P0445PREVALENCE AND PREDICTORS OF GLYCOSURIA IN PRIMARY GLOMERULOPATHIES

Abstract

Abstract Background and Aims Albuminuria is a marker of glomerular lesion, however some studies have suggested that proximal tubule (endocytosis of albumin) is also essential to determine the amount of albumin excreted in the urine. It has been hypothesized that patients with glomerulopathies and concomitant tubular damage might present higher levels of albuminuria. Glycosuria is a marker of proximal tubular dysfunction and may be used as an easy and useful marker of tubular lesion in glomerular diseases. The aim of this transversal study was to evaluate the prevalence of glycosuria in primary glomerulopathies (GP) and identify its predictors. Method We included all patients diagnosed in the last 10 years in our centre with primary GP confirmed by renal biopsy. Clinical, laboratory and biopsy results were collected from patients’ charts. Patients were divided in two groups according to their glycosuric status at the diagnosis. Exclusion criteria: patients with diabetes and glucose intolerance, use of SGLT2 inhibitors, transplant kidney patients and secondary GP. Results We studied 110 patients – 39 (35.5%) IgA Nephropathy (IgAN), 27 (24.5%) Membranous Nephropathy (MN), 26 (23.6%) Focal Segmental Glomerulosclerosis (FSGS) and 18 (16.4%) Minimal Change Disease (MCD). Demographic data were not different between patients with and without glycosuria. Global prevalence of glycosuria was 9.1% (n=10) – patients with MN had higher prevalence of glycosuria (n=4, 17.4%), followed by FSGS (n=3, 15.5%), MCD (n=1, 5.9%) and IgAN (n=2, 5.4%). We found that patients with glycosuria had higher serum creatinine (3.9±5.1 vs 1.7±1.3 mg/dL, p=0.001), higher albuminuria (7.1±6.3 vs 3.2±3.4 g/g, p=0.002), lower serum albumin (2.3±0.7 vs 3.2±1.1 g/dL, p=0.022) and lower hemoglobin (12.0±2.5 vs 13.4±2.0 g/dL, p=0.050). Nevertheless, we did not find differences between glycosuric and non-glycosuric patients in percentage of glomerular sclerosis (%GS) or interstitial fibrosis and tubular atrophy (IFTA). In a multivariate analysis, glycosuria was positively associated with MN diagnosis, serum creatinine and albuminuria, but not with hematuria, %GS and IFTA. Conclusion Glycosuria is not frequent in primary GP. MN is the primary GP that most frequently presents glycosuria. Glycosuria is associated with higher albuminuria and lower serum albumin levels, corroborating the hypothesis that albuminuria as an offender to the tubules will affect the amount of albumin excreted in the urine. We also found that patients with glycosuria presented a more severe renal dysfunction (higher creatinine) at the GP diagnosis.