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Obesity-Related Kidney Disease in Bariatric Surgery Candidates
Pedro Reis Pereira1,2,3, Manuela Almeida4,5,6, Patrícia Braga5,6
1Department of Nephrology, Unidade Local de Saúde de Santo António, (ULS Santo António), Porto, Portugal. pedroreisper@gmail.com.
Background:
Obesity has a negative impact in kidney health. However, the hallmarks of kidney dysfunction in bariatric surgery candidates are poorly characterized. To address this knowledge gap, we used a propensity score-matched analysis to compare kidney lesion biomarkers in bariatric surgery candidates and living kidney donors.
Methods:
Bariatric surgery candidates attending a single center for obesity treatment were pair-matched for sex and age to potential living kidney transplant donors (PLKD) using a 1:1 nearest-neighbor approach (N = 400, n = 200/group). A 24-h urine collection was used to analyze proteinuria and creatinine clearance.
Results:
Patients with obesity (PWO) had higher creatinine clearance when compared to PLKD (143.35 ± 45.50 mL/min vs 133.99 ± 39.06 mL/min, p = 0.03), which was underestimated when correction for body surface area (BSA) was used (creatinine clearance corrected for BSA of 115.25 ± 33.63 mL/min/1.73 m2 in PWO vs 135.47 ± 35.56 mL/min/1.73 m2 in PLKD). Proteinuria was also higher in PWO compared to PLKD (139.82 ± 353.258 mg/day vs 136.35 ± 62.24 mg/day, p < 0.0001). Regression analysis showed that creatinine clearance was strongly correlated with proteinuria in PWO (HR 1.522, p = 0.005), but it was less evident in PLKD (HR 0.376, p = 0.001).
Conclusion:
Hyperfiltration and disproportionate proteinuria are frequent in patients with obesity. Since hyperfiltration can be underestimated by adjusting creatinine clearance for BSA, this should not be used when evaluating kidney function in bariatric surgery candidates.
Insights
Obesity is linked to kidney dysfunction, with patients showing higher creatinine clearance and proteinuria. Adjusting for body surface area may underestimate kidney hyperfiltration in bariatric surgery candidates.
Area of Science:
- Nephrology
- Bariatric Surgery
- Obesity Medicine
Background:
- Obesity negatively impacts kidney health, but specific markers of kidney dysfunction in bariatric surgery candidates are not well-defined.
- Understanding these markers is crucial for assessing surgical risk and patient outcomes.
Purpose of the Study:
- To characterize kidney dysfunction biomarkers in patients with obesity undergoing bariatric surgery.
- To compare kidney function markers between bariatric surgery candidates and living kidney donors.
Main Methods:
- A propensity score-matched analysis was conducted on 400 participants (200 bariatric surgery candidates and 200 potential living kidney donors).
- 24-hour urine collections were analyzed for proteinuria and creatinine clearance.
Main Results:
- Patients with obesity (PWO) exhibited higher creatinine clearance (143.35 ± 45.50 mL/min) than potential living kidney donors (PLKD) (133.99 ± 39.06 mL/min, p=0.03).
- BSA-corrected creatinine clearance underestimated hyperfiltration in PWO.
- Proteinuria was significantly higher in PWO (139.82 ± 353.258 mg/day) compared to PLKD (136.35 ± 62.24 mg/day, p<0.0001).
- Creatinine clearance strongly correlated with proteinuria in PWO, but less so in PLKD.
Conclusions:
- Hyperfiltration and disproportionate proteinuria are common in patients with obesity.
- Adjusting creatinine clearance for BSA can underestimate kidney hyperfiltration in bariatric surgery candidates and should be avoided.
- These findings highlight the need for careful kidney function assessment in this population.
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