Association of time in range levels with diabetic nephropathy in patients with type 2 diabetes

Objective To evaluate the association between time in range(TIR) during continuous glucose monitoring and the prevalence and degree of diabetic nephropathy(DN). Methods A total of 169 subjects with type 2 diabetes mellitus(T2DM) were recruited. Based on the value of urine albumin creatine ratio(UACR), they were divided into three groups of normoal buminuria, microalbuminuria, macroalbuminuria. And 72-hour dynamic blood glucose were monitored by a sensor-based flash glucose monitoring system and glycemic variability parameters calculated, including TIR, glucose coefficient of variation, standard deviation and mean amplitude of glycemic excursions. Spearman's correlation and multivariate Logistic regression were employed for examining the relationship between TIR and DN. Results TIR level was significantly lower in normoalbuminuria group than that in microalbuminuria/macroalbuminuria group(P<0.05). Furthermore, the prevalence of DN declined markedly with ascending quartiles of TIR(P<0.05). Spearman's correlation analysis showed that TIR was negatively correlated with the severity of DN(r=-0.609, P<0.05). Logistic regression analysis after adjusting confounding factors showed that a lower level of TIR was significantly associated with a rising risk of microalbuminuria and/or macroalbuminuria. Conclusion Low TIR level may be a risk factor for DN. And TIR can be employed as a new index for predicting the occurrence risk and severity of DN.