Asymptomatic Congenital Hyperinsulinism due to a Glucokinase-Activating Mutation, Treated as Adrenal Insufficiency for Twelve Years

Table 2

Results of examinations at first visit.

(a) Glucose diurnal rhythm.

Clock time	7:30	10:00	11:30	14:00	17:30	20:00	23:00
Plasma glucose
(mg/dL)	57	59	62	64	61	84	64
(mmol/L)	3.1	3.2	3.4	3.5	3.3	4.6	3.5

(b) OGTT (oral glucose tolerance test) performed with 75 g glucose.

Time (min)	0	30	60	90	120
Plasma glucose
(mg/dL)	62	119	120	84	75
(mmol/L)	3.4	6.6	6.6	4.6	4.1
Insulin (μU/mL)	2.0	24.3	45.5	38	17.9

(c) Plasma glucose, c-peptide, glucagon, cortisol, and ACTH responses to insulin tolerance test (0.05 U/kg BW of Humulin R).

Time (min)	0	15	30	45	60	75	90	120
Plasma glucose
(mg/dL)	53	36	30	48	55	53	52	53
(mmol/L)	2.9	2.0	1.6	2.6	3.0	2.9	2.8	2.9
C-peptide (ng/mL)	1.2	0.7	0.5	0.5	0.5	0.4	0.4	0.5
Glucagon (pg/mL)	213	230	297	232	207	174		174
ACTH (pg/mL)	40	32.8	41.3	42.4	29.5	24.4	17.2	20.1
Cortisol (μg/dL)	6.6	13.2	12	15	12.8	11.9	11.2	8.4

Normal values.
Glucagon 70–174 (pg/mL), ACTH: 7.2–63.3 (pg/mL), and cortisol: 8.0–18.0 (μg/dL).
Interpretation of results.
The normal peak ACTH value poststimulation should be an increment no less than 50 pg/mL at 60′. Baseline cortisol values <5 µg/dL are diagnostic of adrenal insufficiency. The normal peak cortisol value poststimulation should be an increment no less than 7 µg/dL and a maximal level >20 µg/dL at 30′.

(d) Circadian variation in cortisol.

Clock time	8:00	17:00	23:00
ACTH (pg/mL)	23.8	14.3	14.5
Cortisol (μg/dL)	6.9	2.0	>1.0

(e) Cortisol response to the rapid ACTH stimulation test (250 μg, intravenous bolus).

Time (min)	0	30	60
Cortisol (μg/dL)	7.9	16.5	18.4

Interpretation of results.
The normal peak cortisol value poststimulation should be an increment no less than 18 µg/dL.

(f) Cortisol and ACTH responses to the CRH stimulation test (100 μg, intravenous bolus).

Time (min)	0	15	30	60	90	120
ACTH (pg/mL)	35.2	49.3	54.6	54	45.9	37.8
Cortisol (μg/dL)	10.4	11.4	12.2	12.2	11.6	11.4

Interpretation of results.
The normal peak ACTH value poststimulation should be an increment no less than 20 pg/mL. Cortisol should be an increment no less than 5 µg/dL.