Diabetes in Urban African-Americans. I. Cessation of Insulin Therapy Is the Major Precipitating Cause of Diabetic Ketoacidosis

OBJECTIVE To identify the causes of diabetic ketoacidosis (DKA) in a large urban hospital.

RESEARCH DESIGN AND METHODS Consecutive patients admitted during a 3-month period with a primary diagnosis of DKA and who had moderate-to-severe illness as shown by serum glucose >13.9 mmol/l (>250 mg/dl), bicarbonate <15 mmol/l, and pH <7.35 were studied. Diabetes nurse educators interviewed patients and reviewed their medical records for the following: precipitating causes of DKA; content of previous diabetes education; frequency of blood glucose monitoring; recognition of symptoms of metabolic decompensation; and types of medical assistance obtained once patients were ill.

RESULTS There were 56 episodes of DKA, and 75% of the episodes were in patients with known diabetes. In the known diabetic patients, the most common cause of DKA was stopping insulin therapy, which occurred in 67% of episodes. Half of the patients (50%) stopped insulin because of reported lack of money to buy insulin from an outside pharmacy or get transportation to the hospital; 21% stopped insulin because of lack of appetite; 14% stopped insulin because of behavioral or psychological reasons; and 14% did so because they did not know how to manage diabetes on sick days. Of the known diabetic patients, >80% recalled having been instructed as to blood glucose testing and acute and chronic complications, but fewer patients recalled having been instructed as to insulin dose adjustment (28%) or sick day management (35%). Symptoms of decompensated diabetes were recognized in 55% of the 42 episodes of DKA in patients with known diabetes. However, only 5% of patients contacted the Diabetes Unit when they became ill; the majority (95%) went directly to the emergency room.

CONCLUSIONS DKA occurred most often in patients with known diabetes who stopped insulin therapy because of reported lack of money for purchasing insulin or for transportation to the hospital and limited self-care skills in diabetes management. In urban African-American populations, up to two-thirds of the episodes of DKA may be preventable by improving patient education and access to care.