Blood glucose concentrations < or = 125 mg/dl and coronary heart disease risk

Ultra-Fast Label-Free Serum Metabolic Diagnosis of Coronary Heart Disease via a Deep Stabilizer

Although mass spectrometry (MS) of metabolites has the potential to provide real-time monitoring of patient status for diagnostic purposes, the diagnostic application of MS is limited due to sample treatment and data quality/reproducibility. Here, the generation of a deep stabilizer for ultra-fast, label-free MS detection and the application of this method for serum metabolic diagnosis of coronary heart disease (CHD) are reported. Nanoparticle-assisted laser desorption/ionization-MS is used to achieve direct metabolic analysis of trace unprocessed serum in seconds. Furthermore, a deep stabilizer is constructed to map native MS results to high-quality results obtained by established methods. Finally, using the newly developed protocol and diagnosis variation characteristic surface to characterize sensitivity/specificity and variation, CHD is diagnosed with advanced accuracy in a high-throughput/speed manner. This work advances design of metabolic analysis tools for disease detection as it provides a direct label-free, ultra-fast, and stabilized platform for future protocol development in clinics.

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.

Reduction of amputation rates among Alaska Natives with diabetes following the development of a high-risk foot program

OBJECTIVE

The prevalence of diabetes is increasing rapidly among Alaska's Indian, Eskimo and Aleut populations. Approximately half the Native people with diabetes have no road access to hospitals or physicians, presenting a challenge in the attempt to prevent lower extremity amputation as a complication. In late 1998 funding became available for diabetes prevention and treatment among Native Americans. The tribal health corporations in Alaska decided to use a portion of this funding to implement a high-risk foot program to decrease the amputation rate.

PROGRAM DESIGN

The program initially involved a surgical podiatrist who provided training to local staff and performed preventive and reconstructive surgery on several patients with impending amputations. The program then provided training for a physical therapist to become a certified pedorthist. This individual established the long-term maintenance phase of the program by conducting diabetic foot clinics routinely at the Alaska Native Medical Center, a referral center in Anchorage. He also travels to other regions of the state to provide training for village and hospital-based health care providers and to conduct field clinics. A system was established in a common database management program to track the patients' foot conditions. Patient education is emphasized.

RESULTS

The overall amputation incidence among all Alaska Native patients with diabetes decreased from 7.6/1,000 in the pre-program period (1996 to 1998) to 2.7/1,000 in the post-program period (1999-2001) (p<.001). The rate among Aleuts, who previously had the highest amputation incidence, decreased from 17.4/1,000 to 3.1/1,000 over the same time periods (p<.001). Among people who had had diabetes at least 10 years, the overall amputation incidence decreased from 16.4/1,000 to 6.8/1,000 (p=.021); among Aleuts the rate fell from 24.5/1,000 to 2.6/1,000 (p=.01).

CONCLUSIONS

Though longer follow-up is needed, these data suggest that even in populations living in isolated regions, diabetic amputations can be prevented by a coordinated system to identify high-risk feet and provide preventive treatment and education in the context of a comprehensive diabetes management program in an integrated health system.

Impaired Fasting Glucose in Nondiabetic Range: Is It a Marker of Cardiovascular Risk Factor Clustering?

BACKGROUND

Impaired fasting glucose (IFG) through the nondiabetic range (100-125 mg/dL) is not considered in the cardiovascular (CV) risk profile.

AIM

To compare the clustering of CV risk factors (RFs) in nondiabetic subjects with normal fasting glucose (NFG) and IFG.

MATERIAL AND METHODS

Cross-sectional study in 3739 nondiabetic subjects. Demographics, medical history, and CV risk factors were collected and lipid profile, fasting glucose levels (FBG), C-reactive protein (hsCRP), blood pressure (BP), anthropometric measurements, and aerobic capacity were determined.

RESULTS

559 (15%) subjects had IFG: they had a higher mean age, BMI, waist circumference, non-HDL cholesterol, BP, and hsCRP (p < 0.0001) and lower HDL (p < 0.001) and aerobic capacity (p < 0.001). They also had a higher prevalence of hypertension (34% versus 25%; p < 0.001), dyslipidemia (79% versus 74%; p < 0.001), and obesity (29% versus 16%; p < 0.001) and a higher Framingham risk score (8% versus 6%; p < 0.001). The probability of presenting 3 or more CV RFs adjusted by age and gender was significantly higher in the top quintile of fasting glucose (≥98 mg/dL; OR = 2.02; 1.62-2.51).

CONCLUSIONS

IFG in the nondiabetic range is associated with increased cardiovascular RF clustering.

Prediabetes and associated disorders

Prediabetes represents an elevation of plasma glucose above the normal range but below that of clinical diabetes. Prediabetes includes individuals with IFG, IGT, IFG with IGT and elevated HbA1c levels. Insulin resistance and β-cell dysfunction are characteristic of this disorder. The diagnosis of prediabetesis is vital as both IFG and IGT are indeed well-known risk factors for type 2 diabetes with a greater risk in the presence of combined IFG and IGT. Furthermore, as will be illustrated in this review, prediabetes is associated with associated disorders typically only considered in with established diabetes. These include cardiovascular disease, periodontal disease, cognitive dysfunction, microvascular disease, blood pressure abnormalities, obstructive sleep apnea, low testosterone, metabolic syndrome, various biomarkers, fatty liver disease, and cancer. As the vast majority of individuals with prediabetes are unaware of their diagnosis, it is therefore vital that the associated conditions are identified, particularly in the presence of mild hyperglycemia, so they may benefit from early intervention.

Associations of blood glucose and prevalent diabetes with risk of cardiovascular disease in 500 000 adult Chinese: the China Kadoorie Biobank

AIMS

To examine the relationship of self-reported diabetes, and of random blood glucose levels among individuals without known diabetes, with the prevalence of cardiovascular disease in Chinese adults.

METHODS

We examined cross-sectional data from the China Kadoorie Biobank of 0.5 million people aged 30-79 years recruited from 10 diverse regions of China in the period 2004-2008. Logistic regression was used to estimate the odds ratios of prevalent cardiovascular disease associated with self-reported diabetes, and with measured random blood glucose levels among participants with no history of diabetes, adjusting simultaneously for age, sex, area, education, smoking, alcohol, blood pressure and physical activity.

RESULTS

A total of 3.2% of participants had self-reported diabetes (men 2.9%; women 3.3%) and 2.8% had screen-detected diabetes (men 2.6%; women 2.8%), i.e. they had no self-reported history of diabetes but a blood glucose level suggestive of a diagnosis of diabetes. Compared with individuals without a history of diabetes, the odds ratios associated with self-reported diabetes were 2.18 (95% CI 2.06-2.30) and 1.88 (95% CI 1.75-2.01) for prevalent ischaemic heart disease and stroke/transient ischaemic attack, respectively. Among participants without self-reported diabetes there was a positive association between random blood glucose and ischaemic heart disease and stroke/transient ischaemic attack prevalence (P for trend <0.0001). Below the diabetic threshold (<11.1 mmol/l) each additional 1 mmol/l of random blood glucose was associated with 4% (95% CI 2-5%) and 5% (95% CI 3-7%) higher odds of prevalent ischaemic heart disease and stroke/transient ischaemic attack, respectively.

CONCLUSIONS

In this adult Chinese population, self-reported diabetes was associated with a doubling of the odds of prevalent cardiovascular disease. Below the threshold for diabetes there was still a modest, positive association between random blood glucose and prevalent cardiovascular disease.

Association of prediabetes by fasting glucose and/or haemoglobin A1c levels with subclinical atherosclerosis and impaired renal function: observations from the Dallas Heart Study

BACKGROUND

Prediabetes defined by fasting plasma glucose (FPG) and glycosylated haemoglobin (HbA1c) predicts incident diabetes, but their individual and joint associations with micro- and macro-vascular risk remain poorly defined.

METHODS

FPG, HbA1c, coronary artery calcium (CAC), carotid wall thickness, estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR) were measured in adults free from prior diabetes or cardiovascular disease (CVD) in the Dallas Heart Study 2 (DHS-2), a population-based cohort study. Prediabetes was defined by FPG 100-125 mg/dL and/or HbA1c 5.7%-6.4%. Multivariable logistic regression was used to analyse associations of HbA1c and/or FPG in the prediabetes range with subclinical atherosclerosis and renal measures.

RESULTS

The study comprised 2340 participants, median age = 49 years; 60% women and 50% black. Those with prediabetes were older (52 vs 48 years), more often men (63% vs 53%), black (53% vs 47%) and obese (58% vs 40%; p < 0.001 for each). Prediabetes was captured by FPG alone (43%), HbA1c alone (30%) or both (27%). Those with prediabetes by HbA1c or FPG versus normal HbA1c/FPG had more CAC [odds ratio (OR) = 1.8; 95% confidence interval (CI) = 1.5-2.2], higher carotid wall thickness (1.32 vs 1.29 mm, p < 0.001), eGFR < 60 mL/min [OR = 1.6 (95% CI = 1.1-2.4)], UACR > 30 mg/dL [OR = 1.8 (95% CI = 1.2-2.7)] and a higher odds for the composite eGFR + UACR [chronic kidney disease (CKD) ≥ 2] [OR = 1.9 (95% CI = 1.5-2.6)]. After multivariable adjustment, none of these associations remained significant.

CONCLUSION

Prediabetes defined by HbA1c and/or FPG criteria is crudely associated with markers of diabetic macro- and micro-vascular disease, but not after statistical adjustment, suggesting the relationships are attributable to other characteristics of the prediabetes population.

Impaired fasting glucose and risk of cardiovascular disease in Korean men and women: the Korean Heart Study

OBJECTIVE

The relationship between impaired fasting glucose (IFG) and risk of cardiovascular disease (CVD) or ischemic heart disease (IHD) varies widely according to sex and ethnicity. We evaluated the relationship between IFG and CVD or IHD among Korean men and women.

RESEARCH DESIGN AND METHODS

A total of 408,022 individuals who underwent voluntary private health examinations in 17 centers in South Korea were followed for 10 years. Data regarding CVD or IHD events were obtained from the Korean National Health Insurance database. IFG was categorized as grade 1 (fasting glucose 100-109 mg/dL) or grade 2 (110-125 mg/dL).

RESULTS

Incidence rates of CVD (per 100,000 person-years) were 2,203 for diabetes. Age-adjusted hazard ratios (HRs) for CVD were 1.17 (95% CI 1.13-1.20) for grade 1 IFG, 1.30 (1.24-1.35) for grade 2 IFG, and 1.81 (1.75-1.86) for diabetes. The increased risk for women was similar to that of men. Age-adjusted HRs for IHD and ischemic stroke were also significantly increased for men and women with IFG and diabetes. After multivariate adjustment of conventional risk factors (hypertension, dyslipidemia, smoking, obesity, and family history of CVD), the overall risk of CVD was greatly attenuated in all categories. However, the HRs for IHD and ischemic stroke remained significantly increased in men for grade 2 IFG but not in women.

CONCLUSIONS

In Korea, grade 2 IFG is associated with increased risk of IHD and ischemic stroke, independent of other conventional risk factors, in men but not in women.

Definition of prediabetes

Diabetes evolves through prediabetes, defined as impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). Subjects with IFG/IGT have an increased risk of developing diabetes and a higher prevalence of cardiovascular disease than normoglycemic individuals. However, there is considerable evidence that glucose levels lower than those meeting the current definition of prediabetes may also be associated with similar concerns, particularly in high-risk individuals in accordance with a continuous glycemic risk perspective. Therefore, an absolute definition of prediabetes may underestimate the implications and vastness of this disorder. Research should focus on these aspects to minimize the risk of developing a preventable condition.

Inadequacies of absolute threshold levels for diagnosing prediabetes

Prediabetes comprising Impaired Fasting Glucose (IFG) and Impaired Glucose Tolerance (IGT) represents an intermediate stage of altered glucose metabolism between normal glucose levels and type 2 diabetes mellitus and is associated with an increased risk for the development of diabetes and cardiovascular disease. There is considerable evidence that glucose levels lower than those meeting the current definition of prediabetes may also be associated with similar risks particularly in high-risk individuals. Prediabetes is often unrecognized and therefore constitutes a major public health concern suggesting the need for earlier intervention than is currently recommended.

All-cause mortality risk predictors in a preventive cardiology clinic cohort-examining diabetes and individual metabolic syndrome criteria: a PRECIS database study

AIM

It is unclear if metabolic syndrome (MS) is equal to type 2 diabetes mellitus (DM) in predicting cardiovascular disease (CVD) risk and mortality, and its prognostic value compared to Framingham risk model is controversial. We assessed mortality, CVD risk and prevalence in patients with DM and those without DM who met National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) MS criteria compared to patients without DM or MS. We analysed which component(s) of NCEP MS criteria had greatest predictive value for mortality.

METHODS

Retrospective cohort analysis of 1189 DM, 1241 MS (fasting glucose < 126 mg/dl and > or =3 components NCEP-ATP III criteria) and 3023 non-DM/non-MS patients presented for baseline visit to Preventive Cardiology clinic between 1995 and 2006, whose subsequent vital status was determined for a median of 5.2 years. The association with mortality was determined by Cox proportional hazards models. The incremental predictive value of MS components was performed by concordance indexes.

RESULTS AND CONCLUSION

DM group had highest mortality and CVD prevalence vs. MS and non-DM/non-MS groups respectively (all p < or = 0.001). Patients with MS criteria had increased CVD prevalence and 1.5-fold increased mortality vs. non-DM/non-MS group (all p < 0.02). In NCEP MS criteria, only fasting glucose significantly predicted mortality in MS group (p = 0.05). MS criteria predicted CVD prevalence in a parallel manner to Framingham risk score assessment. In a cohort of patients at high risk for CVD whose risk factors are being treated, presence of diabetes in addition to plasma glucose within NCEP MS criteria strongly predicts all-cause mortality.

Sex differences in the relation of depressive symptoms, hostility, and anger expression to indices of glucose metabolism in nondiabetic adults

This study examined the relation of depressive symptomatology, hostility, and anger expression to indices of glucose metabolism and tested whether gender moderates these associations in a sample of 135 healthy, nondiabetic adults (75 men, 60 women). The severity of depressive symptoms, hostility, and anger expression was positively associated with estimated insulin resistance (IR) and insulin in women but not in men. Anger expression was positively associated with glucose in women only. A summary score of depressive symptoms, hostility, and anger expression was positively associated with estimated IR, insulin, and glucose in women but not in men. Hence, in women, IR and elevated levels of fasting insulin and glucose may be one pathophysiological mechanism mediating the increased risk of cardiovascular disease and Type 2 diabetes associated with these psychological attributes.

Preventing cardiovascular disease in diabetes and glucose intolerance: evidence and implications for care

With the increased attention being given to cardiovascular risk factor reduction, the opportunity exists to substantially decrease the largest cause of mortality in diabetic patients. The concept that type 2 diabetes and CVD are linked via a common etiologic pathway (metabolic syndrome) has substantial ramifications for the care of individual patients. Many of the metabolic abnormalities that contribute to both glycemic disorders and CVD are interrelated. For example, hyperinsulinemia and insulin resistance coupled with abdominal obesity further worsens HTN and hyperlipidemia. Likewise, the procoagulant state and endothelial dysfunction increase with worsening glycemic control. Specific interventions include tobacco cessation, a food management and physical activity plan, choice of antidiabetic agent (such as metformin), and use of ACE inhibitors for hypertension and microalbuminuria (Table 5). Programs to enhance cardiovascular risk factor reduction as part of the comprehensive evaluation and management of diabetic patients have been described [95,99]. One community-based program provided free screening to diabetic patients with randomization to either annotated result reports provided to the patient and their physician or results provided by a project nurse (either face-to-face or over the phone). Greater improvements in mean glycohemoglobin, cholesterol, and blood pressure were noted with verbal presentation of results [99]. Recent data from the Centers for Disease Control and Prevention Diabetes Cost-effectiveness Group support the idea that interventions to decrease CVD in diabetics are economically beneficial. Intensive management of hypertension, glycemic control, and hyperlipidemia each improved health outcomes. Hypertension control reduced costs. Although intensive treatment of glucose and hyperlipidemia increased costs, the increase was comparable to that of other frequently used health care interventions [100]. Further directions include further exploration of the implications and management of metabolic syndrome as it relates to CVD prevention. Interventions such as exercise, which can impact on all outcomes, require special attention. Efforts by physicians, health systems, and society are necessary to increase physical activity for individuals of all ages. It makes clinical sense that the recommendations for prevention of CVD in diabetics described in this article may also benefit patients with prediabetes (fasting glucose 110-125 mg/dl), but this remains to be definitively shown.