ABSTRACT
Background. Precise estimation of the glomerular filtration rate (GFR) and the identification of markers of progression are important. We compared creatinine, cystatin, and combined CKD-EPI equations with (99m)Tc-DTPA scintigraphy to measure GFR and proteinuria as markers of progression. Methods. Cross-sectional, observational study including 300 subjects. CKD was classified by (99m)Tc-DTPA scintigraphy. Determinations. Creatinine, 24-hour creatinine clearance, cystatin, Hoek formula, and creatinine, cystatin, and combined CKD-EPI equations. Results. In the global assessment, creatinine CKD-EPI and combined CKD-EPI equations yielded the highest correlations with (99m)Tc-DTPA: ρ = 0.839, P < 0.0001 and ρ = 0.831, P < 0.0001. Intergroup analysis versus (99m)Tc-DTPA: control G, creatinine clearance ρ = 0.414, P = 0.013; G3, combined CKD-EPI ρ = 0.5317, P < 0.0001; G4, Hoek ρ = 0.618, P < 0.0001, combined CKD-EPI ρ = 0.4638, P < 0.0001; and G5, creatinine clearance ρ = 0.5414, P < 0.0001, combined CKD-EPI ρ = 0.5288, P < 0.0001. In the global assessment, proteinuria displayed the highest significant correlations with cystatin ( ρ = 0.5433, P < 0.0001) and cystatin-based equations (Hoek: ρ = -0.5309, P < 0.0001). When GFR < 60 mL/min: in stage 3, proteinuria-cystatin ( ρ = 0.4341, P < 0.0001); proteinuria-Hoek ( ρ = -0.4105, P < 0.0001); in stage 4, proteinuria-cystatin ( ρ = 0.4877, P < 0.0001); proteinuria-Hoek ( ρ = -0.4877, P = 0.0026). Conclusions. At every stage of GFR < 60 mL/min, cystatin-based equations displayed better correlations with (99m)Tc-DTPA. Proteinuria and cystatin-based equations showed strong associations and high degrees of correlation.
ABSTRACT
BACKGROUND: Certain adipokines exert direct effects on proteinuria, a cardiovascular risk factor ignored in hemodialysis. We measured different adipokines according to body mass index (BMI) in relation to proteinuria. METHODS: Patients numbered 57: group A (GA), BMI<25, n = 22; GB, BMI 25-30, n = 15; and GC, BMI > 30, n = 20. There were no statistical differences in age, sex, time on dialysis, cause of renal failure, diabetes, hypertension, C-reactive protein, or nutritional status. Measures were taken of 24-hour diuresis and proteinuria, ultrafltration, albumin, pro-brain natriuretic peptide (Pro-BNP), insulin, adiponectin, leptin, and ghrelin. RESULTS: Proteinuria was signifcantly higher in GC versus (vs) GA (1.5 g/day, range 0.30-14 vs 0.72 g/day, range 0.1-2.7; P < 0.01) and correlated signifcantly with leptin levels (ρ = 0.47, P < 0.05). In GA, elevated levels of Pro-BNP, adiponectin, and ghrelin were associated with lower degrees of proteinuria. Signifcant correlations were found between adiponectin and leptin (ρ = -0.54, P = 0.03), and adiponectin and Pro-BNP (ρ = 0.59, P = 0.02). Though not signifcant, there were more diabetics in GC (GA four, GB three, GC ten). As BMI increased in GB and GC, Pro-BNP, adiponectin, and ghrelin levels decreased signifcantly, while proteinuria, insulin, and homeostasis model assessment of insulin resistance increased. Leptin levels were signifcantly elevated in GC vs GA and GB. In GC, ghrelin correlated signifcantly with Pro-BNP (ρ = 0.51, P = 0.03), while leptin correlation with Pro-BNP was inverse and signifcant in GA (ρ = -0.74, P < 0.001) and inverse and nonsignifcant in GB and GC. CONCLUSION: In patients with BMI < 25, higher adiponectin, ghrelin, and Pro-BNP levels were associated with lower proteinuria and leptinemia. In obesity, hyperleptinemia and hyperinsulinemia associated with higher proteinuria; whether decreased adiponectin-ghrelin-ProBNP and/or elevated leptin-insulin levels aggravate proteinuria remains to be determined.
ABSTRACT
Primary glomerulonephritis stands as the third most important cause of end-stage renal disease, suggesting that appropriate treatment may not be as effective as intended to be. Moreover, proteinuria, the hallmark of glomerular damage and a prognostic marker of renal damage progression, is frequently resistant to thorough control. In addition, proteinuria may be the common end pathway in which different pathogenetic mechanisms may converge. This explains why immunosuppressive and nonimmunosuppressive approaches are partly not sufficient to halt disease progression. One of the commonest causes of primary glomerulonephritis is mesangioproliferative glomerulonephritis. Among the triggered intracellular pathways involved in mesangial cell proliferation, the mammalian target of rapamycin (mTOR) plays a critical role in cell growth, in turn regulated by many cytokines, disbalanced by the altered glomerulopathy itself. However, when inhibition of mTOR was studied in rodents and in humans with primary glomerulonephritis the results were contradictory. In light of these controversial data, we propose an explanation for these results, to dilucidate under which circumstances mTOR inhibition should be considered to treat glomerular proteinuria and finally to propose mTOR inhibitors to be prospectively assessed in clinical trials in patients with primary mesangioproliferative glomerulonephritis, for which a satisfactory standard immunosuppressive regimen is still pending.
ABSTRACT
BACKGROUND: Cardiovascular disease is the leading cause of morbidity and mortality in hemodialysis (HD) patients, the main etiologies being diabetes and hypertension. Cardiac and inflammatory biomarkers are usually employed to assess risk or damage, or during follow-up. Proteinuria is considered a strong predictor of morbidity, a cause of inflammation, oxidative stress, hemodynamic alteration, and progression of chronic kidney disease. However, proteinuria is rarely considered in the clinical assessment of HD patients. METHODS: This was a concurrent, cohort-observational, cross-sectional study in which 52 chronic HD subjects were divided into three groups according to the degree of proteinuria: Group (G) A: <1 g/day, n = 25; GB: 1-3 g/day, n = 13; GC: >3 g/day, n = 14. Baseline hemoglobin, albuminemia, cholesterol, body mass index, Malnutrition-Inflammatory Score, pro-B-type natriuretic peptide, troponin T, C-reactive protein (CRP), and ultrafiltration rates were analyzed. RESULTS: There was no difference between groups in terms of baseline age, gender, hypertension, cause of renal failure, hemoglobin, cholesterol, albumin, CRP levels, cardiac biomarkers, adiponectin, body mass index, or Malnutrition-Inflammatory Score. Time on HD: GA, 34.56 ± 23.3 (range [r]: 6-88); GB, 25.15 ± 19.40 (r: 6-58); GC, 18.21 ± 9.58 (r: 6-74) months; P = 0.048. Proteinuria: GA, 0.33 ± 0.30 (r: 0.0-0.88); GB, 1.66 ± 0.54 (r: 1.03-2.75); GC, 7.18 ± 2.80 (r: 3.04-21.5) g/day; P < 0.001. Mean ultrafiltration rates were significantly different: GA, 2.80 ± 0.73; GB: 1.85 ± 0.96 liters/session; P = 0.003. Fourteen diabetic patients were identified (27%): GA, 3 (12%); GB, 3 (23%); GC, 8 (57%); P = 0.009. A positive and significant correlation was observed between diabetes and proteinuria >3 g/day: rho 0.438, P = 0.027. Although troponin T, pro-B-type natriuretic peptide, adiponectin, and CRP were not different among groups, the positive correlation between troponin T and CRP elevated significantly as proteinuria increased: GA, rho 377, P = 0.063; GB, rho 663, P = 0.013; GC, rho 687, P = 0.007. CONCLUSION: In chronic HD, nephrotic-range proteinuria was significantly higher in diabetic nephropathy patients versus other causes. This was associated with inflammation and cardiac stress and was independent of fluid removal. Proteinuria >3 g/day was associated with shorter time on HD. Whether severe proteinuria is associated with shorter survival in HD, independent of diabetes, is to be determined. Proteinuria should be considered in the assessment of cardiovascular and inflammatory states in HD patients.
