Increased aortic stiffness in glycogenosis type 2 (Pompe's disease)

Background: Pompe's disease, also known as acid maltase deficiency or glycogen storage disease type II, is an autosomal recessive disorder in which deficient activity of the enzyme acid α-glucosidase causes intra-lysosomal accumulation of glycogen in muscle and other tissues. The current study was designed to assess aortic stiffness index (β), as a characteristic of aortic elasticity during transthoracic echocardiography in patients with Pompe's disease. Methods: A total of 17 patients (age 44 ± 8 years, 5 males) with Pompe's disease were studied. Their results were compared to 17 age- and gender-matched controls. In all patients, the ascending aorta was recorded with M-mode echocardiography. β was calculated as ln(SBP/DBP)/[(SD-DD)/DD], where SBP and DBP are the systolic and diastolic blood pressures, SD and DD are the systolic and diastolic aortic diameters, and 'ln' is the natural logarithm. Results: Diastolic aortic diameter was 27.4 ± 2.4 mm in Pompe patients and 25.6 ± 2.7 mm in controls (P < 0.05). Systolic aortic diameters did not differ between the groups (29.4 ± 2.5 mm vs 28.3 ± 2.4 mm, P = ns). Aortic stiffness index (β) was increased in Pompe patients compared to controls (14.6 ± 10.1 vs 5.1 ± 2.6, P < 0.001). Conclusions: The results of this study indicate that aortic stiffness is increased in patients with Pompe's disease. This may be due to glycogen storage in the vessel wall causing reduced vascular elasticity.