Initiating and Titrating Insulin in Patients With Type 2 Diabetes

A 48-year-old African-American man presents to his primary care physician for follow-up of his type 2 diabetes. His diabetes is complicated by peripheral neuropathy, although he has no evidence of retinopathy or nephropathy. His medical history also includes obesity, hyperlipidemia, hypertension, and obstructive sleep apnea.At a visit 3 months earlier, his A1C was 9.2% on a regimen of glipizide extended release, 10 mg daily, and metformin sustained release, 1,000 mg twice daily. He and his physician discussed the possible need for insulin, but he preferred to try an additional oral agent first. Sitagliptin, 100 mg daily, was added to his previous regimen, and he was continued on his angiotensin receptor blocker and statin therapies.At this visit, he reports that he tolerated the sitagliptin poorly because of diarrhea and stopped taking it after only a few weeks. His A1C today is up to 9.4%. His weight is 151 kg, with a BMI of 43 kg/m2. His physical exam is significant for the presence of obesity and acanthosis nigricans. After a thorough discussion of the morbidity associated with poorly controlled diabetes, he agrees to initiate insulin therapy.The initiation of insulin is an important stage in the management of type 2 diabetes. Like the patient in this case, many patients with diabetes are unable to achieve a goal A1C on oral therapies alone. Given the progressive nature of this disease, characterized by gradual impairment in β-cell function and loss of β-cell mass,1 most patients with type 2 diabetes will eventually require insulin therapy to achieve a goal A1C of < 7% as defined by the American Diabetes Association (ADA) or ≤ 6.5% as defined by the American Association of Clinical Endocrinologists.In 1993, the Diabetes Control and Complications Trial confirmed the long-suspected notion that tight glycemic control …