The aim of this article is to evaluate the pros and cons of a specific impact of postprandial hyperglycemia and glycemic variability on the—mainly cardiovascular (CV)—complications of diabetes, above and beyond the average blood glucose (BG) as measured by HbA_1c or fasting plasma glucose (FPG). The strongest arguments in favor of this hypothesis come from impressive pathophysiological studies, also in the human situation. Measures of oxidative stress and endothelial dysfunction seem to be especially closely related to glucose peaks and even more so to fluctuating high and low glucose concentrations and can be restored to normal by preventing those glucose peaks or wide glucose excursions. The epidemiological evidence, which is more or less confined to postprandial hyperglycemia and postglucose load glycemia, is also rather compelling in favor of the hypothesis, although certainly not fully conclusive as there are also a number of conflicting results. The strongest cons are seen in the missing evidence as derived from randomized prospective intervention studies targeting postprandial hyperglycemia longer term, i.e., over several years, and seeking to reduce hard CV end points. In fact, several such intervention studies in men have recently failed to produce the intended beneficial outcome results. As this evidence by intervention is, however, key for the ultimate approval of a treatment concept in patients with diabetes, the current net balance of attained evidence is not in favor of the hypothesis here under debate, i.e., that we should care about postprandial hyperglycemia and glycemic variability. The absence of a uniformly accepted standard of how to estimate these parameters adds a further challenge to this whole debate.

Alpha-glucosidase inhibitors have been available for clinical use for about 20 years. They have shown reasonably good efficacy comparable to other oral blood glucose lowering drugs and in some parts of the world are the most commonly prescribed oral diabetes medication, especially in Asian countries. Unlike as has been observed with some other blood glucose lowering agents, however, no adverse signals of potential cardiovascular harm have emerged in relation to their use. On the contrary, significant beneficial cardiovascular outcome results have been observed in the post-hoc analyses of randomised placebo-controlled trials with the alpha-glucosidase inhibitor acarbose. Targeting mainly postprandial hyperglycaemia, alpha-glucosidase inhibitors favourably affect several cardiovascular risk factors, such as obesity, hypertension and high glycaemic variability with little to no risk for hypoglycaemia. Furthermore, acarbose favourably affects endothelial dysfunction and carotid intima media thickening in humans and, in animal models, improves cardiac interstitial fibrosis and hypertrophy of cardiomyocytes. The ultimate determination of the cardiovascular effects of alpha-glucosidase inhibitors in terms of clinical outcomes awaits the results of ongoing long-term, randomised, placebo-controlled trials.

Type 2 diabetes is one of the most relevant risk factors for heart failure, the prevalence of which is increasing worldwide. The aim of the review is to highlight the current perspectives of the pathophysiology of heart failure as it pertains to type 2 diabetes. This review summarizes the proposed mechanistic bases, explaining the myocardial damage induced by diabetes-related stressors and other risk factors, i.e., cardiomyopathy in type 2 diabetes. We highlight the complex pathology of individuals with type 2 diabetes, including the relationship with chronic kidney disease, metabolic alterations, and heart failure. We also discuss the current criteria used for heart failure diagnosis and the gold standard screening tools for individuals with type 2 diabetes. Currently approved pharmacological therapies with primary use in type 2 diabetes and heart failure, and the treatment-guiding role of NT-proBNP are also presented. Finally, the influence of the presence of type 2 diabetes as well as heart failure on COVID-19 severity is briefly discussed.

The presence of cardiovascular disease (CVD) in Type 1 diabetes largely impairs life expectancy. Hyperglycemia leading to an increase in oxidative stress is considered to be the key pathophysiological factor of both micro- and macrovascular complications. In Type 1 diabetes, the presence of coronary calcifications is also related to coronary artery disease. Cardiac autonomic neuropathy, which significantly impairs myocardial function and blood flow, also enhances cardiac abnormalities. Also hypoglycemic episodes are considered to adversely influence cardiac performance. Intensive insulin therapy has been demonstrated to reduce the occurrence and progression of both micro- and macrovascular complications. This has been evidenced by the Diabetes Control and Complications Trial (DCCT) / Epidemiology of Diabetes Interventions and Complications (EDIC) study. The concept of a metabolic memory emerged based on the results of the study, which established that intensified insulin therapy is the standard of treatment of Type 1 diabetes. Future therapies may also include glucagon-like peptide (GLP)-based treatment therapies. Pilot studies with GLP-1-analogues have been shown to reduce insulin requirements.

Background: This trial compared the long-term safety and efficacy of the basal insulin preparations, insulin detemir and NPH insulin, in basal-bolus therapy for patients with type 1 diabetes. Methods: This multinational open, parallel-group trial randomized patients to receive insulin detemir or NPH insulin twice daily in addition to mealtime human soluble insulin. Doses were titrated towards predefined glycemic targets. After an initial 6-month treatment period, patients were invited to participate in a 6-month extension period. A total of 289 from 421 elected to continue in the trial, of which 252 completed. Results: Glycemic control as assessed by hemoglobin A_1c (insulin detemir, 7.88%; NPH insulin, 7.78%; difference not significant) and fasting plasma glucose (insulin detemir, 10.1 mmol/L; NPH insulin, 9.84 mmol/L; difference not significant) was similar in both treatment groups at end point, with hemoglobin A_1c little changed from baseline and fasting plasma glucose slightly decreased. There was some evidence for a risk reduction for hypoglycemia in association with insulin detemir, although this was not statistically significant (relative risk overall hypoglycemia, 0.71, P = 0.139; relative risk nocturnal hypoglycemia, 0.71, P = 0.067), and hypoglycemic events were fewer in each of the 12 months. There was a significant treatment difference with regard to weight outcome; NPH insulin was associated with weight gain (1.4 kg), but there was no mean weight gain (-0.3 kg) in the insulin detemir cohort (baseline-adjusted between-group difference at 12 months, 1.66 kg, P = 0.002). There were no obvious between-group differences in other safety parameters. Conclusions: Glycemic control is maintained with insulin detemir during long-term treatment. At equivalent glycemic control to NPH insulin, insulin detemir is associated with a lack of weight gain and a trend towards a reduced risk of nocturnal hypoglycemia when used in basal-bolus therapy with mealtime soluble human insulin.

OBJECTIVE We evaluated the specific causes of death and their associated risk factors in a contemporary cohort of patients with type 2 diabetes and atherosclerotic cardiovascular disease (ASCVD). RESEARCH DESIGN AND METHODS We used data from the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS) study (n = 14,671), a cardiovascular (CV) safety trial adding sitagliptin versus placebo to usual care in patients with type 2 diabetes and ASCVD (median follow-up 3 years). An independent committee blinded to treatment assignment adjudicated each cause of death. Cox proportional hazards models were used to identify risk factors associated with each outcome. RESULTS A total of 1,084 deaths were adjudicated as the following: 530 CV (1.2/100 patient-years [PY], 49% of deaths), 338 non-CV (0.77/100 PY, 31% of deaths), and 216 unknown (0.49/100 PY, 20% of deaths). The most common CV death was sudden death (n = 145, 27% of CV death) followed by acute myocardial infarction (MI)/stroke (n = 113 [MI n = 48, stroke n = 65], 21% of CV death) and heart failure (HF) (n = 63, 12% of CV death). The most common non-CV death was malignancy (n = 154, 46% of non-CV death). The risk of specific CV death subcategories was lower among patients with no baseline history of HF, including sudden death (hazard ratio [HR] 0.4; P = 0.0036), MI/stroke death (HR 0.47; P = 0.049), and HF death (HR 0.29; P = 0.0057). CONCLUSIONS In this analysis of a contemporary cohort of patients with diabetes and ASCVD, sudden death was the most common subcategory of CV death. HF prevention may represent an avenue to reduce the risk of specific CV death subcategories.