A recent trial looked at the effectiveness of insulin pump treatment versus multiple daily injections in patients with type I diabetes (see doi: 10.1136/bmj.j1285). Prior studies have suggested that pumps work better, but it may have been that those patients on pumps had received more intensive training and education than those on multiple daily injections. So, this study looked at patients given similar education, finding that the benefits of education/training outweighed the advantage of using the continuous subcutaneous insulin infusion (the pump) over multiple daily injections.
Details:
— 317 adult participants in the UK from multiple sites with type I diabetes were randomized to insulin pump therapy versus multiple daily injections
— Both received structured education: 267 attended one week DAFNE skills training courses (Dose Adjustment for Normal Eating), with a further visit at 6 weeks. This training stresses flexible dose adjustments according to eating, physical activity, and blood glucose level, and was slightly different for those on multiple daily injections vs pumps, to emphasize the specific use and problems with each.
— Mean age 41, 60% male, 91% white, BMI 27, mean duration of diabetes 18 years, 55% with macrovascular complications/43% retinopathy/7% neuropathy/19% nephropathy, 12% with at least one episode of severe hypoglycemia in the past year, mean hemoglobin A1c 9.1 with a range 5.7 to 16.7 and only 9% had a hemoglobin A1c < 7.5%
— Main outcome: changes in hemoglobin A1c at 2 years. Secondary outcomes included body weight, insulin dose, and episodes of moderate or severe hypoglycemia. They also looked at quality-of-life and treatment satisfaction
Results:
— Mean change in hemoglobin A1c at 2 years:
–decreased 0.85% with pump treatment
–decreased 0.42% with multiple daily injections
— with adjustment for missing values etc, the A1c difference was 0.24% between the therapies, which is neither clinically nor statistically significant (0.5% being considered clinically significant)
— on a per protocol analysis, the mean difference favoring pump treatment was 0.36%, which did have a p=0.02, still not clinically significant.
— But at 24 months, combining both treatment groups, there was a hemoglobin A1c decrease of 0.54%. In those with an A1c initially >7.5%, the A1c decrease was 0.64%. These decreases, presumably attributable to the education and training prior to beginning each of the drug regimens, were clinically significant.
— secondary outcomes:
— hypoglycemia: 49 episodes in 25 patients over 24 months, did not differ between groups. The incidence of severe hypoglycemia decreased by about half for both groups as compared to baseline.
— No statistically significant difference in body weight, but there was a slight increase in HDL cholesterol and decrease in total cholesterol in both groups without a difference. Insulin dose decreased in both treatments, a little greater in those on the pumps (0.07 IU/kg). No difference in the odds of proteinuria.
— Diabetic ketoacidosis: this was greater in the pump group compared to the multiple daily injections group (17 versus 5 episodes), most related to infections, and 18% by technical failures in those using pumps
— psychosocial questionnaires: no difference between groups in generic quality-of-life status instrument. Improvement in both groups in the overall diabetes-specific quality-of-life questionnaire, though this was greater in the pump group though not always reaching statistical significance. Pump users showed greater improvement in treatment satisfaction as well as more dietary freedom and less daily hassle at both 12 months in 24 months
— other findings: those on pumps had twice the number of contacts with diabetes professionals, especially during the 1st year. There also were more face-to-face contacts and of longer duration in the 2nd year of the study.
Commentary:
— Pumps are used less frequently in the UK, an estimated 6% of type I diabetics use pumps there versus 40% in the US (which may be related to differences in the medical cultures between the 2 countries, with us going more quickly/easily to high tech fixes).
— Pumps are clearly more expensive than multiple daily injections: the pumps cost £2500 in the UK plus an additional £1500 for consumables (cannulas, reservoirs, batteries). And this does not include the increased number of office visits noted above.
— As per the authors, “These results do not support a policy of using insulin pumps in those with poor glycemic control until the effects of training on participants level of engagement in intensive self-management have been determined”. I personally support a strong effort to encourage a healthier lifestyle for both type 1 and type 2 diabetics (and pretty much everyone else), for its myriad of positive health effects. However, diabetes raises particular challenges, since dosing of insulin in particular is so dependent on consistency in diet/exercise as well as on other events that change insulin effectiveness (eg infections, which increase insulin resistance). There may certainly be some advantages of the pump in some patients, with the potential for having more variations in life (different foods, even a small piece of cake on a birthday; doing less exercise some days when not feeling well or the weather is bad; UTIs, etc) and more flexible dosing to compensate. But this study in type 1 diabetics does point out the primacy of structured education to improve glucose control, and then considering technological fixes in some cases on an individual basis. And I think the lessons are more broadly applicable to type 2’s and beyond…