Secondary prevention of cardiovascular disease in type 2 diabetes and prediabetes: a cardiologist's perspective

An examination of causal associations and shared risk factors for diabetes and cardiovascular diseases in the East Asian population: A Mendelian randomization study

BACKGROUND

One of the major contributors to disability and mortality among diabetics is cardiovascular disease (CVD), with coronary artery disease (CAD) as the most prevalent type. However, previous studies have provided controversial evidence linking diabetes to other types of CVDs, such as atrial fibrillation (AF). In addition, the risk factors that predispose people to the risk of diabetes and its complications differ across ethnicities, but the disease risk profiles in the East Asian population have been less investigated.

METHODS

The causal association between type 2 diabetes (T2D) and two types of CVDs (i.e., AF and CAD) in the East Asian population was first studied using Mendelian randomization (MR) analyses. Next, we examined the causal effect of 49 traits on T2D and CAD to identify their separate and shared risk factors in East Asians. A causal mediation analysis was performed to examine the role of T2D in mediating the relationship between the identified shared risk factors and CAD.

RESULTS

T2D was causally associated with CAD, but not AF, in East Asians. A screening of the risk factors indicated that six and 11 traits were causally associated with T2D and CAD, respectively, with suggestive levels of evidence. Alkaline phosphatase (ALP) was the only trait associated with both T2D and CAD, as revealed by the univariable MR analyses. Moreover, the causal association between ALP and CAD no longer existed after adjusting T2D as a covariable in the causal mediation study.

CONCLUSION

Our study highlights the risk profiles in the East Asian population, which is important in formulating targeted therapies for T2D and CVDs in East Asians.

The Correlation between Carotid Intima-Media Thickness and Neutrophil to Lymphocyte Ratio in Prediabetes Patients

Background

Prediabetes is a metabolic state between normoglycemia and diabetes and is known to carry a higher risk of developing overt diabetes and cardiovascular disease (CVD). The relative and absolute risks of all-cause mortality, CVD, coronary heart disease, and stroke in prediabetes patients, as well as in diabetic patients, is higher than that in patients with normoglycemia. Carotid intima-media thickness (cIMT) is a method used to stratify CVD risk. In this study, we aimed to determine whether the neutrophil-to-lymphocyte ratio (NLR) correlates with cIMT in prediabetes patients.

Methods

From January 1, 2016, to February 20, 2021, 581 adults their 30s–70s who underwent carotid ultrasonography as part of a comprehensive medical examination at the Dongtan Sacred Heart Hospital were enrolled. Statistical analysis using SPSS presented t-test and chi-square test significance levels into a group with normal cIMT (nIMT; cIMT <1 mm) and a group with thick cIMT (tIMT; cIMT ≥1 mm). Binary logistic regression analysis was performed to confirm the correlation between NLR and cIMT.

Results

In prediabetic adults, age, hemoglobin A1c (HbA1c), systolic blood pressure, and NLR were significantly higher in the tIMT group than in the nIMT group. In the regression analysis, NLR, age, and HbA1c were significantly correlated with cIMT.

Conclusion

NLR was significantly higher in the tIMT group than in the nIMT group; therefore, NLR may be used to assess CVD risk in prediabetes patients.

Gluco-Metabolic Effects of Pharmacotherapy-Induced Modulation of Bile Acid Physiology

CONTEXT

The discovery and characterization of the bile acid specific receptors farnesoid X receptor (FXR) and Takeda G protein-coupled receptor 5 (TGR5) have facilitated a wealth of research focusing on the link between bile acid physiology and glucose metabolism. Modulation of FXR and TGR5 activation have been demonstrated to affect the secretion of glucagon-like peptide 1, insulin, and glucagon as well as energy expenditure and gut microbiota composition, with potential beneficial effects on glucose metabolism.

EVIDENCE ACQUISITION

A search strategy based on literature searches in on PubMed with various combinations of the key words FXR, TGR5, agonist, apical sodium-dependent bile acid transporter (ASBT), bile acid sequestrant, metformin, and glucose metabolism has been applied to obtain material for the present review. Furthermore, manual searches including scanning of reference lists in relevant papers and conference proceedings have been performed.

EVIDENCE SYNTHESIS

This review provides an outline of the link between bile acid and glucose metabolism, with a special focus on the gluco-metabolic impact of treatment modalities with modulating effects on bile acid physiology; including FXR agonists, TGR5 agonists, ASBT inhibitors, bile acid sequestrants, and metformin.

CONCLUSIONS

Any potential beneficial gluco-metabolic effects of FXR agonists remain to be established, whereas the clinical relevance of TGR5-based treatment modalities seems limited because of substantial safety concerns of TGR5 agonists observed in animal models. The glucose-lowering effects of ASBT inhibitors, bile acid sequestrants, and metformin are at least partly mediated by modulation of bile acid circulation, which might allow an optimization of these bile acid-modulating treatment modalities. (J Clin Endocrinol Metab XX: 00-00, 2019).

Risk of coronary artery disease according to glucose abnormality status and prior coronary artery disease in Japanese men

OBJECTIVE

Although glucose abnormality status (GAS), prior coronary artery disease (CAD), and other traditional risk factors affect the incidence of subsequent CAD, their impact in the same cohort has been scantly studied.

RESEARCH DESIGN AND METHODS

We analyzed data from a nationwide claims database in Japan that was accumulated during 2008-2016 involving 138,162 men aged 18-72 years. Participants were classified as having normoglycemia, borderline glycemia, or diabetes mellitus (DM) with prior CAD (CAD+) or without prior CAD (CAD-). Cox regression model identified variables related to the incidence of CAD.

RESULTS

Among CAD-, management of traditional risks differed from those with and without subsequent CAD events. On the other hand, such differences were weaker in borderline glycemia and DM CAD+, and the influence of traditional risk factors on subsequent CAD was not observed. Cox regression model showed that borderline glycemia and DM confer approximately 1.2- and 2.8-fold excess risks of CAD, respectively, compared with CAD- with normoglycemia. CAD+ confers approximately a 5- to 8-fold increased risk. The impacts of DM and prior CAD additively reached a hazard ratio (HR) of 15.74 (95% confidence interval [CI]: 11.82-21.00). However, the HR in those with borderline glycemia and CAD+ was 7.20 (95% CI: 5.01-10.34), which was not different from those with normoglycemia and CAD+.

CONCLUSION

Control status of traditional risk factors and impact on subsequent CAD differ among categories of glycemic status with and without prior CAD. Individualizing treatment strategies is needed in consideration of risk factors, such as GAS and CAD+.

Association of Prediabetes With Higher Coronary Atherosclerotic Burden Among Patients With First Diagnosed Acute Coronary Syndrome

Diabetes mellitus (DM) is associated with more extensive coronary atherosclerosis and more vulnerable plaque phenotypes. However, DM should not be considered a homogeneous and purely binary entity in terms of risk assessment. We evaluated the impact of prediabetic status on coronary atherosclerosis burden in patients with first-time acute coronary syndrome (ACS) who underwent urgent coronary angiography. The patients were divided into DM, prediabetes, and control groups. The 3-vessel disease (TVD) rates and SYNTAX and Gensini scoring systems for defining atherosclerotic burden were compared. The study was conducted in 469 consecutive patients admitted with a diagnosis of ACS. Of these, 250 patients were admitted at the first occurrence of ACS undergoing diagnostic coronary angiography. SYNTAX and Gensini scores and TVD rates were higher in prediabetic patients than in nondiabetic patients ( P = .004, P = .008, and P = .014, respectively), but similar in prediabetic and diabetic patients ( P = .912, P = .773, and P = 1.000, respectively). Coronary atherosclerosis burden is more advanced in prediabetic patients than in nondiabetic patients and is comparable between prediabetic and diabetic patients at first presentation of ACS. Cardiologists should not miss the opportunity to diagnose prediabetes and DM when patients present with an ACS.

Continuous and simultaneous determination of venous blood metabolites

Metabolic syndrome is associated with cardiovascular disease, type 2 diabetes mellitus (T2DM) and prediabetes. Metabolic syndrome is a cluster of interrelated clinical disorders. Difficulties in regulating glucose levels in blood are implicated in many of these disorders. Lactate, another energy metabolite, is produced under anaerobic conditions and can be used to monitor the balance between aerobic and anaerobic metabolism. Tested together, these metabolite levels can provide pro-diagnostic information that improves patient outcomes. Glucose and lactate were determined continuously and simultaneously in whole blood using a dual-channel thermal biosensor device in which one channel employed glucose oxidase for glucose analysis in comparison with lactate oxidase for lactate analysis in the others. No detectable clogging or interference was observed using venous blood samples. The linear detection range for both the glucose and lactate assays was 0.5-45mM. The sampling rate of up to 24 samples per hour with assay cycle time of 2.5min was achieved. Comparative analysis between our device and the HemoCue method showed an excellent correlation. The device was stable for hundreds of injections over a period of 45 days. The broad linear range, fast response and detection sensitivity are satisfactory for the clinical requirements, e.g. for diabetic or cardiovascular patients in intensive care units or surgical operation, where the tight control of blood glucose can decrease morbidity or mortality.

Sevelamer in a diabetologist's perspective: a phosphate-binding resin with glucose-lowering potential

Sevelamer is a calcium-free and metal-free phosphate-binding oral drug used in the management of hyperphosphataemia in chronic kidney disease. Preclinical and clinical trials have shown glucose and lipid-lowering effects of sevelamer, thereby giving rise to a potential role of the drug in the treatment of patients with type 2 diabetes. These 'novel' effects are most probably derived from the bile acid-binding properties of sevelamer. The proposed potential is supported by the approval of the bile acid sequestrant colesevelam in the United States for the treatment of type 2 diabetes and hypercholesterolaemia. This article offers a brief review on the effects of sevelamer and a perspective on the potential mechanisms behind the glucose-lowering effect of the drug.

Clinical potential of lixisenatide once daily treatment for type 2 diabetes mellitus

The glucagon-like peptide (GLP)-1 receptor agonist lixisenatide (Lyxumia(®)) was approved for marketing by the European Medicines Agency in February 2013 and has been evaluated in a clinical study program called GetGoal. Lixisenatide activates the GLP-1 receptor and thereby exercises the range of physiological effects generated by GLP-1, which consist of increased insulin secretion, inhibition of glucagon secretion, and decreased gastrointestinal motility alongside the promotion of satiety. In the GetGoal study program, lixisenatide demonstrated significant reductions in glycated hemoglobin (HbA1c), and fasting and postprandial plasma glucose compared with placebo. The effect on glycemia was evident, with both monotherapy and in combination with insulin and various oral antidiabetic agents. Furthermore, a general trend towards reduced bodyweight was reported. In head-to-head trials with the other GLP-1 receptor agonists (exenatide and liraglutide) on the market, lixisenatide demonstrated a superior effect with respect to reduction in postprandial plasma glucose and had a tendency towards fewer adverse events. However, lixisenatide seemed to be less efficient or at best, equivalent to exenatide and liraglutide in reducing HbA1c, fasting plasma glucose, and bodyweight. The combination of a substantial effect on postprandial plasma glucose and a labeling with once daily administration separates lixisenatide from the other GLP-1 receptor agonists. The combination of basal insulin, having a lowering effect on fasting plasma glucose, and lixisenatide, curtailing the postprandial glucose excursions, makes sense from a clinical point of view. Not surprisingly, lixisenatide is undergoing clinical development as a combination product with insulin glargine (Lantus(®)). At present the main place in therapy of lixisenatide seems to be in combination with basal insulin. A large multicenter study will determine the future potential of lixisenatide in preventing cardiovascular events and mortality, in patients with type 2 diabetes and recent acute coronary syndrome.

Prediabetes: the importance of early identification and intervention

Prediabetes is a state of abnormal glucose homeostasis characterized by the presence of impaired fasting glucose, impaired glucose tolerance, or both. Individuals with prediabetes are at increased risk for type 2 diabetes, compared with individuals with normal glucose values (normal fasting plasma glucose, < 100 mg/dL [5.6 mmol/L]). The increased risk for cardiovascular disease in prediabetes is multifactorial, with etiologies including insulin resistance, hyperglycemia, dyslipidemia, hypertension, systemic inflammation, and oxidative stress. The preferred treatment is intensive lifestyle management and aggressive pharmacologic therapies directed toward individual coronary heart disease risk factors. The use of antihyperglycemic agents in this setting is a topic of intense debate. This review discusses the pathophysiology of prediabetes and its clinical implications, highlighting the importance of early identification and intervention.

Anti-inflammatory effects of simvastatin on adipokines in type 2 diabetic patients with carotid atherosclerosis

OBJECTIVE

Statins are extensively used for lowering LDL-cholesterol and reducing cardiovascular events. Recent studies have shown that statins have beneficial anti-inflammatory effects. We aimed to determine whether and how adipokines are regulated during statin treatment in type 2 diabetic patients.

METHOD

In this study,we investigated the changes of CRP and inflammation-related adipokines (SAA,IL-6,TNFalpha and adiponectin) in 23 type 2 diabetic patients with atherosclerosis who received statin therapy, and 20 diabetic patients with atherosclerosis and 14 diabetic patients without atherosclerosis who did not receive statin therapy for a period of three months.

RESULTS

By the end of the simvastatin treatment (40 mg, daily), LDL-cholesterol was decreased by 16.7% and HDL-cholesterol was increased by 31.9%. SAA, CRP, TNFalpha and IL-6 levels were decreased by 31.8%, 66.2%, 53.9% and 14%, respectively and adiponectin was increased by 59.6%, compared with the baseline levels. Interestingly, the decrease of SAA was positively correlated with that of LDL-cholesterol but negatively with HDL-cholesterol during statin treatment. Among the adipokines, the decrease of SAA was positively correlated with TNFalpha (r = 0.50, p = 0.016).

CONCLUSION

The results suggest that adipokines may be differentially regulated and independent of cholesterol changes and that adipokines may be a mediator, and the adipose tissue may be a target of statins' anti-inflammatory effect.

Medical cost associated with prediabetes

In this article, we estimate national health care resource use and medical costs in 2007 associated with prediabetes (PD), defined as either fasting plasma glucose between 100 and 125 or oral glucose tolerance test between 140 and 200. We use Poisson regression with medical claims for an adult population continuously insured between 2004 and 2006 to analyze patterns of health care resource use by PD status. Combining rate ratios that reflect health care use patterns with national PD prevalence rates from the National Health and Nutrition Examination Survey, we calculate etiological fractions to estimate the portion of national health resource use associated with PD. The findings suggest that PD is associated with statistically higher rates of ambulatory visits for hypertension; endocrine, metabolic, and renal complications; and general medical conditions. PD is associated with a slight increase in visit rates for neurological symptoms, peripheral vascular disease, and cardiovascular disease, but the increase is not statistically significant. There is no indication that PD is associated with an increase in emergency visits and inpatient days. Extrapolating these patterns to the 57 million adults with PD in 2007 suggests that national annual medical costs of PD exceed $25 billion, or an additional $443 for each adult with PD. PD is associated with excessive use of ambulatory services for comorbidities known to be related to diabetes. Our findings strengthen the business case for lifestyle interventions to prevent diabetes by adding additional economic benefits that potentially can be achieved by preventing or delaying PD.

Addressing the need to tailor treatment to the spectrum of type 2 diabetes: new perspectives

Type 2 diabetes mellitus is characterized by the progressive loss of beta cell function, which occurs after many years of insulin resistance. Within this definition, clinicians may see a diverse array of presentations, suggesting different proportions of these two pathogenic factors and a complex etiology. There are also differences in the rate of type 2 diabetes progression in each patient, so treatments must be reviewed frequently to respond to changing severity of pathophysiologies. This article first considers some of the heritable factors and the pathogenic heterogeneity of type 2 diabetes. Relevant socioeconomic and demographic factors influencing disease development are reviewed after that, while emphasizing how a patient's treatment requires changes over time.