Question from Kent, United Kingdom:

My father has impaired glucose tolerance and his own mother was insulin dependent for sixty years. My seven year old son has a six week history of increased thirst and urination up to twenty times a day at present. He also has eczema and cellulitis of both hands which has been slow to heal. His doctor did a finger prick test at the surgery which showed a blood glucose of 7.8 mmol/L [140 mg/dl] (even though he’d not eaten for the previous four hours), and a subsequent fasting blood sugar was normal (5.1 mmol/L [72 mg/dl]), but since then he has had several high readings. The highest was 8.6 mmol/L [144 mg/dl] three and a half hours after a meal, and his morning readings have all seemed to return to normal.

We saw a general paediatrician who says that type 1 diabetes in children takes a maximum of three weeks to develop, and, since my son is not in a coma, he can’t have diabetes. He says the drinking and subsequent urination may just be habit. My son is scheduled for a glucose tolerance test next week, although the doctor said it’s unlikely this will be positive as true glucose intolerance is rare. He’s also wondering if my son cannot ‘process’ urine in the correct way.

If the oral GTT is indeed negative, does that mean that my son may just have a natural tendency to a raised blood sugar? Does the fact that it returns to normal during true fasting mean that we should be reassured?