Association of A1C with cardiovascular disease and metabolic syndrome in Asian Indians with normal glucose tolerance

Impact of diabetes on subclinical atherosclerosis and major cardiovascular events in individuals with and without non-alcoholic fatty liver disease

AIMS

To investigate the impact of diabetes on subclinical atherosclerosis and cardiovascular disease (CVD) in individuals with and without non-alcoholic fatty liver disease (NAFLD).

METHODS

The prospective cohort study included 8451 Chinese adults free of baseline CVD in 2010. NAFLD was diagnosed based on hepatic ultrasonography. Fibrosis-4 index as a non-invasive marker was used to evaluate the degree of fibrosis. Subclinical atherosclerosis was evaluated by carotid intima-media thickness, brachial-ankle pulse wave velocity, ankle-brachial index, and carotid plaque. At follow-up during 2014-2016, the composite of incident fatal or nonfatal CVD were ascertained.

RESULTS

Of the 8451 participants, 2557 (30.3%) had NAFLD at baseline. Diabetes was associated with arterial stiffness and carotid plaque in participants with NAFLD (P < 0.001). Similar associations were observed in participants without NAFLD. During a mean 4.6 years of follow-up, 432 incident CVD events occurred. The multivariable-adjusted hazard ratio (HR) for CVD events associated with diabetes was 1.27 (95% CI 0.90-1.81) in participants with NAFLD and 1.73 (95% CI 1.32-2.26) in those without NAFLD (P for interaction = 0.21). Among participants with NAFLD who had pre-existing diabetes, those with ≥5 years of diabetes duration had an adjusted HR of 2.02 (95% CI 1.12-3.62) for CVD as compared to those with <2 years of duration. When categorizing participants with NAFLD by fibrosis severity, diabetes conferred an increased risk of CVD in those with potential advanced fibrosis.

CONCLUSIONS

Among participants with NAFLD, diabetes was associated with prevalent atherosclerosis, and a long duration of diabetes was associated with an increased risk of developing CVD. The effects of diabetes on cardiovascular outcomes did not appreciably differ by NAFLD status.

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.

Clinical characteristics of type 2 diabetes patients with discordance between HbA1c and fasting plasma glucose in the real world: An analysis of the ORBIT study

BACKGROUND

We aimed to determine the clinical characteristics of type 2 diabetes patients on basal insulin therapy with inadequate glucose control due to discordance between glycated haemoglobin (HbA_1c ) and fasting plasma glucose (FPG) in the real world.

METHODS

This was a retrospective analysis of data from the ORBIT study in China. Clinical characteristics of patients with discordance between HbA_1c and FPG at baseline and at the end of 6 months of follow-up were analysed using multinomial logistic regression in 4 study groups divided by HbA_1c and FPG.

RESULTS

Overall, of 6721 patients initiated on basal insulin, 853 achieved HbA_1c  < 7% but FPG ≥ 7 mmol/L (group 2), while 997 had FPG < 7 mmol/L but HbA_1c  ≥ 7% (group 3) at the end of follow-up. Patients in group 3 had a longer duration of type 2 diabetes compared with those in group 2 (7.22 ± 5.30 vs 6.00 ± 4.80 y, P < .05). Patients on glargine (32.90%) or detemir (36.88%) treatment accounted for a higher proportion of patients with both HbA_1c and FPG controlled than those on neutral protamine Hagedorn therapy (23.45%; P < .05). Per the multinomial logistic analysis, higher frequency of self-monitoring of blood glucose (SMBG) and use of glargine or detemir therapy were significantly inversely associated with risk of discordance between HbA_1c and FPG, while dose of insulin was a risk factor for discordance at the end of follow-up (all P < .05).

CONCLUSIONS

Patients treated with insulin analogues (glargine or detemir), instead of neutral protamine Hagedorn, and with more frequent SMBG are more likely to exhibit concordance between HbA_1c and FPG.

Validity of Indian Diabetes Risk Score and its association with body mass index and glycosylated hemoglobin for screening of diabetes in and around areas of Lucknow

OBJECTIVES

The present study aimed to assess the validity of Indian Diabetes Risk Score (IDRS) and its association with body mass index (BMI) and glycosylated hemoglobin (HbA1c) for screening of diabetes and obesity.

METHODOLOGY

A cross-sectional study was designed, and samples were randomly enrolled from Lucknow and its adjoining areas. Totally, 405 subjects were included in the study. We used diabetes risk factors (age, waist circumference, physical activity, and family history of diabetes) for screening of diabetes and abdominal obesity (AO) and BMI for screening of general obesity. HbA1c was used for confirming the diabetes patients in this population. Statistical analysis was applied to all data using SPSS software (version 20.0). P < 0.05 was considered statistically significant.

RESULTS

All 405 subjects were assessed for diabetic risk factors, BMI, and glycated hemoglobin. Of these, 56.3% subjects were aged ≥50 years. 1° and 2° AO was found in 47.9% and 40% subjects, respectively. About 27.1% subjects were found to have sedentary lifestyle, and 72.6% were found to have no family history of diabetes. According to IDRS, 272 subjects (67.2%) were found at high risk of diabetes (score ≥60). Based on BMI calculation, 198 subjects were obese, of which 79.3% were found at high risk for diabetes. A significant association was found between subjects with higher risk score and BMI (P < 0.001). Assessment of HbA1c showed that 97 (23.9%) were prediabetic and 204 (50.4%) were diabetic, of which 63.9% and 77%, respectively was at high risk for diabetes as per IDRS. A significant association was found between subjects with higher risk score and HbA1c (P < 0.001).

CONCLUSION

Our study fully supports the validity of IDRS, as it can be used as a cost-effective tool for primary mass screening of diabetes. Moreover, its combination with BMI value and HbA1c can be used for strict monitoring for diabetes and obesity at primary health care centers to reduce the early development of diabetes complications and severe obesity comorbidities.

Metabolic profile of normal glucose-tolerant subjects with elevated 1-h plasma glucose values

AIM

The aim of this study was to compare the metabolic profiles of subjects with normal glucose tolerance (NGT) with and without elevated 1-h postglucose (1HrPG) values during an oral glucose tolerance test (OGTT).

METHODOLOGY

The study group comprised 996 subjects without known diabetes seen at tertiary diabetes center between 2010 and 2014. NGT was defined as fasting plasma glucose <100 mg/dl (5.5 mmol/L) and 2-h plasma glucose <140 mg/dl (7.8 mmol/L) after an 82.5 g oral glucose (equivalent to 75 g of anhydrous glucose) OGTT. Anthropometric measurements and biochemical investigations were done using standardized methods. The prevalence rate of generalized and central obesity, hypertension, dyslipidemia, and metabolic syndrome (MS) was determined among the NGT subjects stratified based on their 1HrPG values as <143 mg/dl, ≥143-<155 mg/dl, and ≥155 mg/dl, after adjusting for age, sex, body mass index (BMI), waist circumference, alcohol consumption, smoking, and family history of diabetes.

RESULTS

The mean age of the 996 NGT subjects was 48 ± 12 years and 53.5% were male. The mean glycated hemoglobin for subjects with 1HrPG <143 mg/dl was 5.5%, for those with 1HrPG ≥143-<155 mg/dl, 5.6% and for those with 1HrPG ≥155 mg/dl, 5.7%. NGT subjects with 1HrPG ≥143-<155 mg/dl and ≥155 mg/dl had significantly higher BMI, waist circumference, systolic and diastolic blood pressure, triglyceride, total cholesterol/high-density lipoprotein (HDL) ratio, triglyceride/HDL ratio, leukocyte count, and gamma glutamyl aminotransferase (P < 0.05) compared to subjects with 1HrPG <143 mg/dl. The odds ratio for MS for subjects with 1HrPG ≥143 mg/dl was 1.84 times higher compared to subjects with 1HrPG <143 mg/dl taken as the reference.

CONCLUSION

NGT subjects with elevated 1HrPG values have a worse metabolic profile than those with normal 1HrPG during an OGTT.

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.

Associations Between Prediabetes, by Three Different Diagnostic Criteria, and Incident CVD Differ in South Asians and Europeans

OBJECTIVE

We examined longitudinal associations between prediabetes and cardiovascular disease (CVD) (coronary heart disease [CHD] and stroke) in Europeans and South Asians.

RESEARCH DESIGN AND METHODS

This was a U.K. cohort study of 1,336 Europeans and 1,139 South Asians, aged 40-69 years at baseline (1988-1991). Assessment included blood pressure, blood tests, anthropometry, and questionnaires. Prediabetes was determined by OGTT or HbA1c, using either International Expert Committee (IEC) (HbA1c 6.0-6.5% [42-48 mmol/mol]) or American Diabetes Association (ADA) (HbA1c 5.7-6.5% [39-48 mmol/mol]) cut points. Incident CHD and stroke were established at 20 years from death certification, hospital admission, primary care record review, and participant report.

RESULTS

Compared with normoglycemic individuals, IEC-defined prediabetes was related to both CHD and CVD risk in Europeans but not South Asians (subhazard ratio for CHD 1.68 [95% CI 1.19, 2.38] vs. 1.00 [0.75, 1.33], ethnicity interaction P = 0.008, and for CVD 1.49 [1.08, 2.07] vs. 1.03 [0.78, 1.36], ethnicity interaction P = 0.04). Conversely, IEC-defined prediabetes was associated with stroke risk in South Asians but not Europeans (1.73 [1.03, 2.90] vs. 0.85 [0.44, 1.64], ethnicity interaction P = 0.11). Risks were adjusted for age, sex, smoking, total-to-HDL cholesterol ratio, waist-to-hip ratio, systolic blood pressure, and antihypertensive use. Associations were weaker for OGTT or ADA-defined prediabetes. Conversion from prediabetes to diabetes was greater in South Asians, but accounting for time to conversion did not account for these ethnic differences.

CONCLUSIONS

Associations between prediabetes and CVD differed by prediabetes diagnostic criterion, type of CVD, and ethnicity, with associations being present for overall CVD in Europeans but not South Asians. Substantiation of these findings and investigation of potential explanations are required.

Glycated Hemoglobin, Fasting Insulin and the Metabolic Syndrome in Males. Cross-Sectional Analyses of the Aragon Workers' Health Study Baseline

Background and Aims

Glycated hemoglobin (HbA1c) is currently used to diagnose diabetes mellitus, while insulin has been relegated to research. Both, however, may help understanding the metabolic syndrome and profiling patients. We examined the association of HbA1c and fasting insulin with clustering of metabolic syndrome criteria and insulin resistance as two essential characteristics of the metabolic syndrome.

Methods

We used baseline data from 3200 non-diabetic male participants in the Aragon Workers' Health Study. We conducted analysis to estimate age-adjusted odds ratios (ORs) across tertiles of HbA1c and insulin. Fasting glucose and Homeostatic model assessment - Insulin Resistance were used as reference. Here we report the uppermost-to-lowest tertile ORs (95%CI).

Results

Mean age (SD) was 48.5 (8.8) years and 23% of participants had metabolic syndrome. The ORs for metabolic syndrome criteria tended to be higher across HbA1c than across glucose, except for high blood pressure. Insulin was associated with the criteria more strongly than HbA1c and similarly to Homeostatic model assessment - Insulin Resistance (HOMA-IR). For metabolic syndrome, the OR of HbA1c was 2.68, of insulin, 11.36, of glucose, 7.03, and of HOMA-IR, 14.40. For the clustering of 2 or more non-glycemic criteria, the OR of HbA1c was 2.10, of insulin, 8.94, of glucose, 1.73, and of HOMA-IR, 7.83. All ORs were statistically significant. The areas under the receiver operating characteristics curves for metabolic syndrome were 0.670 (across HbA1c values) and 0.770 (across insulin values), and, for insulin resistance, 0.647 (HbA1c) and 0.995 (insulin). Among non-metabolic syndrome patients, a small insulin elevation identified risk factor clustering.

Conclusions

HbA1c and specially insulin levels were associated with metabolic syndrome criteria, their clustering, and insulin resistance. Insulin could provide early information in subjects prone to develop metabolic syndrome.

Glycosylated hemoglobin and coronary artery disease in patients without diabetes mellitus

BACKGROUND

Abnormal glucose metabolism is a major determinant of coronary artery disease (CAD) and mortality in developed countries. Glycosylated hemoglobin (HbA1c) is a more stable, accurate parameter of glucose homeostasis than fasting glycemia, thus providing prognostic information in diabetics. However, its role and relationship with CAD remains unclear in non-diabetics.

PURPOSE

To evaluate the relationship between HbA1c and CAD in a consecutive cohort of patients without diabetes mellitus.

METHODS

Non-diabetic patients undergoing coronary angiography between April 2007 and October 2012 were included. Additionally carotid intima-media thickness (C-IMT) was evaluated during hospitalization in a consecutive cohort of patients.

RESULTS

1,703 consecutive patients were included and divided according to HbA1c tertiles (<5.5%, 5.5%-5.79%, ≥5.8%). HbA1c was associated with aging (p<0.001); hypercholesterolemia (p=0.01); renal failure (p=0.006); hypertension (p=0.002); previous myocardial infarction (p=0.004); previous percutaneous coronary intervention (p=0.01); indication to angiography (p=0.01); use of angiotensin receptor blockers (p=0.01); beta-blockers (p=0.03); nitrates (p=0.02); statins (p=0.008); calcium antagonists (p=0.01); diuretics (p<0.001); acetylsalicylic acid (p<0.001); baseline glycemia (p<0.001); triglycerides (p=0.02); and uric acid (p=0.04). HbA1c, but not fasting glycemia, was significantly associated with the prevalence of CAD (adjusted OR=1.51, 95% CI=1.15, 1.97, p=0.002), with 5.8% identified by the receiver operating characteristic (ROC) curve as the best cut-off value for CAD prediction. HbA1c was significantly associated with C-IMT and carotid plaques prevalence.

CONCLUSIONS

Among non-diabetic patients, higher HbA1c even within the normal range is significantly associated with the risk of CAD. Future large studies are needed to evaluate whether more aggressive cardiovascular prevention can reduce the risk of CAD among patients with HbA1c ≥ 5.8%.

India towards diabetes control: Key issues

The problem of mass diabetes is steadily increasing everyday. This editorial introduces key issues that need to be addressed to support the effective control of diabetes in India as well as globally. Issues like awareness generation for risk reduction, frequency of monitoring for selected parameters, standards for monitoring chronic complications in patients with diabetes, and current recommended targets of various parameters, amongst others, are presented along with extensions to the vaccinations recommended for diabetic patients.

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.

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.

Haemoglobin A1c levels and subsequent cardiovascular disease in persons without diabetes: a meta-analysis of prospective cohorts

AIMS/HYPOTHESIS

The aim of this meta-analysis was to determine the relationship between HbA(1c) levels and subsequent cardiovascular outcomes in individuals without diabetes.

METHODS

We searched Medline, Embase and Scopus from initiation of the study until the end of 2009. One reviewer searched and another verified findings. Data were extracted by one reviewer and verified by another. We accepted prospective studies in any language reporting three or more quartiles for HbA(1c) levels. Within quartiles, authors must have presented both numbers of patient-years at risk and cardiovascular outcomes. Outcomes per person-time at risk were regressed on average HbA(1c) values using Poisson regression. We pooled β coefficients using Cochran's semi-weighted (inverse variance) random-effects model. Study quality was assessed using the Downs-Black scale.

RESULTS

We investigated 16 datasets (nine for total cardiovascular events and seven for death) from five papers with 44,158 patients (44% men) over 404,899 patient-years of follow-up. There were 1,366 cardiovascular deaths (3.1%; 3.37/1,000 person-years) and 2,142 cardiovascular events (4.9%; 5.29/1,000 person-years). The overall meta-analytic β coefficients were 0.720 (95% CI 0.307-1.133) and 0.757 (95% CI 0.382-1.132) for cardiac death and events, respectively. Compared with the baseline value of 0.0427, an HbA(1c) level of 0.05 was associated with a relative risk for cardiovascular death of 1.13 (95% CI 1.05-1.21), a 0.06 value with 1.34 (95% CI 1.13-1.58), and a 0.07 HbA(1c) with relative risk 1.58 (95% CI 1.22-2.06). Results for total cardiovascular events were similar. The average study quality was 0.7 (70%).

CONCLUSIONS/INTERPRETATION

We conclude that HbA(1c) was significantly associated with cardiovascular events and deaths in persons without diabetes.

Prevalence of metabolic syndrome in patients with angiographically proven coronary artery disease presenting to a tertiary care hospital in Delhi, India

BACKGROUND

Coronary artery disease is fast emerging as the major concern for afflicting people across the globe. The Indian subcontinent is highly predisposed to this condition due to distinctive risk factor profile of this population. This fact has led to a condition where the current preventative and management protocols that have worked well in the non-Asian Indian Caucasian populations, have failed to bring about the anticipated control over the incidence and progression of CAD in Asian Indians. Metabolic syndrome has been identified as a major determinant of CAD in this population.

MATERIALS AND METHODS

The prevalence of metabolic syndrome was determined in 431 patients undergoing coronary angiography through various diagnostic algorithms. The Asian modified diagnostic criteria were also implemented to estimate the metabolic syndrome prevalence in patients with different levels of stenosis.

RESULTS

We observed a high incidence of metabolic syndrome in the patients with coronary artery disease. The prevalence of MS increased with increase in severity of coronary artery involvement. The IDF guideline with Asian modification was the most successful diagnostic algorithm.

CONCLUSIONS

It is now imperative to acknowledge the unique pattern of CAD and risk factor profile prevalent among South Asians. This will facilitate more focused and individualized management protocols directed to this population. Metabolic syndrome is a major syndrome prevalent in this population. Hence, effective control of MS may help in reducing the morbidity and mortality due to CAD in a great way.

Identifying adults at high risk for diabetes and cardiovascular disease using hemoglobin A1c National Health and Nutrition Examination Survey 2005-2006

BACKGROUND

The American Diabetes Association (ADA) recently proposed the use of hemoglobin A1c as a practical and valid strategy to identify high-risk people for whom delivery of an intensive lifestyle intervention to prevent type 2 diabetes is likely to be cost effective.

PURPOSE

To estimate composite risks of developing diabetes and cardiovascular disease (CVD) for adults with different hemoglobin A1c test results and to compare those risks with those of adults who met the 2003 ADA definition for prediabetes.

METHODS

Cross-sectional data from the 2005-2006 National Health and Nutrition Examination Survey were analyzed in 2009. The method of Stern and colleagues was used to estimate the 7.5-year probability of type 2 diabetes, and the Framingham General CVD Risk Engine was used to estimate the 10-year probability of CVD for adults with different A1c results. Sample weights were used to account for sampling probability and to adjust for noncoverage and nonresponse.

RESULTS

Among adults meeting the 2003 ADA definition for prediabetes, the probabilities for incident type 2 diabetes (over 7.5 years) and CVD (over 10 years) were 33.5% and 10.7%, respectively. Use of A1c alone, in the range of 5.5% to <6.5%, would identify a population with comparable risks for diabetes (32.4% [SE=1.2%]) and CVD (11.4% [SE=0.6%]). A slightly higher cutoff (≥5.7%) would identify adults with risks of 41.3% (SE=1.5%) for diabetes and 13.3% (SE=0.8%) for CVD-risks that are comparable to people enrolled in the Diabetes Prevention Program.

CONCLUSIONS

A1c-based testing in clinical settings should be considered as a means to identify greater numbers of adults at high risk of developing type 2 diabetes and CVD.

Impact of nonalcoholic fatty liver disease on insulin resistance in relation to HbA1c levels in nondiabetic subjects

OBJECTIVES

A cross-sectional analysis was conducted in healthy, nondiabetic Korean adults to assess the prevalence of nonalcoholic fatty liver disease (NAFLD), to compare the prevalence of NAFLD across different glycemic ranges as assessed by glycosylated hemoglobin (HbA1c), and to examine the impact of NAFLD on insulin resistance in relation to HbA1c levels.

METHODS

After rigorous exclusion criteria, the final number of subjects who participated in a comprehensive health status checkup program was 99,969. All subjects were classified into four categories with respect to HbA1c level (≤4.9, 5.0-5.4, 5.5-5.9, and 6.0-6.4%). We estimated the odds ratio (OR) for prevalence of NAFLD according to the categorized level of HbA1C and evaluated the association of NAFLD with the homeostatic model assessment of insulin resistance (HOMA-IR) in relation to the HbA1c level.

RESULTS

Twenty-eight percent (n=28,130, 40.2% of the men, 10.3% of the women) of the study subjects had NAFLD. Men had a 5.83-fold (95% confidence interval 5.63-6.05) increased risk for having NAFLD than did women. The risk for NAFLD increased with increasing level of HbA1c (OR 1.44, 2.62, and 7.18) when compared with the lowest quartile (HbA1C≤4.9%). HOMA-IR increased in the NAFLD subjects as the level of HbA1c increased. The magnitude of association of HOMA-IR with HbA1c level was greater in NAFLD subjects than in non-NAFLD subjects (P<0.001 for interaction). These associations were consistent even after adjustment for body mass index and other metabolic components.

CONCLUSIONS

NAFLD had an association with HbA1c level and insulin resistance in nondiabetic individuals, and these associations were independent of obesity and other metabolic components.

A1C cut points to define various glucose intolerance groups in Asian Indians

OBJECTIVE To determine A1C cut points for glucose intolerance in Asian Indians. RESEARCH DESIGN AND METHODS A total of 2,188 participants without known diabetes were randomly selected from the Chennai Urban Rural Epidemiology Study. All had fasting plasma glucose (FPG) and 2-h postload plasma glucose measurements after a 75-g load and were classified as having impaired fasting glucose (IFG) (American Diabetes Association [ADA] criteria, FPG > or =5.5 and <7 mmol/l, and World Health Organization [WHO] criteria, FPG > or =6.1 and <7 mmol/l), impaired glucose tolerance (IGT) (2-h postload plasma glucose > or =7.8 and <11.1 mmol/l), or diabetes (FPG > or =7 mmol/l and/or 2-h postload plasma glucose > or =11.1 mmol/l). A1C was measured using the Bio-Rad Variant machine. Based on receiver operating characteristic curves, optimum sensitivity and specificity were derived for defining A1C cut points for diabetes, IGT, and IFG. RESULTS Mean +/- SD values of A1C among subjects with normal glucose tolerance, IGT, and diabetes were 5.5 +/- 0.4, 5.9 +/- 0.6, and 8.3 +/- 2.0%, respectively (P(trend) < 0.001) with considerable overlap. To identify diabetes based on 2-h postload plasma glucose, the A1C cut point of 6.1% had an area under the curve (AUC) of 0.941 with 88.0% sensitivity and 87.9% specificity. When diabetes was defined as FPG > or =7.0 mmol/l, the A1C cut point was 6.4% (AUC = 0.966, sensitivity 93.3%, and specificity 92.3%). For IGT, AUC = 0.708; for IFG, AUC = 0.632 (WHO criteria) and 0.708 (ADA criteria), and the A1C cut point was 5.6%. CONCLUSIONS In Asian Indians, A1C cut points of 6.1 and 6.4% defined diabetes by 2-h postload plasma glucose or FPG criteria, respectively. A value of 5.6% optimally identified IGT or IFG but was <70% accurate.

Obstructive sleep apnea is highly prevalent and correlates with impaired glycemic control in consecutive patients with the metabolic syndrome

Obstructive sleep apnea (OSA) and the metabolic syndrome (MS) are independently associated with increased cardiovascular risk. The objective of the present study was to determine the prevalence of OSA among consecutive patients with MS and to determine whether OSA is associated with impaired glycemic control. Fifty consecutive patients with a recent diagnosis of MS and no previous diagnosis of OSA underwent a polysomnography and anthropometric and laboratory measurements. The prevalence of OSA (apnea-hypopnea index >or=15 events per hour of sleep) was 68% and in the same range of all other individual components of MS. Moreover, OSA was associated with increased levels of glucose (P=.03) and glycosylated hemoglobin (P=.03) but not with body mass index (P=.30). Glycosylated hemoglobin was independently associated with glucose (P<.001) and apnea-hypopnea index (P=.03). The prevalence of OSA is in the same range as all the individual components of MS and is independently associated with impaired glycemic control.

Cognitive dysfunction and diabetes mellitus

The deleterious effects of diabetes mellitus on the retinal, renal, cardiovascular, and peripheral nervous systems are widely acknowledged. Less attention has been given to the effect of diabetes on cognitive function. Both type 1 and type 2 diabetes mellitus have been associated with reduced performance on numerous domains of cognitive function. The exact pathophysiology of cognitive dysfunction in diabetes is not completely understood, but it is likely that hyperglycemia, vascular disease, hypoglycemia, and insulin resistance play significant roles. Modalities to study the effect of diabetes on the brain have evolved over the years, including neurocognitive testing, evoked response potentials, and magnetic resonance imaging. Although much insightful research has examined cognitive dysfunction in patients with diabetes, more needs to be understood about the mechanisms and natural history of this complication in order to develop strategies for prevention and treatment.

Cognitive dysfunction and diabetes mellitus

The deleterious effects of diabetes mellitus on the retinal, renal, cardiovascular, and peripheral nervous systems are widely acknowledged. Less attention has been given to the effect of diabetes on cognitive function. Both type 1 and type 2 diabetes mellitus have been associated with reduced performance on numerous domains of cognitive function. The exact pathophysiology of cognitive dysfunction in diabetes is not completely understood, but it is likely that hyperglycemia, vascular disease, hypoglycemia, and insulin resistance play significant roles. Modalities to study the effect of diabetes on the brain have evolved over the years, including neurocognitive testing, evoked response potentials, and magnetic resonance imaging. Although much insightful research has examined cognitive dysfunction in patients with diabetes, more needs to be understood about the mechanisms and natural history of this complication in order to develop strategies for prevention and treatment.

Dietary strategies for improving post-prandial glucose, lipids, inflammation, and cardiovascular health

The highly processed, calorie-dense, nutrient-depleted diet favored in the current American culture frequently leads to exaggerated supraphysiological post-prandial spikes in blood glucose and lipids. This state, called post-prandial dysmetabolism, induces immediate oxidant stress, which increases in direct proportion to the increases in glucose and triglycerides after a meal. The transient increase in free radicals acutely triggers atherogenic changes including inflammation, endothelial dysfunction, hypercoagulability, and sympathetic hyperactivity. Post-prandial dysmetabolism is an independent predictor of future cardiovascular events even in nondiabetic individuals. Improvements in diet exert profound and immediate favorable changes in the post-prandial dysmetabolism. Specifically, a diet high in minimally processed, high-fiber, plant-based foods such as vegetables and fruits, whole grains, legumes, and nuts will markedly blunt the post-meal increase in glucose, triglycerides, and inflammation. Additionally, lean protein, vinegar, fish oil, tea, cinnamon, calorie restriction, weight loss, exercise, and low-dose to moderate-dose alcohol each positively impact post-prandial dysmetabolism. Experimental and epidemiological studies indicate that eating patterns, such as the traditional Mediterranean or Okinawan diets, that incorporate these types of foods and beverages reduce inflammation and cardiovascular risk. This anti-inflammatory diet should be considered for the primary and secondary prevention of coronary artery disease and diabetes.