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Alhummiany B, Sharma K, Buckley DL, Soe KK, Sourbron SP. Physiological confounders of renal blood flow measurement. MAGMA (NEW YORK, N.Y.) 2023:10.1007/s10334-023-01126-7. [PMID: 37971557 DOI: 10.1007/s10334-023-01126-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 09/26/2023] [Accepted: 10/12/2023] [Indexed: 11/19/2023]
Abstract
OBJECTIVES Renal blood flow (RBF) is controlled by a number of physiological factors that can contribute to the variability of its measurement. The purpose of this review is to assess the changes in RBF in response to a wide range of physiological confounders and derive practical recommendations on patient preparation and interpretation of RBF measurements with MRI. METHODS A comprehensive search was conducted to include articles reporting on physiological variations of renal perfusion, blood and/or plasma flow in healthy humans. RESULTS A total of 24 potential confounders were identified from the literature search and categorized into non-modifiable and modifiable factors. The non-modifiable factors include variables related to the demographics of a population (e.g. age, sex, and race) which cannot be manipulated but should be considered when interpreting RBF values between subjects. The modifiable factors include different activities (e.g. food/fluid intake, exercise training and medication use) that can be standardized in the study design. For each of the modifiable factors, evidence-based recommendations are provided to control for them in an RBF-measurement. CONCLUSION Future studies aiming to measure RBF are encouraged to follow a rigorous study design, that takes into account these recommendations for controlling the factors that can influence RBF results.
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Affiliation(s)
- Bashair Alhummiany
- Department of Biomedical Imaging Sciences, University of Leeds, Leeds, LS2 9NL, UK.
| | - Kanishka Sharma
- Department of Imaging, Infection, Immunity and Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - David L Buckley
- Department of Biomedical Imaging Sciences, University of Leeds, Leeds, LS2 9NL, UK
| | - Kywe Kywe Soe
- Department of Imaging, Infection, Immunity and Cardiovascular Disease, The University of Sheffield, Sheffield, UK
| | - Steven P Sourbron
- Department of Imaging, Infection, Immunity and Cardiovascular Disease, The University of Sheffield, Sheffield, UK.
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2
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Rosner MH, Sprangers B, Sandhu G, Malyszko J. Glomerular Filtration Rate Measurement and Chemotherapy Dosing. Semin Nephrol 2023; 42:151340. [PMID: 37086497 DOI: 10.1016/j.semnephrol.2023.151340] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/24/2023]
Abstract
Many chemotherapeutic drugs used to treat malignancies undergo renal clearance. Thus, accurate knowledge of kidney function is critical to ensure proper dosing, maximize efficacy, and minimize toxicity of drugs that often have a narrow therapeutic index. Making this issue more salient is the fact that impaired kidney function, as assessed by glomerular filtration rate (GFR), is encountered commonly in patients with cancer. Recent data and expert guidelines recommend the use of the Chronic Kidney Disease-Epidemiology Collaboration equation to guide the assessment of kidney function, except when directly measured GFR is clinically necessary. Controversies regarding the measurement of kidney function include the use of race in this equation, indexing to body surface area, and dosing of medications based on stages of chronic kidney disease versus more discrete values of estimated GFR. The development of accurate, real-time GFR measures may hold great promise in allowing for more accurate dosing of these important drugs.
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Affiliation(s)
- Mitchell H Rosner
- Division of Nephrology, University of Virginia Health, Charlottesville, VA.
| | - Ben Sprangers
- Department of Microbiology, Immunology and Transplantation, Laboratory of Molecular Immunology, Rega Institute for Medical Research, KU Leuven, Division of Nephrology, University Hospitals Leuven, Leuven, Belgium
| | - Geeta Sandhu
- eviQ, Cancer Institute New South Wales, St Leonards, New South Wales, Australia
| | - Jolanta Malyszko
- Department of Nephrology, Dialysis and Internal Medicine, Warsaw Medical University, Warsaw, Poland
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3
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Bianchettin RG, Lavie CJ, Lopez-Jimenez F. Challenges in Cardiovascular Evaluation and Management of Obese Patients: JACC State-of-the-Art Review. J Am Coll Cardiol 2023; 81:490-504. [PMID: 36725178 DOI: 10.1016/j.jacc.2022.11.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/12/2022] [Accepted: 11/02/2022] [Indexed: 02/01/2023]
Abstract
Many unique clinical challenges accompany the diagnosis and treatment of cardiovascular disease (CVD) in people living with overweight/obesity. Similarly, physicians encounter numerous complicating factors when managing obesity among people with CVD. Diagnostic accuracy in CVD medicine can be hampered by the presence of obesity, and pharmacological treatments or cardiac procedures require careful adjustment to optimize efficacy. The obesity paradox concept remains a source of confusion within the clinical community that may cause important risk factors to go unaddressed, and body mass index is a misleading measure that cannot account for body composition (eg, lean mass). Lifestyle modifications that support weight loss require long-term commitment, but cardiac rehabilitation programs represent a potential opportunity for structured interventions, and bariatric surgery may reduce CVD risk factors in obesity and CVD. This review examines the key issues and considerations for physicians involved in the management of concurrent obesity and CVD.
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Affiliation(s)
| | - Carl J Lavie
- John Ochsner Heart and Vascular Institute, Ochsner Clinical School, The University of Queensland School of Medicine, New Orleans, Louisiana, USA
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4
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Drug dosing in cancer patients with decreased kidney function: A practical approach. Cancer Treat Rev 2020; 93:102139. [PMID: 33370636 DOI: 10.1016/j.ctrv.2020.102139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 12/06/2020] [Indexed: 10/22/2022]
Abstract
Correct drug dosing of anticancer agents is essential to obtain optimal outcomes. Overdosing will result in increased toxicity, treatment interruption and possible cessation of anticancer treatment. Underdosing may result in suboptimal anti-cancer effects and may increase the risk of cancer-related mortality. As it is practical nor feasible to perform therapeutic drug monitoring for all anti-cancer drugs, kidney function is used to guide drug dosing for those drugs whose primary mode of excretion is through the kidney. However, it is not well-established what method should be utilized to measure or estimate kidney function and the choice of method does influence treatment decisions regarding eligibility for anti-cancer drugs and their dose. In this review, we will provide an overview regarding the importance of drug dosing, the preferred method to determine kidney function and a practical approach to drug dosing of anticancer drugs.
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5
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Assessment of Kidney Function in Patients With Extreme Obesity: A Narrative Review. Ann Pharmacother 2020; 55:80-88. [DOI: 10.1177/1060028020935580] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Objectives: To discuss the evidence and caveats associated with estimated and measured creatinine clearance (eClCr and mClCr) and glomerular filtration rate (eGFR and mGFR) assessments of kidney function in patients with more extreme forms of obesity. Data Sources: PubMed (1976 to mid-May 2020) was used, with bibliographies of retrieved articles searched for additional articles. Study Selection and Data Extraction: Articles using gold standard mGFR to evaluate eClCr, mClCr, and eGFR assessments of kidney function in patients with more extreme forms of obesity were included. Data Synthesis: The overestimation of GFR by mClCr is well established, but mClCr is an alternative to mGFR assessments for determining medication dosing in patients with extremes of body size or muscle mass, or in patients receiving narrow therapeutic index medications when eGFR is likely to be inaccurate. The vast majority of studies comparing eGFR assessments with gold standard indicators of kidney function were attempts to validate eGFR equations for diagnosing and staging chronic kidney disease (CKD). Relevance to Patient Care and Clinical Practice: For dosing medications in patients with stable kidney function and extreme obesity, a deindexed 4-variable Modification of Diet in Renal Disease or CKD Epidemiology Collaboration equation is an alternative to Cockcroft-Gault. Consistent use of the same equation by provider and between providers within any given setting is of paramount importance. Conclusions: In patients with extreme obesity and stable kidney function, eClCr or eGFR using deindexed values provides estimates of function for dosing adjustments of medications with elimination by the kidneys, but more research is needed with respect to the best size descriptor to use with estimating equations.
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6
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May M, Schindler C, Engeli S. Modern pharmacological treatment of obese patients. Ther Adv Endocrinol Metab 2020; 11:2042018819897527. [PMID: 32030121 PMCID: PMC6977225 DOI: 10.1177/2042018819897527] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 12/09/2019] [Indexed: 12/21/2022] Open
Abstract
There are many angles to consider in drug treatment of obese patients. On the one hand, some specific weight loss drugs are available, on the other, several drugs are associated with unintentional weight changes. When treating an obese patient for any given disease, several physiological changes may influence the pharmacokinetic properties of the drugs required. Thus, increased body weight may influence the efficacy and safety of some drug treatments. Even more complicated is the situation after weight reduction surgery. Due to the various changes to the gastrointestinal tract induced by the different surgical techniques used, and the dynamic changes in body composition thereafter, drug dosing has to be constantly reconsidered. Whereas all of these issues are of clinical importance, none of them have been investigated in the necessary depth and broadness to ensure safe and efficacious drug treatment of the massively obese patient. Individual considerations have to be based on comorbidities, concomitant medication, and on specific drug properties, for example, lipophilicity, volume of distribution, and metabolism. In this article we summarize the data available on different aspects of drug treatment in the obese patient with the hope of improving patient care.
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Affiliation(s)
| | - Christoph Schindler
- MHH Clinical Research Center Core Facility (OE 8660) and Center for Pharmacology and Toxicology, Hannover, Germany
| | - Stefan Engeli
- Hannover Medical School, Institute of Clinical Pharmacology, Hannover, Germany
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7
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Arshad A, Hodson J, Chappelow I, Inston NG, Ready AR, Nath J, Sharif A. The impact of donor body mass index on outcomes after deceased kidney transplantation - a national population-cohort study. Transpl Int 2018; 31:1099-1109. [DOI: 10.1111/tri.13263] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/08/2018] [Accepted: 04/10/2018] [Indexed: 02/04/2023]
Affiliation(s)
- Adam Arshad
- College of Medical and Dental Sciences; University of Birmingham; Birmingham UK
| | - James Hodson
- Institute of Translational Medicine; Queen Elizabeth Hospital; Edgbaston, Birmingham UK
| | - Imogen Chappelow
- College of Medical and Dental Sciences; University of Birmingham; Birmingham UK
| | - Nicholas G. Inston
- Department of Nephrology and Transplantation; Queen Elizabeth Hospital Birmingham; Birmingham UK
| | - Andrew R. Ready
- Department of Nephrology and Transplantation; Queen Elizabeth Hospital Birmingham; Birmingham UK
| | - Jay Nath
- College of Medical and Dental Sciences; University of Birmingham; Birmingham UK
- Department of Nephrology and Transplantation; Queen Elizabeth Hospital Birmingham; Birmingham UK
| | - Adnan Sharif
- College of Medical and Dental Sciences; University of Birmingham; Birmingham UK
- Department of Nephrology and Transplantation; Queen Elizabeth Hospital Birmingham; Birmingham UK
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8
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Nix DE, Mayersohn M, Erstad BL. Should estimates of glomerular filtration rate and creatinine clearance be indexed to body surface area for drug dosing? Am J Health Syst Pharm 2017; 74:1814-1819. [PMID: 28947625 DOI: 10.2146/ajhp160467] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- David E Nix
- Department of Pharmacy Practice & Science, College of Pharmacy, University of Arizona, Tucson, AZ.
| | - Michael Mayersohn
- Department of Pharmacy Practice & Science, College of Pharmacy, University of Arizona, Tucson, AZ
| | - Brian L Erstad
- Department of Pharmacy Practice & Science, College of Pharmacy, University of Arizona, Tucson, AZ
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10
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Inker LA, Shafi T, Okparavero A, Tighiouart H, Eckfeldt JH, Katz R, Johnson WC, Dermond N, Tariq Z, Benayache I, Post WS, Coresh J, Levey AS, Shlipak MG. Effects of Race and Sex on Measured GFR: The Multi-Ethnic Study of Atherosclerosis. Am J Kidney Dis 2016; 68:743-751. [PMID: 27555103 DOI: 10.1053/j.ajkd.2016.06.021] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 06/27/2016] [Indexed: 01/02/2023]
Abstract
BACKGROUND Kidney failure disproportionately affects older blacks versus whites. The reasons are unknown and may be related to lower measured glomerular filtration rate (GFR) and higher levels of albuminuria in community-based population samples. STUDY DESIGN Cross-sectional analysis of a substudy of a prospective cohort. SETTING & PARTICIPANTS Ancillary study following Multi-Ethnic Study of Atherosclerosis (MESA) visit 5. PREDICTOR Age, sex, and race. OUTCOMES & MEASUREMENTS Measured GFR using plasma clearance of iohexol and urine albumin-creatinine ratio (ACR). RESULTS GFR was measured in 294 participants. Mean age was 71±9 (SD) years, 47% were black, 48% were women, mean GFR was 73±19mL/min/1.73m2, and median ACR was 10.0 (IQR, 5.8-20.9) mg/g. Measured GFR was on average 1.02 (95% CI, 0.79-1.24) mL/min/1.73m2 lower per year older. Mean GFR indexed for body surface area was not different between blacks versus whites (mean difference, 2.94 [95% CI, -1.37 to 7.26] mL/min/1.73m2), but was lower in women than men (mean difference, -9.34 [95% CI, -13.53 to -5.15] mL/min/1.73m2); this difference persisted and remained significant after adjustment for demographics, clinical characteristics, and measures of body size. The difference between men and women, but not between blacks and whites, was substantially greater when GFR was not indexed for body surface area. ACR was higher in older versus younger participants (mean difference, 3.2% [95% CI, 1.5%-4.8%] per year), but geometric mean ratio of ACR did not differ between blacks versus whites (mean difference, 19.7%; 95% CI, -39.1% to 6.1%) or between men versus women (mean difference, -4.4%; 95% CI, -27.7% to 26.3%). LIMITATIONS This is a study of survivors. People who agreed to participate were younger than those who refused. CONCLUSIONS In this first community-based study that included blacks and whites, no differences in measured GFR between races were found, suggesting that other factors must account for the disproportionately higher burden of kidney failure in older blacks versus whites.
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Affiliation(s)
- Lesley A Inker
- Division of Nephrology, Tufts Medical Center, Boston, MA.
| | | | | | - Hocine Tighiouart
- Division of Nephrology, Tufts Medical Center, Boston, MA; The Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, MA; Tufts Clinical and Translational Science Institute, Tufts University, Boston, MA
| | - John H Eckfeldt
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN
| | - Ronit Katz
- University of Washington, Kidney Research Institute, Seattle, WA
| | - W Craig Johnson
- Department of Biostatistics, School of Public Health and Community Medicine, University of Washington, Seattle, WA
| | - Norma Dermond
- Department of Biostatistics, School of Public Health and Community Medicine, University of Washington, Seattle, WA
| | | | | | | | | | - Andrew S Levey
- Division of Nephrology, Tufts Medical Center, Boston, MA
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11
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Correia-Costa L, Schaefer F, Afonso AC, Bustorff M, Guimarães JT, Guerra A, Barros H, Azevedo A. Normalization of glomerular filtration rate in obese children. Pediatr Nephrol 2016; 31:1321-8. [PMID: 27008644 DOI: 10.1007/s00467-016-3367-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/03/2016] [Accepted: 03/04/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND Glomerular filtration rate (GFR) is conventionally indexed to body surface area (BSA), but this may lead to biased results when applied to subjects of abnormal body size. The aim of our study was to examine the impact of normalization to the BSA and alternative body size descriptors on measured and estimated GFR in overweight and obese children. METHODS This was a cross-sectional study of 313 children aged 8-9 years old. GFR was measured by 24-h creatinine clearance (CrCl) and additionally estimated from serum creatinine and cystatin C (CysC) using the combined Zappitelli formula, both as absolute values and adjusted to various body size descriptors. The results were compared between 163 normal-weight, 89 overweight and 61 obese children. RESULTS Compared to the normal-weight children, mean absolute GFR (both measured and estimated) was higher in the overweight and obese children, whereas BSA-adjusted GFR was lower. Linear regression models fitted in normal-weight children revealed equally close associations between absolute GFR and squared height, ideal body weight (IBW) and BSA derived from IBW. Normalization of GFR to the IBW-derived BSA completely eliminated the discrepancy between absolute and BSA-indexed GFR in overweight and obese children. CONCLUSIONS Indexing of GFR to BSA calculated from the ideal-rather than actual-body weight is a promising approach to avoid overcorrection when studying obese children. Further studies should assess the accuracy of this approach across the full range of age and BMI distribution.
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Affiliation(s)
- Liane Correia-Costa
- Epidemiology Research Unit (EPIUnit), Institute of Public Health, University of Porto (ISPUP), Rua das Taipas nr. 135, 4050-600, Porto, Portugal. .,Division of Pediatric Nephrology, Integrated Pediatric Hospital, Centro Hospitalar São João, Porto, Portugal. .,Department of Pediatrics, Faculty of Medicine, University of Porto, Porto, Portugal.
| | - Franz Schaefer
- Division of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany
| | - Alberto Caldas Afonso
- Epidemiology Research Unit (EPIUnit), Institute of Public Health, University of Porto (ISPUP), Rua das Taipas nr. 135, 4050-600, Porto, Portugal.,Division of Pediatric Nephrology, Integrated Pediatric Hospital, Centro Hospitalar São João, Porto, Portugal.,Department of Pediatrics, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Manuela Bustorff
- Department of Nephrology, Centro Hospitalar São João, Porto, Portugal
| | - João Tiago Guimarães
- Epidemiology Research Unit (EPIUnit), Institute of Public Health, University of Porto (ISPUP), Rua das Taipas nr. 135, 4050-600, Porto, Portugal.,Department of Clinical Pathology , Centro Hospitalar São João, Porto, Portugal.,Department of Biochemistry, Faculty of Medicine, University of Porto, Porto, Portugal
| | - António Guerra
- Department of Pediatrics, Faculty of Medicine, University of Porto, Porto, Portugal.,Division of Pediatric Nutrition, Integrated Pediatric Hospital, Centro Hospitalar São João, Porto, Portugal
| | - Henrique Barros
- Epidemiology Research Unit (EPIUnit), Institute of Public Health, University of Porto (ISPUP), Rua das Taipas nr. 135, 4050-600, Porto, Portugal.,Department of Clinical Epidemiology, Predictive Medicine and Public Health, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Ana Azevedo
- Epidemiology Research Unit (EPIUnit), Institute of Public Health, University of Porto (ISPUP), Rua das Taipas nr. 135, 4050-600, Porto, Portugal.,Department of Clinical Epidemiology, Predictive Medicine and Public Health, Faculty of Medicine, University of Porto, Porto, Portugal
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12
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Obesity-related glomerulopathy: clinical and pathologic characteristics and pathogenesis. Nat Rev Nephrol 2016; 12:453-71. [PMID: 27263398 DOI: 10.1038/nrneph.2016.75] [Citation(s) in RCA: 407] [Impact Index Per Article: 50.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The prevalence of obesity-related glomerulopathy is increasing in parallel with the worldwide obesity epidemic. Glomerular hypertrophy and adaptive focal segmental glomerulosclerosis define the condition pathologically. The glomerulus enlarges in response to obesity-induced increases in glomerular filtration rate, renal plasma flow, filtration fraction and tubular sodium reabsorption. Normal insulin/phosphatidylinositol 3-kinase/Akt and mTOR signalling are critical for podocyte hypertrophy and adaptation. Adipokines and ectopic lipid accumulation in the kidney promote insulin resistance of podocytes and maladaptive responses to cope with the mechanical forces of renal hyperfiltration. Although most patients have stable or slowly progressive proteinuria, up to one-third develop progressive renal failure and end-stage renal disease. Renin-angiotensin-aldosterone blockade is effective in the short-term but weight loss by hypocaloric diet or bariatric surgery has induced more consistent and dramatic antiproteinuric effects and reversal of hyperfiltration. Altered fatty acid and cholesterol metabolism are increasingly recognized as key mediators of renal lipid accumulation, inflammation, oxidative stress and fibrosis. Newer therapies directed to lipid metabolism, including SREBP antagonists, PPARα agonists, FXR and TGR5 agonists, and LXR agonists, hold therapeutic promise.
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13
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Delanaye P, Flamant M, Cavalier É, Guerber F, Vallotton T, Moranne O, Pottel H, Boffa JJ, Mariat C. [Dosing adjustment and renal function: Which equation(s)?]. Nephrol Ther 2015; 12:18-31. [PMID: 26602880 DOI: 10.1016/j.nephro.2015.07.472] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/28/2015] [Accepted: 07/29/2015] [Indexed: 12/18/2022]
Abstract
While the CKD-EPI (for Chronic Kidney Disease Epidemiology) equation is now implemented worldwide, utilization of the Cockcroft formula is still advocated by some physicians for drug dosage adjustment. Justifications for this recommendation are that the Cockcroft formula was preferentially used to determine dose adjustments according to renal function during the development of many drugs, better predicts drugs-related adverse events and decreases the risk of drug overexposure in the elderly. In this opinion paper, we discuss the weaknesses of the rationale supporting the Cockcroft formula and endorse the French HAS (Haute Autorité de santé) recommendation regarding the preferential use of the CKD-EPI equation. When glomerular filtration rate (GFR) is estimated in order to adjust drug dosage, the CKD-EPI value should be re-expressed for the individual body surface area (BSA). Given the difficulty to accurately estimate GFR in the elderly and in individuals with extra-normal BSA, we recommend to prescribe in priority monitorable drugs in those populations or to determine their "true" GFR using a direct measurement method.
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Affiliation(s)
- Pierre Delanaye
- Service de néphrologie, dialyse et transplantation, CHU Sart-Tilman, université de Liège, 4000 Liège, Belgique
| | - Martin Flamant
- Service d'explorations fonctionnelles, hôpital Bichat, AP-HP, université Paris Diderot, Paris, France
| | - Étienne Cavalier
- Service de chimie clinique, CHU Sart-Tilman, université de Liège, 4000 Liège, Belgique
| | - Fabrice Guerber
- Laboratoire Oriade-Vizille, 75, chemin de la Terrasse, 38220 Vizille, France
| | - Thomas Vallotton
- Laboratoire Vialle, Bastia et Syndicat des jeunes biologistes médicaux, 20600 BastiaFrance
| | - Olivier Moranne
- EA 2415, biostatistique, épidémiologie et santé publique, institut universitaire de recherche clinique, université de Montpellier, 34093 Montpellier, France
| | - Hans Pottel
- Department of Primary Care and Public Health at Kulak, KU Leuven Kulak, 8500 Kortrijk, Belgique
| | - Jean-Jacques Boffa
- Inserm 1155, service de néphrologie et dialyse, hôpital Tenon, AP-HP, université Pierre-et-Marie-Curie, 75020 Paris, France
| | - Christophe Mariat
- Service de néphrologie, dialyse et transplantation, hôpital Nord, CHU de Saint-Étienne, université Jean-Monnet, 42055 Saint-Étienne, France.
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14
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Knibbe CAJ, Brill MJE, van Rongen A, Diepstraten J, van der Graaf PH, Danhof M. Drug disposition in obesity: toward evidence-based dosing. Annu Rev Pharmacol Toxicol 2015; 55:149-67. [PMID: 25340929 DOI: 10.1146/annurev-pharmtox-010814-124354] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Obesity and morbid obesity are associated with many physiological changes affecting pharmacokinetics, such as increased blood volume, cardiac output, splanchnic blood flow, and hepatic blood flow. In obesity, drug absorption appears unaltered, although recent evidence suggests that this conclusion may be premature. Volume of distribution may vary largely, but the magnitude and direction of changes seem difficult to predict, with extrapolation on the basis of total body weight being the best approach to date. Changes in clearance may be smaller than in distribution, whereas there is growing evidence that the influence of obesity on clearance can be predicted on the basis of reported changes in the metabolic or elimination pathways involved. For obese children, we propose two methods to distinguish between developmental and obesity-related changes. Future research should focus on the characterization of physiological concepts to predict the optimal dose for each drug in the obese population.
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Affiliation(s)
- Catherijne A J Knibbe
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, 2333 CC Leiden, The Netherlands;
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15
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Ogna A, Forni Ogna V, Bochud M, Guessous I, Paccaud F, Burnier M, Wuerzner G. Association between obesity and glomerular hyperfiltration: the confounding effect of smoking and sodium and protein intakes. Eur J Nutr 2015; 55:1089-97. [PMID: 25971845 DOI: 10.1007/s00394-015-0923-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 05/05/2015] [Indexed: 11/28/2022]
Abstract
PURPOSE Glomerular hyperfiltration has been suggested as a possible mechanism linking obesity and chronic kidney disease (CKD), independently of classical risk factors. We explored the association of overweight and obesity with glomerular hyperfiltration in a large sample of the Swiss adult population, accounting for several confounders including dietary factors. METHODS Data from a 2010 to 2012 cross-sectional population-based survey in Switzerland were used. Creatinine clearance (CrCl) was determined from 24-h urine collection; CrCl > 140 ml/min was used to define glomerular hyperfiltration. Participants were categorized into lean (<25 kg/m(2)), overweight (25-29.9 kg/m(2)) and obese (≥30 kg/m(2)) according to body mass index (BMI). RESULTS A total of 1339 participants were included in the analysis [median (IQR) age 49.4 (34.3-63.5) years, 48.9 % men]. The prevalences of overweight and obesity were 32.2 and 14.2 %, respectively. Median CrCl was 102[84-121] ml/min in lean, 110 [87-136] ml/min in overweight and 124 [97-150] ml/min in obese participants (p < 0.001). The prevalence of glomerular hyperfiltration increased across BMI categories (10.4, 20.8 and 34.7 %, respectively; p < 0.001). This positive association remained significant after adjusting for age, sex, hypertension, diabetes, smoking and dietary factors (sodium and protein intakes): odds ratio [95 %CI] 2.39 [1.52-3.76] (p < 0.001) for overweight versus lean and 4.10[2.31-7.27] (p < 0.001) for obesity versus lean. CONCLUSIONS BMI categories and glomerular hyperfiltration are positively associated, independently of other known CKD risk factors and dietary confounders, suggesting that glomerular hyperfiltration may represent an early renal phenotype in obesity. Our observations confirm the significant association of glomerular hyperfiltration with sodium and protein intakes and identify sodium intake as an important modifying factor of the association between hyperfiltration and obesity.
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Affiliation(s)
- Adam Ogna
- Department of Internal Medicine and Nephrology, Locarno Hospital, 6600, Locarno, Switzerland.
| | - Valentina Forni Ogna
- Service of Nephrology and Hypertension, Lausanne University Hospital, Lausanne, Switzerland
| | - Murielle Bochud
- Community Prevention Unit, University Institute of Social and Preventive Medicine (IUMSP), Lausanne, Switzerland
| | - Idris Guessous
- Community Prevention Unit, University Institute of Social and Preventive Medicine (IUMSP), Lausanne, Switzerland.,Unit of Population Epidemiology, Geneva University Hospitals, Geneva, Switzerland
| | - Fred Paccaud
- Community Prevention Unit, University Institute of Social and Preventive Medicine (IUMSP), Lausanne, Switzerland
| | - Michel Burnier
- Service of Nephrology and Hypertension, Lausanne University Hospital, Lausanne, Switzerland
| | - Gregoire Wuerzner
- Service of Nephrology and Hypertension, Lausanne University Hospital, Lausanne, Switzerland
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Erstad BL. Designing drug regimens for special intensive care unit populations. World J Crit Care Med 2015; 4:139-151. [PMID: 25938029 PMCID: PMC4411565 DOI: 10.5492/wjccm.v4.i2.139] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 09/06/2014] [Accepted: 02/09/2015] [Indexed: 02/06/2023] Open
Abstract
This review is intended to help clinicians design drug regimens for special populations of critically ill patients with extremes of body size, habitus and composition that make drug choice or dosing particularly challenging due to the lack of high-level evidence on which to make well-informed clinical decisions. The data sources included a literature search of MEDLINE and EMBASE with reviews of reference lists of retrieved articles. Abstracts of original research investigations and review papers were reviewed for their relevance to drug choice or dosing in the following special critically ill populations: patients with more severe forms of bodyweight or height, patients with amputations or missing limbs, pregnant patients, and patients undergoing extracorporeal membrane oxygenation or plasma exchange. Relevant papers were retrieved and evaluated, and their associated reference lists were reviewed for citations that may have been missed through the electronic search strategy. Relevant original research investigations and review papers that could be used to formulate general principles for drug choice or dosing in special populations of critically ill patients were extracted. Randomized studies with clinically relevant endpoints were not available for performing quantitative analyses. Critically ill patients with changes in body size, habitus and composition require special consideration when designing medication regimens, but there is a paucity of literature on which to make drug-specific, high-level evidence-based recommendations. Based on the evidence that is available, general recommendations are provided for drug choice or dosing in special critically ill populations.
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Sankaralingam S, Kim RB, Padwal RS. The Impact of Obesity on the Pharmacology of Medications Used for Cardiovascular Risk Factor Control. Can J Cardiol 2015; 31:167-76. [DOI: 10.1016/j.cjca.2014.10.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 10/07/2014] [Accepted: 10/22/2014] [Indexed: 10/24/2022] Open
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Kwakernaak AJ, Toering TJ, Navis G. Body mass index and body fat distribution as renal risk factors: a focus on the role of renal haemodynamics. Nephrol Dial Transplant 2014; 28 Suppl 4:iv42-9. [PMID: 24179015 DOI: 10.1093/ndt/gft331] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Weight excess and/or central body fat distribution are associated with increased long-term renal risk, not only in subjects with renal disease or renal transplant recipients, but also in the general population. As the prevalence of weight excess is rising worldwide, this may become a main renal risk factor on a population basis, even more so because the risk extends to the overweight range. Understanding the mechanisms of this detrimental effect of weight excess on the kidneys is needed in order to design preventive treatment strategies. The increased risk associated with weight excess is partly attributed to associated comorbid conditions, such as hypertension, dyslipidaemia, insulin resistance and diabetes; however, current evidence supports a direct pathogenetic role for renal haemodynamics as well. Weight excess is associated with an altered renal haemodynamic profile, i.e. an increased glomerular filtration rate relative to effective renal plasma flow, resulting in an increased filtration fraction (FF). This renal haemodynamic profile is considered to reflect glomerular hyperfiltration and glomerular hypertension, resulting from a dysbalance between afferent and efferent arterial vasomotor balance. This unfavorable renal haemodynamic profile was found to be associated with renal outcome in experimental models and in human renal transplant recipients, and is associated with a blunted sodium excretion, and reversible by weight loss, renin-angiotensin-aldosterone system blockade or by dietary sodium restriction. More recent evidence showed that a central body fat distribution is also associated with an increased FF, even independent of overall weight excess. In this review, we provide an overview on current literature on the impact of weight excess and central body fat distribution on the renal haemodynamic profile in humans, and its possible role in progressive renal damage.
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Affiliation(s)
- Arjan J Kwakernaak
- Division of Nephrology, Department of Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Soveri I, Berg UB, Björk J, Elinder CG, Grubb A, Mejare I, Sterner G, Bäck SE. Measuring GFR: a systematic review. Am J Kidney Dis 2014; 64:411-24. [PMID: 24840668 DOI: 10.1053/j.ajkd.2014.04.010] [Citation(s) in RCA: 353] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Accepted: 04/04/2014] [Indexed: 02/08/2023]
Abstract
BACKGROUND No comprehensive systematic review of the accuracy of glomerular filtration rate (GFR) measurement methods using renal inulin clearance as reference has been published. STUDY DESIGN Systematic review with meta-analysis of cross-sectional diagnostic studies. SETTING & POPULATION Published original studies and systematic reviews in any population. SELECTION CRITERIA FOR STUDIES Index and reference measurements conducted within 48 hours; at least 15 participants studied; GFR markers measured in plasma or urine; plasma clearance calculation algorithm verified in another study; tubular secretion of creatinine had not been blocked by medicines. INDEX TESTS Endogenous creatinine clearance; renal or plasma clearance of chromium 51-labeled ethylenediaminetetraacetic acid (51Cr-EDTA), diethylenetriaminepentaacetic acid (DTPA), iohexol, and iothalamate; and plasma clearance of inulin. REFERENCE TEST Renal inulin clearance measured under continuous inulin infusion and urine collection. RESULTS Mean bias <10%, median bias <5%, the proportion of errors in the index measurements that did not exceed 30% (P30) ≥80%, and P10 ≥50% were set as requirements for sufficient accuracy. Based on the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach, the quality of evidence across studies was rated for each index method. Renal clearance of iothalamate measured GFR with sufficient accuracy (strong evidence). Renal and plasma clearance of 51Cr-EDTA and plasma clearance of iohexol were sufficiently accurate to measure GFR (moderately strong evidence). Renal clearance of DTPA, renal clearance of iohexol, and plasma clearance of inulin had sufficient accuracy (limited evidence). Endogenous creatinine clearance was an inaccurate method (strong evidence), as was plasma clearance of DTPA (limited evidence). The evidence to determine the accuracy of plasma iothalamate clearance was insufficient. With the exception of plasma clearance of inulin, only renal clearance methods had P30 >90%. LIMITATIONS The included studies were few and most were old and small, which may limit generalizability. Requirements for sufficient accuracy may depend on clinical setting. CONCLUSIONS At least moderately strong evidence suggests that renal clearance of 51Cr-EDTA or iothalamate and plasma clearance of 51Cr-EDTA or iohexol are sufficiently accurate methods to measure GFR.
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Affiliation(s)
- Inga Soveri
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
| | - Ulla B Berg
- Department of Clinical Science, Intervention and Technology, Division of Pediatrics, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Jonas Björk
- Department of Occupational and Environmental Medicine, Lund University, Lund, Sweden
| | - Carl-Gustaf Elinder
- Department of Clinical Science, Intervention and Technology, Division of Renal Medicine, Karolinska Institutet, Stockholm County Council, Stockholm, Sweden
| | - Anders Grubb
- Department of Clinical Chemistry, Lund University Hospital, Lund, Sweden
| | - Ingegerd Mejare
- Swedish Council on Health Technology Assessment, Stockholm, Sweden
| | - Gunnar Sterner
- Department of Nephrology, Skåne University Hospital Malmö, Malmö, Sweden
| | - Sten-Erik Bäck
- Department of Clinical Chemistry, Lund University Hospital, Lund, Sweden
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Redal-Baigorri B, Rasmussen K, Heaf JG. Indexing glomerular filtration rate to body surface area: clinical consequences. J Clin Lab Anal 2013; 28:83-90. [PMID: 24375613 DOI: 10.1002/jcla.21648] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Accepted: 06/03/2013] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Kidney function is mostly expressed in terms of glomerular filtration rate (GFR). A common feature is the expression as ml/min per 1.73 m(2) , which represents the adjustment of the individual kidney function to a standard body surface area (BSA) to allow comparison between individuals. We investigated the impact of indexing GFR to BSA in cancer patients, as this BSA indexation might affect the reported individual kidney function. METHODS Cross-sectional study of 895 adults who had their kidney function measured with (51) chrome ethylene diamine tetraacetic acid. Mean values of BSA-indexed GFR vs. mean absolute GFR were analyzed with a t-test for paired data. Bland-Altman plot was used to analyze agreement between the indexed and absolute GFR values. RESULTS AND CONCLUSION BSA-GFR in patients with a BSA <1.60 m(2) overestimated GFR with a bias of 10.08 ml/min (11.46%) and underestimated GFR in those with a BSA >2 m(2) with a bias up to -20.76 ml/min (-23.59%). BSA is not a good normalization index (NI) in patients with extreme body sizes. Therefore, until a better NI is found, we recommend clinicians to use the absolute GFR to calculate individual drug chemotherapy dosage as well as express individual kidney function.
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Affiliation(s)
- Belén Redal-Baigorri
- Department of Nephrology, Roskilde University Hospital, University of Copenhagen, Roskilde, Denmark
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21
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Prevalence of preclinical renal dysfunction in obese Egyptian patients with primary knee osteoarthritis, preliminary data. THE EGYPTIAN RHEUMATOLOGIST 2013. [DOI: 10.1016/j.ejr.2013.06.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Peters AM, Seshadri N, Neilly MDJ, Perry L, Hooker CA, Howard B, Sobnack R, Irwin A, Dave S, Snelling H, Gruning T, Patel NH, Shabo G, Williams N, Barnfield MC, Lawson RS. Higher extracellular fluid volume in women is concealed by scaling to body surface area. Scandinavian Journal of Clinical and Laboratory Investigation 2013; 73:546-52. [PMID: 24047330 DOI: 10.3109/00365513.2013.819524] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVE The objective was to assess body surface area (BSA) for scaling extracellular fluid volume (ECV) in comparison with estimated lean body mass (LBM) and total body water (TBW) across a range of body mass indices (BMI). METHODS This was a multi-centre study from 15 centres that submitted raw data from routine measurement of GFR in potential kidney transplant donors. There were 819 men and 1059 women in total. ECV was calculated from slope-intercept and slope-only measurements of GFR. ECV was scaled using two methods: Firstly, division of ECV by the scaling variable (ratio method), and secondly the regression method of Turner and Reilly. Subjects were placed into five BMI groups: < 20, 20-24.9, 25-29.9, 30-34.9, and 35 + kg/m(2). LBM and TBW were estimated from previously published, gender-specific prediction equations. RESULTS Ratio and regression scaling gave almost identical results. ECV scaled to BSA by either method was higher in men in all BMI groups but ECV scaled to LBM and TBW was higher in women. There was, however, little difference between men and women in respect to ECV per unit weight in any BMI group, even though women have 10% more adipose tissue. The relations between TBW and BSA and between LBM and BSA, but not between LBM and TBW, were different between men and women. CONCLUSION Lean tissue in women contains more extracellular water than in men, a difference that is obscured by scaling to BSA. The likely problem with BSA is its insensitivity to body composition.
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Affiliation(s)
- A Michael Peters
- Department of Nuclear Medicine, Royal Sussex County Hospital , Brighton
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Brocks DR, Ben-Eltriki M, Gabr RQ, Padwal RS. The effects of gastric bypass surgery on drug absorption and pharmacokinetics. Expert Opin Drug Metab Toxicol 2012; 8:1505-19. [DOI: 10.1517/17425255.2012.722757] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Ortiz J, Gregg A, Wen X, Karipineni F, Kayler LK. Impact of donor obesity and donation after cardiac death on outcomes after kidney transplantation. Clin Transplant 2012; 26:E284-92. [DOI: 10.1111/j.1399-0012.2012.01649.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jorge Ortiz
- Department of Surgery; Albert Einstein Hospital; Philadelphia; PA; USA
| | - Austin Gregg
- Department of Medicine; University of Florida; Gainesville; FL; USA
| | - Xuerong Wen
- Department of Medicine; University of Florida; Gainesville; FL; USA
| | - Farah Karipineni
- Department of Surgery; Albert Einstein Hospital; Philadelphia; PA; USA
| | - Liise K. Kayler
- Department of Surgery; Montefiore Medical Center; Bronx; NY; USA
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Ghobadi C, Johnson TN, Aarabi M, Almond LM, Allabi AC, Rowland-Yeo K, Jamei M, Rostami-Hodjegan A. Application of a systems approach to the bottom-up assessment of pharmacokinetics in obese patients: expected variations in clearance. Clin Pharmacokinet 2012; 50:809-22. [PMID: 22087867 DOI: 10.2165/11594420-000000000-00000] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND AND OBJECTIVES The maintenance dose of a drug is dependent on drug clearance, and thus any biochemical and physiological changes in obesity that affect parameters such as cardiac output, renal function, expression of drug-metabolizing enzymes and protein binding may result in altered clearance compared with that observed in normal-weight subjects (corrected or uncorrected for body weight). Because of the increasing worldwide incidence of obesity, there is a need for more information regarding the optimal dosing of drug therapy to be made available to prescribers. This is usually provided via clinical studies in obese people; however, such studies are not available for all drugs that might be used in obese subjects. Incorporation of the relevant physiological and biochemical changes into predictive bottom-up pharmacokinetic models in order to optimize dosage regimens may offer a logical way forward for the cases where no clinical data exist. The aims of the current report are to apply such a 'systems approach' to identify the likelihood of observing variations in the clearance of drugs in obesity and morbid obesity for a set of compounds for which clinical data, as well as the necessary in vitro information, are available, and to provide a framework for assessing other drugs in the future. METHODS The population-specific changes in demographic, physiological and biochemical parameters that are known to be relevant to obese and morbidly obese subjects were collated and incorporated into two separate population libraries. These libraries, together with mechanistic in vitro-in vivo extrapolations (IVIVE) within the Simcyp Population-based Simulator™, were used to predict the clearance of oral alprazolam, oral caffeine, oral chlorzoxazone, oral ciclosporin, intravenous and oral midazolam, intravenous phenytoin, oral theophylline and oral triazolam. The design of the simulated studies was matched as closely as possible with that of the clinical studies. Outcome was measured by the predicted ratio of the clearance of the drug in obese and lean subjects ± its 90% confidence interval, compared with observed values. The overall statistical measures of the performance of the model to detect differences in compound clearance between obese and lean populations were investigated by measuring sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). A power calculation was carried out to investigate the impact of the sample size on the overall outcome of clinical studies. RESULTS The model was successful in predicting clearance in obese subjects, with the degree to which simulations could mimic the outcome of in vivo studies being greater than 60% for six of the eight drugs. A clear difference in the clearance of chlorzoxazone was correctly picked up via simulation. The overall statistical measures of the performance of the Simcyp Simulator were 100% sensitivity, 66% specificity, 60% PPV and 100% NPV. Studies designed on the basis of the ratio of the absolute values required substantial numbers of participants in order to detect a significant difference, except for phenytoin and chlorzoxazone, where the ratios of the weight-normalized clearances generally showed statistically significant differences with a smaller number of subjects. CONCLUSION Extension of a mechanistic predictive pharmacokinetic model to accommodate physiological and biochemical changes associated with obesity and morbid obesity allowed prediction of changes in drug clearance on the basis of in vitro data, with reasonable accuracy across a range of compounds that are metabolized by different enzymes. Prediction of the effects of obesity on drug clearance, normalized by various body size scalars, is of potential value in the design of clinical studies during drug development and in the introduction of dosage adjustments that are likely to be needed in clinical practice.
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Delanaye P, Krzesinski JM. Indexing of renal function parameters by body surface area: intelligence or folly? Nephron Clin Pract 2012; 119:c289-92. [PMID: 21934328 DOI: 10.1159/000330276] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Indexation of glomerular filtration rate (GFR) by body surface area (BSA) is often done without raising any questions. In this article, we will shortly review the limitations of such indexation and illustrate potential errors in clinical practice due to this indexation. Adjusting the GFR by BSA is particularly misleading in patients with abnormal body size (obese and anorectic). We will also insist on the fact that indexation by BSA is not required for the GFR longitudinal follow-up. Additionally, we will discuss the implications and consequences of BSA indexation on the creatinine-based equations, such as the Cockcroft-Gault and the MDRD study equations.
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Affiliation(s)
- Pierre Delanaye
- Department of Nephrology-Dialysis, University of Liège, CHU Sart Tilman, Liège, Belgium.
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Peters AM, Perry L, Hooker CA, Howard B, Neilly MDJ, Seshadri N, Sobnack R, Irwin A, Snelling H, Gruning T, Patel NH, Lawson RS, Shabo G, Williams N, Dave S, Barnfield MC. Extracellular fluid volume and glomerular filtration rate in 1878 healthy potential renal transplant donors: effects of age, gender, obesity and scaling. Nephrol Dial Transplant 2011; 27:1429-37. [PMID: 22076428 DOI: 10.1093/ndt/gfr479] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
UNLABELLED Aim. The aim of this study was to investigate the influence of age, gender, obesity and scaling on glomerular filtration rate (GFR) and extracellular fluid volume (ECV) in healthy subjects. METHODS This is a retrospective multi-centre study of 1878 healthy prospective kidney transplant donors (819 men) from 15 centres. Age and body mass index (BMI) were not significantly different between men and women. Slope-intercept GFR was measured (using Cr-51-EDTA in 14 centres; Tc-99m-DTPA in one) and scaled to body surface area (BSA) and lean body mass (LBM), both estimated from height and weight. GFR was also expressed as the slope rate constant, with one-compartment correction (GFR/ECV). ECV was measured as the ratio, GFR to GFR/ECV. RESULTS ECV was age independent but GFR declined with age, at a significantly faster rate in women than men. GFR/BSA was higher in men but GFR/ECV and GFR/LBM were higher in women. Young women (<30 years) had higher GFR than young men but the reverse was recorded in the elderly (>65 years). There was no difference in GFR between obese (BMI>30 kg/m2) and non-obese men. Obese women, however, had lower GFR than non-obese women and negative correlations were observed between GFR and both BMI and %fat. The decline in GFR with age was no faster in obese versus non-obese subjects. ECV/BSA was higher in men but ECV/LBM was higher in women. ECV/weight was almost gender independent, suggesting that fat-free mass in women contains more extracellular water. BSA is therefore a misleading scaling variable. CONCLUSION There are several significant differences in GFR and ECV between healthy men and women.
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Affiliation(s)
- A Michael Peters
- Department of Nuclear Medicine, Royal Sussex County Hospital, Brighton, UK.
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Jain R, Chung SM, Jain L, Khurana M, Lau SWJ, Lee JE, Vaidyanathan J, Zadezensky I, Choe S, Sahajwalla CG. Implications of obesity for drug therapy: limitations and challenges. Clin Pharmacol Ther 2011; 90:77-89. [PMID: 21633345 DOI: 10.1038/clpt.2011.104] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Obesity has become a worldwide challenge with significant health and socioeconomic implications. One of the major implications is its impact on drug therapy. In order to gain a better understanding of this impact, we surveyed the regulatory guidances, the newly approved molecular entity drug products, and drug product labels in the Physician's Desk Reference. This review summarizes the findings of the survey along with the existing knowledge on pharmacokinetic and pharmacodynamic changes associated with obesity.
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Affiliation(s)
- R Jain
- Office of Clinical Pharmacology, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
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Botev R, Mallié JP, Wetzels JF, Couchoud C, Schück O. The Clinician and Estimation of Glomerular Filtration Rate by Creatinine-based Formulas: Current Limitations and Quo Vadis. Clin J Am Soc Nephrol 2011; 6:937-50. [DOI: 10.2215/cjn.09241010] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Laville M. [Renal consequences of obesity]. Nephrol Ther 2011; 7:80-5. [PMID: 21208837 DOI: 10.1016/j.nephro.2010.11.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 11/30/2010] [Accepted: 11/30/2010] [Indexed: 11/25/2022]
Abstract
The steady increase in the prevalence of obesity contributes to the increase in the prevalence of chronic kidney disease, through renal damages associated with type-2 diabetes and hypertension. Obesity is also an independent risk factor for the kidney, since it is associated with an increased risk of albuminuria and glomerulosclerosis, and worsens the course of chronic kidney disease regardless of the primary renal disease. The existence of a metabolic syndrome, constant in type-2 diabetes, and associated with abdominal obesity, is not the only requirement for renal anomalies of which the translation is a functional hyperfiltration, a clinical microalbuminuria and histologically a glomerulomegaly and glomerulosclerosis. The estimated glomerular filtration rate (GFR) in obese patients is strongly influenced by the weight or indexation to body surface area, and it is logical to take into account the value of non-indexed GFR to assess renal risk and treatment effects, especially if they lead to weight loss. Hypertension is promoted by salt sensitivity, potentially reversible, and overactivity of the renin-angiotensin system (RAS) in part due to adipose tissue. The cytokines secreted by adipose tissue (adipokines), induce sympathetic hyperactivity through leptin, and low-grade inflammatory state that contributes to the development of glomerular sclerosis lesions, especially because a resistance to adiponectin. The treatment relies on weight loss, possibly through bariatric surgery, and antagonists of the RAS.
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Affiliation(s)
- Maurice Laville
- Inserm U 886, service de néphrologie, hôpital Édouard-Herriot, université de Lyon, 69437 Lyon cedex 03, France.
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Wuerzner G, Bochud M, Giusti V, Burnier M. Measurement of glomerular filtration rate in obese patients: pitfalls and potential consequences on drug therapy. Obes Facts 2011; 4:238-43. [PMID: 21701241 PMCID: PMC6444551 DOI: 10.1159/000329547] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Epidemiological studies have shown that obesity is associated with chronic kidney disease and end stage renal disease. These studies have used creatinine derived equations to estimate glomerular filtration rate (GFR) and have indexed GFR to body surface area (BSA). However, the use of equations using creatinine as a surrogate marker of glomerular filtration and the indexation of GFR for BSA can be questioned in the obese population. First, these equations lack precision when they are compared to gold standard GFR measurements such as inulin clearances; secondly, the indexation of GFR for 1.73 m(2) of BSA leads to a systematic underestimation of GFR compared to absolute GFR in obese patients who have BSA that usually exceed 1.73 m(2). Obesity is also associated with pathophysiological changes that can affect the pharmacokinetics of drugs. The effect of obesity on both renal function and drug pharmacokinetics raises the issue of correct drug dosage in obese individuals. This may be particularly relevant for drugs known to have a narrow therapeutic range or excreted by the kidney.
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Affiliation(s)
| | | | - Vittorio Giusti
- Service of Endocrinology, Diabetology and Metabolism, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Michel Burnier
- Service of Nephrology and Hypertension
- *Service of Nephrology and Hypertension, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon 17, 1011 Lausanne, Switzerland, Tel. +41 21 314 11-54, Fax -39
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Wuerzner G, Pruijm M, Maillard M, Bovet P, Renaud C, Burnier M, Bochud M. Marked association between obesity and glomerular hyperfiltration: a cross-sectional study in an African population. Am J Kidney Dis 2010; 56:303-12. [PMID: 20538392 DOI: 10.1053/j.ajkd.2010.03.017] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Accepted: 03/01/2010] [Indexed: 01/03/2023]
Abstract
BACKGROUND Obesity and African American ethnicity are established independent risk factors for the development of chronic kidney disease. No data exist about the association between obesity and renal hemodynamics in the African region. STUDY DESIGN Cross-sectional study. SETTING & PARTICIPANTS 301 nondiabetic participants (97 lean, 108 overweight, and 96 obese) of African descent with a positive family history of hypertension from the Seychelles islands. PREDICTOR Body mass index (BMI). OUTCOMES Glomerular hyperfiltration, glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and filtration fraction. MEASUREMENTS GFR and ERPF were measured using inulin and para-aminohippurate clearances, respectively. Participants' baseline demographics, laboratory data, and blood pressure were measured using standard techniques. RESULTS The prevalence of glomerular hyperfiltration (defined as GFR >or=140 mL/min) increased across BMI categories (7.2%, 14.8%, and 27.1% for lean, overweight, and obese participants, respectively; P < 0.001). Higher BMI was associated with higher median GFR (99, 110, and 117 mL/min for lean, overweight, and obese participants, respectively; P < 0.001), ERPF (424, 462, and 477 mL/min, respectively; P = 0.01), and filtration fraction (0.23, 0.24, and 0.25; P < 0.001). Multivariate analyses adjusting for age, sex, blood pressure, fasting glucose level, and urinary sodium excretion and accounting for familial correlations confirmed the associations between high BMI (>25 kg/m(2)) and increased GFR, ERPF, and filtration fraction. No association between BMI categories and GFR was found with adjustment for body surface area. LIMITATIONS Participants had a positive family history of hypertension. CONCLUSION Overweight and obesity are associated with increased GFR, ERPF, and filtration fraction and a high prevalence of glomerular hyperfiltration in nondiabetic individuals of African descent. The absence of associations between BMI categories and GFR indexed for body surface area raises questions regarding the appropriateness of indexing GFR for body surface area in overweight populations.
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Affiliation(s)
- Grégoire Wuerzner
- Department of Medicine, Service of Nephrology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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Delanaye P, Mariat C, Cavalier É, Krzesinski JM. Indexation du débit de filtration glomérulaire par la surface corporelle : mythe et réalité. Nephrol Ther 2009; 5:614-22. [DOI: 10.1016/j.nephro.2009.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 04/22/2009] [Accepted: 04/22/2009] [Indexed: 11/25/2022]
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34
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Delanaye P, Mariat C, Cavalier E, Krzesinski JM. Errors induced by indexing glomerular filtration rate for body surface area: reductio ad absurdum. Nephrol Dial Transplant 2009; 24:3593-6. [PMID: 19734136 DOI: 10.1093/ndt/gfp431] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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35
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Tsinalis D, Thiel GT. An easy to calculate equation to estimate GFR based on inulin clearance. Nephrol Dial Transplant 2009; 24:3055-61. [PMID: 19395728 DOI: 10.1093/ndt/gfp193] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND For the estimation of renal function on the basis of serum creatinine, either the Cockcroft-Gault (CG) equation or the MDRD formula is commonly used. Compared to MDRD (using power functions), CG has the advantage of easy calculability at the bedside. MDRD, however, approaches glomerular filtration rate (GFR) more precisely than CG and gives values corrected for a body surface area (BSA) of 1.73 m(2). We wondered whether CG could be adapted to estimate GFR rather than creatinine clearance without losing the advantage of easy calculability. In this prospective study, inulin clearance under well-defined conditions was taken as the gold standard for GFR. METHODS In 182 living kidney donors, inulin clearance was measured under standardized conditions (protein, salt and water intake, overnight stay) before and after nephrectomy. Together with the serum creatinine level, and demographic and clinical data, 281 measurements of inulin clearance were used to compare the accuracy of different estimation equations. Using stepwise multiple regression, a new set of constants was defined for a CG-like equation in order to estimate GFR. RESULTS The MDRD equation underestimated GFR by 9%, and the quadratic equation suggested by Rule overestimated GFR by 12.4%. The new CG-like equation, even when calculated with 'mental arithmetic-friendly' rounded parameters, showed significantly less bias (1.2%). The adapted equation is GFR[mL/min] = ((155 - Age[years]) x weight [kg]/serum creatinine [micromol/L]) x 0.85 if female. CONCLUSIONS We propose the CG-like equation called IB-eGFR (Inulinclearance Based eGFR) to estimate GFR more reliably than MDRD, Rule's equation or the original Cockcroft-Gault equation. As our data represent a Caucasian population, the adapted equation is still to be validated for patients of other ethnicity.
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Affiliation(s)
- Dimitrios Tsinalis
- Clinic for Transplantation Immunology and Nephrology, University Hospital, Basel, Switzerland.
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Peters AM, Ciapryna MB, Bowles PF, Glass DM. Obesity does not accelerate the decline in glomerular filtration rate associated with advancing age. Int J Obes (Lond) 2009; 33:379-81. [PMID: 19188924 DOI: 10.1038/ijo.2009.6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Obesity has been suggested as a risk factor for chronic kidney disease. However, it has also been suggested that the association between obesity and impaired glomerular filtration rate (GFR) arises from the invalid use of body surface area (BSA) for scaling. This study assesses the effect of obesity on GFR by comparing the age-dependent decline in obese (body mass index (BMI) >30 kg/m(2); n=149) and non-obese patients (n=589), aged >30 years, referred for measurement of GFR (Cr-51-EDTA and three blood samples). GFR was scaled to a BSA of 1.73 m(2) (GFR/BSA) and extracellular fluid volume of 13 l (GFR/ECV), both corrected for the one-compartment assumption. When non-obese patients were categorized into 10-year age brackets (from 31 to >70), GFR/BSA and GFR/ECV declined from 92 ml per min per 1.73 m(2) and 95 ml per min per 13 l, respectively, at 31-40 years to 58 and 59 at >70. The declines in obese patients were similar with corresponding values of 88 ml per min per 1.73 m(2) and 97 ml per min per 13 l at 31-40 and 57 and 59 at >70 years. Linear regression analysis of non-categorized data from age 40 years showed rates of decline slightly slower in the obese (0.82 vs 0.95 ml per min per 1.73 m(2) per year and 0.87 vs 1.02 ml per min per 13 l per year). No effect of obesity on renal function was shown. Scaling to BSA did not distort the results.
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Affiliation(s)
- A M Peters
- Nuclear Medicine, Brighton and Sussex Medical School, Eastern Road, Brighton, UK.
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37
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Janmahasatian S, Duffull SB, Chagnac A, Kirkpatrick CMJ, Green B. Lean body mass normalizes the effect of obesity on renal function. Br J Clin Pharmacol 2008; 65:964-5. [PMID: 18279477 DOI: 10.1111/j.1365-2125.2008.03112.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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38
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Griffin KA, Kramer H, Bidani AK. Adverse renal consequences of obesity. Am J Physiol Renal Physiol 2008; 294:F685-96. [PMID: 18234955 DOI: 10.1152/ajprenal.00324.2007] [Citation(s) in RCA: 185] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Emerging evidence indicates that obesity, even in the absence of diabetes, contributes significantly to the development and progression of chronic kidney disease (CKD). Glomerular hyperfiltration/hypertrophy in response to the increased metabolic needs of obesity are postulated to lead to the development of glomerulosclerosis (GS) in a manner analogous to that in reduced renal mass states. Nevertheless, the individual risk for developing GS with obesity is very low. It is proposed that glomerular hyperfiltration/hypertrophy are per se not pathogenic in the absence of an enhanced glomerular blood pressure (BP) transmission, and the modest preglomerular vasodilation that is likely present in the large majority of obese individuals is not sufficient to result in such increased BP transmission. However, in the small subset of obese individuals who are also born with a substantially reduced nephron number, there is a greater risk of enhanced glomerular BP transmission due to the substantially greater preglomerular vasodilation. Of perhaps greater clinical importance, similar additive deleterious effects of obesity on BP transmission would be expected in individuals with reduced renal mass, either congenital or acquired, or with concurrent renal disease, leading to accelerated progression. Of note, a low birth weight may be a risk factor for not only reduced nephron numbers at birth, but also for obesity and hypertension, resulting in a clustering of risk factors for progressive GS. Therefore, even though the individual risk for developing obesity GS is low, the cumulative impact of obesity on the public health burden of CKD is likely to be large because of its huge prevalence.
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Affiliation(s)
- Karen A Griffin
- Loyola Univ. Medical Center, 2160 South First Ave., Maywood, IL 60153, USA.
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39
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The Predictive Value of CRP Levels on Future Severe Renal Disease in Overweight and Obese Subjects Without Diabetes Mellitus and Hypertension. Am J Med Sci 2007; 334:444-51. [DOI: 10.1097/maj.0b013e3180f62b8d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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40
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Abstract
Growth and development can be investigated using readily observable demographic factors such as weight and age. Size is the primary covariate and can be referenced to a 70-kg person with allometry using a coefficient of 0.75 for clearance and 1 for volume. The use of these coefficients is supported by fractal geometric concepts and observations from diverse areas in biology. Fat free mass (FFM) might be expected to do better than total body weight when there are wide variations in fat affecting body composition. Clearance pathways develop in the fetus before birth. The use of postnatal age as a descriptor of maturation is unsatisfactory because birth may occur prematurely; therefore postmenstrual age is a superior predictor of elimination function. A sigmoid E(max) model (Hill equation) describes gradual maturation of clearance in early life leading to a mature adult clearance achieved at a later age.
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Affiliation(s)
- B J Anderson
- Department of Anaesthesiology, University of Auckland School of Medicine, Auckland, New Zealand.
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41
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Bird NJ, Peters C, Michell AR, Peters AM. Comparison between slope–intercept and slope-only techniques for measuring glomerular filtration rate: Use of two independent markers and an independent arbiter. Nucl Med Commun 2007; 28:711-8. [PMID: 17667750 DOI: 10.1097/mnm.0b013e3281ec51b5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE Exclusive use of the half-time of clearance of a filtration marker in the bolus injection, single compartment technique for measuring glomerular filtration rate (GFR) is a convenient approach that gives GFR (GFR(SO)) already scaled for extracellular fluid volume (ECV). It has been criticized as less accurate than the conventional, slope-intercept technique (GFR(SI)). The aim of the study was to compare the respective levels of agreement of GFR(SI) and GFR(SO) with GFR based on plasma creatinine (eGFR) used as an independent arbiter. METHODS GFR was measured with both 51Cr-EDTA and iohexol, simultaneously injected into opposite arms. Plasma obtained bilaterally 20, 40, 60, 120, 180 and 240 min after injection was assayed for marker injected contra-laterally, 51Cr-EDTA by well-counting and iohexol by X-ray fluorescence. ECV and GFR, scaled to body surface area (BSA), were formally measured from six samples and GFR(SI) (scaled to BSA) and GFR(SO) from the last three. RESULTS Disagreement between GFR(SO) measured with 51Cr-EDTA and eGFR was not significantly higher than the corresponding disagreement between eGFR and GFR(SI). Disagreement between GFR(SO) measured with iohexol and eGFR was significantly higher than between eGFR and GFR(SI). GFR(SI) and GFR(SO) correlated more closely when measured with 51Cr-EDTA than with iohexol. Individual differences between GFR(SI) and GFR(SO) using one marker correlated significantly with ECV measured with the other. CONCLUSIONS GFR(SO) is critically dependent on the accuracy of half-time measurement and, measured with iohexol, appeared less reliable than GFR(SI). GFR(SI) and GFR(SO) measured with 51Cr-EDTA, however, have similar levels of reliability.
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Affiliation(s)
- Nicholas J Bird
- Department of Nuclear Medicine, Addenbrooke's Hospital, Cambridge, UK
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42
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Kwakernaak AJ, Tent H, Rook M, Krikken JA, Navis G. Renal hemodynamics in overweight and obesity: pathogenetic factors and targets for intervention. Expert Rev Endocrinol Metab 2007; 2:539-552. [PMID: 30290422 DOI: 10.1586/17446651.2.4.539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Weight excess is a risk factor for progressive renal function loss, not only in subjects with renal disease or renal transplant recipients, but also in the general population. Considering the increasing prevalence of obesity worldwide, weight excess may become the main renal risk factor on a population basis, all the more so because the risk is not limited to morbid obesity, but is already apparent in the overweight range. The mechanism of the renal risk is multifactorial. In addition to the role of comorbid conditions such as hypertension and diabetes, current evidence supports a pathogenetic role for renal hemodynamics, specifically glomerular hyperfiltration, and also glomerular hypertension. Weight excess is associated with an elevated glomerular filtration rate and a less pronounced rise in renal plasma flow, resulting in an elevated filtration fraction. This suggests glomerular hypertension due to afferent-efferent dysbalance, which impairs glomerular protection from systemic hypertension. Data in renal transplant recipients support the pathogenetic role of elevated glomerular pressure for long-term renal prognosis. Blockade of the renin-angiotensin-aldosterone system can reverse the renal hemodynamic abnormalities. The obesity-associated renal risk is unfavourably affected by high sodium intake. This may be due to the effects of sodium on blood pressure, which is often sodium-sensitive in obesity, but direct renal effects are also present. Interestingly, sodium restriction ameliorates overweight-associated hyperfiltration in overweight subjects. More focus on weight excess as a renal risk factor is warranted. Preventive measures should focus on weight excess as well as on specific protection against renal damage, by renin-angiotensin-aldosterone system-blockade and moderate sodium restriction.
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Affiliation(s)
- Arjan J Kwakernaak
- a Department of Medicine, Division of Nephrology, University Medical Center Groningen, The Netherlands.
| | - Hilde Tent
- b Department of Medicine, Division of Nephrology, University Medical Center Groningen, The Netherlands.
| | - Mieneke Rook
- c Department of Medicine, Division of Nephrology, University Medical Center Groningen, The Netherlands.
| | - Jan A Krikken
- d Department of Medicine, Division of Nephrology, University Medical Center Groningen, The Netherlands.
| | - Gerjan Navis
- e Head of Experimental Nephrology Dept., Department of Medicine, Division of Nephrology, University Medical Center Groningen, Hanzeplein 1, 9700 RB The Netherlands.
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Wahba IM, Mak RH. Obesity and obesity-initiated metabolic syndrome: mechanistic links to chronic kidney disease. Clin J Am Soc Nephrol 2007; 2:550-62. [PMID: 17699463 DOI: 10.2215/cjn.04071206] [Citation(s) in RCA: 366] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
There is an epidemic of obesity and the metabolic syndrome in the United States and across the world. Both entities are associated with high mortality, mainly as a result of cardiovascular disease. The epidemic of obesity has been paralleled by an increase in the incidence of chronic kidney disease (CKD). Several recent epidemiologic studies have shown that obesity and the metabolic syndrome are independent predictors of CKD. In addition to diabetes and hypertension, several other mechanisms have been postulated to initiate and maintain kidney injury in patients with obesity and the metabolic syndrome. This article reviews the recent epidemiologic data linking obesity and the metabolic syndrome to CKD and summarizes the potential mechanisms of renal injury in this setting, with a focus on the role of inflammation, lipotoxicity, and hemodynamic factors. Potential preventive and therapeutic modalities based on the limited evidence available are discussed.
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Affiliation(s)
- Ihab M Wahba
- Department of Medicine, Division of Nephrology and Hypertension, Oregon Health & Science University, Portland, Oregon, USA
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44
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The Heart and the Kidney. CARDIOVASCULAR MEDICINE 2007. [DOI: 10.1007/978-1-84628-715-2_139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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45
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Krikken JA, Lely AT, Bakker SJL, Navis G. The effect of a shift in sodium intake on renal hemodynamics is determined by body mass index in healthy young men. Kidney Int 2006; 71:260-5. [PMID: 17091123 DOI: 10.1038/sj.ki.5002011] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A body mass index (BMI)>or=25 kg/m2 increases the risk for long-term renal damage, possibly by renal hemodynamic factors. As epidemiological studies suggest interaction of BMI and sodium intake, we studied the combined effects of sodium intake and BMI on renal hemodynamics. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured in 95 healthy men (median age 23 years (95% confidence interval: 22-24), BMI: 23.0+/-2.5 kg/m2) on low (50 mmol Na+, LS) and high (200 mmol Na+, HS) sodium intake. Mean GFR and ERPF significantly increased by the change to HS (both P<0.001). During HS but not LS, GFR and filtration fraction (FF) positively correlated with BMI (R=0.32 and R=0.28, respectively, both P<0.01). Consequently, BMI correlated with the sodium-induced changes in GFR (R=0.30; P<0.01) and FF (R=0,23; P<0.05). The effects of HS on GFR and FF were significantly different for BMI>or=25 versus <25 kg/m2, namely 7.8+/-12.3 versus 16.1+/-13.1 ml/min (P<0.05) and -0.1+/-2.2 and 1.1+/-2.3% (P<0.05). FF was significantly higher in BMI>or=25 versus <25 kg/m2, (22.6+/-2.9 versus 24.6+/-2.4%, P<0.05) only during HS. ERPF was not related to BMI. Urinary albumin excretion was increased by HS from 6.0 (5.4-6.7) to 7.6 (6.9-8.9). Results were essentially similar after excluding the only two subjects with BMI>30 kg/m2. BMI is a determinant of the renal hemodynamic response to HS in healthy men, and of GFR and FF during HS, but not during LS. Consequently, HS elicited a hyperfiltration pattern in subjects with a BMI>or=25 kg/m2 that was absent during LS. Future studies should elucidate whether LS or diuretics can ameliorate the long-term renal risks of weight excess.
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Affiliation(s)
- J A Krikken
- Division of Nephrology, Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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46
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Ahmed SB, Fisher NDL, Stevanovic R, Hollenberg NK. Body mass index and angiotensin-dependent control of the renal circulation in healthy humans. Hypertension 2005; 46:1316-20. [PMID: 16286575 DOI: 10.1161/01.hyp.0000190819.07663.da] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Obesity is increasingly recognized as a risk factor for renal disease, but the mechanism is unclear. Renal plasma flow response to captopril, as an index of renin-angiotensin system activity, was measured by para-aminohippurate clearance technique in 100 healthy, normotensive subjects in balance on a high-salt diet. Of the 100 subjects, body mass index exceeded 25 in 56 and exceeded 30 in 22. The average vasodilator response to captopril was 27+/-7 mL/min per 1.73 m2 (P<0.0001). After adjustment for other predictors of the renal plasma flow response to captopril using a multivariate linear regression model, there was a highly significant relationship between age- and plasma renin activity-adjusted body mass index and the renal plasma flow response to captopril; however, a quadratic model provided a substantially better fit (r=0.55; P<0.0001; P=0.03 versus linear correlation). The strong association between increasing body mass index and angiotensin-dependent control of the renal circulation suggests that this may be a mechanism by which obesity contributes to renal disease. Weight loss should be considered in the overweight or obese patient for renal protection.
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Affiliation(s)
- Sofia B Ahmed
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
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47
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Delanaye P, Radermecker RP, Rorive M, Depas G, Krzesinski JM. Indexing glomerular filtration rate for body surface area in obese patients is misleading: concept and example. Nephrol Dial Transplant 2005; 20:2024-8. [PMID: 16030047 DOI: 10.1093/ndt/gfh983] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Verhave JC, Fesler P, du Cailar G, Ribstein J, Safar ME, Mimran A. Elevated Pulse Pressure Is Associated With Low Renal Function in Elderly Patients With Isolated Systolic Hypertension. Hypertension 2005; 45:586-91. [PMID: 15738348 DOI: 10.1161/01.hyp.0000158843.60830.cf] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In the past decade, pulse pressure has emerged as a strong predictor of cardiovascular morbidity and mortality. During aging, elevation of pulse pressure is a consequence of stiffening of the arterial wall. The relationship between pulse pressure and the renal aging process was studied in a cohort of 212 patients with never-treated isolated systolic hypertension. Glomerular filtration rate and effective renal plasma flow were measured using constant infusion of technetium 99m (
99m
Tc)-DTPA and
131
I-ortho-iodohippurate, respectively, and timed urine collections. The relationship between pulse pressure and renal function was studied using a linear regression model in the total population and in 40 to 49, 50 to 59, and 60 years and older age categories. In the whole population, there was an inverse relationship between pulse pressure and glomerular filtration rate; however, this relation did not persist after adjustment for age. In fact, the inverse relationship between pulse pressure and glomerular filtration rate was only present in patients 60 years of age or older. This relationship in elderly patients remained after adjustment for age, gender, MAP, and cardiovascular risk factors (
P
=0.006). It is suggested that pulse pressure, a marker of arterial stiffening, may have a detrimental influence on the age-related decline in glomerular filtration rate, after 60 years of age in patients with never-treated isolated systolic hypertension.
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Green B, Greenwood M, Saltissi D, Westhuyzen J, Kluver L, Rowell J, Atherton J. Dosing strategy for enoxaparin in patients with renal impairment presenting with acute coronary syndromes. Br J Clin Pharmacol 2005; 59:281-90. [PMID: 15752373 PMCID: PMC1884796 DOI: 10.1111/j.1365-2125.2004.02253.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2004] [Accepted: 08/12/2004] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Phase III clinical studies have confirmed that enoxaparin is superior to standard heparin in reducing the rate of recurrent ischaemic events in patients with non-ST elevation acute coronary syndromes. Patients with moderate to severe renal impairment were, however, excluded from these studies. Due to the hydrophilic disposition of enoxaparin, accumulation is likely in patients with renal dysfunction, thereby increasing the risk of haemorrhagic complications if standard weight adjusted treatment doses are used. Arbitrary dose reduction has been reported to increase the risk of ischaemic events, presumably due to inadequate enoxaparin concentrations. AIM The aims of this study were to investigate the influence of glomerular filtration rate (GFR) on the pharmacokinetics of subcutaneously administered enoxaparin, and to develop a practical dosing algorithm in renal impairment that can easily be used at the bedside. METHODS Thirty-eight patients, median age 78 years (range 44-87), mean GFR 32 ml min(-1) (range 16-117) and mean weight 69 kg (range 32-95), presenting with acute coronary syndrome were recruited into the study. Approximately 10 anti-Xa concentrations were taken per patient over their period of therapy. A population pharmacokinetic model was developed using non linear mixed effects modelling techniques, utilizing the software NONMEM. Stochastic simulations were performed to identify the most suitable dosing regimen. RESULTS Three hundred and thirteen anti-Xa concentrations were collected. A two compartment, first order input model was identified as the best baseline model. Covariates found to improve model fitting were GFR as a linear function on clearance (CL) and weight as a linear function on the central volume compartment (Vc). The fraction of drug excreted unchanged (Fu) was estimated at 71%. CL and Vc from the final covariate model were estimated as; CL (l h(-1)) = 0.681 per 4.8 l hr(-1) (GFR) + 0.229 Vc (l) = 5.22 per 80 kg (total body weight) CONCLUSIONS Clearance of enoxaparin was predictably related to GFR estimated using the Cockroft and Gault equation, with ideal body weight used as the size descriptor. According to our model no dosage adjustment from the standard 1.0 mg kg(-1) 12 hourly is required for the first 48 h of treatment. Maintenance doses thereafter can be calculated using standard proportional adjustments based on Fu equal to 0.71.
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Affiliation(s)
- B Green
- School of Pharmacy, University of Queensland, St Lucia, Brisbane, Australia.
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50
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Bosma RJ, van der Heide JJH, Oosterop EJ, de Jong PE, Navis G. Body mass index is associated with altered renal hemodynamics in non-obese healthy subjects. Kidney Int 2004; 65:259-65. [PMID: 14675058 DOI: 10.1111/j.1523-1755.2004.00351.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Weight excess is associated with increased renal risk. Data in overt obesity suggest a role for altered renal hemodynamics. Whether body mass index (BMI) is also relevant to renal function in non-obese subjects is unknown. METHODS We studied the relation between BMI and renal hemodynamics in 102 healthy, non-obese (BMI <30 kg/m2) subjects [59 males, 43 females, mean age 39 (18-69) years] in a post-hoc analysis of subjects evaluated as prospective kidney donors or as healthy volunteers in renal hemodynamic studies. RESULTS Mean (+/-SD) BMI was 24.0 +/- 2.8 kg/m2, mean arterial pressure (MAP) 93 +/- 11 mm Hg, glomerular filtration rate (GFR, iothalamate clearance) 111 +/- 19 mL/min/1.73 m2, effective renal plasma flow (ERPF, hippuran clearance) 458 +/- 108 mL/min/1.73 m2, FF (GFR/ERPF) 0.25 +/- 0.04. On univariate analysis, BMI correlated negatively with ERPF/1.73 m2 body surface area (BSA) (r=-0.46; P < 0.001), GFR/1.73 m2 BSA (r=-0.24, P= 0.013) and positively with FF (r= 0.45, P < 0.001), and age (r= 0.47, P < 0.001). On multivariate analysis both BMI and age were independent predictors of ERPF/1.73 m2 BSA (negative) and FF (positive, all P < 0.05). Age was the only predictor of GFR/1.73 m2 BSA (negative). Analyzed for renal function indexed for height (h), BMI correlated negatively with ERPF/h (r=-0.274, P= 0.005), but not with GFR/h (r= 0.13, P= 0.899). On multivariate analysis both BMI (positive) and age (negative) were independent predictors for GFR/h (both P < 0.001). Age was the only predictor for ERPF/h (negative). Predictors for FF (BMI and age, both positive) were by definition unaltered. CONCLUSION The impact of BMI on renal function is not limited to overt obesity, as in subjects with BMI <30 kg/m2 a higher BMI is associated with higher FF, that is, a higher GFR relative to ERPF. This suggests an altered afferent/efferent balance and higher glomerular pressure (i.e., a potentially unfavorable renal hemodynamic profile) that may confer enhanced renal susceptibility when other factors, such as hypertension or diabetes are superimposed.
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Affiliation(s)
- Renate J Bosma
- Department of Medicine, Division of Nephrology, University Hospital Groningen, The Netherlands
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