Glycated haemoglobin, diabetes, and mortality in men in Norfolk cohort of european prospective investigation of cancer and nutrition (EPIC-Norfolk)

Glycemic targets: what is the evidence?

Hyperglycemia is the unifying metabolic abnormality for all forms of diabetes mellitus, forming the basis for its diagnosis and treatment. The strong epidemiologic associations between hyperglycemia and the complications of diabetes have given rise to the glucose hypothesis-that the complications of diabetes are caused by hyperglycemia and that they can be prevented by normalizing glucose levels. Herein the authors review the epidemiologic relationships between hyperglycemia and the complications of diabetes, the major trials of glucose lowering, and the extent to which the glucose hypothesis is supported by these studies and how this information can be translated into clinical practice.

Glycated hemoglobin as a marker of subclinical atherosclerosis and cardiac remodeling among non-diabetic adults from the general population

BACKGROUND

Elevated glycated hemoglobin (HbA1c) is associated with increased risk of cardiovascular disease (CVD) and mortality but little is known about potential mechanisms underlying the reported associations.

METHODS

We used data from 1798 non-diabetic participants from the population-based cohort Study of Health in Pomerania (SHIP) to investigate cross-sectional and longitudinal associations of HbA1c with subclinical atherosclerosis (common carotid artery intima-media thickness [CCA-IMT]), cardiac structure (left ventricular mass [LVM]), and cardiac function (fractional shortening).

RESULTS

Cross-sectional analyses revealed a positive association between HbA1c and mean CCA-IMT with a 0.02 mm (95% confidence interval: 0.01-0.04) increase in CCA-IMT per 1% increase in HbA1c, and a similar positive trend across HbA1c quartiles (overall p-value <0.01). We also observed a graded association between HbA1c and high CCA-IMT (>75th percentile) with an odds ratio of 1.42 (95% CI: 1.11-1.81) per 1% increase in HbA1c. Longitudinal analyses showed no consistent associations of baseline HbA1c with mean follow-up CCA-IMT. There were no consistent associations of HbA1c with cardiac remodeling in cross-sectional and longitudinal analyses, respectively.

CONCLUSIONS

The association between HbA1c and CCA-IMT in non-diabetic adults may be a crucial link between high-normal HbA1c levels and an increased risk of CVD and mortality.

Type of β-blocker use among patients with versus without diabetes after myocardial infarction

BACKGROUND

Discharge β-blocker prescription after myocardial infarction (MI) is recommended for all eligible patients. Numerous β-blocker choices are presently available with variable glycometabolic effects, which could be an important consideration in patients with diabetes mellitus (DM). Whether patients with DM preferentially receive β-blockers with favorable metabolic effects after MI and if this choice is associated with better glycemic control postdischarge is unknown.

METHODS

Among patients from 24 US hospitals enrolled in an MI registry (2005-2008), we investigated the frequency of "DM-friendly" β-blocker prescription at discharge by DM status. β-Blockers were classified as DM-friendly (eg, carvedilol and labetalol) or non-DM-friendly (eg, metoprolol and atenolol), based on their effects on glycemic control. Hierarchical, multivariable logistic regression examined the association of DM with DM-friendly β-blocker use. Among DM patients, we examined the association of DM-friendly β-blockers with worsened glycemic control at 6 months after MI.

RESULTS

Of 4,031 MI patients, 1,382 (34%) had DM. β-Blockers were prescribed at discharge in 93% of patients. Diabetes mellitus-friendly β-blocker use was low regardless of DM status, although patients with DM were more likely to be discharged on a DM-friendly β-blocker compared with patients without DM (13.5% vs 10.3%, P = .003), an association that remained after multivariable adjustment (odds ratio 1.41, 95% CI 1.13-1.77). There was a trend toward a lower risk of worsened glucose control at 6 months in DM patients prescribed DM-friendly versus non-DM-friendly β-blockers (Relative Risk 0.80, 95% CI 0.60-1.08).

CONCLUSION

Most DM patients were prescribed non-DM-friendly β-blockers-a practice that was associated with a trend toward worse glycemic control postdischarge. Although in need of further confirmation in larger studies, our findings highlight an opportunity to improve current practices of β-blockers use in patients with DM.

The HbA1c and all-cause mortality relationship in patients with type 2 diabetes is J-shaped: a meta-analysis of observational studies

BACKGROUND

Low blood glucose and HbA1c levels are recommended in the literature on management of diabetes. However, data have shown that low blood glucose is associated with serious adverse effects for the patients and the recommendation has been criticized. Therefore, this article revisits the relationship between HbA1c and all-cause mortality by a meta-analysis of observational studies.

AIM

The aim of this study is to determine whether there is a J- or U-shaped non-linear relationship between HbA1c and all-cause mortality in type 2 diabetes patients, implying an increased risk to premature all-cause mortality at high and low levels of HbA1c.

METHODS

A comprehensive literature search was conducted using PubMed, Medline, and Cochrane Library databases with strict inclusion/exclusion criteria. The published adjusted hazard ratios (HR) with 95% confidence intervals of all-cause mortality for each HbA1c category and per study were analyzed. Fractional polynomial regression was used with random effect modeling to assess the non-linear relationship of the HR trends between studies. Seven eligible observational studies with a total of 147,424 participants were included in the study.

RESULTS

A significant J-shaped relationship was observed between HbA1c and all-cause mortality. Crude relative risk for all-cause mortality identified a decreased risk per 1% increase in HbA1c below 7.5% (58 mmol/mol) (0.90, CI 0.86-0.94) and an increased risk per 1% increase in HbA1c above 7.5% (58 mmol/mol) (1.04, CI 1.01-1.06). Observational studies revealed a J-shaped relationship between HbA1c and all-cause mortality, equivalent to an increased risk of mortality at high and low HbA1c levels.

CONCLUSIONS

This increased mortality at high and low HbA1c levels has significant implications on investigating optimum clinical HbA1c targets as it suggests that there are upper and lower limits for creating a 'security zone' for diabetes management.

Revising the fasting glucose threshold for detection of cardiovascular risk factors: analysing two representative population-based studies of more than 50,000 Iranians in 3 years: The National Survey of Risk Factors for Non-Communicable Diseases of Iran

OBJECTIVES

To study the prevalence of cardiovascular risk factors across different glycaemia strata and to assess the optimal cut-off value of fasting plasma glucose (FPG) to identify the constellation of cardiovascular risk factors.

METHODS

Data of the National Survey of Risk Factors for Non-Communicable Diseases of Iran (SURFNCD 2005-2007) were analysed. Prevalence rates of obesity, central obesity, hypertension and hypercholesterolemia of individuals with Impaired Fasting Glucose (IFG) were compared with those of individuals with normal fasting glycaemia and newly diagnosed diabetes. Optimal FPG cut-point to diagnose subjects with cardiovascular risk factors was assessed.

RESULTS

Prevalence of each and combinations of cardiovascular risk factors were higher among subjects with IFG compared to those with normal fasting glycaemia. The areas under the curve (AUC) for detecting cardiovascular risk were highest at FPG values of 90 mg/dL. FPG of 90 mg/dL was the optimal cut-off and, in comparison to 100 mg/dL, corresponds to correct detection of 26-29% of obese, 22-27% of centrally obese, 26-29% of hypertensive and 25-30% of hypercholesterolemic individuals.

CONCLUSIONS

IFG and even lower levels of FPG are associated with high prevalence of cardiovascular risk factors in Iranian adults. This study suggests the FPG cut-off to be revised at 90 mg/dL to identify people with increased cardiovascular risk.

Hemoglobin A(1c) in nondiabetic patients: an independent predictor of coronary artery disease and its severity

OBJECTIVE

To examine the association between hemoglobin A(1c) (HbA(1c)) and the presence, severity, and complexity of angiographically proven coronary artery disease (CAD) in nondiabetic patients.

PATIENTS AND METHODS

We performed a single-center, observational, cross-sectional study of 1141 consecutive nondiabetic patients who underwent coronary angiography from January 1, 2011, through December 31, 2011. The study population was divided into 4 interquartiles according to HbA(1c) levels (<5.5%, 5.5%-5.7%, 5.8%-6.1%, and >6.1%).

RESULTS

Patients with higher HbA(1c) levels tended to be older, overweight, and hypertensive, had higher blood glucose levels, and had lower glomerular filtration rates. Higher HbA(1c) levels were associated in a graded fashion with the presence of CAD, disease severity (higher number of diseased vessels and presence of left main and/or triple vessel disease), and disease complexity (higher SYNTAX score, higher number of patients in intermediate or high SYNTAX tertiles, coronary calcium, and chronic total occlusions). After adjustment for major conventional cardiovascular risk factors, compared with patients with HbA(1c) levels less than 5.5%, the odds ratios of occurrence of CAD in the HbA(1c) quartiles of 5.5% to 5.7%, 5.8% to 6.1%, and greater than 6.1% were 1.8 (95% CI, 1.2-2.7), 3.5 (95% CI, 2.3-5.3), and 4.9 (95% CI, 3.0-8.1), respectively.

CONCLUSION

The HbA(1c) level has a linear incremental association with CAD in nondiabetic individuals. The HbA(1c) level is also independently correlated with disease severity and higher SYNTAX scores. Thus, HbA(1c) measurement could be used to improve cardiovascular risk assessment in nondiabetic individuals.

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%.

PLA1A2 platelet polymorphism predicts mortality in prediabetic subjects of the population based KORA S4-Cohort

OBJECTIVE

The genetic polymorphism concerning the ß3-subunit of platelet integrin receptor glycoprotein IIIa is held responsible for enhanced binding of adhesive proteins resulting in increased thrombogenic potential. Whether it is associated with mortality, HbA1c or platelet volume is tested prospectively in an epidemiological cohort.

RESEARCH DESIGN AND METHODS

Population-based Cooperative Health Research in the Region of Augsburg (KORA) S4-Survey (N = 4,028) was investigated for prognostic value of PLA1A2-polymorphism regarding all-cause mortality, correlation with HbA1c, and mean platelet volume. Multivariate analysis was performed to investigate association between genotype and key variables.

RESULTS

Prevalence of thrombogenic allele variant PLA2 was 15.0%. Multivariate analysis revealed no association between PLA1A2 polymorphism and mortality in the KORA-cohort. HbA1c was a prognostic marker of mortality in non-diabetic persons resulting in J-shaped risk curve with dip at HbA1c = 5.5% (37 mmol/mol), confirming previous findings regarding aged KORA-S4 participants (55-75 years). PLA1A2 was significantly associated with elevated HbA1c levels in diabetic patients (N = 209) and reduced mean platelet volume in general population. In non-diabetic participants (N = 3,819), carriers of PLA2 allele variant presenting with HbA1c > 5.5% (37 mmol/mol) showed higher relative risk of mortality with increasing HbA1c.

CONCLUSION

PLA1A2 polymorphism is associated with mortality in participants with HbA1c ranging from 5.5% (37 mmol/mol) to 6.5% (48 mmol/mol). Maintenance of euglycemic control and antiplatelet therapy are therefore regarded as effective primary prevention in this group.

Clinical significance of glycated hemoglobin in the acute phase of ST elevation myocardial infarction

In population-based studies, including diabetic and nondiabetic cohorts, glycated hemoglobin A1c (HbA1c) has been reported as an independent predictor of all-cause and cardiovascular disease mortality. Data on the prognostic role of HbA1c in patients with acute myocardial infarction (MI) are not univocal since they stem from studies which mainly differ in patients' selection criteria, therapy (thrombolysis vs mechanical revascularization) and number consistency. The present review is focused on available evidence on the prognostic significance of HbA1c measured in the acute phase in patients with ST-elevation myocardial infarction (STEMI) submitted to primary percutaneous coronary intervention (PCI). We furthermore highlighted the role of HbA1c as a screening tool for glucose intolerance in patients with STEMI. According to available evidence, in contemporary cohorts of STEMI patients submitted to mechanical revascularization, HbA1c does not seem to be associated with short and long term mortality rates. However, HbA1c may represent a screening tool for glucose intolerance from the early phase on in STEMI patients. On a pragmatic ground, an HbA1c test has several advantages over fasting plasma glucose or an oral glucose tolerance test in an acute setting. The test can be performed in the non-fasting state and reflects average glucose concentration over the preceding 2-3 mo. We therefore proposed an algorithm based on pragmatic grounds which could be applied in STEMI patients without known diabetes in order to detect glucose intolerance abnormalities from the early phase. The main advantage of this algorithm is that it may help in tailoring the follow-up program, by helping in identifying patients at risk for the development of glucose intolerance after MI. Further validation of this algorithm in prospective studies may be required in the contemporary STEMI population to resolve some of these uncertainties around HbA1c screening cutoff points.

Outcomes from a diabetes self-management intervention for Native Hawaiians and Pacific People: Partners in Care

BACKGROUND

Culturally adapted interventions are needed to reduce diabetes-related morbidity and mortality among Native Hawaiian and Pacific People.

PURPOSE

The purpose of this study is to pilot test the effectiveness of a culturally adapted diabetes self-management intervention.

METHODS

Participants were randomly assigned in an unbalanced design to the Partners in Care intervention (n = 48) or wait list control group (n = 34). Assessments of hemoglobin A1c, understanding of diabetes self-management, performance of self-care activities, and diabetes-related distress were measured at baseline and 3 months (post intervention). Analysis of covariance was used to test between-group differences. The community steering committee and focus group data informed the cultural adaptation of the intervention.

RESULTS

There were significant baseline adjusted differences at 3 months between the Partners in Care and wait list control group in intent-to-treat (p < 0.001) and complete case analyses (p < 0.0001) for A1c, understanding (p < 0.0001), and performing diabetes self-management (p < 0.0001).

CONCLUSIONS

A culturally adapted diabetes self-management intervention of short duration was an effective approach to improving glycemic control among Native Hawaiian and Pacific Islanders.

Evaluation of buspirone on streptozotocin induced type 1 diabetes and its associated complications

We have evaluated the effect of buspirone (1.5 mg/kg/day, p.o.) type 1 diabetes induced cardiovascular complications induced by streptozotocin (STZ, 45 mg/kg, i.v.) in Wistar rats. Various biochemical, cardiovascular, and hemodynamic parameters were measured at the end of 8 weeks of treatment. STZ produced significant hyperglycaemia, hypoinsulinemia, and dyslipidemia, which was prevented by buspirone treatment. STZ produced increase in serum creatinine, urea, lactate dehydrogenase, creatinine kinase, and C-reactive protein levels and treatment with buspirone produced reduction in these levels. STZ produced increase in cardiac and LV hypertrophy index, LV/RV ratio, and LV collagen, which were decreased by buspirone treatment. Buspirone also prevented STZ induced hemodynamic alterations and oxidative stress. These results were further supported by histopathological studies in which buspirone showed marked reduction in fibrosis and cardiac fiber disarray. In conclusion, our data suggests that buspirone is beneficial as an antidiabetic agent in type 1 diabetes mellitus and also prevents its cardiac complications.

Lifestyle factors and mortality risk in individuals with diabetes mellitus: are the associations different from those in individuals without diabetes?

AIMS/HYPOTHESIS

Thus far, it is unclear whether lifestyle recommendations for people with diabetes should be different from those for the general public. We investigated whether the associations between lifestyle factors and mortality risk differ between individuals with and without diabetes.

METHODS

Within the European Prospective Investigation into Cancer and Nutrition (EPIC), a cohort was formed of 6,384 persons with diabetes and 258,911 EPIC participants without known diabetes. Joint Cox proportional hazard regression models of people with and without diabetes were built for the following lifestyle factors in relation to overall mortality risk: BMI, waist/height ratio, 26 food groups, alcohol consumption, leisure-time physical activity, smoking. Likelihood ratio tests for heterogeneity assessed statistical differences in regression coefficients.

RESULTS

Multivariable adjusted mortality risk among individuals with diabetes compared with those without was increased, with an HR of 1.62 (95% CI 1.51, 1.75). Intake of fruit, legumes, nuts, seeds, pasta, poultry and vegetable oil was related to a lower mortality risk, and intake of butter and margarine was related to an increased mortality risk. These associations were significantly different in magnitude from those in diabetes-free individuals, but directions were similar. No differences between people with and without diabetes were detected for the other lifestyle factors.

CONCLUSIONS/INTERPRETATION

Diabetes status did not substantially influence the associations between lifestyle and mortality risk. People with diabetes may benefit more from a healthy diet, but the directions of association were similar. Thus, our study suggests that lifestyle advice with respect to mortality for patients with diabetes should not differ from recommendations for the general population.

Diabetes mellitus may induce cardiovascular disease by decreasing neuroplasticity

Neuroplasticity has been defined "the ability of the nervous system to respond to intrinsic or extrinsic stimuli by reorganizing its structure, function and connections". The nervous system monitors and coordinates internal organ function. Thus neuroplasticity may be associated with the pathogenesis of other diseases besides neuropsychiatric diseases. Decreased neuroplasticity is associated with cardiovascular disease (CVD) and a disease related to decreased neuroplasticity may confer a greater CVD risk. Diabetes mellitus (DM) is related to CVD and DM induces decreased neuroplasticity, which is manifested as depression, Alzheimer's disease and diabetic neuropathy. Therefore we conclude that DM may induce CVD by decreasing neuroplasticity.

Factors influencing the decline in stroke mortality: a statement from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

Stroke mortality has been declining since the early 20th century. The reasons for this are not completely understood, although the decline is welcome. As a result of recent striking and more accelerated decreases in stroke mortality, stroke has fallen from the third to the fourth leading cause of death in the United States. This has prompted a detailed assessment of the factors associated with the change in stroke risk and mortality. This statement considers the evidence for factors that have contributed to the decline and how they can be used in the design of future interventions for this major public health burden.

METHODS

Writing group members were nominated by the committee chair and co-chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council's Scientific Statements Oversight Committee and the American Heart Association Manuscript Oversight Committee. The writers used systematic literature reviews, references to published clinical and epidemiological studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize evidence and to indicate gaps in current knowledge. All members of the writing group had the opportunity to comment on this document and approved the final version. The document underwent extensive American Heart Association internal peer review, Stroke Council leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee.

RESULTS

The decline in stroke mortality over the past decades represents a major improvement in population health and is observed for both sexes and for all racial/ethnic and age groups. In addition to the overall impact on fewer lives lost to stroke, the major decline in stroke mortality seen among people <65 years of age represents a reduction in years of potential life lost. The decline in mortality results from reduced incidence of stroke and lower case-fatality rates. These significant improvements in stroke outcomes are concurrent with cardiovascular risk factor control interventions. Although it is difficult to calculate specific attributable risk estimates, efforts in hypertension control initiated in the 1970s appear to have had the most substantial influence on the accelerated decline in stroke mortality. Although implemented later, diabetes mellitus and dyslipidemia control and smoking cessation programs, particularly in combination with treatment of hypertension, also appear to have contributed to the decline in stroke mortality. The potential effects of telemedicine and stroke systems of care appear to be strong but have not been in place long enough to indicate their influence on the decline. Other factors had probable effects, but additional studies are needed to determine their contributions.

CONCLUSIONS

The decline in stroke mortality is real and represents a major public health and clinical medicine success story. The repositioning of stroke from third to fourth leading cause of death is the result of true mortality decline and not an increase in mortality from chronic lung disease, which is now the third leading cause of death in the United States. There is strong evidence that the decline can be attributed to a combination of interventions and programs based on scientific findings and implemented with the purpose of reducing stroke risks, the most likely being improved control of hypertension. Thus, research studies and the application of their findings in developing intervention programs have improved the health of the population. The continued application of aggressive evidence-based public health programs and clinical interventions is expected to result in further declines in stroke mortality.

Hemoglobin A1C in non-diabetic patients: an independent predictor of coronary artery disease and its severity

AIMS

To determine the association between glycated hemoglobin (HbA1c) and angiographically proven coronary artery disease (CAD) and its severity in nondiabetic individuals.

METHODS

We enrolled 299 consecutive individuals undergoing coronary angiography for suspected ischemia. Patients were included if they had no history of prior revascularization or diabetes mellitus and had fasting blood glucose<126mg/dl (7.0mmol/l) and HbA1c<6.5% (47mmol/mol). The severity of the CAD was also evaluated using the Gensini score. Serum HbA1c (NGSP certified Method), highly sensitive C-reactive protein (hsCRP), lipid profile, insulin and APO lipoprotein A1 and B100 levels were measured.

RESULTS

Mean age was 58.8±10.4 year; 60.9% men. One hundred forty seven patients had significant CAD (≥50% stenosis in any major vessel). With increasing HbA1c levels, there was a significant increase in the prevalence of CAD and number of vessels involved. In multivariate analysis, HbA1c emerged as an independent predictor of significant CAD (OR: 2.8, 95% CI: 1.3-6.2, p=0.009). Adjusted ORs for the occurrence of CAD were highest in subjects with both hsCRP and HbA1c in the upper 2 quartiles (OR: 4.183; 95% CI: 1.883-9.290, p<0.0001). There was a significant association between Gensini score and increasing HbA1c tertiles (p=0.038). The ideal cut-off value of HbA1c for prediction of the occurrence of CAD was 5.6% 38mmol/mol) (sensitivity: 60.5%, specificity: 52%).

CONCLUSIONS

In non-diabetic subjects, HbA1c could be utilized for risk stratification of CAD and its severity, independent of traditional cardiovascular risk factors, insulin resistance and inflammatory markers.

Distinctions between the islets of mice and men: implications for new therapies for type 1 and 2 diabetes

OBJECTIVE

To elucidate why diabetes is so difficult to treat despite the present tools and pharmacologic armamentarium and to provide insights into emerging therapies by describing human and rodent data that demonstrates the ability to transform progenitor cells within the adult pancreas into new islets.

METHODS

A literature review focused on the distinctions between human and rodent islets.

RESULTS

We are beginning to elucidate important differences between the architecture and composition of the islets of Langerhans in humans and rodents. In contrast to rodent islets, human islets are more heterogeneous in cellular composition and have more prominent intra-islet vascularity, with smooth muscle-containing blood vessels that are not present in rodent islets. Some studies report that more than 70% of human beta cells have direct physical contact with other cell types, whereas others describe that smaller human islets possess features more typical of rodents, while larger islets exhibit greater vascularity and a cellular distribution distinct from centrally clustered beta cells surrounded by a mantle of alpha and delta cells found in rodents.

CONCLUSIONS

The differences between the islets of mice and men may influence why treatments hailed as reversing diabetes among rodents have not been successfully translated into humans. Increased understanding of the complexities within the human islet may yield unique insights into reversing diabetes in humans.

HbA1c and the risks for all-cause and cardiovascular mortality in the general Japanese population: NIPPON DATA90

OBJECTIVE

Associations between HbA1c and cardiovascular diseases (CVD) have been reported mainly in Western countries. It is not clear whether HbA1c measurements are useful for assessing CVD mortality risk in East Asian populations.

RESEARCH DESIGN AND METHODS

The risk for cardiovascular death was evaluated in a large cohort of participants selected randomly from the overall Japanese population. A total of 7,120 participants (2,962 men and 4,158 women; mean age 52.3 years) free of previous CVD were followed for 15 years. Adjusted hazard ratios (HRs) and 95% CIs among categories of HbA1c (<5.0%, 5.0-5.4%, 5.5-5.9%, 6.0-6.4%, and ≥6.5%) for participants without treatment for diabetes and HRs for participants with diabetes were calculated using a Cox proportional hazards model.

RESULTS

During the study, there were 1,104 deaths, including 304 from CVD, 61 from coronary heart disease, and 127 from stroke (78 from cerebral infarction, 25 from cerebral hemorrhage, and 24 from unclassified stroke). Relations to HbA1c with all-cause mortality and CVD death were graded and continuous, and multivariate-adjusted HRs for CVD death in participants with HbA1c 6.0-6.4% and ≥6.5% were 2.18 (95% CI 1.22-3.87) and 2.75 (1.43-5.28), respectively, compared with participants with HbA1c <5.0%. Similar associations were observed between HbA1c and death from coronary heart disease and death from cerebral infarction.

CONCLUSIONS

High HbA1c levels were associated with increased risk for all-cause mortality and death from CVD, coronary heart disease, and cerebral infarction in general East Asian populations, as in Western populations.

Effect of strict glycemic control in patients with diabetes mellitus on frequency of macrovascular events

Despite a better understanding of cardiovascular risk factors and attempts at optimal management, diabetes-related macrovascular events remain a significant cause of morbidity and mortality in the United States and worldwide. The trials to date have validated strict glycemic control as a method to achieve sustained reductions in the rate of nephropathy, neuropathy, and retinopathy due to diabetes. For these microvascular complications, the closer hemoglobin A1c is to normal levels, the better the outcome. Although reducing hemoglobin A1c levels to 7% has been shown to reduce macrovascular events, demonstrating an additional reduction in macrovascular events with tighter glycemic control has been more difficult to achieve. A careful review of recent trials, however, has demonstrated that treatment early in the disease course and the ability to safely maintain lower hemoglobin A1c levels might be critical factors in further reducing macrovascular events. In conclusion, with the introduction of novel antidiabetic agents, future trials using these drugs might be able to definitively establish the safety and efficacy of reducing cardiovascular events with stringent glycemic control; however, the current evidence is inconsistent.

Three 15-min bouts of moderate postmeal walking significantly improves 24-h glycemic control in older people at risk for impaired glucose tolerance

OBJECTIVE

The purpose of this study was to compare the effectiveness of three 15-min bouts of postmeal walking with 45 min of sustained walking on 24-h glycemic control in older persons at risk for glucose intolerance.

RESEARCH DESIGN AND METHODS

Inactive older (≥60 years of age) participants (N=10) were recruited from the community and were nonsmoking, with a BMI<35 kg/m2 and a fasting blood glucose concentration between 105 and 125 mg dL(-1). Participants completed three randomly ordered exercise protocols spaced 4 weeks apart. Each protocol comprised a 48-h stay in a whole-room calorimeter, with the first day serving as the control day. On the second day, participants engaged in either 1) postmeal walking for 15 min or 45 min of sustained walking performed at 2) 10:30 a.m. or 3) 4:30 p.m. All walking was on a treadmill at an absolute intensity of 3 METs. Interstitial glucose concentrations were determined over 48 h with a continuous glucose monitor. Substrate utilization was measured continuously by respiratory exchange (VCO2/VO2).

RESULTS

Both sustained morning walking (127±23 vs. 118±14 mg dL(-1)) and postmeal walking (129±24 vs. 116±13 mg dL(-1)) significantly improved 24-h glycemic control relative to the control day (P<0.05). Moreover, postmeal walking was significantly (P<0.01) more effective than 45 min of sustained morning or afternoon walking in lowering 3-h postdinner glucose between the control and experimental day.

CONCLUSIONS

Short, intermittent bouts of postmeal walking appear to be an effective way to control postprandial hyperglycemia in older people.

Evaluation of serum zinc status and glycated hemoglobin of type 2 diabetes mellitus patients in a tertiary care hospital of assam

The present study was undertaken to find out any correlation between serum zinc concentration and HbA_1C% in patients with type 2 diabetes mellitus (DM). The study was carried out on 50 newly diagnosed patients of type 2 diabetes and controls in the Department of Biochemistry, Assam Medical College and Hospital, Dibrugarh. Analyses of blood glucose (fasting and postprandial), glycated hemoglobin (HbA_1c), serum zinc, urea, and creatinine concentrations were performed by standard methods. Concentrations of fasting and postprandial blood glucose were significantly higher in the diabetic group than controls (P < 0.001) and the mean HbA₁c% was also higher in cases (8.32% ±1.58%). The mean serum zinc concentration in cases was found to be significantly lower than controls (79.85 ± 13.4 vs. 109.74 ± 9.72 μg/dL) and P < 0.001 with correlation coefficient r = –0.804. Present study revealed an inverse relationship between HbA_1C% and serum zinc concentration in patients with type 2 DM, substantiated by regression analysis.

Evaluation of the dual peroxisome proliferator-activated receptor α/γ agonist aleglitazar to reduce cardiovascular events in patients with acute coronary syndrome and type 2 diabetes mellitus: rationale and design of the AleCardio trial

BACKGROUND

Peroxisome proliferator-activated receptors (PPARs) regulate transcription of genes involved in glucose uptake, lipid metabolism, and inflammation. Aleglitazar is a potent dual PPAR agonist with insulin-sensitizing and glucose-lowering actions and favorable effects on lipid profiles and biomarkers of cardiovascular risk. The AleCardio trial examines whether the addition of aleglitazar to standard medical therapy reduces the risk of cardiovascular morbidity and mortality in patients with type 2 diabetes mellitus and recent acute coronary syndrome.

STUDY DESIGN

AleCardio is a phase 3, multicenter, randomized, double-blind, placebo-controlled trial. A total of 7,228 patients were randomized to aleglitazar 150 μg or placebo daily in addition to standard medical therapy. The primary efficacy end point is time to the first event of cardiovascular death, myocardial infarction, or stroke. Principal safety end points are hospitalization due to heart failure and changes in renal function. Treatment will continue until 7,000 patients are followed up for at least 2.5 years and 950 primary end point events are adjudicated.

CONCLUSIONS

AleCardio will establish whether the PPAR-α/γ agonist aleglitazar improves cardiovascular outcomes in patients with diabetes and high-risk coronary disease.

Dysglycaemia, vasculopenia, and the chronic consequences of diabetes

High glucose concentrations are independent risk factors for many serious disorders. Glucose lowering can reduce or prevent many of these disorders. The mechanisms that cause glucose-linked tissue damage are unclear; however, the sequence of tissue changes that lead to one of these consequences (ie, retinopathy) have been understood for decades because the retina can be easily inspected and changes in its vascular supply can easily be assessed. The possibility that the long-term harms of raised glucose concentrations are mediated through reduced capillary perfusion (ie, vasculopenia) is suggested by strong epidemiological links between capillary abnormalities in the retina and most of the complications of diabetes, a delay between the therapeutic effect of glucose lowering in the retina and in other tissues, laboratory evidence that atherosclerosis is promoted by abnormalities in the capillary-rich vasa vasorum of conductance vessels, and similarities in capillary abnormalities in the retina and the kidney of people with diabetes. These findings also suggest that the retina might be a window through which the effect of raised glucose concentrations on a wide range of tissues can be seen. If continuing research lends support to this theory, treatments that counteract the effect of glucose on capillaries such as those in the retina might ultimately also reduce other serious consequences of dysglycaemia.

Accuracy and clinical utility of a point-of-care HbA1c testing device

BACKGROUND

Point-of-care testing (POCT) is widely used to measure blood glucose levels in people with diabetes, although its use in measuring glycated hemoglobin (HbA1c) levels is less common, perhaps due to perceived performance issues and access to the technology.

METHODS

Forty blood samples were analyzed in duplicate using Bayer's A1CNow + ® Multi-Test A1C system (A1CNow + ) with 3 different reagent lots; HbA1c levels of the samples spanned the clinically relevant range of 4% to 10%. Corresponding samples were sent to a National Glycohemoglobin Standardization Program (NGSP) secondary reference laboratory (University of Missouri Secondary Reference Laboratory #9), which analyzed the samples with a Tosoh Automated Glycohemoglobin Analyzer HLC-723G8 (Tosoh G8; Tosoh Bioscience, Inc).

RESULTS

Glycated hemoglobin levels measured with the A1CNow + aligned with measurements obtained using the laboratory method, with correlation coefficients of 0.985, 0.987, and 0.989 for the 3 lots, respectively. The 95% CIs for the differences between the A1CNow + levels and the mean HbA1c levels were within -0.55% to +0.50% for the 3 reagent lots, which is well within the currently acceptable limits of ±0.75% HbA1c required by the NGSP. Results were further analyzed per the new tighter NGSP performance criteria effective September 1, 2012, requiring that 37 of 40 results be within ±7% (relative bias) of the NGSP reference laboratory measures. All 3 lots met the tighter NGSP criteria.

CONCLUSION

The A1CNow + provides accuracy and precision when performing POCT of HbA1c as an aid in diabetes management. Ongoing improvements in this and other HbA1c POCT devices may lead to a greater global acceptance of the role of POCT of HbA1c in diabetes management.

Oral antidiabetic therapy in a large Italian sample: drug supply and compliance for different therapeutic regimens

OBJECTIVES

To define the main features of patients treated with oral antidiabetics, evaluating monotherapy (MT), loose-dose combination therapy (LDCT) and fixed-dose combination therapy (FDCT); to describe medication adherence to the different therapies; and to evaluate the differences in compliance with the prescribed therapy regimen among prevalent and incident patient cohorts.

STUDY DESIGN

This study was a retrospective cohort analysis based on the ARNO database, a national record that tracks reimbursable prescription claims submitted from selected pharmacies to the Italian national health system. In total, 169,375 subjects, from an overall population of 4,040,624 were included in this study. The patients represented 12 different local health units. Each patient had at least one oral antidiabetic prescription claim (A10B ATC code).

METHODS

Patients were divided into four groups according to their treatment regimen during the recruitment period (1 January 2008-31 December 2008): MT, FDCT, LDCT and switching therapy. A timespan of 5 years was considered, from 4 years before to 1 year after the index date (i.e. date of the prescription selected in the recruitment period). A medication possession ratio (MPR) with a cut-off value of 80% was used to measure medication adherence. Descriptive statistics and multiple logistic regression were used to define the objectives, while P < 0.05 was considered to indicate significance.

RESULTS

The median age of patients (n = 169,375, prevalence 4.2%) was 70 years [interquartile range (IQR) 17], and 49.1% were females. Considering the entire sample, the median MPRs for the treatment regimens were: MT, 0.73 (IQR 0.53; 43.9% compliant); FDCT, 1 (IQR 0.29, 68,5% compliant); and LDCT, 0.89 (IQR 0.33, 60.3% compliant). FDCT and LDCT were significantly correlated with MPR. Compliance was 48.9% in the prevalent patient cohort (i.e. patients prescribed oral antidiabetic therapy in both prerecruitment and recruitment periods); median MPRs for the treatment regimens were: MT, 0.73 (IQR 0.52); FDCT, 1 (IQR 0.28); and LDCT, 0.90 (IQR 0.32). Compliance was 43.0% in the incident patient cohort (i.e. patients who were first prescribed oral antidiabetic therapy in the recruitment period); median MPRs for the treatment regimens were: MT, 0.70 (IQR, 0.58); FDCT, 1 (IQR 0.34); and LDCT, 0.64 (IQR 0.39).

CONCLUSIONS

Compliance was better for FDCT than the other therapeutic regimens in the study population. The same trend was observed in both the prevalent and incident patient cohorts. As type 2 diabetes is a chronic lifelong pathology, and multiple agents are often required to achieve glycaemic control, the preference for FDCT in the population, when clinically applicable, could be an effective strategy for functional administration of clinical outcome and sources. Evaluation of specific population fractions (age, sex, compliance, etc.) and specific agents or drug combinations could also be relevant in order to reach the healthcare objectives.

CARBOHYDRATE METABOLISM DISORDERS AND CORONARY HEART DISEASE: PROGNOSTIC VALUE AND REVASCULARISATION EFFECTIVENESS

This literature review presents the data on the prevalence and prognostic value of carbohydrate metabolism disorders, such as Type 2 diabetes mellitus (DM) and pre-diabetes — fasting hyperglycaemia and impaired glucose tolerance), among patients with coronary heart disease (CHD). The authors present the results of large studies on comparative effectiveness of modern pharmacological treatment and myocardial revascularisation (percutaneous coronary intervention and coronary artery bypass graft surgery) in patients with CHD and DM. 

Hemoglobin a1c is positively correlated with framingham risk score in older, apparently healthy nondiabetic korean adults

BACKGROUND

Several studies have suggested that elevated levels of hemoglobin A1c (HbA1c) are associated with cardiovascular disease (CVD) in nondiabetic individuals. However, it is unclear whether HbA1c levels can serve as a simple screening marker for increased CVD risk in nondiabetic individuals. Our objective was to evaluate the relationship between HbA1c levels and CVD risk using the Framingham risk score (FRS) in older, apparently healthy nondiabetic Korean adults.

METHODS

We retrospectively studied 2,879 Korean adults between the ages of 40 and 79 who underwent voluntary health check-ups at the Health Promotion Center of our hospital from July 2009 to June 2011. Subjects were subdivided based on their HbA1c levels into four groups: tertiles within the HbA1c normal tolerance range and a group for subjects with an increased risk for diabetes (IRD).

RESULTS

The mean FRS for the upper tertile (9.6±3.8) group was significantly higher than that of the middle tertile (8.4±4.0) and lower tertile (7.6±3.8) groups. In addition, FRS was highest in the IRD group (10.5±3.7). Multiple linear regression analysis demonstrated that HbA1c levels exhibited a significant positive correlation with FRS when adjusted for confounding variables in all subjects (β±standard error [SE], 0.018±0.002; R (2), 0.131), women (β±SE, 0.023±0.003; R (2), 0.170), and men (β±SE, 0.016±0.004; R (2), 0.109).

CONCLUSION

HbA1c levels were positively correlated with FRS in older, apparently healthy nondiabetic Korean adults. We propose that HbA1c levels may reflect CVD risk in nondiabetic individuals.

Multiple functional polymorphisms in the G6PC2 gene contribute to the association with higher fasting plasma glucose levels

AIMS/HYPOTHESIS

We previously identified the G6PC2 locus as a strong determinant of fasting plasma glucose (FPG) and showed that a common G6PC2 intronic single nucleotide polymorphism (SNP) (rs560887) and two common G6PC2 promoter SNPs (rs573225 and rs13431652) are highly associated with FPG. However, these promoter SNPs have complex effects on G6PC2 fusion gene expression, and our data suggested that only rs13431652 is a potentially causative SNP. Here we examine the effect of rs560887 on G6PC2 pre-mRNA splicing and the contribution of an additional common G6PC2 promoter SNP, rs2232316, to the association signal.

METHODS

Minigene analyses were used to characterise the effect of rs560887 on G6PC2 pre-mRNA splicing. Fusion gene and gel retardation analyses characterised the effect of rs2232316 on G6PC2 promoter activity and transcription factor binding. The genetic association of rs2232316 with FPG variation was assessed using regression adjusted for age, sex and BMI in 4,220 Europeans with normal FPG.

RESULTS

The rs560887-G allele was shown to enhance G6PC2 pre-mRNA splicing, whereas the rs2232316-A allele enhanced G6PC2 transcription by promoting Foxa2 binding. Genetic analyses provide evidence for association of the rs2232316-A allele with increased FPG (β = 0.04 mmol/l; p = 4.3 × 10(-3)) as part of the same signal as rs560887, rs573225 and rs13431652.

CONCLUSIONS/INTERPRETATION

As with rs13431652, the in situ functional data with rs560887 and rs2232316 are in accord with the putative function of G6PC2 in pancreatic islets, and suggest that all three are potentially causative SNPs that contribute to the association between G6PC2 and FPG.

G6PC2: a negative regulator of basal glucose-stimulated insulin secretion

Elevated fasting blood glucose (FBG) is associated with increased risk for the development of type 2 diabetes and cardiovascular-associated mortality. Genome-wide association studies (GWAS) have linked polymorphisms in G6PC2 with variations in FBG and body fat, although not insulin sensitivity or glucose tolerance. G6PC2 encodes an islet-specific, endoplasmic reticulum-resident glucose-6-phosphatase catalytic subunit. A combination of in situ perfused pancreas, in vitro isolated islet, and in vivo analyses were used to explore the function of G6pc2 in mice. G6pc2 deletion had little effect on insulin sensitivity and glucose tolerance, whereas body fat was reduced in female G6pc2 knockout (KO) mice on both a chow and high-fat diet, observations that are all consistent with human GWAS data. G6pc2 deletion resulted in a leftward shift in the dose-response curve for glucose-stimulated insulin secretion (GSIS). As a consequence, under fasting conditions in which plasma insulin levels were identical, blood glucose levels were reduced in G6pc2 KO mice, again consistent with human GWAS data. Glucose-6-phosphatase activity was reduced, whereas basal cytoplasmic calcium levels were elevated in islets isolated from G6pc2 KO mice. These data suggest that G6pc2 represents a novel, negative regulator of basal GSIS that acts by hydrolyzing glucose-6-phosphate, thereby reducing glycolytic flux.

Presence of macroalbuminuria predicts severe hypoglycemia in patients with type 2 diabetes: a 10-year follow-up study

OBJECTIVE

We investigated the factors that might influence the development of severe hypoglycemia in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

From January 2000 to December 2002, patients with type 2 diabetes aged 25-75 years without chronic kidney disease (estimated glomerular filtration rate ≥60 mL/min/1.73 m(2)) were consecutively recruited (n = 1,217) and followed-up in January 2011 and May 2012. Severe hypoglycemia (SH) was defined as an event requiring the assistance of another person to actively administer glucose, hospitalization, or medical care in an emergency department. We used Cox proportional hazard regression analysis to test the association between SH episodes and potential explanatory variables.

RESULTS

After a median 10.4 years of follow-up, 111 (12.6%) patients experienced 140 episodes of SH, and the incidence was 1.55 per 100 patient-years. Mean age and duration of diabetes were 55.3 ± 9.8 and 9.8 ± 6.5 years, respectively. The incidence of SH events was higher in older patients (P < 0.001), in those with a longer duration of diabetes (P < 0.001), in those who used insulin (P < 0.001) and sulfonylurea (P = 0.003), and in those who had macroalbuminuria (P < 0.001) at baseline. Cox hazard regression analysis revealed that SH was associated with longer duration of diabetes and the presence of macroalbuminuria (normoalbuminuria versus macroalbuminuria: hazard ratio, 2.52; 95% CI 1.31-4.84; P = 0.006).

CONCLUSIONS

The development of SH was independently associated with duration of diabetes and presence of macroalbuminuria, even with normal renal function in patients with type 2 diabetes.

Thermogenesis-based interventions for obesity and Type 2 diabetes mellitus

Obesity is one of the key noncommunicable diseases leading to significant comorbidities. In recent years, obesity has become a major public health issue and has threatened the wellbeing of millions of patients. Although there are multiple reasons for people becoming obese, sustained positive energy balance - energy intake is greater than energy expenditure - is the key for accumulating excess bodyfat. Prevention of obesity by lifestyle changes, healthy eating and increased physical activity are more cost effective than pharmacotherapy, bariatric surgery or ultimately treating complications of Type 2 diabetes mellitus (T2DM). Not all patients with obesity experience complications such as T2DM. The distribution of bodyfat is important in determining whether a person is obese and healthy or needs medical attention; however, the use of BMI alone will not differentiate this. Obesity patients with excess abdominal fat have the highest risk for T2DM, insulin resistance and thus, higher incidence of cardiovascular diseases. Obesity-associated complications can be reversed through healthy eating habits and increased duration and intensity of physical activity. Increasing work- and leisure-related physical activities increase the energy expenditure, having salutary effects on weightloss programs. Although treating symptoms of obesity and related disorders is important, it is not a solution for the obesity epidemic. Causes that lead to weight-gain need to be identified in individual patients, who should be educated about the causes of weight gain and ways to prevent it, and be provided with simple and practical interventions to lose weight.

Relation of glycated hemoglobin with carotid atherosclerosis in ischemic stroke patients: An observational study in Indian population

CONTEXT

Glycated hemoglobin A1c(HbA1c) indicates long-term uncontrolled hyperglycemia in the body, which in diabetic patients leads to various vascular complications as a part of generalized atherosclerosis culminating ultimately into ischemic stroke.

AIMS

Study aims to show the association between marker of uncontrolled long-term hyperglycemia HbA1c and marker of atherosclerosis (Carotid intima media thickness [CIMT] and carotid plaque) in ischemic stroke patients.

SUBJECTS AND METHODS

Carotid sonography using high resolution 7.5 MHz sonography technique was done in each patient to find the occurrence of increased CIMT and presence of plaque according to Mannheim CIMT Consensus (2004-2006). Levels of HbA1c measured in blood in both diabetic and non-diabetic patients and a comparison made between them. Finally an association sought between HbA1c levels with CIMT and plaque.

RESULTS

The average value of HbA1c of this cohort was 7.51 ± 1.75% with higher values in diabetic patients (9.29 ± 1.73%). The patients with high CIMT (>0.8 mm) had higher values of HbA1c then that of normal CIMT patients and this was nearly significantly (P = 0.06). However, HbA1c levels of blood were significantly associated with stroke patients with presence of carotid arteries plaque (P = 0.008).

CONCLUSIONS

Prediction of future risk and prevention strategies for ischemic stroke could be formulated by utilizing HbA1c levels in both diabetic and non-diabetic population.

Physical activity in obesity and metabolic syndrome

Biological aging is typically associated with a progressive increase in body fat mass and a loss of lean body mass. Owing to the metabolic consequences of reduced muscle mass, it is understood that normal aging and/or decreased physical activity may lead to a higher prevalence of metabolic disorders. Lifestyle modification, specifically changes in diet, physical activity, and exercise, is considered the cornerstone of obesity management. However, for most overweight people it is difficult to lose weight permanently through diet or exercise. Thus, prevention of weight gain is thought to be more effective than weight loss in reducing obesity rates. A key question is whether physical activity can extenuate age-related weight gain and promote metabolic health in adults. Current guidelines suggest that adults should accumulate about 60 minutes of moderate-intensity physical activity daily to prevent unhealthy weight gain. Because evidence suggests that resistance training may promote a negative energy balance and may change body fat distribution, it is possible that an increase in muscle mass after resistance training may be a key mediator leading to better metabolic control.

Epidemiology of Diabetes

The incidence of diabetes mellitus, particularly type 2 diabetes, is increasing dramatically in the United States and in other Westernized, industrialized societies because of increasing obesity, sedentary lifestyle, and population aging. There are currently 20 million persons with diabetes in the United States, of whom more than 5 million remain undiagnosed. The diabetic population consumes a disproportionate share of health care resources because of both microvascular and macrovascular complications. Diabetes is a major cause of new-onset blindness, end-stage renal disease, and nontraumatic amputation in the United States. Cardiovascular disease accounts for up to 80% of premature excess mortality in diabetic patients. Strategies to lessen the disease burden in these patients include hygienic measures (diet and exercise) as well as rigorous treatment of hypertension, dyslipidemia, and hyperglycemia.

Does occupational driving increase the risk of cardiovascular disease in people with diabetes?

Occupational driving may increase cardiovascular events. We studied the risk of overall cardiovascular events in occupational professional drivers against matched controls in a cohort of people with diabetes (N=6563). There was an increase in overall cardiovascular events in occupational drivers despite similar risk factors. This particular occupational risk factor may need to be addressed.

The metabolic deterioration that antedates diabetes: personal trajectories of HbA(1c) and fasting glucose as early indicators and possible triggers for intervention

HbA(1c) testing has become an accepted means of diagnosing diabetes as an alternative to blood glucose levels. However, population-based norms of glucose and of HbA(1c) levels do not enable the detection of diabetes at an early enough stage to thwart complications. Personal trajectories of glucose levels show steep increases a number of years prior to diabetes diagnosis. Here, we hypothesize that a comparable time-dependent deviation in an individual's HbA(1c) level may be an early manifestation of disease that should prompt lifestyle modifications. We predict that analysis of personal trajectories of glucose and of HbA(1c) will promote earlier intervention and a greater reduction in disease complications than current standards, which are based on population-based norms.

Long-Term Impact of Caregiving and Metabolic Syndrome with Perceived Decline in Cognitive Function 8 Years Later: A Pilot Study Suggesting Important Avenues for Future Research

The chronic stress of caregiving has been associated with increased risk for cognitive decline and dementia. One theoretical model suggests that a group of risk factors known as the metabolic syndrome MET_SYN (e.g. hypertension, poor glucose regulation, central obesity, and high triglyceride levels) that have demonstrated associations with both stress and cognitive decline, may mediate the association between caregiver stress and cognitive decline. It is also possible that caregiving may moderate the association between MET_SYN and cognitive decline. The present study examined these two potential models. The study sample consisted of 53 caregivers for a relative with dementia and 24 participants who did not have caregiving responsibilities at baseline. We examined associations among caregiving history (yes/no), self-reported decline in cognitive function (the AD8) at follow-up, and a MET_SYN factor comprised of increased systolic blood pressure (SBP), glycosylated hemoglobin concentration (HbA1c), waist circumference, and triglyceride levels at baseline when caregiving was assessed. MET_SYN was associated with AD8 (p = 0.010). Caregiving history was not directly associated with AD8 ratings, however, caregiving did moderate the association between MET_SYN and AD8 (p = 0.043) assessed 8 years later. In caregivers MET_SYN scores reflecting higher risk were associated with scores on the AD8 indicting decline, whereas, in controls MET_SYN was unrelated to AD8 assessment. Thus, it can be concluded that caregiver stress may increase the association between metabolic risk factors and decline in cognitive functioning up to 8 years later.

Glycated haemoglobin and the risk of cardiovascular disease, diabetes and all-cause mortality in the Copenhagen City Heart Study

OBJECTIVE

Individuals with diabetes mellitus (DM) have a considerably elevated risk of developing serious health problems including cardiovascular disease (CVD). Long-term elevated levels of blood glucose in nondiabetic individuals may also be associated with increased risk of CVD. The aim of this study was to investigate the relationships between glycated haemoglobin A(1c) (HbA(1c) ) and CVD, DM and all-cause mortality.

SUBJECTS AND DESIGN

The Copenhagen City Heart Study is a prospective study of individuals from the Danish general population. The cohort was followed for 10 years via national registers with respect to incident CVD, DM and all-cause mortality. Follow-up was 100% complete.

RESULTS

A total of 5127 subjects were included, of whom 597 had DM. In the nondiabetic population, HbA(1c) was significantly associated with incident CVD events in both univariate [hazard ratio (HR) 1.38, 95% CI 1.11-1.71] and multivariate analyses (HR 1.31, 95% CI 1.05-1.64). In the nondiabetic population, increased levels of HbA(1c) were correlated with developing DM. There was a threefold increase in risk of incident DM per unit increase in HbA(1c) with a univariate HR of 3.83 (95% CI 1.96-7.51). This relationship was essentially unchanged after multivariate adjustments (HR 4.19, 95% CI 2.01-8.71). Furthermore, we found that net reclassification improvement for diagnosed DM and CVD was significantly improved with the addition of HbA(1c) in the analyses. Although not statistically significant, we found a strong trend towards an association between HbA(1c) and all-cause mortality (HR 1.21, 95% CI 0.99-1.47). We did not find the same associations amongst the population with DM.

CONCLUSION

In the Danish general population, HbA(1c) was strongly associated with CVD in individuals without DM.

Haemoglobin A(1c) , acute hyperglycaemia and short-term prognosis in patients without diabetes following acute ST-segment elevation myocardial infarction

AIMS

To assess the prognostic impact of HbA(1c) and blood glucose level in patients with acute ST-segment elevation myocardial infarction and without diabetes. The relationship between HbA(1c) and acute hyperglycaemia was also explored.

METHODS AND RESULTS

We evaluated 4793 ST-segment elevation myocardial infarction patients with baseline HbA(1c) and three glucose measurements in the first 24 h. First, patients were stratified into quintiles by HbA(1c) and mean/admission glucose level. A total of 373 deaths (7.8%) occurred at 7 days, and 486 deaths (10.1%) occurred at 30 days. There were no significant differences in 7- and 30-day mortality, and major adverse cardiovascular event rates across HbA(1c) quintiles (< 34.4 mmol/mol (5.3% ), 34.4 to < 37.7 mmol/mol (5.6%), 37.7 to < 41.0 mmol/mol (5.9% ), 41.0 to < 47.5 mmol/mol (6.5%), and ≥ 47.5 mmol/mol; P for trend > 0.05). The risks of mortality and major adverse cardiovascular events were significantly increased in patients with higher glucose quintiles and lower quintile compared with the middle quintile after multivariable adjustment (P < 0.001). Patients were then reclassified into four groups according to mean/admission glucose and HbA(1c) levels. The group with elevated glucose and non-elevated HbA(1c) was associated with the highest mortality and major adverse cardiovascular event risk (P < 0.001).

CONCLUSIONS

Unlike acute hyperglycaemia, an elevated HbA(1c) level was not a risk factor for short-term outcomes in ST-segment elevation myocardial infarction patients without diabetes. Patients with acute hyperglycaemia and non-elevated HbA(1c) were associated with the worst prognosis. That suggests chronic glycaemic control/HbA(1c) level may help to recognize stress-induced hyperglycaemia and identify high-risk 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.

All-cause mortality and pharmacological treatment intensity following a high risk screening program for diabetes. A 6.6 year follow-up of the ADDITION study, Denmark

AIM

To study all-cause mortality and pharmacological treatment intensity in relation to baseline glucose metabolism and HbA1c following high risk screening for diabetes in primary care.

METHODS

Persons aged 40-69 years (N=163,185) received mailed diabetes risk questionnaires. 20,916 persons without diabetes but with high risk of diabetes were stratified by glucose metabolism (normal glucose tolerance (NGT), dysglycemia (IFG or IGT) or diabetes) and by HbA1c at screening (<6%, 6.0-6.4% or ≥ 6.5%). Median follow-up was 6.6 years. Excess mortality was calculated by hazard ratio.

RESULTS

HR for all-cause mortality increased with increasing levels of HbA1c at screening in people with NGT and dysglycemia. In people with screen detected diabetes the opposite relation was found. In people with diabetes redeemed prescription rates for lipid-, blood pressure- and glucose-lowering drugs increased significantly following screening and prescription rates increased with increasing levels of HbA1c at screening. The same trend in redeemed prescriptions was seen for people with dysglycemia and NGT, but the absolute rates were significantly lower than those among people with screen detected diabetes.

CONCLUSIONS

This study confirms HbA1c as an independent predictor of all-cause mortality in non-diabetic individuals. A likely explanation for the inverse relation found between all-cause mortality and HbA1c at screening among those with screen detected diabetes would be that intensive treatment near-normalizes mortality. The small group of people with NGT and HbA1c ≥ 6.5%, who had the highest all-cause mortality, may benefit from being labelled and treated as having diabetes although this group may have special characteristics not accounted for in this study.

Pharmacologic prevention of microvascular and macrovascular complications in diabetes mellitus: implications of the results of recent clinical trials in type 2 diabetes

Observational epidemiologic data indicate that lower blood glucose levels, blood pressure (BP), and lipid parameters are associated with a lower incidence of micro- and macrovascular complications in people with diabetes. While no threshold for this effect is discernible in these observational studies, intervention studies do not mirror this finding. The earliest glycemia target study in type 2 diabetes mellitus, UKPDS, demonstrated unequivocal benefits of tight glucose control on microvascular complications, but needed a prolonged follow-up to demonstrate a benefit on macrovascular outcomes and mortality. Recently, three major studies, ACCORD, ADVANCE, and VADT, evaluated the impact of attaining euglycemia (ACCORD) or near-euglycemia (ADVANCE, VADT) in older patients with diabetes and high cardiovascular (CV) risk. None of these studies, either individually or on pooled analysis, demonstrated any reduction in all-cause or CV mortality, although the meta-analyses revealed 15-17% reductions in the incidence of non-fatal myocardial infarction in those exposed to tight glucose control. A higher mortality was observed in the intensive glucose control arm of ACCORD, resulting in the premature termination of the glucose-lowering component of this study. Also, the occurrence of hypoglycemic episodes (total and major) was significantly higher in the intensive glucose control arm. ADVANCE and ACCORD also had BP-lowering components. While data from ADVANCE demonstrated a benefit of routine use of a combination of perindopril and indapamide, with a decline in all-cause mortality, CV mortality, and new-onset microalbuminuria, reducing systolic BP to <120 mmHg in ACCORD did not result in any incremental benefits over a systolic BP<140 mmHg. A residual CV risk observed in people with diabetes even after low-density lipoprotein (LDL) cholesterol lowering has led to trials evaluating additional therapy with fibric acid derivatives to reduce triglyceride levels. The lipid-lowering arm of ACCORD failed to demonstrate any benefit of add-on therapy with fibric acid derivatives to LDL-lowering treatment with HMG-CoA reductase inhibitors (statins) on vascular outcomes in patients with diabetes. However, data from earlier studies, and also from the subgroup analysis of ACCORD, indicate a probable benefit of adding treatment with fibric acid derivatives to individuals with persistently elevated triglyceride levels despite statin therapy. The most compelling evidence comes from studies assessing the impact of multiple risk factors - glucose, BP, and cholesterol. Studies like the Steno study unequivocally demonstrate the benefit of aggressive control of all three parameters on vascular outcomes in patients with diabetes. In conclusion, attempts to achieve euglycemia in older patients with type 2 diabetes with co-morbidities are not associated with any survival benefit, but may reduce the occurrence of non-fatal CV events. There is a significant risk of major hypoglycemia with this approach, thereby probably limiting its utility to younger patients with new-onset disease. Similarly, lowering systolic BP below 120 mmHg in high CV risk people with diabetes is associated with significant excess adverse events, limiting the utility of such an intervention. However, a clear benefit, which is also cost effective, is observed with strategies for multiple risk-factor control, which should be universally adopted in clinical practice.

Changes in glycemic control are associated with changes in cognition in non-diabetic elderly

The aim of the present study was to examine the relationship of changes in long term glucose levels as measured by Hemoglobin A1c (HbA1c) with simultaneous changes in cognition. The sample included in the present analysis consisted of 101 community dwelling non-diabetic elderly subjects participating in ongoing longitudinal studies of cognition. Subjects were included in this study if they were cognitively normal at baseline, had at least one co-temporaneous follow-up assessment of HbA1c and the Mini Mental State Exam (MMSE), and complete data on age, gender, race, and years of education. MMSE decline over time was the main outcome measure. In TOBIT mixed regression models, MMSE was the dependent variable and HbA1c the time-varying covariate. Sociodemographic (age, gender, and education), cardiovascular (hypertension and APOE4 status), and lifestyle (smoking and physical activity) covariates were included in the statistical model. After adjusting for age at follow-up, there was a decrease of 1.37 points in the MMSE (p = 0.0002) per unit increase in HbA1c. This result remained essentially unchanged after adjusting also for gender and education (p = 0.0005), cardiovascular factors (p = 0.0003), and lifestyle (p = 0.0006). Additionally, results remained very similar after excluding subjects with potentially incipient diabetes with HbA1c between 6 and 7. These findings suggest that in non-diabetic non-demented elderly subjects, an increase in HbA1c over time is associated with cognitive decline. Such results may have broad clinical applicability since manipulation of glucose control, even in non-diabetics, may affect cognitive performance, perhaps enabling preventive measures against dementia.

Comparative effectiveness of switching antipsychotic drug treatment to aripiprazole or ziprasidone for improving metabolic profile and atherogenic dyslipidemia: a 12-month, prospective, open-label study

We studied the effects of switching antipsychotic drug-treated patients with schizophrenia or bipolar disorder who evidenced adverse metabolic side effects as indicated by a triglyceride/high-density lipoprotein ratio (TG/HDL) ≥ 3.5 to aripiprazole (ARIP; 5-30 mg/day, n = 24) or ziprasidone (ZIP; 40-160 mg/day, n = 28). Anthropometric and metabolic measures, psychopathology, quality of life and motor adverse effects were assessed over a 52-week period with evaluations at baseline, 6, 12, 26 and 52 weeks. There were statistically significant improvements in body weight, body mass index (BMI), TG, HDL and TG/HDL which did not differ between treatments. However, numerous secondary measures including weight and BMI, and the proportion of patients who lost ≥ 7% or who no longer met criteria for obesity, favored ZIP over ARIP. Decreases in total cholesterol and increases in HDL-cholesterol also favored ZIP. On the other hand, decreases in TG/HDL ratio and reduction in HgbA1c favored ARIP. There were no significant time or group × time interaction effects for most psychopathology measures; however, Global Assessment of Functioning Scores favored ARIP at 6 and 12 months. We conclude that switching patients with evidence of metabolic side effects to either ARIP or ZIP may be beneficial for some, but not all metabolic measures, with minimal risk of worsening of psychopathology and possibly some benefit in that regard as well.