Objective: To investigate the association between treatment induced change in continuous glucose monitored (CGM) time in range (TIR) and microalbuminuria in persons with type 1 diabetes (T1D) treated with sensor-augmented pumps (SAP).
Methods: In an open labelled controlled trial, 60 participants with T1D treated with multiple daily injections (MDI) and history of albuminuria were randomised to MDI- or SAP-therapy for 1 year. During the study, the SAP group wore a CGM (Enlite®, Medtronic). The MDI group wore blinded CGMs (Ipro2®, Medtronic) for 6 days at baseline and study end. Anthropometrics, CGM data, blood and urine samples were collected at 0, 1, 3, 6, 9, and 12-month visits. Based on CGM data collected between each visit, the percentage of time spent within 3.9-10.0 mmol/l (%TIR) was calculated. Urine albumin creatinine ratio (UACR) was measured in 3 samples at all visits. Only CGM data for the SAP group were included in the analysis. A linear mixed model with a participant-specific random intercept was used to analyse the effect of %TIR during 1 year after start of SAP on UACR, adjusting for changes in mean arterial pressure (MAP), HbA1c and body mass index.
Results: Twenty-six participants were assigned to the SAP group and had a baseline median (interquartile range) age of 51.5 (45.9; 62.1) years, HbA1c of 66 (58; 77) mmol/mol, UACR of 78.8 (37; 205) mg/g and 51Cr-EDTA-GFR 85.0 (73.0; 96.5) ml/min/1.73m2. From baseline to study end, the mean improvement (95% CI) in %TIR was 11.3 (6.0; 16.6) %, HbA1C was -14.4 (-17.5; -11.2) mmol/mol and UACR was -13 (-33; -22) %; all p<0.001. HbA1c decreased with 4.7 mmol/mol per 10% increase in %TIR (p<0.001). The UACR decreased with 13% per 10% increase in %TIR (p=0.038), with 15% per 10 mmol/mol decrease in HbA1c (p=0.071), and with 31 % per 10 mmHg decrease in MAP (p<0.001).
Conclusion: In this longitudinal study, treatment induced increase in CGM-derived %TIR were significantly associated with decrease in albuminuria in T1D.
A. Ranjan: None. S. Rosenlund: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. T.W. Hansen: None. P. Rossing: Advisory Panel; Self; Sanofi. Consultant; Self; Astellas Pharma Inc., AstraZeneca, Bayer Healthcare Pharmaceuticals Inc., Boehringer Ingelheim International GmbH, Gilead Sciences, Inc., Novo Nordisk A/S. Research Support; Self; Novo Nordisk A/S. Speaker’s Bureau; Self; Eli Lilly and Company. Stock/Shareholder; Self; Novo Nordisk A/S. S. Andersen: None. K. Nørgaard: Advisory Panel; Self; Abbott, Medtronic. Research Support; Self; Novo Nordisk A/S. Speaker’s Bureau; Self; Medtronic, Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk Inc.
Novo Nordisk Foundation (NNF17SA0031406); Medtronic A/S