Question

Diabetes is a common disease in Rhea’s family. Her grandfather died of this disease and her dad was also recently diagnosed as a diabetic. Not only is Rhea a hypochondriac but she has truly been having symptoms of the disease (or so she thinks). She has been experiencing increased urination, frequent thirst, her urine tested confirmed her belief with the presence of sugar in her urine. Based on this type of diabetes do you think Rhea is at risk for developing Hypoglycemia?

Answer 1

Diabetes mellitus (DM) is caused either by a deficiency of insulin or due to insulin insensitivity. DM is known to run in families where the people in the family are predisposed to diabetes mellitus type 2 (insulin insensitivity). As Rhea’s father and grandfather had diabetes, she will be predisposed to DM as well. Her symptoms of frequent urination and thirst may be due to development towards DM. Presence of glucose (sugar) in urine confirms the diagnosis of DM. Diabetes insipidus, which also shows frequent urination and thirst, does not exhibit glucose in urine. DI is due to lack of ADH hormone secretion.

Insulin is secreted by beta cells of islets of Langerhans in the pancreas when food is digested and carbohydrate levels rise in blood. Insulin binds to insulin receptors on target cells and activates PI3K pathway. This leads to increased production of glucose transporters (GLUTs) or increased translocation of GLUTs from cytoplasm to cell membrane. As a result, glucose is transported to cell cytoplasm and broken down by glycolysis. This leads to decrease in blood glucose levels. However, in DM, there is low secretion of insulin, or its action on target cells is hampered. Hence, glucose is not utilized and the levels of blood glucose remain high. This condition is known as hyperglycemia. Glucose will be seen in urine because the kidneys cannot filter or reabsorb all the glucose from blood. Glucose in filtrate will clog the kidney filtration apparatus.

Rhea is at a risk of having hyperglycemia as she is predisposed to developing diabetes mellitus. She will only develop hypoglycemia (low blood glucose levels) if she takes insulin or diabetic medicine like metformin in excess ,when she does develop DM.