Prognostic significance of interstitial fibrosis and tubular atrophy in biopsy-proven diabetic kidney disease: a single-center retrospective cohort study.
Interstitial fibrosis and tubular atrophy (IFTA) is an important pathological feature of diabetic kidney disease (DKD). Its prognostic value in biopsy-proven DKD remains incompletely understood.
In this retrospective study, 164 patients with type 2 diabetes and biopsy-confirmed pure DKD were followed for a median of 38 months. The primary composite kidney endpoint was initiation of kidney replacement therapy or kidney-related death. Predictors were selected using LASSO Cox regression. Random survival forest was used as an exploratory complementary analysis.
Thirty-four patients reached the composite kidney endpoint. After LASSO selection and multivariable adjustment, IFTA score 2/3 (vs. IFTA score 1, HR 3.96, 95%, CI 1.71-9.16, P = 0.001), 24-hour proteinuria (per 1 g/day increase; HR 1.52, 95%, CI 1.19-1.94, P < 0.001), and lower serum calcium (per 1 mmol/L increase; HR 0.140, 95% CI 0.041-0.481, P = 0.002) were independently associated with the composite kidney endpoint. In the random survival forest analysis, serum calcium, baseline eGFR, and IFTA were among the most important variables. Patients with IFTA 2/3 had significantly lower kidney survival than those with IFTA 1 (log-rank P = 0.0056).
In biopsy-proven DKD, IFTA 2/3 was associated with the composite kidney endpoint. Higher 24-hour proteinuria and lower serum calcium were associated with poor kidney outcomes. Further studies are needed to confirm these findings and clarify their clinical implications.
In this retrospective study, 164 patients with type 2 diabetes and biopsy-confirmed pure DKD were followed for a median of 38 months. The primary composite kidney endpoint was initiation of kidney replacement therapy or kidney-related death. Predictors were selected using LASSO Cox regression. Random survival forest was used as an exploratory complementary analysis.
Thirty-four patients reached the composite kidney endpoint. After LASSO selection and multivariable adjustment, IFTA score 2/3 (vs. IFTA score 1, HR 3.96, 95%, CI 1.71-9.16, P = 0.001), 24-hour proteinuria (per 1 g/day increase; HR 1.52, 95%, CI 1.19-1.94, P < 0.001), and lower serum calcium (per 1 mmol/L increase; HR 0.140, 95% CI 0.041-0.481, P = 0.002) were independently associated with the composite kidney endpoint. In the random survival forest analysis, serum calcium, baseline eGFR, and IFTA were among the most important variables. Patients with IFTA 2/3 had significantly lower kidney survival than those with IFTA 1 (log-rank P = 0.0056).
In biopsy-proven DKD, IFTA 2/3 was associated with the composite kidney endpoint. Higher 24-hour proteinuria and lower serum calcium were associated with poor kidney outcomes. Further studies are needed to confirm these findings and clarify their clinical implications.
Authors
Zhang Zhang, Wu Wu, Yang Yang, Zhou Zhou, Guo Guo, Yu Yu, Song Song, Bao Bao, Yang Yang, Yan Yan
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