Observational Study
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World J Nephrol. Nov 6, 2014; 3(4): 317-323
Published online Nov 6, 2014. doi: 10.5527/wjn.v3.i4.317
Residual urinary output in high body mass index individuals on chronic hemodialysis: A disregarded life vest?
Hernán Trimarchi, María S Raña, Alejandra Karl, José Andrews, Mariana Dicugno, Vanesa Pomeranz, Pablo Young, Mariano Forrester, Mirta Alonso, Fernando Lombi, Alexis Muryan
Hernán Trimarchi, María S Raña, Alejandra Karl, José Andrews, Vanesa Pomeranz, Mariano Forrester, Fernando Lombi, Nephrology, Hospital Británico de Buenos Aires, C1280AEB Buenos Aires, Argentina
Mariana Dicugno, Mirta Alonso, Alexis Muryan, Biochemistry, Hospital Británico de Buenos Aires, C1280AEB Buenos Aires, Argentina
Pablo Young, Internal Medicine Services, Hospital Británico de Buenos Aires, C1280AEB Buenos Aires, Argentina
Author contributions: All the authors solely contributed to this paper.
Correspondence to: Hernán Trimarchi, MD, Nephrology, Hospital Británico de Buenos Aires, Perdriel 74, C1280AEB Buenos Aires, Argentina. htrimarchi@hotmail.com
Telephone: +54-11-43096400 Fax: +54-11-43043393
Received: April 18, 2014
Revised: September 19, 2014
Accepted: September 23, 2014
Published online: November 6, 2014
Abstract

AIM: To assess residual diuresis and diverse variables according to body mass index (BMI).

METHODS: Cross-sectional study (n = 57), with 3 groups. Group A: BMI < 25, n = 22; Group B: BMI 25-30, n = 15; Group C: BMI > 30, n = 20. Diuresis, hematocrit, albumin, C-reactive protein, Malnutrition inflammatory score, Pro-BNP, Troponin T, leptin and insulin levels are expressed as median and ranges (r).

RESULTS: Albumin (g/dL): GA vs GC, 3.70 (r2.20-4.90) vs 3.85 (r3.40-4.90), P = 0.02. Diuresis (mL/d): GA 690 (r0-1780); GB 660 (r60-1800); GC 840 (r40-2840). Diuresis GA vs GC, P = 0.01. Leptin (ng/mL): GA vs GC, 3.81 (r0.78-69.60) vs GC, 32.80 (r0.78-124.50), P < 0.001. Insulin (µU/mL): GA vs GB, 7 (r2-44) vs 11.50 (r4-38), P = 0.02; GA vs GC, 7 (r2-44) vs 19.5 (r5-155), P = 0.0001. Troponin T and Pro-BNP levels were not different. Significant correlations: GC, Insulin-UF: ρ = 0.53; P = 0.03; TroponinT-diuresis: ρ = -0.48, P < 0.05; Pro-BNP-diuresis: ρ = -0.39, P < 0.01; Troponin T-ProBNP: ρ = 0.77, P < 0.0001; albumin-Troponin T: ρ = -0.66, P < 0.0001; albumin-ProBNP: ρ = -0.44, P < 0.05.

CONCLUSION: High BMI associated positively with higher diuresis and albuminemia, and negatively with TropT and Pro-BNP. High BMI-associated better survival may be explained by better urinary output, lowering cardiovascular stress.

Keywords: Hemodialysis, Residual diuresis, Body mass index, Troponin T, Pro-BNP, Insulin

Core tip: Cardiovascular disease is the major cause of death in hemodialysis, while residual diuresis and increased body mass index (BMI) are associated with better survival. We found that an elevated BMI > 30 associated positively with higher diuresis, insulin levels and albuminemia. This higher urinary output dialysis individuals with BMI > 30%, may reflect water retention, in part due to hyperinsulinemia, hyperleptinemia and secondary higher ultrafiltration rates. The ability to excrete water correlates negatively and significantly with Troponin T and Pro-BNP levels, reflecting lower myocardial and vascular overload. High BMI-associated better survival may be explained by better diuresis, and lower cardiovascular stress.