Aim: To examine the impact of different types of insulin pumps (CSII) on HbA1c lowering control in a large UK type 1 diabetes practice.
Methods: Observational retrospective study of electronic database. We identified 597 adults (≥18 years) in our service who started on CSII between 2002 and 2017 with HbA1c data available at baseline and at 6 +/or 12 months after starting CSII. We classified by the starting pump model/manufacturer into traditional “tethered pumps” (Medtronic n=369; Roche n=79; Animas n=60) and “small pumps” (Omnipod n=79 and Cellnovo n=6). We examined change in HbA1c data (shown here in mmol/mol except where otherwise indicated) over the first year of CSII treatment.
Results: In general, CSII improved HbA1c during the first 12 months (72±0.7 to 64±0.6 and 65±0.6 mmol/mol at baseline, 6 and 12 months). Despite similar starting HbA1c, those using tethered pumps achieved a significantly lower HbA1c compared with small pump users after 6 and 12 months CSII therapy.
Conclusions: In real world data from a large pump service, we found significant differences in glycemic outcomes between different pumps. Those starting on tethered pumps had greater HbA1c lowering over first 12 months.
HbA1c Outcomes for Tethered vs small Pumps
| Pump type | Initial HbA1c range mol/mol (%) | Baseline HbA1c | 6 months HbA1c | p vs baseline | 12 months HbA1c | p vs baseline |
| Tethered (n=509) | All starting values | 71±0.7 | 63±0.6* | <0.001 | 65±0.7* | <0.001 |
| Small (n=85) | 71±0.9 | 70±1.6 | NS | 69±1.6 | NS | |
| Tethered (n=273) | ≥ 69 (85%) | 83±0.7 | 69±0.8** | <0.001 | 71±0.9* | <0.001 |
| Small (n=43) | 83±2.3 | 77±2 | <0.05 | 77±2.1 | <0.05 | |
| Tethered (n=132) | 59-68 (7.5-8.4%) | 64±0.2 | 59±0.7** | <0.001 | 59±0.8* | <0.001 |
| Small (n=28) | 64±0.5 | 66±1.4 | NS | 64±1.4 | NS | |
| Data shown as mean±SEM. * p<0.05, ** p<0.001 for tethered vs small | ||||||
| Pump type | Initial HbA1c range mol/mol (%) | Baseline HbA1c | 6 months HbA1c | p vs baseline | 12 months HbA1c | p vs baseline |
| Tethered (n=509) | All starting values | 71±0.7 | 63±0.6* | <0.001 | 65±0.7* | <0.001 |
| Small (n=85) | 71±0.9 | 70±1.6 | NS | 69±1.6 | NS | |
| Tethered (n=273) | ≥ 69 (85%) | 83±0.7 | 69±0.8** | <0.001 | 71±0.9* | <0.001 |
| Small (n=43) | 83±2.3 | 77±2 | <0.05 | 77±2.1 | <0.05 | |
| Tethered (n=132) | 59-68 (7.5-8.4%) | 64±0.2 | 59±0.7** | <0.001 | 59±0.8* | <0.001 |
| Small (n=28) | 64±0.5 | 66±1.4 | NS | 64±1.4 | NS | |
| Data shown as mean±SEM. * p<0.05, ** p<0.001 for tethered vs small | ||||||
S.D. De Soysa: None. J. Grey: None. K.H. Davenport: Advisory Panel; Self; Novo Nordisk Inc. E.M. Gurnell: Advisory Panel; Spouse/Partner; AstraZeneca, Pfizer Inc. S. Hartnell: Speaker's Bureau; Self; Medtronic, Roche Pharma. M. Evans: Advisory Panel; Self; Novo Nordisk A/S, Eli Lilly and Company, Cellnovo, Roche Pharma. Speaker's Bureau; Self; Abbott, Novo Nordisk A/S.
