For the electronic database search, the following terms and strategy were used: diabetes mellitus, type 2, insulin, thirst, weight loss, weight gain, polyuria, nocturia, fatigue, infection, vision disorders, haemoglobin A, glycosylated, blood glucose, diabetes complications, mortality, death, mortality, hypoglycaemia, weight gain, lipodystrophy. The gene discussed is INS; the disease is Hypoglycemia.