Preliminary investigation on application value of polyethylene glycol precipitation and gel chromatography in differential diagnosis of hypoglycemia induced by exogenous insulin in patients with diabetes mellitus

To preliminarily investigate application value of polyethylene glycol precipitation (PEG) and gel chromatography in the differential diagnosis of hypoglycemia induced by exogenous insulin in patients with diabetes mellitus. PEG precipitation and gel chromatography were used to detect the serum in two diabetic patients with recurrent unexplained hypoglycemia during injection of insulin. The results showed that case 1 was diagnosed as hypoglycemia induced by excess exogenous insulin, because there was no significant difference in the level of serum insulin before and after PEG precipitation, gel chromatography showed normal insulin peak. Case 2 was diagnosed as exogenous insulin antibody syndrome, because the level of serum insulin after PEG precipitation was significantly lower than before PEG precipitation, gel chromatography showed high molecular weight of insulin peak. The study shows PEG precipitation and gel chromatography can be used to determine whether there is insulin antibody for diabetic patients with unexplained hypoglycemia during injection of insulin. Key words: Diabetes mellitus; Insulin antibodies; Hypoglycemia