Low hemoglobin levels are associated with upper gastrointestinal bleeding.

Upper gastrointestinal (GI) bleeding can be fatal. Blood test variables were reviewed in search of threshold values to detect the presence of occult upper GI bleeding. The records of 1,023 patients who underwent endoscopy at the National Hospital Organization Shimoshizu Hospital from October 2014, to September 2015, were retrospectively reviewed. Of those, 95 had upper GI bleeding. One-way analysis of variance was applied to blood test variables comparing patients with and without upper GI bleeding. Logistic regression analysis was applied to detect the association of blood test parameters with upper GI bleeding, and receiver-operator characteristics were applied to establish threshold values. White blood cell count (WBC), platelet (Plt) count, and blood urea nitrogen (BUN) levels were higher, and hemoglobin (Hb) and albumin (Alb) levels were lower in patients with upper GI bleeding. Logistic regression analysis showed that low Hb was significantly associated with upper GI bleeding and a Hb value of 10.8 g/dl was established as the threshold for the diagnosis. In patients with upper GI bleeding, WBC, Plt count, and BUN levels were higher and Hb and Alb levels were reduced. Hb at 10.8 g/dl was established as a threshold value to detect upper GI bleeding.