AVP and neurohypophyseal diabetes insipidus: Median Day 1 copeptin for patients who developed AVP deficiency (n = 14) was 2.5 pmol/L (IQR 2.0–3.0) versus 3.9 pmol/L (IQR 2.8–6.1) for those who did not develop AVP deficiency (n = 107), p = .004.