Ultrasound Renal Score to Predict the Renal Disease Prognosis in Patients with Diabetic Kidney Disease: An Investigative Study

Abstract

Renal disease associated with type 2 diabetes mellitus (T2DM) has become the leading cause of chronic kidney disease (CKD). Renal ultrasonography is an imaging examination required in the work-up of renal disease. This study aimed to identify the differences in renal ultrasonographic findings between patients with and without DM, and to evaluate the relationship between renal ultrasound findings and renal prognosis in patients with DM. A total of 252 patients who underwent renal ultrasonography at Chungnam National University Hospital were included. Kidney disease progression was defined as a ≥10% decline in the annual estimated glomerular filtration rate (eGFR), which, in this paper, is referred to as ΔeGFR/year, or the initiation of renal replacement therapy after follow-up. The renal scoring system was evaluated by summing up the following items: the value of renal parenchymal echogenicity (0: normal; 1: mildly increased; and 2: increased) and the shape of the cortical margin (0: normal and 1: irregular; right kidney length/height (RH-0 or 1), mean cortical thickness/renal length/height (CKH-0 or 1), and cortical thickness/parenchymal thickness (CK/PK-0 or 1) based on the median: 0-above median, and 1-below median). Patients with DM had thicker renal PKH than those without, despite having lower eGFRs (0.91 ± 0.15, 0.86 ± 0.14, p = 0.006). In the progression group, the renal scores were significantly higher than those from the non-progression group. In the multivariate logistic regression analysis, the higher renal scores, presence of DM, and younger age were independently predicted for renal disease progression after adjusting for confounding variables, such as the presence of hypertension, serum hemoglobin and albumin levels, and UPCR. In conclusion, patients with high renal scores were significantly associated with renal disease progression. Our results suggest that renal ultrasonography at the time of diagnosis provides useful prognostic information in patients with kidney disease.

Keywords: diabetes mellitus; renal replacement therapy; renal ultrasound.

Figure 1

Representative pictures of ultrasound findings: (A) a 63-year-old male with normal renal ultrasound; (B) a 54-year-old female with diabetes; (C) a 54-year-old male with eGFR > 60 mL/min/1.73 m²; (D) a 65-year-old male with eGFR 45 mL/min/1.73 m² (arrow: measurement of cortical thickness; bar: measurement of parenchymal thickness).

Figure 2

Representative picture of measurements using renal scoring.

Figure 3

Correlation between ultrasound findings and baseline eGFR. (A) RH and eGFR. (B) CK and eGFR. (C) PK and eGFR. Abbreviations: eGFR: estimated glomerular filtration rate; RH: renal length/height; CK: cortical thickness; PK: parenchymal thickness.