Young adults with GSD-1 need nocturnal glucose therapy to prevent hypoglycemia and associated biochemical abnormalities. The purpose of this study was to compare divided doses of UCS during the night with a single dose at bedtime. We studied 7 GSD-1 patients (4m,3f), mean age 19.5±1.1 (SD) y, height and weight SDS -1.9±1.0 and -.8±.9, respectively. All had received continuous glucose therapy for 16.7±1.9 y and currently consumed UCS at 2-5 h intervals during the day and at 5 h intervals at night. In random order, on consecutive nights subjects received either divided doses of UCS, 45-60 g, at 2100 and 0200 h (9-12 g/h;.9±.2 g/kg/h) or one dose, 90-120 g, at 2100 h. Otherwise, dietary regimens were identical. Plasma glucose (PG), serum insulin (IRI), free fatty acids (FFA), blood lactate(Lact) were measured at 30-60 min intervals for 10 h; venous pH and bicarbonate were measured at 0700 h. Baseline PG (88±20 vs. 90±21 [SD] mg/dL), IRI (35±24 vs. 31±16 μU/mL). Lact(2.2±.7 vs. 2.5±1.8 mmol/L), and FFA (1.01±.84 vs..91±.85 mmol/L) were similar on divided vs. single dose regimens, respectively. Table shows m±SD time-averaged values and area under curve (AUC) from 0-6 h. *p<.05 Compared to divided doses, after a single dose of UCS (1.76±.4 g/kg) at 2100 h, mean PG was significantly higher (P<.05) at 2-5 h and lower at 7-9 h. PG was ≥70 mg/dL for 10 h in only 2/7 subjects and for 7, 8, and 8.5 h in 3 others; hypoglycemia (PG≤40 mg/dL) occurred at 6.5-9.5 h in 4 subjects. On divided doses, 6 had mean PG 84±14 (64-103) mg/dL and Lact 2.7±.9(1.7-3.8) mmol/L at 10 h; hypoglycemia occurred in one subject at 6 h. Because inter-individual responses to UCS vary, the optimal dose and schedule of UCS administration to prevent nighttime hypoglycemia and hyperlactacidemia must be determined empirically for each patient.

Table 1
Full size table