Flexible Intensive Insulin Therapy in Adults With Type 1 Diabetes and High Risk for Severe Hypoglycemia and Diabetic Ketoacidosis

Abstract

OBJECTIVE—Diabetes treatment and teaching programs (DTTPs) for type 1 diabetes, which teach flexible intensive insulin therapy to enable dietary freedom, have proven to be safe and effective in routine care. This study evaluates DTTP outcomes in patients at high risk for severe hypoglycemia and severe ketoacidosis.

RESEARCH DESIGN AND METHODS—There were 96 diabetes centers that participated between 1992 and 2004. A total of 9,583 routine-care patients with type 1 diabetes were examined before and 1 year after a DTTP. History of repeated severe hypoglycemia/severe ketoacidosis was an indication for DTTP participation. Before-after analyses were performed for subgroups of patients with three or more episodes of severe hypoglycemia or two or more episodes of severe ketoacidosis during the year before a DTTP. Main outcome measures were GHb, severe hypoglycemia, severe ketoacidosis, and hospitalization.

RESULTS—A total of 341 participants had three or more episodes of severe hypoglycemia the year before a DTTP. Mean baseline GHb was 7.4 vs. 7.2% after the DTTP, incidence of severe hypoglycemia was 6.1 vs. 1.4 events · patient⁻¹ · year⁻¹, and hospitalization was 8.6 vs. 3.9 days · patient⁻¹ · year⁻¹. In mixed-effects models taking effects of centers and diabetes duration into account, mean difference was −0.3% (95% CI −0.5 to −0.1%; P = 0.0006) for GHb and −4.7 events · patient⁻¹ · year⁻¹ (−5.4 to −4; P < 0.0001) for severe hypoglycemia. A total of 95 patients had two or more episodes of severe ketoacidosis. GHb was 9.4% at baseline versus 8.7% after DTTP; incidence of severe ketoacidosis was 3.3 vs. 0.6 events · patient⁻¹ · year⁻¹, and hospitalization was 19.4 vs. 10.2 days · patient⁻¹ · year⁻¹. In linear models with diabetes duration as the fixed effect, the adjusted mean difference was −2.7 events · patient⁻¹ · year⁻¹ (95% CI −3.3 to −2.1; P < 0.0001) for severe ketoacidosis and −8.1 days (−12.9 to −3.2; P = 0.0014) for hospitalization.

CONCLUSIONS—Patients at high risk for severe hypoglycemia or severe ketoacidosis may benefit from participation in a standard DTTP for intensive insulin therapy and dietary freedom.