Long-term efficacy of a 5-day structured teaching and treatment programme for intensified conventional insulin therapy and risk for severe hypoglycemia

Abstract

In the DCCT, intensification of insulin therapy led to a threefold increase in the risk of severe hypoglycemia (defined as the need for third party assistance). The reasons for this strong exponential relationship appears to be unclear to date. The present trial, a long-term evaluation of a 5-day structured teaching and treatment programme (5-DTTP) for intensified conventional insulin therapy (ICT), was performed to elucidate factors determining HbA1c and the incidence of severe hypoglycemia. A total of 71 patients were examined at baseline and 45.5 ± 4.2 months following participation in a 5-DTTP. Comparing the data at follow-up examination with baseline measurements, HbA1c improved (8.52 ± 2.29% vs. 8.0 ± 1.43%, P = 0.04), the frequency of daily insulin injections (3.1 ± 1.6 vs. 4.8 ± 0.8, P < 0.001) and weekly blood-glucose self-tests (5.2 ± 8.9 vs. 25.5 ± 9.6, P < 0.001) increased, and the incidence of severe hypoglycemia (glucose i.v., glucagon injection) remained stable (0.18 vs. 0.17, P = 0.99). But, comparing the 21 patients who suffered from severe hypoglycemia during the follow-up period with the 50 patients without hypoglycemia, no differences between the two groups were found with respect to metabolic control (7.70 ± 1.48% vs. 8.21 ± 1.43%, P = 0.17), quality of life or treatment satisfaction. However differences arose with respect to diabetes knowledge. In the group of 21 patients with severe hypoglycemia we identified certain crucial gaps in diabetes knowledge: insulin self-adjustment; dietary aspects; hypo- and hyperglycemia. Performing multiple regression analysis, strong correlations were found between HbA1c and diabetes knowledge ( r = −0.58, P = 0.002 for 50 patients without hypoglycemia and r = −0.63, P = 0.05 for 21 patients with hypoglycemia). In the total group, the most important factors determining HbA1c, were diabetes knowledge ( r = −0.055, P = 0.007) and daily insulin dosage/kg body weight ( r = 2.13, P = 0.0008, R 2 = 0.26). Intervention like education of patients on a continous basis and modifications of the DTTP's with more information and training in the recognition and treatment of hypoglycemic episodes seems to be essential to prevent hypoglycemia and to improve the efficacy of DTTP's over longer periods of time.