In this retrospective study, we aimed to investigate the plasma copeptin levels in the SAH patients, and therefore, presence of other prior systemic diseases including uremia, liver cirrhosis, malignancy, chronic heart or lung disease, diabetes mellitus and hypertension, that may be associated with plasma copeptin levels [1-7,17], may become the confounding variables, and finally, were excluded. Here, AVP is linked to diabetes mellitus.