To evaluate the effects of uncooked cornstarch (UCS) on metabolic control, growth, and complications of pubertal and postpubertal subjects with type 1a glycogen storage disease, we studied 26 subjects (16 males), mean age 20.8+/-5.1 years, in whom continuous glucose therapy with cornstarch began at 6.8+/-4.3 years. At the time of this analysis, subjects had received cornstarch for 14.1+/-3.5 years. Metabolic control was determined with subjects receiving their usual home dietary regimens: 4.1+/-1.3 doses of UCS in the day (9.7+/-2.6 g/h) and 2.0+/-0.4 doses at night (11.7+/-2.2 g/h). Mean height standard deviation score (SDS) was -1.2+/-1.3, significantly less than the mean target height of -0.2+/-1.1 ( P<0.01). Mean weight SDS was 0.5+/-1.9 and body mass index SDS was 0.7+/-1.0. Of all subjects, 50% had at least one focal hepatic lesion consistent with an adenoma. Urinary albumin excretion was increased (>20 micro g/min) in 31% of subjects; two subjects had clinical albuminuria (>300 mg per 24 h), but none has progressed to chronic renal insufficiency. Of 26 subjects, 13 (50%) had anemia. All of the complications were associated with evidence of suboptimal metabolic control, whereas subjects with no evidence of any long-term complications had near normal blood lactate and total CO(2) concentrations.
Conclusion: The achievement of optimal biochemical control of glycogen storage disease type 1a continues to be a challenge, but is attainable by meticulous adherence to an individualized dietary regimen based on the results of periodic metabolic evaluation and home blood glucose monitoring. Minimizing the metabolic abnormalities of the disease may decrease the risk of long-term complications.