# Association between urinary albumin-to-creatinine ratio within the normal range and continuous glucose monitoring-derived metrics in children and adolescents with type 1 diabetes

## TL;DR

This study finds that even small increases in albumin excretion in children with type 1 diabetes are linked to poorer glucose control and higher fluctuations in blood sugar.

## Contribution

The study is the first to investigate the relationship between normal-range albuminuria and continuous glucose monitoring metrics in children with type 1 diabetes.

## Key findings

- Higher urinary albumin-to-creatinine ratio correlates with lower time in glucose target range and higher glucose variability.
- Time in range, glucose variability, and puberty independently predict higher albumin excretion in children with type 1 diabetes.
- Early glucose control and fluctuations may influence the development of kidney complications in childhood type 1 diabetes.

## Abstract

Albuminuria within the normal range may predict an increased risk of subsequent nephropathy in type 1 diabetes (T1D). The role of sustained hyperglycaemia in the development of nephropathy is well-known. The relationship between albuminuria within the normal range and parameters of continuous glucose monitoring (CGM) in childhood has not yet been investigated. The aim of the present study was to analyze this relationship in young T1D patients.

A total of 54 normoalbuminuric, normotensive, real time CGM user pubertal children and adolescents with T1D were recruited for this study. Patients with medium to high normal (1.0-2.9 mg/mmol; n = 18) and those with low normal (< 1.0 mg/mmol; n = 36) urinary albumin-to-creatinin ratio (UACR) were compared regarding CGM metrics data. Relationships of UACR with clinical variables and CGM-derived metrics were analysed by multiple logistic regression.

Time in range (TIR) was lower in medium to high normal UACR patients than in low normal UACR patients (mean ± SD: 58.2 ± 8.4% vs. 64.5 ± 10.1%, p = 0.0199). Patients with medium to high normal UACR had a higher coefficient of variation for mean glucose (CV) than those with low normal UACR (42.4 ± 6.0% vs. 38.0 ± 6.1%, p = 0.0163). UACR was related to TIR (r=-0.55, p = 0.02), to CV (r=-0.51, p = 0.04) and to mean glucose (MG) (r=-0.48, p = 0.05). TIR, CV and puberty proved to be independently predictive for medium to high normal UACR [adjusted RR (95% CI): 0.70 (0.58–0.92), p = 0.0231; 1.28 (1.02–1.67), p = 0.0222; 1.19 (1.10–1.36), p = 0.0321, respectively].

The duration of the blood glucose level within the target range and the extent of its fluctuation may contribute to the early increase in albumin excretion within the normal range, which may play a role in the development of later complications of childhood T1D.