Glycemic Relapse After an Intensive Outpatient Intervention for Type 2 Diabetes

The effectiveness of interventions that reduce hyperglycemia in patients with diabetes (1,2) is limited by the tendency for glycemic relapse after the intervention ends. We sought to characterize the occurrence of glycemic relapse after initial improvement and to describe predictors of relapse.

Glycemic relapse was evaluated in 265 consecutive patients with type 2 diabetes who participated in a 3-month intensive outpatient intervention and were followed at least 1 year after completion of the intervention. Details of the intervention have been previously described (3). All had HbA_1c >8% before the intervention and had achieved marginal glycemic control (nadir HbA_1c <8%) after the intervention. Glycemic relapse was defined as a subsequent HbA_1c ≥8% and an absolute increase of at least 1% above the postintervention nadir HbA_1c. All data were analyzed using SAS 8.12 (SAS Institute, Cary, NC).

The mean ± SD age was 56 ± 13.4 years; 54% were women; 71% were Caucasian; and 27% were African American. The mean duration of diabetes was 6.4 ± 8.4 years. Mean BMI was 32.2 ± 8.6 kg/m². The mean HbA_1c before intervention was 10.1 ± 1.7%. The mean HbA_1c nadir after intervention was 6.8 ± 0.7%. Twenty-five percent were receiving insulin therapy before the intervention, and an additional 25% initiated insulin during the program.

The cumulative incidence of relapse at 1 year was 25%. The initiation of insulin therapy during the intervention was the only identifiable independent predictor of relapse (hazard ratio 1.96, 95% CI 1.02–3.74). Female sex, African-American race, duration of diabetes, lack of weight loss during the intervention period, and the levels of HbA_1c before the intervention and at nadir after the intervention increased the risk of relapse in univariate analysis, but these associations were not statistically significant in multivariate modeling. For those patients who relapsed, the median time to relapse was 9 months. Kaplan-Meier plots estimated that 50% of the population would relapse by 30.3 months.

Twenty-five percent of type 2 patients who attained satisfactory glycemic control after an intensive outpatient intervention relapsed within a year. Patients who initiated insulin therapy during the intervention had an almost double risk of relapse. Future studies should characterize social and behavioral variables as well as the frequency and type of insulin in order to better understand the relapse process. In the interim, this high-risk subgroup should receive priority for continuation of intensive care or other relapse preventive measures.