Influence of glycemic control on gain in VO2 peak, in patients with type 2 diabetes enrolled in cardiac rehabilitation after an acute coronary syndrome. The prospective DARE study.

BACKGROUND: Gain in VO2 peak after cardiac rehabilitation (CR) following an acute coronary syndrome (ACS), is associated with reduced mortality and morbidity. We have previously shown in CR, that gain in VO2 peak is reduced in Type 2 diabetic patients and that response to CR is impaired by hyperglycemia. METHODS: We set up a prospective multicenter study (DARE) whose primary objective was to determine whether good glycemic control during CR may improve the gain in VO2 peak. Sixty four type 2 diabetic patients, referred to CR after a recent ACS, were randomized to insulin intensive therapy or a control group with continuation of the pre-CR antidiabetic treatment. The primary objective was to study the effect of glycemic control during CR on the improvement of peak VO2 by comparing first the 2 treatment groups (insulin intensive vs. control) and second, 2 pre-specified glycemic control groups according to the final fructosamine level (below and above the median). RESULTS: At the end of the CR program, the gain in VO2 peak and the final fructosamine level (assessing glycemic level during CR) were not different between the 2 treatment groups. However, patients who had final fructosamine level below the median value, assessing good glycemic control during CR, showed significantly higher gain in VO2 peak (3.5 ± 2.4 vs. 1.7 ± 2.4 ml/kg/min,p = 0.014) and ventilatory threshold (2.7 ± 2.5 vs. 1.2 ± 1.9 ml/kg/min,p = 0.04) and a higher proportion of good CR-responders (relative gain in VO2 peak ≥ 16 %): 66 % vs. 36 %, p = 0.011. In multivariate analysis, gain in VO2 peak was associated with final fructosamine level (p = 0.010) but not with age, gender, duration of diabetes, type of ACS, insulin treatment or basal fructosamine. CONCLUSIONS: The DARE study shows that, in type 2 diabetes, good glycemic control during CR is an independent factor associated with gain in VO2 peak. This emphasizes the need for good glycemic control in CR for type 2 diabetic patients. TRIAL REGISTRATION: Trial registered as NCT00354237 (19 July 2006).

Detection of glucose metabolism disorders in coronary patients enrolled in cardiac rehabilitation: Is glycated haemoglobin useful? Data from the prospective REHABDIAB study.

Introduction Diabetes and pre-diabetes are highly prevalent in patients with a history of acute coronary syndrome. This is why screening for glucose metabolism disorders is recommended in patients following an acute coronary syndrome. The aim of our study was to determine whether glycated haemoglobin alone compared with the oral glucose tolerance test could allow effective screening for glucose metabolism disorders in acute coronary syndrome patients undergoing cardiac rehabilitation. Patients and methods Among 347 patients with a recent history of acute coronary syndrome enrolled in our cardiac rehabilitation centre, 267 patients without previously known diabetes were recruited for this prospective study with performance of both oral glucose tolerance test and glycated haemoglobin measurement. The patients were divided into three groups: newly diagnosed diabetes mellitus, pre-diabetes and normoglycaemia according to the oral glucose tolerance test and glycated haemoglobin results. The results obtained with glycated haemoglobin were compared with those obtained with the oral glucose tolerance test, considered as the reference. Results For the diagnosis of diabetes, glycated haemoglobin had a sensitivity of 72% and a specificity of 100%. Positive and negative predictive values were high at 100% and 96%, respectively. However, for the diagnosis of pre-diabetes the sensitivity of glycated haemoglobin was low at 64% as were the specificity (53%) and the positive predictive values (37%). Glycated haemoglobin overdiagnosed pre-diabetes (52% vs 30%, p < 0.0001). For the diagnosis of normoglycaemia, the sensitivity of glycated haemoglobin was also low (48%). Conclusion According to our study, glycated haemoglobin has low sensitivity and specificity for the detection of pre-diabetes in patients with coronary disease enrolled in cardiac rehabilitation, and glycated haemoglobin over-diagnoses pre-diabetes in comparison with the oral glucose tolerance test.