AVP and ablepharon macrostomia syndrome: Multiple groups demonstrated that individuals, exposed to high altitude exhibited increased ANP, brain natriuretic peptide (BNP), epinephrine, endothelin-1 (ET-1), and adrenomedullin levels, as well as decreased ADH, renin, and aldosterone levels, leading to hypoxic a diuretic response.205,211–215 Furthermore, elevated BNP was associated with increased AMS occurrence and severity.214–216 However, the correlation between the above altered ANP/BNP/ADH levels and TBW needs additional investigations.