This Week’s Question:
Case Study: Type 1 and Type 2, Too?
QUESTION:
Does this patient have
1. Type 1 diabetes
2. Type 2 diabetes
3. Type 1.5 diabetes
4. Both Type 1 and Type 2 diabetes
R.M. is a 17-year-old African-American girl with new-onset
diabetes. She presented to her pediatrician during the winter
months with the classic symptoms of polyuria and polydipsia. She reported
weight loss over the preceding weeks, but was otherwise well. Her family
history was positive for type 2 diabetes in grandparents and some distant
relatives and negative for autoimmune diseases.
Physical examination revealed a blood pressure of 103/53 mmHg. Her weight
was 60 kg (132 lb, 50–75th percentile), height was 155 cm (61
inches, 10th percentile), and body mass index (BMI) was 25 kg/m2 (85th
percentile). She had acanthosis nigricans.
Urinalysis revealed a glucose level of >1,000 mg/dl and ketones of
40 mg/dl. Her initial laboratory studies included a blood glucose measurement
of 726 mg/dl, bicarbonate of 21 mmol/l (normal range 23–32 mmol/l),
venous pH of 7.37, hemoglobin A1c (A1C) of 8.6%, and C-peptide of 1.0
ng/ml (normal range 0.6–3.2 ng/ml).
R.M. was admitted to the hospital for subcutaneous insulin therapy,
fluids, and diabetes education. She was discharged to her home on metformin,
500 mg twice daily, and a split-mixed insulin regimen of NPH and lispro
at 1 unit/kg/day, with two-thirds being taken in the morning and one-third
in the evening. She was also started on a fixed carbohydrate, reduced-fat
meal plan.
Does this patient have
1. Type 1 diabetes
2. Type 2 diabetes
3. Type 1.5 diabetes
4. Both Type 1 and Type 2 diabetes
