Idiopathic Arginine Vasopressin Deficiency With Mild and Reversible Hypercalcemia

Article Figures & Data

Download figure
Open in new tab
Download powerpoint
Figure.
(A) Noncontrast sagittal T1-weighted image shows an absent posterior pituitary bright spot (normal location marked by white arrow). (B) Contrast-enhanced image shows normally enhancing pituitary stalk (white arrow) without any thickening.

Table 1.

Laboratory Results at Baseline and After Overnight Water Deprivation

Laboratory Test	Baseline, Unstimulated State	After Overnight (8 Hours) Water Deprivation	Reference Range
Hemoglobin, g/dL	14.8	–	13.2-16.6
Hematocrit, %	43.5	–	38.3-48.6
Serum urea, mg/dL	13	15	20-40
Serum creatinine, mg/dL	0.97	1.09	0.6-1.2
Serum sodium, mmol/L	143^a	144	135-145
Serum potassium, mmol/L	3.9	4.6	3.5-5.5
Serum uric acid, mg/dL	7.1	–	3.5-7.2
Serum total calcium, mg/dL	–	11.1	8.5-10.5
Serum phosphate, mg/dL	–	4.0	2.5-4.5
Serum aspartate transaminase, IU/L	–	38	<40
Serum alanine transaminase, IU/L		46	<40
Serum alkaline phosphatase, IU/L	–	103	30-120
Serum albumin, g/dL	–	4.4	3.5-5.2
Random plasma glucose, mg/dL	92	–	<140
HbA1c, %	5.1	–	<5.7
Serum osmolality, mOsm/kg	278^a	317	275-295
Urine osmolality, mOsm/kg	215	156	50-1,200, depending on fluid intake
Serum free T4, ng/dL	–	1.29	0.7-1.48
Serum thyroid stimulating hormone, μIU/mL	–	0.996	0.4-4.9
Serum anti-thyroid peroxidase, IU/mL	–	1.61	<60
Serum 8 AM cortisol, fasting, μg/dL	–	9.3	3.7-19
Serum 8 AM testosterone, fasting, ng/dL	–	816.9	300-1,000

↵^aSerum sodium and serum osmolality measurements at the baseline timepoint are not paired; the reported values are from 2 different days.

Table 2.

Laboratory Results Before and After Arginine Vasopressin Challenge Test

		After Arginine Vasopressin Administration^a
Laboratory Test	Before Arginine Vasopressin Administration Baseline, 0 minutes	60 minutes	120 minutes
Serum osmolality, mOsm/kg	297	–	283
Serum sodium, mmol/L	139	–	137
Urine osmolality, mOsm/kg	124	488	427
Urine output, mL/h	300		20