Increased mortality in very old patients treated by continuous subcutaneous insulin infusion (CSII)

Abstract

To compare glycemic control, safety and health burden in ambulatory elderly patients with diabetes treated by continuous subcutaneous insulin infusion (CSII) versus multiple daily injections (MDI). Adults ( n = 68) > 75 years of age (mean age 80 ± 4) with insulin-treated diabetes (mean duration 31 ± 13 years, BMI 27 ± 6 kg/m 2 and HbA1 C 9.0 ± 1.6%) treated by CSII or MDI were recruited in a systematic retrospective study. Efficacy was assessed with composite criteria : adjusted for frailty HbA1 C target without occurrence of severe or frequent hypoglycemia. Safety was assessed by frequency of severe hypoglycemia, diabetes ketoacidosis, major cardiovascular events or death. Health burden was considered through hospitalization duration per year. Thirty CSII subjects and 38 MDI subjects were analyzed. The most frequent reason to initiate CSII was mostly instable blood glucose control in TD1 whereas it was insufficient blood glucose control in TD2. A lower HbA1 C was decreased in both groups (7.7 ± 0.9% vs. 7.8 ± 1.1% CSII vs. MDI). Number of severe hypoglycemia, diabetic ketoacidosis and patient's hospitalizations for uncontrolled diabetes/year were similar in both group ns. More deaths occurred in the CSII group than in the MDI group (9 vs. 2, OR adjusted 0.118 IC [0.017–0.520], P 0.011). In very elderly patients with insulin-treated diabetes both CSII and MDI achieved optimal glycemic control. However, more deaths occurred in the CSII group. The improvement in blood control obtained by CSII does not compensate the increased frailty in these patients.