1
|
Cheval L, Viollet B, Klein C, Rafael C, Figueres L, Devevre E, Zadigue G, Azroyan A, Crambert G, Vogt B, Doucet A. Acidosis-induced activation of distal nephron principal cells triggers Gdf15 secretion and adaptive proliferation of intercalated cells. Acta Physiol (Oxf) 2021; 232:e13661. [PMID: 33840159 DOI: 10.1111/apha.13661] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 04/03/2021] [Accepted: 04/05/2021] [Indexed: 12/11/2022]
Abstract
AIM Type A intercalated cells of the renal collecting duct participate in the maintenance of the acid/base balance through their capacity to adapt proton secretion to homeostatic requirements. We previously showed that increased proton secretion stems in part from the enlargement of the population of proton secreting cells in the outer medullary collecting duct through division of fully differentiated cells, and that this response is triggered by growth/differentiation factor 15. This study aimed at deciphering the mechanism of acid load-induced secretion of Gdf15 and its mechanism of action. METHODS We developed an original method to evaluate the proliferation of intercalated cells and applied it to genetically modified or pharmacologically treated mice under basal and acid-loaded conditions. RESULTS Gdf15 is secreted by principal cells of the collecting duct in response to the stimulation of vasopressin receptors. Vasopressin-induced production of cAMP triggers activation of AMP-stimulated kinases and of Na,K-ATPase, and induction of p53 and Gdf15. Gdf15 action on intercalated cells is mediated by ErbB2 receptors, the activation of which triggers the expression of cyclin d1, of p53 and anti-proliferative genes, and of Egr1. CONCLUSION Acidosis-induced proliferation of intercalated cells results from a cross talk with principal cells which secrete Gdf15 in response to their stimulation by vasopressin. Thus, vasopressin is a major determinant of the collecting duct cellular homeostasis as it promotes proliferation of intercalated cells under acidosis conditions and of principal cells under normal acid-base status.
Collapse
Affiliation(s)
- Lydie Cheval
- Centre de Recherche des Cordeliers INSERMSorbonne UniversitéUniversité de Paris Paris France
- CNRS ERL 8228 ‐ Laboratoire de Physiologie Rénale et Tubulopathies Paris France
| | - Benoit Viollet
- Université de ParisInstitut CochinINSERMCNRS Paris France
| | - Christophe Klein
- Centre de Recherche des Cordeliers INSERMSorbonne UniversitéUniversité de Paris Paris France
| | - Chloé Rafael
- Centre de Recherche des Cordeliers INSERMSorbonne UniversitéUniversité de Paris Paris France
- CNRS ERL 8228 ‐ Laboratoire de Physiologie Rénale et Tubulopathies Paris France
| | - Lucile Figueres
- Centre de Recherche des Cordeliers INSERMSorbonne UniversitéUniversité de Paris Paris France
- CNRS ERL 8228 ‐ Laboratoire de Physiologie Rénale et Tubulopathies Paris France
| | - Estelle Devevre
- Centre de Recherche des Cordeliers INSERMSorbonne UniversitéUniversité de Paris Paris France
| | - Georges Zadigue
- Centre de Recherche des Cordeliers INSERMSorbonne UniversitéUniversité de Paris Paris France
| | - Anie Azroyan
- Program in Membrane Biology Nephrology Division Center for Systems Biology Massachusetts General Hospital Harvard Medical School Boston MA USA
| | - Gilles Crambert
- Centre de Recherche des Cordeliers INSERMSorbonne UniversitéUniversité de Paris Paris France
- CNRS ERL 8228 ‐ Laboratoire de Physiologie Rénale et Tubulopathies Paris France
| | - Bruno Vogt
- Department of Nephrology and Hypertension, Inselspital Bern University Hospital Bern Switzerland
| | - Alain Doucet
- Centre de Recherche des Cordeliers INSERMSorbonne UniversitéUniversité de Paris Paris France
- CNRS ERL 8228 ‐ Laboratoire de Physiologie Rénale et Tubulopathies Paris France
| |
Collapse
|
2
|
Renal response to an oral protein load in patients with central diabetes insipidus before and after treatment with vasopressin. J Nephrol 2019; 32:411-415. [PMID: 30778919 DOI: 10.1007/s40620-018-00575-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 12/18/2018] [Indexed: 10/27/2022]
Abstract
AIM Different factors have been hypothesized to play a role in the cascade of events associated with the protein-induced glomerular response. However, scant data are available on the possible functional effect of vasopressin (VP) on the glomerular filtration rate (GFR) in humans with central diabetes insipidus (CDI), which was the aim of the present study. METHOD Renal function was studied under fasting conditions (baseline) and after a meat meal in 16 patients with CDI before and after treatment with desmopressin (DDAVP) and in 16 control subjects. GFR was measured by the inulin method. RESULTS At baseline, the GFR was lower in patients with CDI. Treatment with DDAVP resulted in an insignificant increase in GFR, which was not statistically different from untreated patients. After an acute oral protein load, the GFR increased, peaking at 45 min post meal in controls, and at 135 min post meal in treated and untreated CDI patients. CONCLUSION After a meat meal, the peak GFR response is delayed in CDI patients suggesting that VP might indirectly affect tubule-glomerular feedback.
Collapse
|
3
|
Wu LW, Chen WL, Liaw FY, Sun YS, Yang HF, Wang CC, Lin CM, Tsao YT. Association between fluid intake and kidney function, and survival outcomes analysis: a nationwide population-based study. BMJ Open 2016. [PMID: 27173809 DOI: 10.1136/bmjopen-2015010708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/09/2023] Open
Abstract
OBJECTIVES Fluid intake, one of the most common daily activities, has not been well studied in chronic kidney disease (CKD) populations, and clinical outcomes are rarely addressed. The aim of this nationwide study is to explore the influence of daily fluid intake on cardiovascular and all-cause mortality and its association with renal function. DESIGN Observational cohort study. PARTICIPANTS In all, 2182 participants aged more than 20 years participated in the Third National Health and Nutrition Examination Survey (1988-1994). MAIN OUTCOME MEASURES Survival outcomes in patients with or without CKD, using multiple variable adjusted Cox proportional hazard models. RESULTS In a longitudinal survey with a median follow-up length of 15.4 years, 1080 participants died and 473 cardiovascular deaths were recorded. For all-cause mortality in the CKD group, individuals in the highest quartile of fluid intake (≧3.576 L/day) had better survival outcomes than those in the lowest quartile of fluid intake (≤2.147 L/day) (p=0.029) after adjustment of several pertinent variables. CONCLUSIONS Although the interpretation of this observational study was limited by the failure to identify the compositions of ingested fluids, adequate hydration may offer some advantages in patients with CKD. However, the underlying pathophysiological mechanisms of the responses of normal and injured kidneys to chronic changes in fluid consumption warrant further investigation.
Collapse
Affiliation(s)
- Li-Wei Wu
- Division of Family Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC) Division of Geriatric Medicine, Department of Family and Community Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC) Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Wei-Liang Chen
- Division of Family Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC) Division of Geriatric Medicine, Department of Family and Community Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC) Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Fang-Yih Liaw
- Division of Family Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Yu-Shan Sun
- Division of Family Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Hui-Fang Yang
- Division of Family Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Chung-Ching Wang
- Division of Family Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Chien-Ming Lin
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Yu-Tzu Tsao
- Division of Nephrology, Department of Medicine, Taoyuan General Hospital, Taoyuan City, Taiwan (ROC) Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan (ROC)
| |
Collapse
|
4
|
Wu LW, Chen WL, Liaw FY, Sun YS, Yang HF, Wang CC, Lin CM, Tsao YT. Association between fluid intake and kidney function, and survival outcomes analysis: a nationwide population-based study. BMJ Open 2016; 6:e010708. [PMID: 27173809 PMCID: PMC4874113 DOI: 10.1136/bmjopen-2015-010708] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES Fluid intake, one of the most common daily activities, has not been well studied in chronic kidney disease (CKD) populations, and clinical outcomes are rarely addressed. The aim of this nationwide study is to explore the influence of daily fluid intake on cardiovascular and all-cause mortality and its association with renal function. DESIGN Observational cohort study. PARTICIPANTS In all, 2182 participants aged more than 20 years participated in the Third National Health and Nutrition Examination Survey (1988-1994). MAIN OUTCOME MEASURES Survival outcomes in patients with or without CKD, using multiple variable adjusted Cox proportional hazard models. RESULTS In a longitudinal survey with a median follow-up length of 15.4 years, 1080 participants died and 473 cardiovascular deaths were recorded. For all-cause mortality in the CKD group, individuals in the highest quartile of fluid intake (≧3.576 L/day) had better survival outcomes than those in the lowest quartile of fluid intake (≤2.147 L/day) (p=0.029) after adjustment of several pertinent variables. CONCLUSIONS Although the interpretation of this observational study was limited by the failure to identify the compositions of ingested fluids, adequate hydration may offer some advantages in patients with CKD. However, the underlying pathophysiological mechanisms of the responses of normal and injured kidneys to chronic changes in fluid consumption warrant further investigation.
Collapse
Affiliation(s)
- Li-Wei Wu
- Division of Family Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC)
- Division of Geriatric Medicine, Department of Family and Community Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC)
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Wei-Liang Chen
- Division of Family Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC)
- Division of Geriatric Medicine, Department of Family and Community Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC)
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Fang-Yih Liaw
- Division of Family Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Yu-Shan Sun
- Division of Family Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Hui-Fang Yang
- Division of Family Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Chung-Ching Wang
- Division of Family Medicine, Tri-Service General Hospital; and School of Medicine, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Chien-Ming Lin
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan (ROC)
| | - Yu-Tzu Tsao
- Division of Nephrology, Department of Medicine, Taoyuan General Hospital, Taoyuan City, Taiwan (ROC)
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan (ROC)
| |
Collapse
|
5
|
Weber M, Berglund D, Reule S, Jackson S, Matas AJ, Ibrahim HN. Daily fluid intake and outcomes in kidney recipients: post hoc analysis from the randomized ABCAN trial. Clin Transplant 2015; 29:261-7. [PMID: 25619874 DOI: 10.1111/ctr.12514] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2015] [Indexed: 11/28/2022]
Abstract
Generous and even excessive fluid intake is routinely recommended to kidney transplant recipients despite minimal evidence to support this practice. We hypothesized that increased fluid intake, ascertained by 24-h urine volume output, may adversely affect graft outcomes as it would impose an extra workload on a limited number of nephrons. Kidney transplant recipients who were randomized to losartan vs. placebo in the Angiotensin II Blockade for Chronic Allograft Nephropathy (ABCAN) trial (n = 153) underwent baseline, five-yr biopsies, and annual iothalamate glomerular filtration rate assessment. Recipients with higher urine volume at randomization had higher urinary sodium and also higher urinary protein. The proportion using diuretics or CNI based regimens were similar across urinary volume tertiles. The highest urinary volume tertile (>2.56 L/d) did not predict the development of interstitial volume doubling or end-stage renal disease (ESRD) from interstitial fibrosis/tubular atrophy (OR = 3.52, 95% CI 0.4, 31.24, p = 0.26), interstitial volume doubling or all-cause ESRD (OR = 7.04, 95% CI 0.66, 74.87, p = 0.11), and was not associated with the conventional endpoint of doubling serum creatinine, all-cause ESRD, or death (OR = 0.89, 95% CI 0.21, 3.71, p = 0.87). These results suggest that the current practice of liberal fluid intake may not be beneficial in low risk and mostly Caucasian transplant recipients.
Collapse
Affiliation(s)
- M Weber
- Division of Renal Diseases and Hypertension, University of Minnesota, Minneapolis, MN, USA
| | | | | | | | | | | |
Collapse
|
6
|
Plischke M, Kohl M, Bankir L, Shayganfar S, Handisurya A, Heinze G, Haas M. Urine osmolarity and risk of dialysis initiation in a chronic kidney disease cohort--a possible titration target? PLoS One 2014; 9:e93226. [PMID: 24675963 PMCID: PMC3968127 DOI: 10.1371/journal.pone.0093226] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 03/01/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Increasing evidence is linking fluid intake, vasopressin suppression and osmotic control with chronic kidney disease progression. Interestingly, the association between urine volume, urine osmolarity and risk of dialysis initiation has not been studied in chronic kidney disease patients before. OBJECTIVE To study the relationship between urine volume, urine osmolarity and the risk of initiating dialysis in chronic kidney disease. DESIGN In a retrospective cohort analysis of 273 patients with chronic kidney disease stage 1-4 we assessed the association between urine volume, urine osmolarity and the risk of dialysis by a multivariate proportional sub-distribution hazards model for competing risk data according to Fine and Gray. Co-variables were selected via the purposeful selection algorithm. RESULTS Dialysis was reached in 105 patients over a median follow-up period of 92 months. After adjustment for age, baseline creatinine clearance, other risk factors and diuretics, a higher risk for initiation of dialysis was found in patients with higher urine osmolarity. The adjusted sub-distribution hazard ratio for initiation of dialysis was 2.04 (95% confidence interval, 1.06 to 3.92) for each doubling of urine osmolarity. After 72 months, the estimated adjusted cumulative incidence probabilities of dialysis were 15%, 24%, and 34% in patients with a baseline urine osmolarity of 315, 510, and 775 mosm/L, respectively. CONCLUSIONS We conclude that higher urine osmolarity is associated with a higher risk of initiating dialysis. As urine osmolarity is a potentially modifiable risk factor, it thus deserves further, prospective research as a potential target in chronic kidney disease progression.
Collapse
Affiliation(s)
- Max Plischke
- Division of Nephrology and Dialysis, Department of Internal Medicine III, Medical University Vienna, Vienna, Austria
| | - Maria Kohl
- Section for Clinical Biometrics, Center of Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Lise Bankir
- INSERM UMRS 1138, Equipe 2, Centre de Recherche des Cordeliers, Paris, France
| | - Sascha Shayganfar
- Division of Cardiology, Pulmonology, and Vascular Medicine, Medical Faculty, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Ammon Handisurya
- Division of Nephrology and Dialysis, Department of Internal Medicine III, Medical University Vienna, Vienna, Austria
| | - Georg Heinze
- Section for Clinical Biometrics, Center of Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Martin Haas
- Division of Nephrology and Dialysis, Department of Internal Medicine III, Medical University Vienna, Vienna, Austria
- * E-mail:
| |
Collapse
|
7
|
Abstract
Urea transporter gene knockout mice have been created for the study of the urine-concentrating mechanism. The major findings in studies of the renal phenotype of these mice are as follows: (1) Urea accumulation in the inner medullary interstitium is dependent on intrarenal urea recycling mediated by urea transporters; (2) urea transporters are essential for preventing urea-induced osmotic diuresis and thus for water conservation; (3) NaCl concentration in the inner medullary interstitium is not significantly affected by the absence of IMCD, descending limb of Henle and descending vasa recta urea transporters. Studies in urea transporter knockout mouse models have highlighted the essential role of urea for producing maximally concentrated urine.
Collapse
Affiliation(s)
- Robert A Fenton
- Department of Biomedicine, Interpret Center, Aarhus University, Aarhus, Building 233/234, 8000, Aarhus, Denmark,
| | | |
Collapse
|
8
|
Clark WF, Sontrop JM, Huang SH, Gallo K, Moist L, House AA, Weir MA, Garg AX. The chronic kidney disease Water Intake Trial (WIT): results from the pilot randomised controlled trial. BMJ Open 2013; 3:e003666. [PMID: 24362012 PMCID: PMC3884598 DOI: 10.1136/bmjopen-2013-003666] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Increased water intake may benefit kidney function. Prior to initiating a larger randomised controlled trial (RCT), we examined the safety and feasibility of asking adults with chronic kidney disease (CKD) to increase their water intake. DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS Beginning in October 2012, we randomly assigned 29 adults with stage 3 CKD (estimated glomerular filtration rate (eGFR) 30-60 mL/min/1.73 m(2) and albuminuria) to one of the two groups of water intake: hydration (n=18) or standard (n=11). We asked the hydration group to increase their water intake by 1.0-1.5 L/day (in addition to usual intake, depending on sex and weight) for 6 weeks, while the control group carried on with their usual intake. Participants collected a 24 h urine sample at baseline and at 2 and 6 weeks after randomisation. Our primary outcome was the between-group difference in change in 24 h urine volume from baseline to 6 weeks. RESULTS (63%)of participants were men, 81% were Caucasians and the average age was 61 years (SD 14 years). The average baseline eGFR was 40 mL/min/1.73 m(2) (SD 11 mL/min/1.73 m(2)); the median albumin to creatinine ratio was 19 mg/mmol (IQR 6-74 mg/mmol). Between baseline and 6-week follow-up, the hydration group's average 24 h urine volume increased by 0.7 L/day (from 2.3 to 3.0 L/day) and the control group's 24 h urine decreased by 0.3 L/day (from 2.0 to 1.7 L/day; between-group difference in change: 0.9 L/day (95% CI 0.4 to 1.5; p=0.002)). We found no significant changes in urine, serum osmolality or electrolyte concentrations, or eGFR. No serious adverse events or changes in quality of life were reported. CONCLUSIONS A pilot RCT indicates adults with stage 3 CKD can successfully and safely increase water intake by up to 0.7 L/day in addition to usual fluid intake. TRIAL REGISTRATION REGISTERED WITH CLINICAL TRIALSGOVERNMENT IDENTIFIER: NCT01753466.
Collapse
Affiliation(s)
- William F Clark
- Division of Nephrology, Department of Medicine, London Health Sciences Centre, London, Ontario, Canada
| | - Jessica M Sontrop
- Division of Nephrology, Department of Medicine, London Health Sciences Centre, London, Ontario, Canada
- Department of Epidemiology & Biostatistics, Western University, London, Ontario, Canada
| | - Shih-Han Huang
- Division of Nephrology, Department of Medicine, London Health Sciences Centre, London, Ontario, Canada
| | - Kerri Gallo
- Department of Epidemiology & Biostatistics, Western University, London, Ontario, Canada
| | - Louise Moist
- Division of Nephrology, Department of Medicine, London Health Sciences Centre, London, Ontario, Canada
- Department of Epidemiology & Biostatistics, Western University, London, Ontario, Canada
| | - Andrew A House
- Division of Nephrology, Department of Medicine, London Health Sciences Centre, London, Ontario, Canada
| | - Matthew A Weir
- Division of Nephrology, Department of Medicine, London Health Sciences Centre, London, Ontario, Canada
| | - Amit X Garg
- Division of Nephrology, Department of Medicine, London Health Sciences Centre, London, Ontario, Canada
- Department of Epidemiology & Biostatistics, Western University, London, Ontario, Canada
| |
Collapse
|
9
|
The effects of tolvaptan on patients with severe chronic kidney disease complicated by congestive heart failure. Clin Exp Nephrol 2013; 17:834-8. [PMID: 23483323 PMCID: PMC3859890 DOI: 10.1007/s10157-013-0788-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Accepted: 02/21/2013] [Indexed: 12/04/2022]
Abstract
Background Tolvaptan, a diuretic with a new mechanism of action, selectively binds to the vasopressin V2 receptor and inhibits reabsorption of water. Its effect on heart failure is proven, but its benefit for patients with chronic kidney disease (CKD) has not been not confirmed. In this study, we examined the effect of tolvaptan on patients with severe CKD. Methods We analyzed patients with stage 4 or higher CKD who had congestive heart failure that was resistant to existing diuretics. The patients were administered an initial tolvaptan dose of 7.5 mg/day. We assumed urine volume and urine osmolality to be the main effective endpoint and recorded free water clearance, serum osmolality, serum creatinine (Cr) level, and adverse events. Results There was no instance of clinically significant hypernatremia. The urine volume increased significantly (P < 0.0001), as did the urine osmolality (P = 0.0053). Free water clearance showed a tendency to increase, although the difference was not statistically significant. The serum creatinine level did not change significantly, and there was no clear effect on renal function. However, in patients with stage 5 CKD, the serum creatinine level decreased significantly (n = 5, P = 0.0435). There were no adverse events. Conclusion We confirmed that tolvaptan has a diuretic effect in patients with both severe CKD and congestive heart failure without causing either clinically significant hypernatremia or an adverse effect on renal function. Tolvaptan is an effective diuretic for patients with CKD.
Collapse
|
10
|
Clark WF, Sontrop JM, Macnab JJ, Suri RS, Moist L, Salvadori M, Garg AX. Urine volume and change in estimated GFR in a community-based cohort study. Clin J Am Soc Nephrol 2011; 6:2634-41. [PMID: 21885793 DOI: 10.2215/cjn.01990211] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND OBJECTIVES The effect of increased fluid intake on kidney function is unclear. This study evaluates the relationship between urine volume and renal decline over 6 years in a large community-based cohort. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS This prospective cohort study was undertaken in Canada from 2002 to 2008. We obtained 24-hour urine samples from adult participants with an estimated GFR (eGFR) ≥60 ml/min per 1.73 m(2) at study entry. Percentage annual change in eGFR from baseline was categorized as average decline <1% per year, between 1% and 4.9% (mild-to-moderate decline) or ≥5% (rapid decline). RESULTS 2148 participants provided valid 24-hour urine samples, grouped as <1 L/d (14.5%); 1 to 1.9 L/d (51.5%); 2 to 2.9 L/d (26.3%); and ≥3 L/d (7.7%). Baseline eGFR for each category of urine volume was 90, 88, 84, and 87 ml/min per 1.73 m(2), respectively. Overall, eGFR declined by 1% per year, with 10% demonstrating rapid decline and 40% demonstrating mild-to-moderate decline. An inverse, graded relationship was evident between urine volume and eGFR decline: For each increasing category of 24-hour urine volume, percentage annual eGFR decline was progressively slower, from 1.3%, 1.0%, 0.8%, to 0.5%, respectively; P = 0.02. Compared with those with urine volume 1 to 1.9 L/d, those with urine volume ≥3 L/d were significantly less likely to demonstrate mild-to-moderate decline (adjusted odds ratio 0.66; 95% confidence interval 0.46 to 0.94) or rapid decline (adjusted odds ratio 0.46; 95% confidence interval 0.23 to 0.92); adjusted for age, gender, baseline eGFR, medication use for hypertension (including diuretics), proteinuria, diabetes, and cardiovascular disease. CONCLUSIONS In this community-based cohort, decline in kidney function was significantly slower in those with higher versus lower urine volume.
Collapse
Affiliation(s)
- William F Clark
- Division of Nephrology, Department of Medicine, London Health Sciences Centre, London, Ontario, Canada.
| | | | | | | | | | | | | |
Collapse
|
11
|
Ali BH, Al-Salam S, Al Husseni I, Kayed RR, Al-Masroori N, Al-Harthi T, Al Zaabi M, Nemmar A. Effects of Gum Arabic in rats with adenine-induced chronic renal failure. Exp Biol Med (Maywood) 2010; 235:373-82. [PMID: 20404056 DOI: 10.1258/ebm.2009.009214] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gum Arabic (GA [Acacia senegal]) is reputed, in Arabian medicinal practices, to be useful in treating patients with chronic renal failure (CRF), albeit without strong scientific evidence. We have previously shown that GA had no significant effect in rats with CRF induced by surgical nephrectomy. Here, we used another animal model of human CRF (feeding adenine at a concentration of 0.75%(w/w) for four weeks) to test the effect of GA on CRF. Renal morphology and measurements of plasma concentrations of urea and creatinine (Cr), and Cr clearance, in addition to urinary volume, osmolarity and protein concentrations, and N-acetylglucosamine and lactate dehydrogenase activities were performed. Interleukin-6 and the total antioxidant levels in urine, as well as the activity of superoxide dismutase in renal tissues, were estimated. Adenine feeding resulted in marked renal damage. GA (6%(w/v) and 12%(w/v) in drinking water for four consecutive weeks) significantly ameliorated the adverse biochemical alterations indicative of renal failure, abated the decrease in body weight and reduced the glomerular, tubular and interstitial lesions induced by adenine. Our study provides evidence that GA attenuated renal dysfunction in this model of CRF, suggesting a promising potential for it in protecting against renal failure progression. The mechanism(s) of this nephroprotection is uncertain but may involve anti-oxidant and/or anti-inflammatory actions.
Collapse
Affiliation(s)
- Badreldin H Ali
- Department of Pharmacology, Sultan Qaboos University, Al-Khod, Sultanate of Oman
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Okada T, Sakaguchi T, Hatamura I, Saji F, Negi S, Otani H, Muragaki Y, Kawachi H, Shigematsu T. Tolvaptan, a selective oral vasopressin V2 receptor antagonist, ameliorates podocyte injury in puromycin aminonucleoside nephrotic rats. Clin Exp Nephrol 2009; 13:438-446. [PMID: 19452240 DOI: 10.1007/s10157-009-0196-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Accepted: 04/20/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND Proteinuria caused by glomerular disease is characterized by podocyte injury. Vasopressin V2 receptor antagonists are effective in reducing albuminuria, although their actions on glomerular podocytes have not been explored. The objective of this study was to evaluate the effects of tolvaptan, a selective oral V2 receptor antagonist, on podocytes in a puromycin aminonucleoside (PAN)-induced nephrosis rat model. METHODS Rats were allocated to a control, PAN nephrosis, or tolvaptan-treated PAN nephrosis group (n = 9 per group). Urinary protein excretion and serum levels of total protein, albumin, creatinine, and total cholesterol were measured on day 10. The influence of tolvaptan on podocytes was examined in renal tissues by immunofluorescence and electron microscopy. RESULTS PAN induced massive proteinuria and serum creatinine elevation on day 10, both of which were significantly ameliorated by tolvaptan. Immunofluorescence studies of the podocyte-associated proteins nephrin and podocin revealed granular staining patterns in PAN nephrosis rats. In tolvaptan-treated rats, nephrin and podocin expressions retained their normal linear pattern. Electron microscopy showed foot process effacement was ameliorated in tolvaptan-treated rats. CONCLUSIONS Tolvaptan is protective against podocyte damage and proteinuria in PAN nephrosis. This study indicates that tolvaptan exerts a renoprotective effect by affecting podocyte morphology and probably function in PAN nephrosis. Tolvaptan is a promising pharmacological tool in the treatment of renal edema.
Collapse
Affiliation(s)
- Tadashi Okada
- Division of Nephrology and Blood Purification Medicine, Wakayama Medical University, 811-1, Kimiidera, Wakayama, 641-0012, Japan.
| | - Toshifumi Sakaguchi
- Division of Nephrology and Blood Purification Medicine, Wakayama Medical University, 811-1, Kimiidera, Wakayama, 641-0012, Japan
| | - Ikuji Hatamura
- First Department of Pathology, Wakayama Medical University, Wakayama, Japan
| | - Fumie Saji
- Division of Nephrology and Blood Purification Medicine, Wakayama Medical University, 811-1, Kimiidera, Wakayama, 641-0012, Japan
| | - Shigeo Negi
- Division of Nephrology and Blood Purification Medicine, Wakayama Medical University, 811-1, Kimiidera, Wakayama, 641-0012, Japan
| | - Haruhisa Otani
- Division of Nephrology and Blood Purification Medicine, Wakayama Medical University, 811-1, Kimiidera, Wakayama, 641-0012, Japan.,Ryoshukai Wakayama Kidney Disease Clinic, Wakayama, Japan
| | - Yasuteru Muragaki
- First Department of Pathology, Wakayama Medical University, Wakayama, Japan
| | - Hiroshi Kawachi
- Department of Cell Biology, Institute of Nephrology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Takashi Shigematsu
- Division of Nephrology and Blood Purification Medicine, Wakayama Medical University, 811-1, Kimiidera, Wakayama, 641-0012, Japan
| |
Collapse
|
13
|
Fenton RA. Essential role of vasopressin-regulated urea transport processes in the mammalian kidney. Pflugers Arch 2009; 458:169-77. [PMID: 19011892 DOI: 10.1007/s00424-008-0612-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Revised: 10/17/2008] [Accepted: 10/23/2008] [Indexed: 10/21/2022]
Abstract
Movement of urea across plasma membranes is modulated by specialized urea transporter proteins. Two urea-transporter genes have been cloned: UT-A (Slc14a2) and UT-B (Slc14a1). In the mammalian kidney, urea transporters are essential for the urinary concentrating mechanism and maintaining body fluid homeostasis. In this article, we discuss (1) an overview of historic discoveries in urea transport mechanisms; (2) an overview of recent discoveries in the regulation of urea transporters; (3) physiological studies in UT-A1/3 (-/-) mice highlighting the essential role of urea transporters in the urinary concentrating mechanism; and (4) physiological studies in UT-A2 and UT-B knockout mice examining the role of countercurrent exchange in the production of a maximally concentrated urine.
Collapse
Affiliation(s)
- Robert A Fenton
- The Water and Salt Research Center, Institute of Anatomy, University of Aarhus, Denmark.
| |
Collapse
|
14
|
Alonso G, Galibert E, Boulay V, Guillou A, Jean A, Compan V, Guillon G. Sustained elevated levels of circulating vasopressin selectively stimulate the proliferation of kidney tubular cells via the activation of V2 receptors. Endocrinology 2009; 150:239-50. [PMID: 18787031 DOI: 10.1210/en.2008-0068] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The hypothalamic hormone vasopressin (AVP) has known mitogenic effects on various cell types. This study was designed to determine whether sustained elevated levels of circulating AVP could influence cell proliferation within adult tissues known to express different AVP receptors, including the pituitary, adrenal gland, liver, and kidney. Plasmatic AVP was chronically increased by submitting animals to prolonged hyperosmotic stimulation or implanting them with a AVP-containing osmotic minipump. After several days of either treatment, increased cell proliferation was detected only within the kidney. This kidney cell proliferation was not affected by the administration of selective V1a or V1b receptor antagonists but was either inhibited or mimicked by the administration of a selective V2 receptor antagonist or agonist, respectively. Kidney proliferative cells mostly concerned a subpopulation of differentiated tubular cells known to express the V2 receptors and were associated with the phosphorylation of ERK. These data indicate that in the adult rat, sustained elevated levels of circulating AVP stimulates the proliferation of a subpopulation of kidney tubular cells expressing the V2 receptor, providing the first illustration of a mitogenic effect of AVP via the activation of the V2 receptor subtype.
Collapse
Affiliation(s)
- Gérard Alonso
- Départements d'Endocrinologie, Institut de Génomique Fonctionnelle, 141 Rue de la Cardonille, 34094 Montpellier cedex 05, France
| | | | | | | | | | | | | |
Collapse
|
15
|
Poon LCY, Kametas N, Bonino S, Vercellotti E, Nicolaides KH. Urine albumin concentration and albumin-to-creatinine ratio at 11+0to 13+6weeks in the prediction of pre-eclampsia. BJOG 2008; 115:866-73. [DOI: 10.1111/j.1471-0528.2007.01650.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
16
|
Fenton RA, Knepper MA. Urea and renal function in the 21st century: insights from knockout mice. J Am Soc Nephrol 2007; 18:679-88. [PMID: 17251384 DOI: 10.1681/asn.2006101108] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Since the turn of the 21st century, gene knockout mice have been created for all major urea transporters that are expressed in the kidney: the collecting duct urea transporters UT-A1 and UT-A3, the descending thin limb isoform UT-A2, and the descending vasa recta isoform UT-B. This article discusses the new insights that the results from studies in these mice have produced in the understanding of the role of urea in the urinary concentrating mechanism and kidney function. Following is a summary of the major findings: (1) Urea accumulation in the inner medullary interstitium depends on rapid transport of urea from the inner medullary collecting duct (IMCD) lumen via UT-A1 and/or UT-A3; (2) as proposed by Robert Berliner and colleagues in the 1950s, the role of IMCD urea transporters in water conservation is to prevent a urea-induced osmotic diuresis; (3) the absence of IMCD urea transport does not prevent the concentration of NaCl in the inner medulla, contrary to what would be predicted from the passive countercurrent multiplier mechanism in the form proposed by Kokko and Rector and Stephenson; (4) deletion of UT-B (vasa recta isoform) has a much greater effect on urinary concentration than deletion of UT-A2 (descending limb isoform), suggesting that the recycling of urea between the vasa recta and the renal tubules quantitatively is less important than classic countercurrent exchange; and (5) urea reabsorption from the IMCD and the process of urea recycling are not important elements of the mechanism of protein-induced increases in GFR. In addition, the clinical relevance of these studies is discussed, and it is suggested that inhibitors that specifically target collecting duct urea transporters have the potential for clinical use as potassium-sparing diuretics that function by creation of urea-dependent osmotic diuresis.
Collapse
Affiliation(s)
- Robert A Fenton
- Water and Salt Research Center, Institute of Anatomy, Building 233/234, University of Aarhus, DK-8000 Aarhus, Denmark.
| | | |
Collapse
|
17
|
Fenton RA, Smith CP, Knepper MA. Role of collecting duct urea transporters in the kidney--insights from mouse models. J Membr Biol 2007; 212:119-31. [PMID: 17264985 DOI: 10.1007/s00232-006-0871-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/18/2006] [Indexed: 12/22/2022]
Abstract
Urea movement across plasma membranes is modulated by specialized urea transporter proteins. These proteins are proposed to play key roles in the urinary concentrating mechanism and fluid homeostasis. To date, two urea-transporter genes have been cloned; UT-A (Slc14a2), encoding at least five proteins and UT-B (Slc14a1) encoding a single protein isoform. Recently we engineered mice that lack the inner medullary collecting duct (IMCD) urea transporters, UT-A1 and UT-A3 (UT-A1/3 -/- mice). This article includes 1) a historical review of the role of renal urea transporters in renal function; 2) a review of our studies utilizing the UT-A1/3 -/- mice; 3) description of an additional line of transgenic mice in which beta-galactosidase expression is driven by the alpha-promoter of the UT-A gene, which is allowing better physiological definition of control mechanisms for UT-A expression; and 4) a discussion of the implications of the studies in transgenic mice for the teaching of kidney physiology.
Collapse
Affiliation(s)
- R A Fenton
- The Water and Salt Research Center, Institute of Anatomy, Building 1233, University of Aarhus, DK-8000, Aarhus, Denmark.
| | | | | |
Collapse
|
18
|
De Cosmo S, Lamacchia O, Rauseo A, Viti R, Gesualdo L, Pilotti A, Trischitta V, Cignarelli M. Cigarette smoking is associated with low glomerular filtration rate in male patients with type 2 diabetes. Diabetes Care 2006; 29:2467-70. [PMID: 17065686 DOI: 10.2337/dc06-0940] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The relationship between cigarette smoking and renal dysfunction in diabetes has predominantly been documented in patients with type 1 diabetes. The aim of the present study was to explore the relationship between cigarette smoking and glomerular filtration rate (GFR) in a large cross-sectional study carried out in male subjects with type 2 diabetes. The role of metabolic syndrome in modulating this relationship was also investigated. RESEARCH DESIGN AND METHODS One hundred fifty-eight current smokers and 158 never smokers with type 2 diabetes were consecutively recruited. Low GFR was defined as GFR <60 ml/min per 1.73 m(2). RESULTS The proportion of patients affected by low GFR was significantly higher in current smokers (20.9 vs. 12.0%, P = 0.03). The adjusted risk (odds ratio [OR]) of low GFR in current smokers was 2.20 (95% CI 1.14-4.26, P = 0.02) and markedly higher in patients from the first tertile of disease duration (4.27 [1.26-14.40], P = 0.02). When metabolic syndrome was added to the statistical model exploring the relationship between smoking and low GFR, the risk of low GFR showed a small change, although it did not become any more significant (1.84 [0.98-3.45], P = 0.06). Current smokers showed even higher free oxygen radical test unit values (560.0 +/- 91.5 vs. 442.7 +/- 87.2, P < 0.0001). CONCLUSIONS In a large population of male patients with type 2 diabetes, the risk of low GFR is markedly enhanced by smoking and is at least partially mediated by metabolic syndrome.
Collapse
Affiliation(s)
- Salvatore De Cosmo
- Unit of Endocrinology and Metabolic Diseases, Department of Medical Sciences, University of Foggia, via Luigi Pinto, 71100 Foggia, Italy
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Wenzel UO, Hebert LA, Stahl RAK, Krenz I. My doctor said I should drink a lot! Recommendations for fluid intake in patients with chronic kidney disease. Clin J Am Soc Nephrol 2006; 1:344-6. [PMID: 17699227 DOI: 10.2215/cjn.01140905] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Ulrich O Wenzel
- University Hospital of Hamburg-Eppendorf, Department of Medicine, Division of Nephrology, Martinistrasse 52, Hamburg, 20246 Germany.
| | | | | | | |
Collapse
|
20
|
Schmitt F, Bresson JL, Beressi N, Bichet DG, Chauveau D, Bankir L. Influence of plasma amino acid level on vasopressin secretion. DIABETES & METABOLISM 2003; 29:352-61. [PMID: 14526263 DOI: 10.1016/s1262-3636(07)70046-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVES Vasopressin (VP) is known to be elevated in patients with diabetes mellitus (DM). While the influence of acute hyperglycemia has been ruled out, the mechanism or the osmotically active compound responsible for the increase in VP secretion is still not elucidated. Because the plasma level of several amino acids (AAs) is increased in DM, we evaluated whether AAs could represent an effective osmotic stimulus for VP secretion. RESEARCH DESIGN AND METHODS In a cross-over study, eight healthy volunteers randomly received an infusion of isotonic saline (control) or mixed AA solution, i.v., at a low or a high rate (2 or 4.5 mg/min/kg BW, respectively). Plasma VP (P(VP)) was measured for two hours before and three hours during AA or control infusion. RESULTS AA infusion induced a dose-dependent elevation in plasma AA concentration but did not alter P(VP). However, effective plasma osmolality (P(osm)) (osmolality minus urea concentration) remained unchanged because a concommittant fall in plasma sodium concentration (P(Na)), likely due to sodium-linked uptake of AA in peripheral cells, compensated for the rise in plasma AA. CONCLUSION The stability of effective P(osm) may explain the lack of change observed in P(VP). Because sodium is a very efficient stimulus for VP secretion, it may be assumed that the fall in P(Na) occurring during AA infusion should have reduced VP secretion and thus P(VP). In this setting, the stability of P(VP) suggests that AAs induced an increase in VP secretion which counterbalanced the fall attributable to the decrease in P(Na). In conclusion, in acute experiments, AAs seem to represent an effective stimulus for VP secretion, almost equally potent as sodium. Further studies are needed to evaluate their contribution to the high P(VP) seen in the chronic setting of DM.
Collapse
Affiliation(s)
- F Schmitt
- INSERM Unité 367, Institut du Fer à Moulin, Paris
| | | | | | | | | | | |
Collapse
|
21
|
Hebert LA, Greene T, Levey A, Falkenhain ME, Klahr S. High urine volume and low urine osmolality are risk factors for faster progression of renal disease. Am J Kidney Dis 2003; 41:962-71. [PMID: 12722030 DOI: 10.1016/s0272-6386(03)00193-8] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND Increased fluid intake slows renal disease progression in animal models. The relevance of these findings to human renal disease is not clear, although increased fluid intake often is recommended to patients with chronic renal insufficiency. This study tested the hypothesis that urine volume, urine osmolality (Uosm), or both are significantly associated with glomerular filtration rate (GFR) decline in patients with chronic renal insufficiency. METHODS This is a retrospective analysis of Modification of Diet in Renal Disease (MDRD) study A patients with (N = 139) and without polycystic kidney disease (PKD; N = 442). The key outcome measure was GFR slope in relation to mean 24-hour urine volume and Uosm during follow-up in study A (mean, 2.3 years). RESULTS The regression of GFR slope on mean follow-up 24-hour urine volume (adjusted for body surface area and MDRD diet and blood pressure group) showed that the greater the urine volume, the faster the GFR decline in patients both with and without PKD. For example, the difference in GFR slope for those with a mean follow-up 24-hour urine volume of 2.4 versus 1.4 L was -1.01 mL/min/y (confidence interval, -0.27 to -1.75) for patients without PKD and -1.20 mL/min/y (confidence interval, -0.06 to -2.34) for those with PKD. A similar but inverse relationship was shown between GFR decline and mean 24-hour Uosm in patients with (P = 0.01) and without PKD (P = 0.001). These associations remained significant after adjustment for 13 relevant baseline and follow-up covariates. CONCLUSION Sustained high urine volume and low Uosm are independent risk factors for faster GFR decline in patients with chronic renal insufficiency. Thus, high fluid intake does not appear to slow renal disease progression in humans. We suggest that until better evidence becomes available, patients with chronic renal insufficiency should generally let their thirst guide fluid intake. The advice to avoid "pushing fluids" might be particularly important for patients with PKD.
Collapse
Affiliation(s)
- Lee A Hebert
- Ohio State University, Nephrology, Columbus 43210, USA.
| | | | | | | | | |
Collapse
|
22
|
Tozawa M, Iseki K, Iseki C, Oshiro S, Ikemiya Y, Takishita S. Influence of smoking and obesity on the development of proteinuria. Kidney Int 2002; 62:956-62. [PMID: 12164878 DOI: 10.1046/j.1523-1755.2002.00506.x] [Citation(s) in RCA: 161] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Proteinuria is a significant risk factor for end-stage renal disease. Previous evidence suggested that smoking and obesity increase the risk of proteinuria. However, it is unclear whether these risk factors predict the development of proteinuria independently of hypertension and diabetes mellitus. The aim of this study was to analyze the effects of obesity and smoking on the development of proteinuria in a screened cohort of subjects with normal kidney function. METHODS A total of 5403 subjects (3403 men and 2000 women) who participated in the 1997 and 1999 health screening examinations in Okinawa Japan, and who were normal renal function (serum creatinine < or =1.2 mg/dL in men, < or =1.0 mg/dL in women) and negative proteinuria by dipstick examination in 1997 were eligible for study. Logistic analysis was used to examine the relation between the baseline state of smoking or obesity in 1997, and the development of proteinuria in 1999, adjusted for age, sex, and other confounding factors. RESULTS Proteinuria developed in 5.8% of participants (6.7% in men, 4.4% in women; dipstick score, 1+ in 277, 2+ in 37, and > or =3+ in 4 participants). The incidence of proteinuria was positively associated with the number of cigarettes smoked per day (P = 0.04), and a body mass index (P < 0.0001) at baseline. Analysis showed that the relative risk (95% confidence interval) of developing proteinuria was 1.32 (1.00 to 1.74), P = 0.04 for cigarette smoking, 1.45 (1.13 to 1.86), P = 0.002 for obesity, 1.56 (1.19 to 2.06), P = 0.001 for hypertension, and 2.27 (1.55 to 3.32), P < 0.0001 for diabetes mellitus. Stratified with men and women, the relative risk was 1.28 (0.96 to 1.72), P = 0.09 for smoking, and 1.60 (1.19 to 2.14), P = 0.001 for obesity in men; the relative risk was 1.30 (0.44 to 3.80), P = 0.62 for smoking, and 1.04 (0.63 to 1.72), P = 0.87 for obesity in women. CONCLUSIONS Hypertension and diabetes mellitus were superior to smoking and obesity in predicting the development of proteinuria in all subjects. Stratified with men and women, obesity was a significant risk factor for the development of proteinuria independently of both hypertension and diabetes mellitus in men. The risk of developing proteinuria also tended to be increased with cigarette smoking in men. Smoking and obesity in women were not significant in this data set.
Collapse
Affiliation(s)
- Masahiko Tozawa
- Third Department of Internal Medicine, University of The Ryukyus, 207 Uehara, Nishihara-cho, Okinawa 903-0215, Japan.
| | | | | | | | | | | |
Collapse
|
23
|
Sugiura T, Yamauchi A, Kitamura H, Matsuoka Y, Horio M, Imai E, Hori M. High water intake ameliorates tubulointerstitial injury in rats with subtotal nephrectomy: possible role of TGF-beta. Kidney Int 1999; 55:1800-10. [PMID: 10231442 DOI: 10.1046/j.1523-1755.1999.00443.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND It has been shown that tubulointerstitial injury correlates well with a decline of renal function. In this study, we investigated the effect of high water intake (HWI) on functional and structural parameters in rats with subtotal nephrectomy. METHODS Two weeks after the ablative procedure, rats were divided into two groups. One group received the treatment with HWI (3% sucrose added to drinking water) for eight weeks. Functional parameters were compared with sham-operated control (CONT) or nephrectomized rats without treatment (NX). Remnant kidneys were then assessed histologically for evidence of interstitial fibrosis and glomerulosclerosis. RESULTS Creatinine clearance was significantly improved in HWI rats compared with NX rats. Simultaneously, urinary protein was also significantly reduced in HWI rats. HWI predominantly ameliorated interstitial lesions and, to a lesser extent, glomerular lesions. Northern blot analysis demonstrated that transforming growth factor-beta (TGF-beta) mRNA expression was significantly suppressed in HWI rats. In situ hybridization revealed that HWI suppressed TGF-beta mRNA expression mainly in the outer medulla. Fibronectin mRNA was also reduced by the HWI treatment. The changes in TGF-beta and fibronectin mRNA were in parallel with Na+/myo-inositol cotransporter (SMIT) mRNA, which is regulated by extracellular osmolarity. Immunohistochemistry demonstrated that protein expression of TGF-beta and fibronectin coincided with the mRNA expression. CONCLUSION These results suggest that HWI reduces TGF-beta mRNA expression in medullary interstitium and ameliorates tubulointerstitial injury in rats with reduced renal mass.
Collapse
MESH Headings
- Animals
- Blood Pressure
- Blotting, Northern
- Carrier Proteins/genetics
- DNA, Complementary
- Drinking/physiology
- Fibronectins/genetics
- Gene Expression/immunology
- Glomerulosclerosis, Focal Segmental/immunology
- Glomerulosclerosis, Focal Segmental/surgery
- Glomerulosclerosis, Focal Segmental/therapy
- Heat-Shock Proteins/genetics
- Hypertonic Solutions/pharmacology
- Immunoenzyme Techniques
- In Situ Hybridization
- Male
- Membrane Proteins
- Nephrectomy
- Nephritis, Interstitial/immunology
- Nephritis, Interstitial/surgery
- Nephritis, Interstitial/therapy
- RNA, Messenger/analysis
- Rats
- Rats, Sprague-Dawley
- Symporters
- Transforming Growth Factor beta/genetics
- Transforming Growth Factor beta/metabolism
- Water/pharmacology
Collapse
Affiliation(s)
- T Sugiura
- First Department of Medicine, Osaka University School of Medicine, Japan
| | | | | | | | | | | | | |
Collapse
|
24
|
Affiliation(s)
- S R Orth
- Sektion Nephrologie der Medizinischen Universitütsklinik Heidelberg, Germany
| | | | | |
Collapse
|
25
|
Bankir L, Bouby N, Trinh-Trang-Tan MM, Ahloulay M, Promeneur D. Direct and indirect cost of urea excretion. Kidney Int 1996; 49:1598-607. [PMID: 8743462 DOI: 10.1038/ki.1996.232] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Urea, the major end product of protein metabolism in mammals, is the most abundant solute in the urine. Urea excretion is thought to result from filtration curtailed by some passive reabsorbtion along the nephron. This reabsorption is markedly enhanced by vasopressin and slow urinary flow rate (V), the fraction of filtered urea excreted in the urine (FEurea) falling from approximately 60% at high V to only approximately 20% at low V. In concentrated urine, normal urea excretion can be maintained only if urea filtration is elevated. This can be achieved by increasing plasma urea concentration (Purea) and/or GFR. We have shown that both parameters do increase when normal rats are submitted to chronic alterations in the water intake/vasopressin axis within the normal range of physiologic regulation. This situation is very similar to that observed after alterations in protein intake. In both cases more urea needs to be filtered, either because more of it has to be excreted, or because the efficiency of its excretion is reduced. A common mechanism is proposed to explain the rise in GFR observed in the two situations. In summary, our studies demonstrate that the antidiuretic effects of vasopressin are responsible for a significant elevation of GFR. This GFR adaptation limits the rise in Purea, a favorable effect because urea is not as harmless as usually thought. However, this hyperfiltration might have deleterious consequences in diseased kidneys.
Collapse
Affiliation(s)
- L Bankir
- INSERM Unité 90, Hôpital Necker-Enfants Malades, Paris, France.
| | | | | | | | | |
Collapse
|