The patient described above is likely suffering from type I diabetes mellitus. She displays the hallmarks of polyphagia, polyuria, and polydipsia. An elevated ketone level is a possible manifestation of type I diabetes.
Elevated ketones seen in type 1 diabetics can be due to the increased breakdown of fatty acids in the liver, leading to the formation of ketone bodies. Eventually, the excess production of ketones can lead to ketoacidosis. Another result of insulin deficiency is the increased breakdown of proteins. Several of the resulting amino acids can be used for the production of glucose (gluconeogenic amino acids). Therefore, in the absence of insulin, there is a switch from protein-building and fatty acid storage, to protein and fatty acid degradation.
Trachtenbarg states that diabetic ketoacidosis is diagnosed with plasma glucose concentrations above 250 mg/dL, pH levels less than 7.30, and bicarbonate levels 18 mEq/L or less. Additionally, cerebral edema has been found to be a major complication of ketoacidosis in children.
Kennedy et al. discuss the role of exercise in improving glycemic control in type 1 diabetics. Since regular exercise is often advocated for those suffering from type 1 diabetes, it is important to know whether benefits of this therapy actually exist. This meta-analysis did not reveal evidence for a glycemic benefit of exercise as measured by HbA1c. Despite this finding, there are many other proven benefits of exercise in patients with type 1 diabetes, and it will remain an important part of its management.
Illustration A depicts an overview of type 1 diabetes. It is a low insulin state which prevent cellular uptake of glucose.
Answer 1: Amyloid deposits are more consistent with type II diabetes.
Answer 2: High levels of thyroid hormone (as in hyperthyroidism) would also lead to the unintentional weight loss and increased hunger, but her symptoms are more common and consistent with type I diabetes.
Answer 4: Type I diabetes results in hyperglycemia, not hypoglycemia.
Answer 5: Hyperinsulinemia is more common in the early stages of type II diabetes.
Trachtenbarg DE. Diabetic ketoacidosis. Am Fam Physician. 2005 May 1;71(9)
PMID:15887449 (Link to Abstract)
Kennedy A, Nirantharakumar K, Chimen M, Pang TT, Hemming K, Andrews RC, Narendran P. Does exercise improve glycaemic control in type 1 diabetes? A systematic review and meta-analysis.
PMID:23554942 (Link to Abstract)
USMLE World Step 1 QBank Question #921. Copyright © USMLEWorld, LLC 2012