In cases where osteopenia progresses with age, bone mineral density in the ribs is typically more severe than in the vertebrae. In some cases bone mineral density T-score will drop below -2.5, indicating osteoporosis. There is some evidence that osteopenia may be connected with associated kidney abnormalities in GSD I, particularly glomular hyperfiltration. The condition also seems responsive to calcium supplementation. In many cases bone mineral density can increase and return to the normal range given proper metabolic control and calcium supplementation alone, reversing osteopenia. Kidney effects
The kidneys are usually 10 to 20% enlarged with stored glycogen. In adults with GSD I, chronic glomerular damage similar to diabetic nephropathy may lead to kidney failure. GSD I may present with various kidney complications. Renal tubular abnormalities related to hyperlactatemia are seen early in life, likely because prolonged lactic acidosis is more likely to occur in childhood. This will often present as Fanconi syndrome with multiple derangements of renal tubular reabsorption, including tubular acidosis with bicarbonate and phosphate wasting. These tubular abnormalities in GSD I are typically detected and monitored by urinary calcium. Long term these derangements can exacerbate uric acid nephropathy, otherwise driven by hyperlactatemia. In adolescence and beyond, glomerular disease may independently develop, initially presenting as glomerular hyperfiltration indicated by elevated urinary eGFR. Splenomegaly
Enlargement of the spleen (splenomegaly) is common in GSD I and has two primary causes.
For mild acidosis, an effective fluid is 10% dextrose in ½ normal saline with 20 mEq/L KCl, but if acidosis is severe, 75–100 mEq/L NaHCO3 and 20 mEq/L of K acetate can be substituted for the NaCl and KCl. Metabolic control
Metabolic control often diminishes during and after puberty, as a result of a patient outgrowing their dietary treatment plan. Prognosis
Without adequate metabolic treatment, patients with GSD I have died in infancy or childhood of overwhelming hypoglycemia and acidosis. Those who survived were stunted in physical growth and delayed in puberty because of chronically low insulin levels. Intellectual disability resulting from recurrent, severe hypoglycemia is considered preventable with appropriate treatment. Liver complications have been serious in some patients. Adenomas of the liver can develop in the second decade or later, with a small chance of later malignant transformation to hepatoma or hepatic carcinomas (detectable by  alpha-fetoprotein screening). Several children with advanced hepatic complications have improved after liver transplantation. Additional problems reported in adolescents and adults with GSD I have included hyperuricemic gout, pancreatitis, and chronic kidney failure. Despite hyperlipidemia, atherosclerotic complications are uncommon. With diagnosis before serious harm occurs, prompt reversal of acidotic episodes, and appropriate long-term treatment, most children will be healthy. With exceptions and qualifications, adult health and life span may also be fairly good, although lack of effective treatment before the mid-1970s means information on long-term efficacy is limited. Epidemiology
In the United States, GSD I has an incidence of approximately 1 in 50,000 to 100,000 births.