UTILITY OF SERIAL MULTIPARAMETRIC MRI FOR MONITORING DISEASE PROGRESSION IN DIABETIC KIDNEY DISEASE: A PROSPECTIVE STUDY

Introduction:

Diabetes is a major cause of chronic kidney disease globally, highlighting the need for new non-invasive markers to better understand the pathogenesis and progression of diabetic kidney disease (DKD). We previously demonstrated that non-contrast multiparametric MRI (mpMRI) using a wide range of techniques enables both functional and structural assessment of DKD. However, there is a lack of longitudinal studies evaluating disease progression. In this follow-up study, we aimed to investigate the utility of serial mpMRI in monitoring DKD progression.

Methods:

This prospective study included:

· 38 subjects with diabetic kidney disease (DKD) aged 18–79 years and 20 age- and gender-matched healthy volunteers (HV) at baseline.  

· At 2 years ± 6 months, 31 DKD subjects (2 stage 2, 13 stage 3, 14 stage 4, and 2 stage 5) and 17 HV were re-examined. 

Measured glomerular filtration rate (mGFR) was assessed using iohexol clearance, while kidney volume and renal artery resistive index (RARI) were evaluated by mpMRI, both at baseline and 2-years.

Subjects were categorized as stable or as progressors if they met at least one of the following criteria at 2 years:

·       Decrease in mGFR slope >5 mL/year/1.73m²

·       Worsening UACR category

·       Any major adverse kidney event, defined as:

               o   Sustained decrease in estimated GFR (eGFR) >40%

               o   Doubling of serum creatinine from baseline

               o   Development of kidney failure (eGFR <15 mL/min/1.73m²)

               o   Death from renal cause

Results:

Among the included subjects, 8 out of 31 (26%) with DKD and 4 out of 17 (24%) HVs experienced progression. The mean 2-year mGFR decline (ml/min/1.73m²) was 2.7 ± 5.4 in DKD patients and 1.9 ± 10.7 in HVs. 

A high correlation between kidney volume and RARI at baseline and after 2 years was observed, as shown in Figure 1 (R² = 0.91 and 0.78, respectively). Figure 2 illustrates changes in kidney volume and RARI for both HV and DKD subjects, categorized as stable or progressors. Progressors in both groups showed a tendency for greater decreases in kidney volume and increases in RARI compared to stable subjects. Additionally, these changes tended to be more pronounced in individuals with DKD than in HVs.

Figure 1: Correlations between kidney volume and RARI at baseline and after 2-years.

Figure 2: Changes in kidney volume and RARI for Healthy Volunteers (HV) and subjects with Diabetic Kidney Disease (DKD) who were either stable (S) or progressors (P).

Conclusions:

The strong correlation found in kidney volume and RARI changes over time indicates stability in kidney structure and function measurements using mpMRI. Moreover, the tendency of greater magnitude of these changes in DKD suggests accelerated structural and functional kidney decline beyond normal aging. These findings highlight the potential of mpMRI-derived kidney volume and RARI as biomarkers for monitoring disease progression, particularly in DKD. Larger studies are needed to confirm and validate their clinical utility.

I have potential conflict of interest to disclose.
Funding support was received from Antaros Medical and AstraZeneca for conduct of this study.

I did not use generative AI and AI-assisted technologies in the writing process.