Sensor-augmented insulin pump for Diabetic Patients

PICHON RIVIERE, A.; AUGUSTOVSKI, F.; GARCIA MARTI, S.; GLUJOVSKY, D.; ALCARAZ, A.; LOPEZ, A.; BARDACH, A.; CIAPPONI, A; KLEIN, K

Documento de Evaluación de Tecnologías Sanitarias

IECS

Año: 2012 p. 1 - 30

1668-2793

In Argentina, the ENFR recorded a 12%-national prevalence of hyperglycemia and/or Diabetes Mellitus (DM). The incidence is growing worldwide and it has a high impact in terms of use of resources.Type I DM, which represents 5-10% of the DM diagnosed cases, consists in a deficiency in insulin production which patients should self-administer exogenously daily. Type II DM (90-95% of the adult cases) occurs due to an altered action of insulin or due to target organ resistance. As disease progresses the individual may also require exogenous insulin. For correct diabetes management, leading to better clinical results and to less complications, strict glucose control is required and, if necessary, an adequate exogenous insulin therapy. One of the intensive glucose control schemes is the external insulin pump. Currently there are two systems: one open loop system consisting of the infusion pump only, and another one consisting of a pump plus a continuous glucose sensor/monitor. It has been proposed that the new pump would improve glucose control and reduce the hypo and hyperglycemic episodes.TechnologyIt is a device which includes a subcutaneous insulin infusion pump, the continuous glucose sensor and a program to manage data online and perform a retrospective analysis. It has the size of cell phone and it can be plugged and unplugged by the patient. The rapid or ultra-rapid-acting insulin is administered throughout the day at a baseline concentration and as bolus on patient demand. This system supplements, but does not replace the glucose self-monitoring, which will continue being the basis for treatment adjustments and sensor calibration. This is so because the sensor continuously monitors interstitial glucose concentration, but there is a 10-minute delay if compared to blood glucose.The device also includes an alert system to detect hypo and hyperglycemia and it may suspend baseline insulin administration for up to two hours, in case of hypoglycemia.PurposeTo assess the available evidence on the efficacy, safety and other issues related with coverage policies on the use of insulin pumps with continuous glucose sensor for diabetic patients.MethodsA bibliographic search was carried out on the main databases: DARE, NHS EED, on Internet general search engines, in health technology evaluation agencies and health sponsors. Priority was given to the inclusion of systematic reviews; controlled, randomized clinical trials (RCTs); health technology assessments and economic evaluations; clinical practice guidelines and coverage policies of other health systems.ResultsThree RCTs comparing the sensor-augmented pump therapy with the conventional insulin pump therapy, and one observational study were found. No studies with type II DM patients were found, but coverage policies which do cover them were found. Only the RCTs which include more than 100 patients are described in this abstract.One RCT carried out in 2009 included 115 patients with type I DM (N=55 with glucose sensor and 60 without it) followed up for a 6-month period. They studied if starting to use the pump with and without sensor, in patients receiving multiple-insulin doses, might result in an improvement in metabolic control. Those patients using the pump with sensor more than 70% of the time had a significant HbA1c decrease (8.9+/- 1.12 down to 0.96 +/- 0.93% in the sensor-augmented pump group; vs. 9.25 +/- 1.19; down to 0.55 +/- 0.93% in the conventional pump group, p=0.004. The HbA1c level at the end of the study was 7.5-8 in the sensor group and over 8.5 in the control group). Regarding glucose changes, the mean glucose level significantly decreased in the sensor group, from a mean 185.5 m/dL to 30.6 +/- 54.0 vs. 192.9 mg/dL to 10.8 +/- 39.6; p=0.005). Regarding the length of the hyperglycemic events, the reported values were significantly lower in the sensor group (p<0.05) whereas there were no differences in the hypoglycemias reported.Another multicenter RCT conducted in 2008 studied the efficacy and safety of the insulin pump with real-time continuous glucose monitoring. The study was carried out on 138 adolescents and adults (66 in the group with sensor and 72 in the group without sensor; between 12 and 72 years old) with HbA1c <=7.5% and type I DM diagnosis and a 6-month follow-up. No significant differences were found in the average HbA1c value at the end of the study. Regarding severe hypoglycemic events, 14 cases occurred, 11 of them were in the sensor group (p=0.04).In addition, the RCT full text mentions another RCT with less than 100 patients as well as an observational feasibility study.Coverage PoliciesA U.S. health provider (2011) covers the sensor-augmented insulin pump for selected cases.Clinical Practice GuidelinesThe American Diabetes Association (ADA 2011) reports the infusion pump with real-time continuous glucose monitoring would be a useful tool for selected type I DM patients under 25 years old, although it considers it is not supported by studies of good methodological quality.ConclusionsA difference favoring the sensor-augmented pump might be relevant, although only few studies were found and with a short follow-up and moderate methodological quality. With the evidence available, the sensor-augmented insulin pump might have good results in type I DM, reducing HbA1c and glycemia, without reporting important benefits in decreasing hypoglycemia events. It is worth mentioning that, in order to optimally use the pump with sensor, it is important to have proper training by professionals, good and timely clinical and family support and a motivated patient. More prospective randomized comparative studies are required with a larger number of patients and a longer follow-up to be able to draw adequate conclusions.