Question: I went to my Doctor for general check up, and mentioned frequent urination, and a feeling that my bladder was full. I thought I may have urinary tract infection. Urine sample revealed sugar in urine although my blood was only 7.5 mmo/L nearly two hours after a breakfast of Special K. I am scheduled for a fasting blood sugar.
I would be very grateful if you could advise me whether sugar can be present in urine for reasons other than diabetes and also if there is a link between having underactive thyroid and developing diabetes?
Answer: Hello Kate! You ask good questions and have astute observation! The most common cause of sugar in the urine, by far, is the presence of diabetes mellitus. There is other potential cause for sugar in the urine which includes the use of certain drugs that may increase urine glucose measurements; and renal glycosuria which is a rare condition in which glucose is excreted in the urine, even when blood glucose levels are normal or low, due to improper functioning of the renal tubules in the kidneys.
Fasting blood glucose levels in the 5.5 to 7 mmol/L range (100 to126 mg/dl), and blood glucose levels two hours following an oral glucose tolerance test in the 7.7 to 11.11 mmol/L range (140 to 200 mg/dl) are considered Impaired Glucose Tolerance (IGT) and are indicative of Pre-Diabetes. Your blood glucose reading of 7.5 mmol/L two hours following a light meal of Special-K (most likely a lesser glucose load than a glucose tolerance test involves) would therefore raise concern that you may have Pre-Diabetes or Diabetes. And sugar in the urine is not indicative of the actual blood glucose level at time of a urine test, but rather of blood glucose levels prior to the time of sampling . . . perhaps in the early AM hours when blood glucose levels tend to rise in people who have Pre-Diabetes, or Diabetes.
Urinary tract infections and genital or vaginal itching are also common in women who have diabetes, and can be caused by the presence of excess glucose in the urine. An opportunistic infection, such as Candida or “Yeast” overgrowth, often occurs when the warm moist vaginal environment meets with excess glucose in the urine, and is often exacerbated by use of antibiotics which destroy the delicate balance of bacteria in the intestinal system.
And, YES indeed, there is a link between hypothyroid function and diabetes.
Thanks for asking, and I wish you the best of health and happiness as you continue your journey of discovery . . . with or without diabetes!