A 23-year-old woman has noted an increase in her appetite and thirst over the past six months, although she has lost 2 kg (5 pounds). The patient also has had considerable frequency of urine output, without associated dysuria. On physical examination her vital signs include T 37 C, P 77/min, RR 16/min, and BP 120/70 mm Hg. A midstream clean catch urine sample is obtained.

Questions:

1. What disease is suggested by these findings?

Diabetes mellitus, type I

2. Will all sugars be detected by the reagent test strip for glucose? Why?

Only glucose will be detected, because the reagent strip uses glucose oxidase. Other sugars must be detected by a test for reducing substances (Benedict's copper reduction method) which will pick up such sugars as fructose. Sucrose will not be present unless you are a member of the plant kingdom.

3. What is the significance of the positive test for ketones? What would you suspect if the ketones were positive and everything else was normal?

The ketones suggest that insulin is lacking and that adipose tissue is being metabolized with utilization of fatty acids to produce ketone bodies, typical of type I diabetes mellitus. In the absence of glucosuria, ketone bodies suggest starvation.

4. What other laboratory tests should be done in this patient?

Serum glucose. Persons with diabetes mellitus do not use urine dipsticks to monitor their urine, but use fingerstick measurements of blood glucose obtained with a portable meter, and they become very adept at getting accurate results. Measuring hemoglobin A1C would give an indication of glucose control over a longer time frame.

5. What are some complications of her disease that can affect the urinary tract?

Persons with diabetes mellitus are prone to get infections, including urinary tract infections, both of the lower and upper urinary tract. Long term complications could consist of renal vascular disease from atherosclerosis and glomerular disease from glomerulosclerosis. In the lower urinary tract, diabetic cystopathy, with impaired voiding and increased residual urine volume, may occur.