Predicting the glomerular filtration rate in bariatric su

Allon Friedman, Sharon Moe, William F. Fadel, Margaret Inman, Samer G. Mattar, Zak Shihabi, Sara Quinney

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

Background/Aims: Identifying the best method to estimate the glomerular filtration rate (GFR) in bariatric surgery patients has important implications for the clinical care of obese patients and research into the impact of obesity and weight reduction on kidney health. We therefore performed such an analysis in patients before and after surgical weight loss. Methods: Fasting measured GFR (mGFR) by plasma iohexol clearance before and after bariatric surgery was obtained in 36 severely obese individuals. Estimated GFR was calculated using the Modification of Diet in Renal Disease equation, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation using serum creatinine only, the CKD-EPI equation using serum cystatin C only and a recently derived equation that uses both serum creatinine and cystatin C (CKD-EPIcreat-cystC) and then compared to mGFR. Results: Participants were primarily middle-aged white females with a mean baseline body mass index of 46 ± 9, serum creatinine of 0.81 ± 0.24 mg/dl and mGFR of 117 ± 40 ml/min. mGFR had a stronger linear relationship with inverse cystatin C before (r = 0.28, p = 0.09) and after (r = 0.38, p = 0.02) surgery compared to the inverse of creatinine (before: r = 0.26, p = 0.13; after: r = 0.11, p = 0.51). mGFR fell by 17 ± 35 ml/min (p = 0.007) following surgery. The CKD-EPI creat-cystC was unquestionably the best overall performing estimating equation before and after surgery, revealing very little bias and a capacity to estimate mGFR within 30% of its true value over 80% of the time. This was true whether or not mGFR was indexed for body surface area. Conclusions: In severely obese bariatric surgery patients with normal kidney function, cystatin C is more strongly associated with mGFR than is serum creatinine. The CKD-EPI creat-cystC equation best predicted mGFR both before and after surgery.

Original languageEnglish
Pages (from-to)8-15
Number of pages8
JournalAmerican Journal of Nephrology
Volume39
Issue number1
DOIs
StatePublished - Feb 2014

Fingerprint

Bariatrics
Cystatin C
Glomerular Filtration Rate
Creatinine
Chronic Renal Insufficiency
Bariatric Surgery
Epidemiology
Serum
Kidney
Weight Loss
Iohexol
Diet Therapy
Body Surface Area
Fasting
Patient Care
Body Mass Index
Obesity
Health
Research

Keywords

  • Bariatric surgery
  • Creatinine
  • Cystatin C
  • Estimating equation
  • Glomerular filtration rate
  • Obesity
  • Weight loss

ASJC Scopus subject areas

  • Nephrology

Cite this

Predicting the glomerular filtration rate in bariatric su. / Friedman, Allon; Moe, Sharon; Fadel, William F.; Inman, Margaret; Mattar, Samer G.; Shihabi, Zak; Quinney, Sara.

In: American Journal of Nephrology, Vol. 39, No. 1, 02.2014, p. 8-15.

Research output: Contribution to journalArticle

Friedman, Allon ; Moe, Sharon ; Fadel, William F. ; Inman, Margaret ; Mattar, Samer G. ; Shihabi, Zak ; Quinney, Sara. / Predicting the glomerular filtration rate in bariatric su. In: American Journal of Nephrology. 2014 ; Vol. 39, No. 1. pp. 8-15.
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KW - Creatinine

KW - Cystatin C

KW - Estimating equation

KW - Glomerular filtration rate

KW - Obesity

KW - Weight loss

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