Effects of acute hyperglycaemia on cardiac function: an echocardiographic study of monozygotic twins

Cardiovascular impairment in children, adolescents, and young adults with type 1 diabetes mellitus (T1DM)

Left ventricular (LV) function was assessed in 42 patients (mean age +/- SD, 18.45 +/- 3.76 years; 17 males) with type I diabetes mellitus (T1DM; mean duration 9.89 years) and in 43 healthy controls (mean age +/- SD, 18.27 +/- 3.36 years; 18 males). Systolic, diastolic cardiac function and LV dimensions were assessed using M-mode and Doppler echocardiography. Neural autonomic function was assessed by measuring RR variation during deep breathing, Valsava maneuver, 30/15 ratio, and blood pressure response to standing. Fractional shortening, peak velocity of early ventricular filling (E wave), peak velocity of LV filling (A wave), E/A ratio, deceleration time, isovolumic relaxation time, LV dimensions (interventricular septum, posterior wall thickness, end diastolic diameter [EDD] and systolic diameter [ESD]) were all comparable between patients with T1DM and controls. However, in 11 T1DM patients with microalbuminuria and/or retinopathy, EDD, ESD, E/A ratio, and E wave were all lower (p = 0.0011, p = 0.019, p = 0.0011, and p = 0.030, respectively) while, A wave, heart rate, and diastolic blood pressure were all higher (p = 0.008, p = 0.0024 and p = 0.004, respectively) compared to matched for age and sex controls. Furthermore, in six of the 11 T1DM patients with microangiopathy who had E/A <1.12 (<2 SD of the control mean), significant and marginally significant correlations were found between E/A ratio and the duration of the disease as well as the mean HbA1c of the last year (r = -0.38, p = 0.011 and r = -0.287, p = 0.064, respectively). In conclusion, it has been found that impairment of diastolic, but not systolic, LV function can be detected early in young patients with T1DM and microangiopathy.

Impaired glucose metabolism predicts mortality after a myocardial infarction

Diabetes is a risk factor for increased mortality after a myocardial infarction. Whether this applies for patients with hyperglycemia during the acute phase of a acute myocardial infarction is unclear. Therefore we determined the relation between admission plasma glucose level and mortality in a prospectively collected series of 336 consecutive AMI patients. Patients were divided in four groups based on WHO criteria for glucose levels: I: <5.6 mmol/l, II: 5.6--8.3 mmol/l, III: 8.4--11.0 mmol/l, IV: 11.1 mmol/l. The average age was 68+/-11 years with a peak CK of 1378+/-160 U/l, 34% were anterior wall AMIs and 52% were treated with thrombolysis. All patients had a long-term follow-up control at an average of 14.2 months. One year mortality rate was 19.3% and rose to 44% in patients with glucose levels >11.1 mmol/l. The mortality was higher in diabetic patients than in non-diabetic patients (40 vs. 16%; P<0.05). Multivariate analysis revealed an independent effect of glucose level on mortality. In conclusions, our study in an unselected patient population demonstrates that admission plasma glucose level independently predicts 1 year mortality even in absence of diagnosed diabetes mellitus. Further studies evaluating the effect of acute insulin intervention in reducing mortality are warranted.