Hyperuricemia and hypertriglyceridemia indicate tubular atrophy/interstitial fibrosis in patients with IgA nephropathy and membranous nephropathy

Abstract

Purpose: Hyperuricemia (HUA) and hypertriglyceridemia (HTG) were very common in chronic kidney disease (CKD) and associated with accelerated progression of CKD. This was a retrospective, cross-sectional study which aimed to explore the relationship between serum uric acid levels or triglyceride levels and tubular atrophy/interstitial fibrosis (proven by renal biopsy).

Methods: The present study enrolled 229 CKD individuals who included 127 biopsy-proven primary IgA nephrology (IgAN) patients and 102 biopsy-proven primary membranous nephropathy (MN) patients. The baseline characteristics at the time of the kidney biopsy were collected. According to the serum uric acid (UA) or triglyceride (TG) whether it exceeds the normal reference range, patients were divided into non-HUA (n = 127), HUA (n = 102), non-HTG (n = 119), and HTG group (n = 110). Based on the extent of tubular atrophy/interstitial fibrosis, patients were divided into no/mild injury (T0, n = 127), moderate injury (T1, n = 102). Multivariable logistic regression for factors predicting moderate tubular atrophy/interstitial fibrosis was performed.

Results: There were 127 IgAN and 102 MN cases among 229 patients in the present study. The prevalence of HUA was 44.5% (n = 102), 40.9% (n = 52), and 49.0% (n = 50) in all patients, IgAN patients and MN patients, respectively (P = 1.49). The prevalence of HTG was 48.0% (n = 110), 29.9% (n = 38), and 70.6% (n = 72) (P < 0.001), respectively, as well. Multivariate logistic regression analysis showed that HUA and HTG were independent risk factors for moderate tubular atrophy/interstitial fibrosis (HUA OR = 2.335, 95% CI = 1.147-4.755, P = 0.019; HTG OR = 2.646, 95% CI = 1.289-5.432, P = 0.008). The area under curve (AUC) of model 1 (HUA + eGFR + HTG + age + serum globulin + 24 h urinary protein, AUC = 0.876) was larger than the other two models; however, there was no significant difference among these models (all P > 0.05).

Conclusions: Hyperuricemia and hypertriglyceridemia, which were prevalent in CKD patients, were the independent risk factors for moderate tubular atrophy/interstitial fibrosis. HUA together with HTG could improve the value of diagnosis for moderate tubular atrophy/interstitial fibrosis to some extent.

Keywords: Hypertriglyceridemia; Hyperuricemia; IgA nephrology; Membranous nephropathy; Tubular atrophy/interstitial fibrosis.