5-anhydroglucitol levels is associated with the presence of a first-degree family history of diabetes in a Chinese population with normal glucose tolerance

AIM

This study aimed to investigate alterations in HbA_1c , glycated albumin (GA) and 1,5-anhydroglucitol (1,5-AG) in Chinese first-degree relatives of individuals with diabetes (FDR) in pursuit of an index for early screening of glucose metabolism disturbance.

METHODS

A total of 467 participants (age range: 20-78 years) with normal weight and normal glucose tolerance, as determined by a 75-g oral glucose tolerance test, were enrolled. HbA_1c was measured using high-performance liquid chromatography. Serum GA and 1,5-AG levels were determined by enzymatic methods. Serum insulin levels were measured using an electrochemiluminescence immunoassay.

RESULTS

The study population included 208 FDR and 259 non-FDR. Serum 1,5-AG levels were lower in FDR than that in non-FDR (20.4 ± 7.5 vs 23.8 ± 8.3 μg/ml, P < 0.001), but HbA_1c and GA levels did not differ between them (P = 0.835 and 0.469, respectively). Logistic regression analysis revealed an independent relationship between a first-degree family history of diabetes and reduced serum 1,5-AG levels (odds ratio = 0.944, P < 0.001). Multiple regression analysis showed that a first-degree family history of diabetes (β = -3.041, P < 0.001) and insulinogenic index (β = 0.081, P = 0.001) were independently associated with serum 1,5-AG levels.

CONCLUSION

In a Chinese population with normal glucose tolerance, serum 1,5-AG levels were lower among FDR, and serum 1,5-AG levels were independently associated with FDR status. For FDR, serum 1,5-AG levels were more sensitive than HbA_1c or GA levels to early-phase abnormality in glucose metabolism.

HbA1c Levels Are Associated with Chronic Kidney Disease in a Non-Diabetic Adult Population: A Nationwide Survey (KNHANES 2011-2013)

BACKGROUND

Many studies have reported an association between glycated hemoglobin A1c (HbA1c) and metabolic syndrome (MetS) in non-diabetes patients. Each component of MetS is in fact related to chronic kidney disease (CKD) incidence and progression. Therefore, HbA1c in non-diabetic mellitus (DM) may be intrinsically associated with the prevalence of CKD. The hypothesis of the present study was that high HbA1c in non-DM patients is associated with CKD.

PATIENTS AND METHODS

The total number of participants in this study was 24,594. The participants were divided into three groups according to their HbA1c levels: a Low group (<5.7% or <39 mmol/mol), a Middle group (5.7-6.0% or 39-42 mmol/mol), and a High group (>6.0% or >42 mmol/mol). The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation.

RESULTS

The number of participants allocated to the Low, Middle, and High groups was 8,651, 4,634, and 1,387, respectively. Linear regression analyses were performed to evaluate the association between variables. Standardized β ± standard error was 0.25 ± 0.22 for waist circumference, 0.44 ± 0.20 for fasting glucose, -0.14 ± 0.30 for high-density lipoprotein cholesterol levels, 0.15 ± 2.31 for triglyceride levels, 0.21 ± 0.00 for systolic blood pressure, 0.10 ± 0.00 for diastolic blood pressure, and -0.22 ± 0.42 for eGFR (P < 0.001 for all variables). eGFR in non-diabetes participants was inversely associated with the HbA1c level, where eGFR decreased as HbA1c levels increased. Standardized βs were -0.04 ± 0.42 in multivariable analysis (P < 0.001). The proportion of participants with only MetS, only CKD, or both MetS and CKD was higher in the High group than in the Low and Middle groups.

CONCLUSION

High HbA1c in non-DM patients may be associated with CKD. Renal function in patients with high HbA1c levels may need to be monitored.

The role of education in explaining racial/ethnic allostatic load differentials in the United States

This study expands on earlier findings of racial/ethnic and education-allostatic load associations by assessing whether racial/ethnic differences in allostatic load persist across all levels of educational attainment. This study used data from four recent waves of the National Health and Nutrition Survey (NHANES). Results from this study suggest that allostatic load differs significantly by race/ethnicity and educational attainment overall, but that the race/ethnicity association is not consistent across education level. Analysis of interactions and education-stratified models suggest that allostatic load levels do not differ by race/ethnicity for individuals with low education; rather, the largest allostatic load differentials for Mexican Americans (p < .01) and non-Hispanic blacks (p < .001) are observed for individuals with a college degree or more. These findings add to the growing evidence that differences in socioeconomic opportunities by race/ethnicity are likely a consequence of differential returns to education, which contribute to higher stress burdens among minorities compared to non-Hispanic whites.

Stressful life events, sexual orientation, and cardiometabolic risk among young adults in the United States

OBJECTIVE

The goal of the present study was to examine whether sexual minority young adults are more vulnerable to developing cardiometabolic risk following exposure to stressful life events than heterosexual young adults.

METHOD

Data came from the National Longitudinal Study for Adolescent Health (Shin, Edwards, & Heeren, 2009; Brummett et al., 2013), a prospective nationally representative study of U.S. adolescents followed into young adulthood. A total of 306 lesbian, gay, and bisexual (LGB) respondents and 6,667 heterosexual respondents met inclusion criteria for this analysis. Measures of cumulative stressful life events were drawn from all 4 waves of data collection; sexual orientation and cardiometabolic biomarkers were assessed at Wave 4 (2008-2009).

RESULTS

Gay/bisexual men exposed to 1-2 (β = 0.71, p = .01) and 5+ (β = 0.87, p = .01) stressful life events had a statistically significant elevation in cardiometabolic risk, controlling for demographics, health behaviors, and socioeconomic status. Moreover, in models adjusted for all covariates, lesbian/bisexual (β = 0.52, p = .046) women with 5+ stressful life events had a statistically significant elevation in cardiometabolic risk. There was no relationship between stressful life events and cardiometabolic risk among heterosexual men or women.

CONCLUSION

Stressful life events during childhood, adolescence, and young adulthood place LGB young adults at heightened risk for elevated cardiometabolic risk as early as young adulthood. The mechanisms underlying this relationship require future study.

Childhood adversity, adult neighborhood context, and cumulative biological risk for chronic diseases in adulthood

OBJECTIVE

We examined the association between childhood adversity and cumulative biological risk for a variety of chronic diseases in adulthood, and whether this association varied by neighborhood affluence.

METHODS

Data were drawn from the Chicago Community Adult Health Study (2001-2003), a cross-sectional probability sample that included interviews and blood collection (n = 550 adults). A childhood adversity score was calculated from eight items. Neighborhood affluence was defined using Census data. An index to reflect cumulative biological risk was constructed as a count of eight biomarkers above clinically established thresholds, including systolic and diastolic blood pressure, resting heart rate, C-reactive protein, waist circumference, hemoglobin A1c, and total and high-density lipoprotein cholesterol. Generalized linear models with a Poisson link function were used to estimate incident rate ratios (IRRs).

RESULTS

A 1-standard-deviation increase in the childhood adversity score was associated with a 9% increase in cumulative biological risk, after adjustment for demographic and behavioral characteristics (IRR = 1.09, 95% confidence interval (CI) = 1.02-1.17). This association was modified by neighborhood affluence (IRR = 0.92, 95% CI = 0.86, 0.99). Stratified models indicated that childhood adversity was associated with elevated cumulative biological risk only among individuals who resided in low-affluence (bottom tertile) neighborhoods (IRR = 1.16, 95% CI = 1.05, 1.28); there was no association in high-affluence (top tertile) neighborhoods (IRR = 0.97, 95% CI = 0.83, 1.14).

CONCLUSIONS

Childhood adversity is associated with elevated cumulative biological risk in adulthood, and neighborhood affluence may buffer this association. Results demonstrate the importance of neighborhood characteristics for associations between childhood adversity and disease risk, even after accounting for adult socioeconomic status.

Consequences of Abdominal Adiposity within the Metabolic Syndrome Paradigm in Black People of African Ancestry

The metabolic syndrome (MetS) is a constellation of risk factors that are associated with increased risks for coronary heart disease and type 2 diabetes. Although the cause is unknown, abdominal adiposity is considered the underpinning of these metabolic alterations. Hence, increased abdominal adiposity contributes to dyslipidemia, hyperglycemia, beta cell dysfunction, insulin resistance, hypertension and inflammation. The role of abdominal adiposity in the causation of metabolic alterations that lead to the clinical expression of the MetS has become a focus of active research. In addition, there are ethnic/racial differences in the manifestation of the MetS. Therefore, the focus of this current review is to: (1) explore the consequences of abdominal obesity within the MetS paradigm; and (2) discuss the impact of ethnicity/race on MetS in Black People of African Ancestry (PAA).

Gestational diabetes mellitus worsens the profile of cardiometabolic risk markers and decrease indexes of beta-cell function independently of insulin resistance in nondiabetic women with a parental history of type 2 diabetes

BACKGROUND

Women with a history of both parental type 2 diabetes (pt2DM) and previous gestational diabetes (pGDM) represent a group at high risk of cardiovascular events. We hypothesized that pGDM changes cardiometabolic risk markers levels as well as theirs associations with glucose indices in nondiabetic pt2DM women.

METHODS

Anthropometric parameters, glucose regulation (OGTT), insulin resistance (HOMA-IR), beta-cell function, lipid levels, parameters of endothelial dysfunction, and inflammation were evaluated in 55 women with pt2DM, 40 with both pt2DM and pGDM 2-24 months postpartum, and 35 controls.

RESULTS

Prediabetes was diagnosed more frequently in women with both pt2DM and pGDM in comparison with women with only pt2DM (10 versus 8, P = 0.04). The pGDM group had higher LDL-cholesterol, sICAM-1, tPa Ag, fibrinogen, and lower beta-cell function after adjustment for HOMA-IR, in comparison with pt2DM group. In pt2DM group postchallenge glucose correlated independently with hsCRP and in pGDM group fasting glucose with HOMA-IR.

CONCLUSIONS

pGDM exerts a combined effect on cardiometabolic risk markers in women with pt2DM. In these women higher LDL-cholesterol, fibrinogen, sICAM-1, tPa Ag levels and decreased beta cell function are associated with pGDM independently of HOMA-IR index value. Fasting glucose is an important cardiometabolic risk marker and is independently associated with HOMA-IR.

Educational differentials in US adult mortality: An examination of mediating factors

We use human capital theory to develop hypotheses regarding the extent to which the association between educational attainment and US adult mortality is mediated by such economic and social resources as family income and social support; such health behaviors as inactivity, smoking, and excessive drinking; and such physiological measures as obesity, inflammation, and cardiovascular risk factors. We employ the NHANES Linked Mortality File, a large nationally representative prospective data set that includes an extensive number of factors thought to be important in mediating the education-mortality association. We find that educational differences in mortality for the total population and for specific causes of death are most prominently explained by family income and health behaviors. However, there are age-related differences in the effects of the mediating factors. Higher education enables individuals to effectively coalesce and leverage their diverse and substantial resources to reduce their mortality and increase their longevity.

Utility of screening for diabetes in a burn center: hemoglobin A1c, Diabetes Risk Test, or simple history?

OBJECTIVE

Rates of diabetes mellitus (DM) are increasing. Early identification and treatment of hyperglycemia in the critical care setting can decrease morbidity and mortality. Many burn centers measure hemoglobin A1c (A1c). This study evaluates the prevalence of pre-existing DM and the utility of using A1c for identifying DM compared with a non-invasive risk assessment.

METHODS

Adult patients admitted to our regional ABA-verified burn center from July 2008 to July 2009 had A1c levels evaluated and were asked to complete the American Diabetes Association Diabetes Risk Test (DRT).

RESULTS

Forty-one patients consented to participate: 24 patients with burn (19 male) and 17 patients with non-burns (10 male). Non-burn patients had greater BMIs (BMI 32 vs. 28, p=0.093) and had a higher rate of DM prior to admission (35% vs. 17%, p=0.159) than the burn patients. These differences were not statistically significant. Most patients (23/41) were at high risk for developing DM based on the DRT. Patients with pre-existing DM were significantly more likely to have elevated A1c levels (>6.5%) compared with those without pre-existing DM (60% vs. 0%, p<0.001). Compared with history of DM, DRT had a poor positive predictive value of 36% and 50% (burn and non-burn respectively) but a 100% negative predictive value for DM for both groups.

CONCLUSION

DM and obesity were more common in non-burn patients than in burn patients. A history of DM provides a simple, accurate method for identifying patients with DM. Use of A1c in the ICU provides little additional data for diagnosis of DM and does not impact patient management.

Predictors of ischaemic heart disease in a Malaysian population with the metabolic syndrome

AIMS

Cardiovascular disease is the foremost cause of mortality in Malaysia but little is known about the prevalence of the metabolic syndrome and its associations with other known cardiovascular risk markers. We undertook a population-based study to examine these.

METHODS

For the study, 4341 subjects were selected using a multistage stratified sampling method. Subjects were interviewed for personal and past medical history. Biomedical markers and anthropometric indices were measured. The metabolic syndrome was defined using the harmonized criteria. The associations between the metabolic syndrome and cardiovascular risk markers, including high-sensitivity C-reactive protein, microalbuminuria and HbA(1c) were examined.

RESULTS

The prevalence of the metabolic syndrome was 42.5%. Subjects with the metabolic syndrome are significantly more likely to have higher BMI (> 25 kg/m(2)), HbA(1c) [≥ 42 mmol/mol (6.0%)], LDL (≥ 2.6 mmol/l), elevated albumin:creatinine ratio (> 2.5 μg/mmol creatinine for men, 3.5 μg/mmol creatinine for women) and high-sensitivity C-reactive protein (> 3 mg/l); odds ratio 5.48, 6.14, 1.44, 3.68 and 1.84, respectively, P < 0.001. The presence of an elevated albumin:creatinine ratio and high-sensitivity C-reactive protein are strong predictors for the presence of a higher number of positive criteria of the metabolic syndrome. HbA(1c) > 48 mmol/mol (6.5%) is associated with increased relative risk of elevated albumin:creatinine ratio, high-sensitivity C-reactive protein and LDL (relative risk 3.10, 2.46 and 1.65 respectively, P < 0.001).

CONCLUSIONS

We confirmed the high prevalence of the metabolic syndrome in Malaysia. Our study revealed a strong relationship between risk markers of elevated BMI, HbA(1c), LDL, albumin:creatinine ratio and high-sensitivity C-reactive protein with the presence of the metabolic syndrome, putting them at a statistically high risk for cardiovascular mortality.

Glycated hemoglobin as a predictor for metabolic syndrome in an Iranian population with normal glucose tolerance

BACKGROUND

The aim of this study was to determine the ability of glycated hemoglobin (GHb) to predict metabolic syndrome in an Iranian population with normal glucose tolerance (NGT).

METHODS

A cross-sectional study of first-degree relatives (FDRs) of patients with type 2 diabetes was conducted from 2003 to 2005. A total of 1386 FDRs of consecutive patients with type 2 diabetes 30-60 years old (355 men and 1031 women) with NGT were examined. All subjects underwent a standard 75-gram 2-h oral glucose tolerance test and GHb measurement. Consensus criteria in 2009 were used to identify metabolic syndrome. Unadjusted and adjusted multivariate logistic regression analysis was performed to assess the risk of metabolic syndrome. The mean [standard deviation (SD)] age of participants was 42.4 (6.3) years.

RESULTS

The prevalence of metabolic syndrome was 17.5% in men and 21.5% in women. The multivariate-adjusted odds ratio (95% CI) of metabolic syndrome was 2.01 (1.03, 3.93) for the highest quintile of GHb compared with lowest quintile. These data indicate that GHb was associated with metabolic syndrome, independently of gender among FDRs of patients with type 2 diabetes with NGT.

CONCLUSIONS

These data indicate that GHb below the level for prediabetes might be a predictive measure of metabolic syndrome in FDRs of patients with type 2 diabetes with NGT.

Usefulness of glycated hemoglobin as diagnostic criteria for metabolic syndrome

The metabolic syndrome (MetS) is the clustering of cardiovascular risk factors and known as a powerful predictor of diabetes and cardiovascular disease. Glycated hemoglobin (HbA1c) is used as one of the diagnostic criteria for diabetes and category of increased risk for diabetes. We examined the usefulness of HbA1c as a diagnostic tool for MetS and to determine the cut-off value of HbA1c as a criterion for MetS, in non-diabetic Korean subjects. We analyzed 7,307 participants (male: 4,181, 57%) in a medical check-up program, and applied the newly recommended guidelines of the International Diabetes Federation for diagnosis of MetS. The mean HbA1c was 5.54% in all subjects and showed no significant difference between genders. Using receiver-operating characteristic curve, HbA1c value corresponding to the fasting plasma glucose value of 100 mg/dL was 5.65% (sensitivity 52.3%, specificity 76.7%). The prevalence of MetS was 8.5% according to the IDF guideline and 10.9% according to HbA1c value of 5.7%, showing 69.5% agreement rate. The detection rate of MetS increased to 25.7% using the HbA1c criterion of 5.7% instead of fasting hyperglycemia. This study suggests that HbA1c might be used as a diagnostic criterion for MetS and the appropriate cut-off value of HbA1c may be 5.65% in this Korean population.

The Utility of HbA1c as a Diagnostic Criterion of Diabetes

Background

Hemoglobin A1c (HbA1c) was adopted as a new standard criterion for diagnosing diabetes. We investigated the diagnostic utility of HbA1c by comparing the 2003 American Diabetes Association (ADA) diagnostic criteria of diabetes with HbA1c of 6.5%. Furthermore, the cut-off value for HbA1c was investigated using receiver operating characteristic curves.

Methods

This study included 224 subjects without a history of diabetes that had a fasting plasma glucose level of above 100 mg/dL. The subjects had undergone a 75 g oral glucose tolerance test, and diabetes was defined as according to 2003 ADA criteria.

Results

The prevalence of newly diagnosed diabetes was 58.2% by the 2003 ADA criteria, and 47.8% by HbA1c of 6.5%, which underestimated the prevalence of diabetes. Compared with the 2003 ADA criteria, the sensitivity and specificity of HbA1c of 6.5% were 73.5% and 89.1%, respectively. The kappa index of agreement between 2003 ADA and HbA1c criteria was 0.60. The cut-off point of HbA1c for diagnosing diabetes was 6.45% (sensitivity, 73.3%; specificity, 88.2%; area under the curve, 0.85). HbA1c was significantly associated with fasting glucose (r = 0.82, P < 0.01), postprandial glucose (r = 0.78, P < 0.01), and homeostasis model assessment of insulin resistance (r = 0.16, P < 0.05).

Conclusion

For high risk patients whose fasting glucose was more than 100 mg/dL, HbA1c criterion underestimated the prevalence of newly diagnosed diabetes compared to the 2003 ADA criteria, and showed moderate agreement. The cut-off value for HbA1c was 6.45%, which was similar to the recommended diagnostic criterion of HbA1c by the 2009 ADA.

Neighborhood context and social disparities in cumulative biological risk factors

OBJECTIVE

This study examines the role of neighborhood context in the accumulation of biological risk factors and racial/ethnic and socioeconomic disparities.

METHODS

Data came from face-to-face interviews and blood sample collection on a probability sample of adults (n = 549) in the 2002 Chicago Community Adult Health Study. Following the approach of prior studies, we constructed an index of cumulative biological risk (CBR) by counting how many of eight biomarkers exceeded clinically defined criteria for "high risk": systolic and diastolic blood pressure, resting heart rate, hemoglobin A(1c), C-reactive protein, waist size, and total and high-density lipoprotein cholesterol. Data are presented as incidence rate ratios (IRRs) based on generalized linear models with a Poisson link function and population-average estimates with robust standard errors.

RESULTS

Non-Hispanic blacks (n = 200), Hispanics (n = 149), and people with low (n = 134) and moderate (n = 275) level of education had significantly higher numbers of biological risks than their respective reference groups (IRR = 1.48, 1.59, 1.62, and 1.48, respectively, with p < .01). Black-white (p < .001) and Hispanic-white (p < .003) disparities in CBR remained significant after adjusting for individual-level socioeconomic position and behavioral factors, whereas individual-level controls substantially diminished the low/high (p < .069) and moderate/high (p < .042) educational differences. Estimating "within-neighborhood" disparities to adjust for neighborhood context fully explained the black-white gap in CBR (p < .542) and reduced the Hispanic-white gap to borderline significance (p < .053). Neighborhood affluence predicted lower levels of CBR (IRR = 0.82, p < .027), but neighborhood disadvantage was not significantly associated with CBR (IRR = 1.00, p < .948).

CONCLUSIONS

Neighborhood environments seem to play a pivotal role in the accumulation of biological risk and disparities therein.

Prevalence of metabolic syndrome in obese children and adolescents using three different criteria and evaluation of risk factors

OBJECTIVE

To compare the prevalence of the metabolic syndrome (MS) in Turkish obese children and adolescents by using three different definitions and to assess the risk factors through a retrospective evaluation of anthropometric and laboratory parameters.

METHODS

Sixty hundred and fourteen obese patients (307 male, 307 female; mean age: 11.3±2.5 years) were included in the study. Medical history, physical examination, anthropometric measurements, results of biochemical and hormonal assays were obtained from the hospital records. MS was diagnosed according to the modified World Health Organization (WHO), Cook and the International Diabetes Federation (IDF) consensus criteria.

RESULTS

The prevalence of MS was found to be 39%, 34% and 33% according to the modified WHO, Cook and the IDF consensus criteria, respectively. MS prevalence in patients aged 12-18 years was significantly higher than that in patients between 7 and 11 years of age (p<0.05). Pubertal patients had a significantly higher MS prevalence than the non-pubertal cases (p<0.05). MS prevalence was also significantly higher in children who had a family history of heart disease, diabetes, obesity and hypertension as well as in those who had not been breast-fed (p<0.05).

CONCLUSION

The use of the modified WHO criteria was found to result in a slightly higher prevalence rate for MS as compared to the other criteria. The prevalence of MS in our study population was higher than that reported in most previous studies in Turkey. A positive family history, puberty and not being breastfed in infancy were shown to be significant risk factors for MS in childhood.

The relationship between glycosylated haemoglobin (HbA1c) and measures of insulin resistance across a range of glucose tolerance

AIM

This study aimed to assess the correlation between HbA1c and insulin resistance as measured by a variety of different indices in subjects from across the glycaemic spectrum.

METHODS

Subjects with normal glucose tolerance (NGT; n = 24), impaired fasting glucose (IFG; n = 12), impaired glucose tolerance (IGT; n = 12), and type 2 diabetes (DM; n = 13) were studied. All had specimens taken in the context of a standard oral glucose tolerance test at their first visit and had the insulin sensitivity parameter (Si) determined by frequently-sampled intravenous glucose tolerance test at a second visit.

RESULTS

HbA1c was more strongly associated with Si in NGT (r = - 0.65) than in IFG (r = - 0.48). Compared to other indices of insulin resistance HbA1c has minimal overlap in values (0.0%) between NGT and subjects with type 2 diabetes.

CONCLUSIONS

HbA1c can be used as a simple and reliable marker of insulin resistance in NGT adults with relatively high insulin sensitivity.

African americans may have to consume more than 12 grams a day of resistant starch to lower their risk for type 2 diabetes

African Americans have a high prevalence rate of type 2 diabetes mellitus (DM). High-maize 260 (National Starch and Chemical Co., Bridgewater, NJ, USA) resistant starch (RS) is a promising food ingredient to reduce risk factors for type 2 DM. A 14-week, double-blind, crossover design study was conducted with African American male (n = 8) and female (n = 7) subjects at risk for type 2 DM. All subjects consumed bread containing 12 g of added RS or control bread (no added RS) for 6 weeks, separated by a 2-week washout period. There were no significant differences in the subjects' fasting plasma glucose levels due to the consumption of the RS bread versus the control bread. Fructosamine levels were significantly lower after consumption of both RS and control bread than at baseline. However, we found no significant difference in fructosamine levels due to treatment effects, i.e., RS bread intake versus the control bread. There were no significant differences in insulin or C-reactive protein levels due to treatment, gender, or sequence effects. Mean homeostasis model assessment of insulin resistance decreased to normal values (>2.5) at the end of the 14-week study, although there were no significant treatment effects. The results of this study suggest that African Americans may need to consume more than 12 g/day of RS to lower their risk for type 2 DM.

Neighbourhood socioeconomic status and biological 'wear and tear' in a nationally representative sample of US adults

OBJECTIVE

To assess whether neighbourhood socioeconomic status (NSES) is independently associated with disparities in biological 'wear and tear' measured by allostatic load in a nationally representative sample of US adults.

DESIGN

Cross-sectional study.

SETTING

Population-based US survey, the Third National Health and Nutrition Examination Survey (NHANES III), merged with US census data describing respondents' neighbourhoods.

PARTICIPANTS

13,184 adults from 83 counties and 1805 census tracts who completed NHANES III interviews and medical examinations and whose residential addresses could be reliably geocoded to census tracts.

MAIN OUTCOME MEASURES

A summary measure of biological risk, incorporating nine biomarkers that together represent allostatic load across metabolic, cardiovascular and inflammatory subindices.

RESULTS

Being male, older, having lower income, less education, being Mexican-American and being both black and female were all independently associated with a worse allostatic load. After adjusting for these characteristics, living in a lower NSES was associated with a worse allostatic load (coefficient -0.46; CI -0.079 to -0.012). The relationship between NSES and allostatic load did not vary significantly by gender or race/ethnicity.

CONCLUSIONS

Living in a lower NSES in the USA is associated with significantly greater biological wear and tear as measured by the allostatic load, and this relationship is independent of individual SES characteristics. Our findings show that where one lives is independently associated with allostatic load, thereby suggesting that policies that improve NSES may also yield health returns.

Social, behavioral, and biological factors, and sex differences in mortality

Few studies have examined whether sex differences in mortality are associated with different distributions of risk factors or result from the unique relationships between risk factors and mortality for men and women. We extend previous research by systematically testing a variety offactors, including health behaviors, social ties, socioeconomic status, and biological indicators of health. We employ the National Health and Nutritional Examination Survey III Linked Mortality File and use Cox proportional hazards models to examine sex diferences in adult mortality in the United States. Our findings document that social and behavioral characteristics are key factors related to the sex gap in mortality. Once we controlfor women's lower levels of marriage, poverty, and exercise, the sex gap in mortality widens; and once we control for women 's greater propensity to visit with friends and relatives, attend religious services, and abstain from smoking, the sex gap in mortality narrows. Biological factors-including indicators of inflammation and cardiovascular risk-also inform sex differences in mortality. Nevertheless, persistent sex differences in mortality remain: compared with women, men have 30% to 83% higher risks of death over the follow-up period, depending on the covariates included in the model. Although the prevalence of risk factors difers by sex, the impact of those risk factors on mortality is similar for men and women.

Surrogate markers of insulin resistance: A review

Insulin resistance is a hallmark of obesity, diabetes, and cardiovascular diseases, and leads to many of the abnormalities associated with metabolic syndrome. Our understanding of insulin resistance has improved tremendously over the years, but certain aspects of its estimation still remain elusive to researchers and clinicians. The quantitative assessment of insulin sensitivity is not routinely used during biochemical investigations for diagnostic purposes, but the emerging importance of insulin resistance has led to its wider application research studies. Evaluation of a number of clinical states where insulin sensitivity is compromised calls for assessment of insulin resistance. Insulin resistance is increasingly being assessed in various disease conditions where it aids in examining their pathogenesis, etiology and consequences. The hyperinsulinemic euglycemic glucose clamp is the gold standard method for the determination of insulin sensitivity, but is impractical as it is labor- and time-intensive. A number of surrogate indices have therefore been employed to simplify and improve the determination of insulin resistance. The object of this review is to highlight various aspects and methodologies for current and upcoming measures of insulin sensitivity/resistance. In-depth knowledge of these markers will help in better understanding and exploitation of the condition.

A1C predicts type 2 diabetes and impaired glucose tolerance in a population at risk: the community diabetes prevention project

AIMS

In a population at risk for type 2 diabetes (T2DM), we assessed early physical and metabolic markers that predict progression from normal to impaired glucose tolerance (IGT) and T2DM.

METHODS

A total of 388 individuals (22% male, age 46 + 11 years) at risk for T2DM were randomized to Standard (n = 182) or Intervention (n = 206) care and evaluated at baseline and 5 annual follow-up visits, including blood pressure, BMI, A1C, lipids, urine albumin/creatinine ratio, VO2max, fasting glucose, insulin and C-peptide. The Standard group received results of annual lab tests and quarterly newsletters, while the Intervention group received quarterly newsletters and detailed discussions of lab results, routine self-directed activities, semi-annual group meetings and monthly telephone calls for ongoing support.

RESULTS

Overall, 359 (93%) returned for at least one follow-up visit and 272 (70%) completed the final 5-year assessment. Return rates, changes in measures and incidence of IGT/T2DM were similar between groups. Low cardiorespiratory fitness (VO2max) was the most prevalent baseline abnormality. A1C and BMI were significant predictors of IGT/T2DM after controlling for other factors. The risk of IGT/T2DM within 5 years was 17.16 (95% CL: 6.169, 47.736) times greater for those with baseline A1C>=5.8% as compared to those <5.8% (p < 0.0001).

CONCLUSION

Baseline A1C>=5.8% was a significant predictor of IGT/T2DM within 5 years in a population at high risk for T2DM. A1C is routinely performed among patients with diabetes, however these data and other evidence suggest that it may also be a useful tool for risk assessment and screening.

Neighborhoods and cumulative biological risk profiles by race/ethnicity in a national sample of U.S. adults: NHANES III

PURPOSE

To examine race/ethnic-specific patterns of association between neighborhood socioeconomic status (NSES) and a cumulative biological risk index in a nationally representative population.

METHODS

The study sample included 13,199 white, black, and Mexican-American men and women, ages 20 and older, who attended the National Health and Examination Survey examination (1988-1994). Neighborhoods were defined as census tracts and linked to U.S. Census measures from 1990 and 2000, interpolated to the survey year; the NSES score included measures of income, education, poverty, and unemployment and was categorized into quintiles, with the highest indicating greater NSES. A summary biological risk score, allostatic load (AL; range 0-9), was created from 9 biological indicators of elevated risk: serum levels of C-reactive protein, albumin, glycated hemoglobin, total and high-density lipoprotein cholesterol, waist-to-hip ratio, systolic and diastolic blood pressure, and resting heart rate. Regression models stratified by race/ethnicity examined AL as a continuous and dichotomous (>or=3 vs. <3) outcome.

RESULTS

We found strong inverse associations between NSES and AL for black subjects, after adjusting for age, sex, U.S. birth, urban location, and individual SES. These associations were weaker and less consistent for Mexican Americans and whites.

CONCLUSIONS

Our results indicate that living in low NSES neighborhoods is most strongly associated with greater cumulative biological risk profiles in the black U.S. population.

Endothelial dysfunction in African-Americans

The journey of atherosclerosis begins with endothelial dysfunction and culminates into its most fearful destination producing ischemia, myocardial infarction and death. The excess cardiovascular disease morbidity and mortality in African-Americans is one of the major public health problems. In this review, we discuss vascular endothelial dysfunction as a key element for excess cardiovascular disease burden in this target population. It can be logical window of future atherosclerotic outcomes, and further efforts should be made to detect it at the earliest in African American individuals even if they are appearing healthy as the therapeutic interventions if instituted early, might prevent the subsequent cardiac events.

Distribution and cardiovascular risk correlates of hemoglobin A(1c) in nondiabetic younger adults: the Bogalusa Heart Study

Excess glycated hemoglobin (HbA(1c)), an indicator of long-term glucose homeostasis, is recognized as a risk factor for cardiovascular (CV) disease and mortality even among persons without diabetes. However, information is scant regarding its distribution and correlates of CV risk in nondiabetic younger adults. This aspect was examined in a biracial (black-white) community-based sample of 1111 younger adults (mean age: 36.2 years; 71% white, 43% male) enrolled in the Bogalusa Heart Study. Blacks vs whites and women vs men had higher HbA(1c) values (P < .0001). In bivariate analysis adjusted for age, race, sex, and smoking status, significant adverse trends were noted for body mass index, waist circumference, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), total cholesterol to HDL-C ratio, insulin, glucose, and homeostasis model assessment of insulin resistance across HbA(1c) quartiles; trends were not significant for mean arterial blood pressure, triglycerides, C-reactive protein, adiponectin, and estimated glomerular filtration rate. In multivariate analysis, besides race and sex, total cholesterol to HDL-C ratio and waist circumference were independent correlates of HbA(1c). Furthermore, the prevalence of excess (top decile) HbA(1c) was 1.6-fold (P < .05) higher among those with metabolic syndrome defined by the National Cholesterol Education Program Adult Treatment Panel III and 2.1-fold (P < .01) and 1.5-fold (P < .05) higher, respectively, among those with positive parental history of CV disease and type 2 diabetes mellitus. These findings underscore the potential value of HbA(1c) in risk assessments of CV disease and type 2 diabetes mellitus in nondiabetic, apparently "healthy" younger adults.

Relationships of low serum vitamin D3 with anthropometry and markers of the metabolic syndrome and diabetes in overweight and obesity

Low serum 25 hydroxyvitamin D₃ (vitamin D₃) is known to perturb cellular function in many tissues, including the endocrine pancreas, which are involved in obesity and type II diabetes mellitus (TIIDM). Vitamin D₃ insufficiency has been linked to obesity, whether obesity is assessed by body mass index (BMI) or waist circumference (waist). Central obesity, using waist as the surrogate, is associated with the metabolic syndrome (MetSyn), insulin resistance, TIIDM and atherosclerotic cardiovascular disease (CVD). We tested how vitamin D₃ was related to measures of fat mass, MetSyn markers, haemoglobin A_1c (HbA_1c) and MetSyn in a cross-sectional sample of 250 overweight and obese adults of different ethnicities. There were modest inverse associations of vitamin D₃ with body weight (weight) (r = -0.21, p = 0.0009), BMI (r = -0.18, p = 0.005), waist (r = -0.14, p = 0.03), [but not body fat % (r = -0.08, p = 0.24)], and HbA_1c (r = -0.16, p = 0.01). Multivariable regression carried out separately for BMI and waist showed a decrease of 0.74 nmol/L (p = 0.002) in vitamin D₃ per 1 kg/m² increase in BMI and a decrease of 0.29 nmol/L (p = 0.01) per 1 cm increase in waist, with each explaining approximately 3% of the variation in vitamin D₃ over and above gender, age, ethnicity and season.

The similar relationships of BMI and waist with vitamin D₃ may have been due to associations between BMI and waist, or coincidental, where different mechanisms relating hypovitaminosis D₃ to obesity occur concurrently. Previously reviewed mechanisms include that 1) low vitamin D₃, may impair insulin action, glucose metabolism and various other metabolic processes in adipose and lean tissue 2) fat soluble-vitamin D₃ is sequestered in the large adipose compartment, and low in serum, 3) obese people may be sensitive about their body shape, minimising their skin exposure to view and sunlight (not tested). We showed evidence for the first theory but no evidence to support the second.

In the current study, serum vitamin D₃ was inversely related to weight, BMI and markers of TIIDM (large waist, raised HbA_1c) but not to adipose mass nor to MetSyn per se.

Education, income and ethnic differences in cumulative biological risk profiles in a national sample of US adults: NHANES III (1988-1994)

Data from the nationally representative US National Health and Nutrition Examination Survey (NHANES) III cohort were used to examine the hypothesis that socio-economic status is consistently and negatively associated with levels of biological risk, as measured by nine biological parameters known to predict health risks (diastolic and systolic blood pressure, pulse, HDL and total cholesterol, glycosylated hemoglobin, c-reactive protein, albumin and waist-hip ratio), resulting in greater cumulative burdens of biological risk among those of lower education and/or income. As hypothesized, consistent education and income gradients were seen for biological parameters reflecting cardiovascular, metabolic and inflammatory risk: those with lower education and income exhibiting greater prevalence of high-risk values for each of nine individual biological risk factors. Significant education and income gradients were also seen for summary indices reflecting cumulative burdens of cardiovascular, metabolic and inflammatory risks as well as overall total biological risks. Multivariable cumulative logistic regression models revealed that the education and income effects were each independently and negatively associated with cumulative biological risks, and that these effects remained significant independent of age, gender, ethnicity and lifestyle factors such as smoking and physical activity. There were no significant ethnic differences in the patterns of association between socio-economic status and biological risks, but older age was associated with significantly weaker education and income gradients.

Glycated haemoglobin as a predictor for metabolic syndrome in non-diabetic Korean adults

AIMS

With increasing prevalence of diabetes mellitus and metabolic syndrome (MS), the importance of early detection of insulin resistance is emphasized. However, a simple and practical method of measurement is not readily available. Therefore, we examined the sensitivity and specificity of HbA(1c) for predicting impaired fasting glucose (IFG) and MS and its association with cardiovascular risk factors, particularly in the normal range of HbA(1c) levels in non-diabetic Korean subjects.

METHODS

In 40,155 participants (median age 40 years) participating in a medical check-up programme, analysis of the distribution of HbA(1c) and its association with various cardiovascular risk factors was performed. In 22,465 selected participants, an analysis was conducted of the ability of HbA(1c) to predict MS and IFG. Anthropometric measurements were made in all subjects and fasting glucose, lipid profiles and HbA(1c) were measured. The presence of MS was defined according to the definitions of the Adult Treatment Panel III (ATP III) guideline and the new International Diabetes Federation (IDF) guideline. Patients with diabetes were excluded from the study.

RESULTS

The incidence of MS was 12.2% according to ATP III criteria and 7.6% according to IDF criteria. When subjects were grouped by quartile of HbA(1c), cardiovascular risk factors significantly increased as the HbA(1c) increased. An HbA(1c) of 5.45% predicted the presence of MS (ATP III: sensitivity/specificity 57.4/64.3%, area under the curve 64.8%; IDF: sensitivity 60.2/63.4%, area under the curve 66.1%) and fasting blood glucose > or = 5.6 mmol/l (sensitivity/specificity 53.7/70%, area under the curve 66.1%). When the analyses were done separately by gender, female subjects showed higher cut-off of HbA(1c) for the prediction of MS (5.55% for both ATP III and IDF criteria).

CONCLUSIONS

HbA(1c) increased as cardiovascular risk factors increased and HbA(1c) of 5.45% predicted the presence of MS. HbA(1c) might be a predictive measure of IFG and MS, and also cardiovascular risk factors in the Korean population.

Characterization and heritability of obesity and associated risk factors in vervet monkeys

OBJECTIVE

The objective was to determine the prevalence and heritability of obesity and risk factors associated with metabolic syndrome (MS) in a pedigreed colony of vervet monkeys.

DESIGN

A cross-sectional study of plasma lipid and lipoprotein concentrations, glycemic indices, and morphometric measures with heritability calculated from pedigree analysis. A selected population of females was additionally assessed for insulin sensitivity and glucose tolerance.

SUBJECTS

All mature male (n=98), pregnant (n=40) and non-pregnant female (n=157) vervet monkeys were included in the study. Seven non-pregnant females were selected on the basis of high or average glycated hemoglobin (GHb) for further characterization of carbohydrate metabolism.

MEASUREMENTS

Morphometric measurements included body weight, length, waist circumference, and calculated BMI. Plasma lipids [total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C)] and glycemic measures (fasting blood glucose, insulin, and GHb) were measured. A homeostasis model assessment index was further reported. Glucose tolerance testing and hyperinsulinemic-euglycemic clamps were performed on 7 selected females.

CONCLUSION

Vervet monkeys demonstrate obesity, insulin resistance, and associated changes in plasma lipids even while consuming a low-fat (chow) diet. Furthermore, these parameters are heritable. Females are at particular risk for central obesity and an unfavorable lipid profile (higher TG, TC, and no estrogen-related increase in HDL-C). Selection of females by elevated GHb indicated impaired glucose tolerance and was associated with central obesity. This colony provides a unique opportunity to study the development of obesity-related disorders, including both genetic and environmental influences, across all life stages.