Objective To investigate the effect of circadian rhythm imbalance of blood pressure on renal tubules in type 2 diabetes mellitus (T2DM) patients without hypertension or renal damage by observing the indexes of urinary renal tubule-related injury.Methods A total of 100 T2DM patients admitted to the Department of Nephrology,Hexin Hospital and Weifang Endocrinology and Metabolic Disease Hospital from January 2022 to October 2023 were selected as research subjects.According to the results of 24 h ambulate blood pressure monitoring,they were divided into arytenotype blood pressure group (45 cases) and non-arytenotype blood pressure group (55 cases).Urinary β2-microglobulin (β2-MG),retinol-binding protein (RBP),N-acetyl-β-D-glucosidase (NAG) to urine creatinine (UCr) ratio,the ratio of diurnal urine volume and urinary specific gravity between the two groups were compared.Results The urinary ratios of β2-MG,RBP,NAG and UCr in non-arytenotype blood pressure group were higher than those in arytenotype blood pressure group,and the differences were statistically significant (P＜0.05).There were no significant differences in the ratio of diurnal urine volume and urinary specific gravity between the two groups (P ＞0.05).Conclusion The circadian rhythm imbalance of blood pressure can damage the proximal renal tubules in T2DM patients,but has no significant effect on the distal renal tubules.The circadian rhythm imbalance of blood pressure can be used as a reference index of early kidney injury in diabetic patients.