The correlation between cardiac structure and renal function deterioration in patients with metabolic kidney disease: a cohort study

Metabolic kidney disease (MKD) has become a significant cause of end-stage renal disease. This study aims to investigate the factors associated with the deterioration of renal function in patients with MKD (G2 ~ G4). This study is a single-center retrospective cohort analysis involving 618 paticipants with MKD (G2 ~ G4). It collected baseline clinical data and parameters of transthoracic echocardiography. Based on changes in renal function observed during the follow-up period, participants were categorized into a group exhibiting rapid renal function deterioration (RD group) and a relatively stable (RS) group. Death from non-renal causes was considered a competing risk event. A multifactorial competing risk regression model was employed to identify independent factors associated with rapid renal function deterioration. Interaction tests and sensitivity analyses were conducted to identify the consistence of the results. Internal validation was achieved through 1,000 Bootstrap resamplings, and time-dependent receiver operating characteristic (ROC) curves along with calibration curves were generated to assess the model’s predictive efficacy and accuracy. The optimal cut-off values for the anteroposterior diameter of the left atrium (LAD) and the interventricular septum thickness in diastole (IVSD) were established using the Maximally Selected Rank Statistics of Gray’s test. The average age of the 618 participants was 66.5. Multi-factor competing risk regression analysis revealed that cardiovascular disease (CVD) (sHR = 1.38), elevated urinary microalbumin/creatinine ratio (UACR) (30 ~ 300 mg/g: sHR = 2.04; >300 mg/g: sHR = 1.77), increased LAD (sHR = 1.06/mm), and thickening of the IVSD (sHR = 1.27/mm) were independently associated with an elevated risk of rapid deterioration of renal function. In contrast, patients with hemoglobin ≥ 110 g/L (sHR = 0.59) exhibited a reduced risk of rapid deterioration of renal function (P 0.05). The optimal cut-off values for LAD and IVSD, based on the maximum selection rank statistic, were determined to be 38.5 mm and 8.7 mm, respectively. Internal validation using 1,000 Bootstrap iterations indicates that the model exhibits strong calibration and discrimination, with a 36-month area under curve (AUC) of 0.84. CVD, elevated UACR, and cardiac structural abnormalities—specifically, an enlarged LAD and a thickened IVSD—are independently associated with an increased risk of rapid deterioration of renal function in MKD, while patients with hemoglobin ≥ 110 g/L have a lower risk of rapid deterioration of renal function. Monitoring these indicators aids in the early identification of high-risk patients. Not applicable.