Blood lipids and endothelial function in glycogen storage disease type III.

We have assessed early indicators of arterial disease in patients with glycogen storage disease type III (GSD III; McKusick 232400), investigating the plasma lipid and lipoprotein profile and endothelial function. Eleven patients, aged 10-39 years, were recruited together with age-, sex- and smoking status-matched controls. Brachial artery responses were assessed by high-resolution ultrasonographic measurement of the diameter of the brachial artery at baseline, after reactive hyperaemia and in response to sublingual glyceryl trinitrate (GTN). The means of plasma cholesterol (total and HDL and LDL subfractions), triglycerides, apo-A1, apo-B, Lp(a) and the atherogenic index were similar in both groups. Cardiac troponin I was below the lower limits of detection (< 0.03 g/L) in all subjects. The GSD III patients had similar body mass index (BMI) and brachial artery diameter to the control group (BMI 22.6 +/- 5.6 vs 22.3 +/- 5 kg/m2; brachial artery diameter 3.4 +/- 0.5 vs 3 +/- 0.7 mm). When compared to the baseline diameter, the maximal flow-mediated dilatation of the brachial artery after reactive hyperaemia was 9.3% +/- 2.1% (mean +/- SD) in the GSD III patients and 6.5% +/- 3.5% in the control group, a difference of 1.8% (95% CI 0.07% to 5.5%). The maximal dilatation of the brachial artery after GTN administration was 18.3% +/- 6.4% in the GSD III patients and 17.9% +/- 6.5% in the control group, a difference of 0.4% (95% CI-6.9% to 7.7%). In conclusion, we found no evidence of abnormal plasma lipid and lipoprotein profile or endothelial dysfunction in patients with GSD III. They are unlikely to be at increased risk of premature atherosclerosis.