In light of concerns surrounding rosiglitazone (Avandia), what agent would you recommend for a newly diagnosed type 2 diabetic with a baseline glomerular filtration rate (GFR) <60 mL/min/1.73 m2?
—Michael J. Dolan, MD, La Crosse, Wis.
There is no evidence-based answer to this question, nor is there clear consensus. I base my choice on patient preference, comorbidities, cost, and hemoglobin A1c (HbA1c) on presentation. The agents to consider are a sulfonylurea, a thiazolidinedione, or insulin, since the usual first choice, metformin, should be avoided in patients with GFR <60. Most patients prefer oral agents, so in a patient with a reduced GFR, I start with a shorter-acting sulfonylurea, such as glipizide, to minimize hypoglycemia. I do not generally start with a thiazolidinedione given the considerably higher cost and increased fluid retention and congestive heart failure. This despite data from A Diabetes Outcome Progression Trial (ADOPT), which found the greatest longevity of monotherapy in terms of HbA1c control and insulin sensitivity with rosiglitazone as compared with metformin or glyburide.
If I were to start with a thiazolidinedione, e.g., in a patient with a contraindication to or inability to tolerate a sulfonylurea, it would be pioglitazone given the adverse cardiovascular outcomes reported with rosiglitazone.
Last in patients’ minds but most effective and cheapest is insulin, which can be considered a first-line agent, particularly for patients whose presentation suggests type 1 diabetes (rapid weight loss, being underweight, or ketonuria). Insulin should also be considered first-line for patients with a high HbA1c (i.e., >10%) given that each oral agent results in at most a 1%-2% HbA1c reduction and is thus unlikely to be strong enough to allow the patient to reach goal. I start with a bedtime dose of NPH insulin and titrate up as needed.
I cannot overemphasize the importance of patient education on exercise, weight loss, and following a diabetic diet, preferably in the form of a multidisciplinary diabetic teaching class, which can convey more information than is possible in an office visit.
—Susan Kashaf, MD, MPH (119-7)