Practice Update: Diabetes

EDITOR’S PICKS 7

Higher Two-Hour Post-Load Glucose Predicts Risk for Cardiovascular Events in CAD Diabetes Care

Take-home message • The authors of this study sought to characterize the prognostic value of three screening tools for diabetes—fasting glucose (FPG), 2-hour post-load glucose (2h-PG) from an oral glucose tolerance test, and HbA1c—in a population of patients with coronary artery disease (CAD). Researchers screened 4004 patients with CAD and no history of diabetes with all three screening tools. After 2 years, 246 patients (6.5%) experienced the primary outcome, a composite of cardiovascular mortality, nonfatal myocardial infarction, stroke, and hospitalization for heart failure. The 2h-PG test was the only screening tool that correlated with the primary outcome. Both a HbA1c of 5.7% to 6.5% and a 2h-PG of 7.8 to 11.0 mmol/L independently predicted the risk of diabetes during follow-up. • The authors conclude that, in patients with CAD, 2h-PG can provide valuable prognostic information on the risk of future cardiovascular events. In addition, increases in HbA1c and 2h-PG can signal a greater risk for diabetes.

glycemic parameters was available in 3,775 patients (94.3%), of whom246 (6.5%) experienced the primary end point. Neither FPG nor HbA1c pre- dicted the primary outcome, whereas the 2h-PG, dichotomized as <7.8 vs. ≥7.8mmol/L, was a signif- icant predictor (hazard ratio 1.38, 95% CI 1.07-1.78; P = 0.01). During follow-up, diabetes developed in 78 of the 2,609 patients (3.0%) without diabetes at baseline. A FPG between 6.1 and 6.9 mmol/L did not predict incident diabetes, whereas HbA1c 5.7-6.5% and 2h-PG 7.8-11.0mmol/L were both sig- nificant independent predictors. CONCLUSIONS The 2h-PG, in contrast to FPG and HbA1c, provides significant prognostic informa- tion regarding cardiovascular events in patients with CAD. Furthermore, elevated 2h-PG and HbA1c are significant prognostic indicators of an increased risk of incident diabetes. The prognostic value of fasting plasma glu- cose, two-hour postload glucose, and HbA1c in patients with coronary artery disease: a report from EUROASPIRE IV: a Survey from the Euro- pean Society of Cardiology Diabetes Care 2017 Jun 21;[EPub Ahead of Print], B Shahim, D De Bacquer, G De Backer, et al. profiles: is the OGTT a valid predictor of postprandial hyperglycaemia and vice versa? Diabetes Obes Metab 2009;11(3):213-222. 3. Cavalot F, Pagliarino A, Valle M, et al. Postprandial blood glucose predicts cardiovascular events and all-cause mortality in type 2 diabetes in a 14-year follow-up: lessons from the San Luigi Gonzaga Diabetes Study. Diabetes Care 2011;34(10):2237-2243. 4. Takao T, Suka M, Yanagisawa H, Iwamoto Y. The impact of postprandial hyperglycemia at clinic visits on the incidence of cardiovascular events and all-cause mortality in patients with type 2 diabetes [published online December 15, 2016]. J Diabetes Investig doi: 10.1111/jdi.12610. 5. Standl E, Schnell O, Ceriello A. Postprandial hyperglycemia and glycemic variability: should we care? Diabetes Care 2011;34(Suppl 2):S120–S127. 6. Ceriello A. Point: postprandial glucose levels are a clinically important treatment target. Diabetes Care 2010;33(8):1905-1907. Dr Ceriello is P.I. of the Research Department on Diabetes and CVD, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; and Head Diabetes Department, IRCCS MultiMedica, Milan, Italy. www.practiceupdate.com/c/55020

HbA1c were used to screen 4,004 CAD patients without a history of diabetes (age 18-80 years) for dysglycemia. The prognostic value of these tests was studied after 2 years of follow-up. The primary end point included cardiovascular mor- tality, nonfatal myocardial infarction, stroke, or hospitalization for heart failure and a secondary end point of incident diabetes. RESULTS Complete information including all three

Abstract OBJECTIVES Three tests are recommended for identifying dysglycemia: fasting glucose (FPG), 2-h postload glucose (2h-PG) from an oral glucose tolerance test (OGTT), and glycated hemoglobin A1c (HbA1c). This study explored the prognostic value of these screening tests in patients with coronary artery disease (CAD). RESEARCH DESIGN AND METHODS FPG, 2h-PG, and COMMENT By Antonio Ceriello MD, MPH T his study confirms, in a large cohort of people with CAD and without diabetes, the role of 2-hour glyce- mia during an oral glucose tolerance test (OGTT) as an independent risk factor for a future cardiovascular event. What can be the clinical impact of this new evidence? Some epidemiological evi- dence in the past led to the hypothesis that postprandial glycemia (PPG) should be considered an independent risk fac- tor for CVD, 1 but that OGTT could not be considered equivalent to a meal. This con- cern was overcome by the demonstration of the existence of a direct correlation, at any time, between the values of glycemia during OGTT and those during standard meals and home blood glucose monitor- ing in individuals with or without impaired glucose tolerance or overt diabetes. 2 Furthermore, the San Luigi Gonzaga Dia- betes Study confirmed, after a very long follow-up of people with type 2 diabetes,

that 2-hour PPG is an independent pre- dictor of CVD 3 —evidence more recently confirmed. 4 At the same time, results from specific intervention trials are inconclu- sive. 5 In this respect, however, it should be noted that perhaps no trial has yet been well-designed specifically for this purpose. 6 Several, if not almost all, current guide- lines suggest controlling PPG for the optimal management of diabetes and its complications; therefore, in my opinion, this study is further stressing the need for controlling PPG in people with diabetes to reduce the risk of CVD. References 1. Ceriello A, Hanefeld M, Leiter L, et al. Postprandial glucose regulation and diabetic complications. Arch Intern Med 2004;164(19):2090-2095. 2. Meier JJ, Baller B, Menge BA, et al. Excess glycaemic excursions after an oral glucose tolerance test compared with a mixed meal challenge and self-measured home glucose

VOL. 1 • NO. 2 • 2017