Protocol of a Prospective Observational Study on the Relationship Between Glucose Fluctuation and Cardiovascular Events in Patients with Type 2 Diabetes

IntroductionA recent study demonstrated that large glucose fluctuations were associated with an increased incidence of cardiovascular disease (CVD) in patients with type 2 diabetes mellitus (T2DM) and acute myocardial infarction. However, it is unknown whether glucose fluctuations are related to the incidence of CVD or the progression of atherosclerosis in patients with T2DM with no apparent history of CVD. In this protocol, we will be investigating the relationships of glucose fluctuations evaluated by continuous glucose monitoring (CGM) to the incidence of composite cardiovascular events and the progression of atherosclerosis in patients with T2DM who had no apparent history of CVD.MethodsThis is a prospective, multicenter, 5-year follow-up observational study. Between April 2018 and October 2019, 1000 participants are expected to be recruited at 34 medical institutions. CGM using FreeStyle Libre Pro is useful for evaluating glucose fluctuations by continuously monitoring glucose levels in interstitial fluid for up to 14 days. The primary study outcome is the relationship between fluctuations in glucose levels evaluated by CGM and the incidence of composite cardiovascular events. Secondary outcomes include the relationships of fluctuations in glucose levels evaluated by CGM to changes in carotid intima media thickness evaluated by echography or grayscale median (an index of tissue characteristics of the carotid wall), brachial–ankle pulse wave velocity, development or progression of diabetic retinopathy or nephropathy, quality-of-life-related diabetes therapy, quality of sleep, development of dementia, and autonomic nerve function.Planned OutcomeThis protocol is designed to investigate the relationship between glucose fluctuations and the incidence of composite cardiovascular events. We completed the registration of 1000 participants in March 2019. Thus, results will be available in 2024. We expect that evaluating glucose fluctuations will aid the identification of patients with a high probability of developing CVD.Trial RegistrationClinicalTrials.gov identifier, UMIN000032325

Associations between continuous glucose monitoring-derived metrics and diabetic retinopathy and albuminuria in patients with type 2 diabetes

Introduction Preventing the development and progression of diabetic microvascular complications through optimal blood glucose control remains an important challenge. Whether metrics based on continuous glucose monitoring are useful for the management of diabetic microvascular complications is not entirely clear.Research design and methods This is an exploratory analysis of an ongoing prospective, multicenter, 5-year follow-up observational study. Study participants included 999 outpatients with type 2 diabetes who underwent continuous glucose monitoring at baseline. Associations between continuous glucose monitoring-derived metrics and the severity of diabetic retinopathy or albuminuria were investigated using multivariable proportional odds models.Results The overall prevalence of diabetic retinopathy was 22.2%. Multivariate analysis with proportional odds models demonstrated that continuous glucose monitoring-derived metrics related to intraday and interday glucose variability are significantly associated with the severity of diabetic retinopathy, even after adjusting for various possible risk factors. However, significant relationships were not observed after adjusting for hemoglobin A1c (HbA1c) levels. The prevalence of microalbuminuria and macroalbuminuria was 20.3% and 6.7%, respectively. Similarly, multivariate analysis demonstrated that those metrics are significantly associated with the severity of albuminuria. These relationships remained significant even after further adjusting for HbA1c levels.Conclusions Continuous glucose monitoring-derived metrics related to intraday and interday glucose variability are significantly associated with the severity of diabetic retinopathy or albuminuria in patients with type 2 diabetes. Thus, evaluating these metrics might possibly be useful for risk assessment of diabetic microvascular complications.Trial registration number UMIN000032325

Effects of peroxisome proliferator-activated receptor-α and -γ agonist, JTT-501, on diabetic complications in Zucker diabetic fatty rats

1. This study has investigated the effects of JTT-501, a peroxisome proliferator-activated receptor (PPAR)-α and PPAR-γ agonist, on the pathogenesis of diabetic complications in the Zucker diabetic fatty (ZDF) rats, a model of type 2 diabetes. Comparison is made with troglitazone, a PPAR-γ agonist. 2. The ZDF rats exhibited hyperglycaemia and hyperlipidaemia, and developed diabetic complications such as cataract, nephropathy, and neuropathy. Treatment with JTT-501 from the prediabetic stage controlled glycaemia and lipidaemia, and prevented the development of diabetic complications. Troglitazone was less effective in controlling serum cholesterol and neuropathy. 3. ZDF rats developed diabetic osteopenia with reduced bone turnover, and this was prevented by JTT-501 and troglitazone, possibly mediated by increased bone turnover and bone formation. 4. Since JTT-501 controlled glycaemia and lipidaemia in ZDF rats and prevented several diabetic complications, it is suggested that treatment with JTT-501, which activates both PPAR-α and PPAR-γ, could provide a valuable therapeutic approach against diabetic complications in type 2 diabetes