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Abstract: FR-PO466

Non-Proteinuric versus Proteinuric Phenotypes in Diabetic Nephropathy: A Propensity Score Matched Analysis of a Nationwide, Biopsy-Based Cohort Study

Session Information

Category: Diabetic Kidney Disease

  • 602 Diabetic Kidney Disease: Clinical

Authors

  • Yamanouchi, Masayuki, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
  • Furuichi, Kengo, Kanazawa University, Kanazawa, Japan
  • Hoshino, Junichi, Toranomon Hospital, Tokyo, Japan
  • Ubara, Yoshifumi, Toranomon Hospital, Tokyo, Japan
  • Wada, Takashi, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
Background

Several cross-sectional studies have recently shown that a proportion of patients with type 2 diabetes mellitus develop loss of renal function without overt proteinuria or even without microalbuminuria, suggesting the existence of non-proteinuric phenotype of diabetic nephropathy. Their clinicopathological characteristics and renal prognosis, however, are scarce.

Methods

We retrospectively assessed patients with type 2 diabetes mellitus, who underwent clinical renal biopsy from Jan 1, 1985 to Dec 31, 2016 and had follow-up data until Dec 31, 2017, from the Japan’s nationwide multicenter renal biopsy registry. Among 795 patients, we restricted 526 patients with reduced renal function (defined as estimated glomerular filtration rate <60 mL/min/1.73m2) and had a pathological diagnosis of diabetic nephropathy as the only glomerular disease diagnosis. 88 were non-proteinurics (urine albumin to creatinine ratio (UACR) <300 mg/gCre), and 438 patients were proteinurics (UACR ≥300 mg/gCre). For comparative analyses, we derived one-to-one paired cohorts of those without proteinuria versus those with proteinuria using propensity-score matching (matched by age, gender, and baseline eGFR). The primary endpoint was progression of CKD defined as new-onset ESRD, decrease of eGFR by ≥ 50%, or doubling of serum creatinine.

Results

In the matched analyses (82 patients in each group), patients with non-proteinuric diabetic nephropathy had lower systolic blood pressure and total cholesterol level, higher serum albumin level, and less frequent typical pathological lesions. After a median follow-up of 3.0 years (IQR 1.0-6.6) from the date of renal biopsy, 65 (40%) of the 164 matched patients had renal events. The 5-year CKD progression-free survival for all patients was 63.3% (95% CI, 53.3-71.7): 86.7% (95% CI, 72.5-93.8) for the non-proteinuric diabetic nephropathygroup and 43.2% (95% CI, 30.2-55.6) for the proteinuric diabetic nephropathygroup (log-rank test p<0.001). The lower renal risk in non-proteinuric diabetic nephropathy group was consistent across all subgroup analysis.

Conclusion

Patients with non-proteinuric diabetic nephropathy had lower blood pressure and less typical morphological changes, and were at lower risk of CKD progression.