Baseline fasting plasma insulin levels predict risk for major adverse cardiovascular events among patients with diabetes and high-risk vascular disease: Insights from the ACCELERATE trial

Background: Despite optimal treatment, type II diabetes mellitus remains associated with an increased risk for future cardiovascular events. We sought to determine the association between baseline fasting plasma insulin levels and major adverse cardiovascular outcomes in patients with type II diabetes mellitus and high-risk vascular disease enrolled in the ACCELERATE (Assessment of Clinical Effects of Cholesteryl Ester Transfer Protein Inhibition with Evacetrapib in Patients at a High Risk for Vascular Outcomes) trial. Methods: We included all patients with type II diabetes mellitus who had a central laboratory measured fasting plasma insulin level drawn at baseline as part of the study protocol. Hazard ratios were generated for the risk of major adverse cardiovascular outcomes (composite of cardiovascular death, non-fatal myocardial infarction, stroke, hospitalization for unstable angina and coronary revascularization) with increasing quartile of baseline fasting plasma insulin level. We then performed a multivariable regression adjusting for significant baseline characteristics. Results: Among 12,092 patients in ACCELERATE, 2042 patients with type II diabetes mellitus had a baseline fasting plasma insulin level drawn. Median follow-up was 28 months. The study population had a mean age of 66.6 years, 79.2% male and 96.2% had established coronary artery disease. During follow-up, major adverse cardiovascular outcomes occurred in 238 patients (11.6%); of these events, 177 were coronary revascularization (8.7%). We observed a statistically significant relationship between rates of revascularization and rising quartile of baseline fasting plasma insulin level which was not noted for the other individual components of major adverse cardiovascular outcomes. Patients with type II diabetes mellitus who underwent revascularization were noted to have significantly higher baseline fasting plasma insulin levels (27.7 vs 21.4 mU/L, p-value = 0.009) although baseline haemoglobin A1c (6.63% vs 6.55%), body mass index (31.5 vs 31.1 kg/m2) and medical therapy were otherwise similar to the group not undergoing revascularization. Following multivariable regression adjusting for significant characteristics including exposure to evacetrapib, the log of baseline fasting plasma insulin level was found to be an independent predictor for major adverse cardiovascular outcomes (hazard ratio = 1.36, 95% confidence interval = 1.09–1.69, p-value = 0.007); this was driven by need for future revascularization (hazard ratio = 1.56, 95% confidence interval = 1.21–2.00, p-value = 0.001). Conclusion: In a contemporary population of patients with type II diabetes mellitus and high-risk vascular disease on optimum medical therapy, baseline hyperinsulinaemia was an independent predictor for major adverse cardiovascular outcomes and need of future coronary revascularization. These results suggest a pathophysiological link between hyperinsulinaemia and progression of atherosclerotic vascular disease among diabetics.

Raised plasma insulin level and homeostasis model assessment (HOMA) score in cerebral malaria: evidence for insulin resistance and marker of virulence.

To study the glycaemic profile of patients with severe malaria (SM). For this purpose, 110 SM patients were recruited. Pre-treatment random blood glucose and plasma insulin were measured in a subset of donors. An ex-vivo experiment was developed for estimation of glucose consumption by parasitized erythrocytes. Hyperglycaemia was frequent in SM but more commonly associated with cerebral malaria (CM), while hyperinsulinaemia was recognized in severe-malarial-hypotension (median, 25 %-75 %, 188.2, 93.8-336.8 pmol/L). The plasma insulin level was positively correlated with age (CC = 0.457, p < 0.001) and negatively with parasitaemia (CC = -0.368, p = 0.045). Importantly, fatal-CM was associated with hyperglycaemia (12.22, 6.5-14.6 mmol/L), hyperinsulinaemia (141.0, 54.0-186.8 pmol/L) and elevated homeostasis model assessment (HOMA) values. However, there was a trend of higher glucose consumption by parasites in CM compared with that in uncomplicated malaria (UM). Hyperglycaemia, hyperinsulinaemia and elevated HOMA are evidence for insulin resistance and possibly pancreatic B-cell dysfunction in fatal-CM.

Metabolic Implications of Hepatitis C Virus Infection and it's Correlation to Steatohepatitis in Chronic Hepatitis C Patients with and without Type 2 Diabetes

Background Chronic hepatitis C virus (HCV) infection is not a simple viral infection; it has many metabolic and autoimmune complications. Objective To investigate the impacts of chronic HCV infection on glucose and lipid metabolism and its correlation-if any-with body mass index (BMI) and hepatosteatosis in chronic HCV patients. Patients and Methods One hundred and three (103) chronic HCV patients were involved in this study. After blood sugar testing patients were classified into three groups; Group I: 68 chronic HCV patients with type 2 diabetes. Group II: 35 chronic HCV patients without Type 2 Diabetes and Group III: 25 patients with Type 2 Diabetes as a control group. With informed written consents and approval from Ain Shams medical ethics committee, all groups were subjected to the following: full history taking, thorough clinical examination, calculation of BMI, and measurement of the waist/hip ratio were done. Assessment of fasting plasma insulin level was done by the immune-enzymatic method. Assessment of the insulin resistance state was done by Homeostatic Model Assessment (HOMA-IR). Detection of anti-HCV was done by the 3rd generation ELISA test and confirmed by qualitative polymerase chain reaction (PCR). Results Diabetic and non diabetic chronic HCV patients were found to have significantly higher fasting plasma insulin levels and insulin resistance states than the control group. This insulin resistance was not due to increased body mass index as there was a non significant difference in BMI between all the studied groups. Positive correlations were found between plasma insulin level, liver enzymes and steatohepatitis in HCV patients whether they were diabetic or not. No correlation was found between BMI and plasma insulin level in group II patients (HCV only). Conclusion Chronic HCV infection may be regarded as an independent risk factor for the development of insulin resistance and type 2 diabetes. HCV induces insulin resistance; the key step for glucose intolerance, and virus C induced steatohepatitis therefore leading to faster progression to cirrhosis. The impacts of chronic HCV infection on glucose and lipid metabolism should be recognized in clinical care centers and addressed in future studies.