A cohort study on the correlation between serum uric acid trajectory and the progression of renal function in patients with Type 2 diabetes mellitus / 中南大学学报(医学版)

OBJECTIVES@#Diabetic kidney disease is one of the most serious complications of diabetes mellitus (DM), and it is a main cause for chronic kidney disease and end-stage kidney disease (ESRD). It is important to find out the factors that cause the progression of renal function. The study aims to explore the relationship between serum uric acid (SUA) trajectory and the progression of renal function in patients with Type 2 diabetes mellitus (T2DM).@*METHODS@#A total of 846 patients with T2DM, who were admitted to the Department of Nephrology and Endocrinology, the Third Xiangya Hospital of Central South University, from January 2009 to December 2021 and met the criteria of baseline estimated glomerular filtration rate (eGFR)≥60 mL/(min·1.73 m2), were selected as the research subjects. The SUA data of multiple measurements were collected and identified as different SUA trajectories by group-based trajectory modeling (GBTM). According to the SUA trajectories, the patients were divided into a low trajectory group (105 cases), a middle trajectory group (396 cases), a middle high trajectory group (278 cases), and a high trajectory group (67 cases). Cox regression analysis was used to examine the effect of SUA trajectory on the progression of renal function in patients with T2DM. Subgroup analysis was performed by sex, age, course of disease, body mass index (BMI) and hemoglobin A1c (HbA1c).@*RESULTS@#The median follow-up was 4.8 years. At the end of follow-up, 158 patients had different degrees of decline in renal function. After adjusting for multiple confounding factors by Cox regression analysis, the risks of eGFR<60 mL/(min·1.73 m2), eGFR reduction rate≥50%, serum creatinine (Scr) doubling and composite endpoint (eGFR reduction rate≥50%, Scr doubling or ESRD) in the high trajectory group were significantly higher than those in the low trajectory group, with HR of 3.84 (95% CI 1.83 to 8.05), 6.90 (95% CI 2.27 to 20.96), 6.29 (95% CI 2.03 to 19.52), and 8.04 (95% CI 2.68 to 24.18), respectively. There was no significant difference in the risk of ESRD among the above 4 groups (all P>0.05). Subgroup analysis showed that: compared with the low trajectory group, the risks of eGFR<60 mL/(min·1.73 m2) in patients with high trajectory in the subgroup of male, female, age<65 years, course of disease<10 years, BMI≥24 kg/m2 and HbA1c≥7% were increased (all P<0.05). The SUA trajectory had no interaction with sex, age, course of disease, BMI and HbA1c (all interactive P>0.05).@*CONCLUSIONS@#The high SUA trajectory increases the risk for progression of renal function in patients with T2DM. Long-term longitudinal changes of SUA should be paid attention to.

Association between serum C3 and progression of renal function in IgA nephropathy / 中华肾脏病杂志

Objective:To investigate the relationship between serum C3 and progression of renal function in IgA nephropathy.Methods:A single-center retrospective cohort study was conducted in patients with IgA nephropathy confirmed by renal biopsy who were admitted to the Second People's Hospital of Shenzhen from January 2011 to June 2020 and the patients were followed up until January 2021. Patients with secondary IgA nephropathy, baseline estimated glomerular filtration rate (eGFR)<30 ml·min -1·(1.73 m 2) -1, lack of baseline serum C3 or creatinine, and follow-up time<6 months were excluded. The clinical data, laboratory examination and renal pathology were collected. The threshold effect analysis was used to obtain the cut-off point, and inflection point and 95% confidence interval were obtained using bootstrapping resampling technique. According to the cut-off point, the patients were divided into serum C3<0.97 g/L group and C3≥0.97 g/L group. The baseline data between the two groups were compared. Cox regression model was used to analyze the correlation between serum C3 level and renal function progression. Results:A total of 414 patients were enrolled in this study, with 145 males (35.0%), and age of (35.15±9.18) years old. The baseline eGFR was 77.80(46.67, 106.10) ml·min -1·(1.73 m 2) -1, and the serum C3 was (1.04 ± 0.19) g/L. There were 153 patients with serum C3<0.97 g/L and 261 patients with serum C3≥0.97 g/L. Compared to patients with serum C3≥0.97 g/L, those patients with serum C3<0.97 g/L were younger and had higher proportion of females, higher levels of hemoglobin and eGFR, and lower levels of mean arterial pressure, total cholesterol, triglyceride, serum uric acid, serum creatinine, 24 h urinary protein, IgA and C4 (all P<0.05). The relationship between serum C3 and progression of renal function was found to be U-shaped by smooth curve fitting. After adjustment for confounding factors such as age, sex, mean arterial pressure, serum uric acid, 24 h urinary protein, and renal pathology (MESTC), the results of the threshold effect and multivariate Cox regression showed, for patients with C3<0.97 g/L, the risk of renal function progression decreased by 40% for every 0.1 g/L increase of C3 ( HR=0.60, 95% CI 0.39-0.94, P=0.024), but for patients with C3≥0.97 g/L, every 0.1 g/L increase in serum C3 increased the risk of renal function progression by 27%( HR=1.27, 95% CI 1.03-1.57, P=0.027). The inflection point was 0.97(95% CI 0.92-1.01) g/L. Conclusions:Serum C3 is nonlinear correlated with the progression of renal function in patients with IgA nephropathy. Serum C3 level maintaining at 0.92-1.01 g/L is associated with better renal prognosis.