Copeptin, a Surrogate Marker of Vasopressin, Is Associated With Accelerated Renal Function Decline in Renal Transplant Recipients

Is mild dehydration a risk for progression of childhood chronic kidney disease?

Children with chronic kidney disease (CKD) can have an inherent vulnerability to dehydration. Younger children are unable to freely access water, and CKD aetiology and stage can associate with reduced kidney concentrating capacity, which can also impact risk. This article aims to review the risk factors and consequences of mild dehydration and underhydration in CKD, with a particular focus on evidence for risk of CKD progression. We discuss that assessment of dehydration in the CKD population is more challenging than in the healthy population, thus complicating the definition of adequate hydration and clinical research in this field. We review pathophysiologic studies that suggest mild dehydration and underhydration may cause hyperfiltration injury and impact renal function, with arginine vasopressin as a key mediator. Randomised controlled trials in adults have not shown an impact of improved hydration in CKD outcomes, but more vulnerable populations with baseline low fluid intake or poor kidney concentrating capacity need to be studied. There is little published data on the frequency of dehydration, and risk of complications, acute or chronic, in children with CKD. Despite conflicting evidence and the need for more research, we propose that paediatric CKD management should routinely include an assessment of individual dehydration risk along with a treatment plan, and we provide a framework that could be used in outpatient settings.

Copeptin as a surrogate marker for arginine vasopressin: analytical insights, current utility, and emerging applications

Copeptin is a 39-amino-acid long glycosylated peptide with a leucine-rich core segment in the C-terminal part of pre-pro-vasopressin. It exhibits a rapid response comparable to arginine vasopressin (AVP) in response to osmotic, hemodynamic, and nonspecific stress-related stimuli. This similarity can be attributed to equimolar production of copeptin alongside AVP. However, there are markedly different decay kinetics for both peptides, with an estimated initial half-life of copeptin being approximately two times longer than that of AVP. Like AVP, copeptin correlates strongly over a wide osmolality range in healthy individuals, making it a useful alternative to AVP measurement. While copeptin does not appear to be significantly affected by food intake, small amounts of oral fluid intake may result in a significant decrease in copeptin levels. Compared to AVP, copeptin is considerably more stable in vitro. An automated immunofluorescent assay is now available and has been used in recent landmark trials. However, separate validation studies are required before copeptin thresholds from these studies are applied to other assays. The biological variation of copeptin in presumably healthy subjects has been recently reported, which could assist in defining analytical performance specifications for this measurand. An established diagnostic utility of copeptin is in the investigation of polyuria-polydipsia syndrome and copeptin-based testing protocols have been explored in recent years. A single baseline plasma copeptin >21.4 pmol/L differentiates AVP resistance (formerly known as nephrogenic diabetes insipidus) from other causes with 100% sensitivity and specificity, rendering water deprivation testing unnecessary in such cases. In a recent study among adult patients with polyuria-polydipsia syndrome, AVP deficiency (formerly known as central diabetes insipidus) was more accurately diagnosed with hypertonic saline-stimulated copeptin than with arginine-stimulated copeptin. Glucagon-stimulated copeptin has been proposed as a potentially safe and precise test in the investigation of polyuria-polydipsia syndrome. Furthermore, copeptin could reliably identify those with AVP deficiency among patients with severe hypernatremia, though its diagnostic utility is reportedly limited in the differential diagnosis of profound hyponatremia. Copeptin measurement may be a useful tool for early goal-directed management of post-operative AVP deficiency. Additionally, the potential prognostic utility of copeptin has been explored in other diseases. There is an interest in examining the role of the AVP system (with copeptin as a marker) in the pathogenesis of insulin resistance and diabetes mellitus. Copeptin has been found to be independently associated with an increased risk of incident stroke and cardiovascular disease mortality in men with diabetes mellitus. Increased levels of copeptin have been reported to be independently predictive of a decline in estimated glomerular filtration rate and a greater risk of new-onset chronic kidney disease. Furthermore, copeptin is associated with disease severity in patients with autosomal dominant polycystic kidney disease. Copeptin predicts the development of coronary artery disease and cardiovascular mortality in the older population. Moreover, the predictive value of copeptin was found to be comparable with that of N-terminal pro-brain natriuretic peptide for all-cause mortality in patients with heart failure. Whether the measurement of copeptin in these conditions alters clinical management remains to be demonstrated in future studies.

Copeptin as a potential biomarker of chronic kidney disease to predict the disease progression in children with chronic kidney disease

Background

Biomarkers to predict the onset and progression of chronic kidney disease (CKD) in children are lacking, and no such definite biomarkers have been implicated in the diagnosis of CKD. We conducted this study to evaluate copeptin as a CKD marker and predict the disease progression by estimating the copeptin levels at baseline and 12 months follow-up in children with CKD stage 2 and above.

Materials and Methods

This prospective single-centre cohort study was conducted in children under 14 years with CKD stages 2-4. Blood and urine samples were collected at enrolment and 1-year follow-up for routine investigations and serum copeptin, cystatin C and urinary neutrophil gelatinase-associated lipocalcin (uNGAL) estimation.

Results

A total of 110 children (60 cases and 50 controls) were enrolled in the study. The mean estimated glomerular filtration rate (eGFR) of cases was 58.3 ± 18.7 ml/min/1.73 m2. Among the cases, there was a significant rise in the serum copeptin levels from baseline 483.08 ± 319.2 pg/ml to follow-up at 1 year, that is, 1046.82 ± 823.53 pg/ml (P < 0.0001). A significant difference was noted in the baseline values of serum cystatin C, that is, 1512.98 ± 643.77 ng/ml and 719.68 ± 106.96 ng/ml (P < 0.0001), and uNGAL, that is, 13.53 ± 11.72 and 1.76 ± 2.37 ng/ml (P < 0.0001) between the cases and controls. There was no significant correlation (correlation coefficient = 0.10) between change in eGFR and copeptin levels during 12 months of follow-up.

Conclusion

No significant correlation was found between the change in eGFR and copeptin levels during 12 months of follow-up. This can be due to the slow deterioration of renal functions, as most of the cases had underlying congenital anomalies of the kidney and urinary tract (CAKUT), which is known to have a slow progression of CKD and a small sample size.

[Pituitary disorders in patients with end-stage chronic renal failure]

Disorders in the kidneys lead to disturbance of homeostasis. As the glomerular filtration rate decreases, the metabolism of numerous biologically active substances, including pituitary hormones, decreases. The article presents an overview of pituitary dysfunction in patients with chronic kidney disease (CKD) and discusses the possible reasons of the pathogenetic mechanisms. Particular focus is being given to the assessment of changes in the concentration of pituitary hormones in patients with end-stage chronic kidney disease (CKD) and discusses the pathogenetic mechanisms of their formation. Particular attention is paid to the assessment of changes in the concentration of pituitary hormones in patients receiving renal replacement therapy (RRT). CKD leads to an increase in the level of prolactin, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Concentrations of growth hormone (GH), isulin-like growth factor-1 (IGF-1), thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH) and vasopressin may remain within normal values or increase in this group of patients. RRT does not reduce the levels of prolactin, LH, FSH, while the concentration of growth hormone, IGF-1, TSH tends to normalize. The content of ACTH and vasopressin may remain unchanged or decrease. Kidney transplantation in most cases corrects hormonal disorders. Correction of hormonal changes can improve the clinical outcome and quality of life of patients with end stage CKD.

Fibroblast growth factor 23 but not copeptin is independently associated with kidney failure and mortality in patients with chronic kidney disease

Background

Copeptin and intact fibroblast growth factor 23 (iFGF23) increase early during chronic kidney disease (CKD) and may be predictive of unfavourable outcomes. The aim of this study was to evaluate their respective associations with renal and vital outcomes in CKD patients.

Methods

We included CKD patients from the NephroTest cohort with concomitant measurements of plasma copeptin and iFGF23 concentrations and isotopic glomerular filtration rate measurement (mGFR). The primary endpoint was a composite outcome including kidney failure (KF) (dialysis initiation, pre-emptive transplantation or a 57% decrease of mGFR, corresponding to doubling of serum creatinine) or death before KF. Hazard ratios (HRs) of the primary endpoint associated with log-transformed copeptin and iFGF23 concentrations were estimated by Cox models. The slope of mGFR over time was analysed using a linear mixed model.

Results

A total of 329 CKD patients (243 men, mean age 60.3 ± 14.6 years) were included. Among them, 301 with an mGFR >15 ml/min/1.73 m2 were included in survival and mGFR slope analyses. During a median follow-up of 4.61 years (quartile 1-quartile 3: 3.72-6.07), 61 KFs and 32 deaths occurred. Baseline iFGF23 concentrations were associated with the composite outcome after multiple adjustments {HR 2.72 [95% confidence interval (CI) 1.85-3.99]}, whereas copeptin concentrations were not [HR 1.01 (95% CI 0.74-1.39)]. Neither copeptin nor iFGF23 were associated with mGFR slope over time.

Conclusion

Our study shows for the first time in population of CKD patients an independent association between iFGF23 and unfavourable renal and vital outcomes and shows no such association regarding copeptin, encouraging the integration of iFGF23 measurement into the follow-up of CKD.

Predicting autosomal dominant polycystic kidney disease progression: review of promising Serum and urine biomarkers

Autosomal dominant polycystic kidney disease (ADPKD) is one of the leading causes of end-stage renal disease. In spite of the recent tremendous progress in the understanding of ADPKD pathogenesis, the molecular mechanisms of the disease remain incompletely understood. Considering emerging new targeted therapies for ADPKD, it has become crucial to disclose easily measurable and widely available biomarkers for identifying patients with future rapid disease progression. This review encompasses all the research with a shared goal of identifying promising serum or urine biomarkers for predicting ADPKD progression or response to therapy. The rate of the ADPKD progress varies significantly between patients. The phenotypic variability is only partly explained by the underlying genetic lesion diversity. Considering significant decline in kidney function in ADPKD is not usually evident until at least 50% of the parenchyma has been destroyed, conventional kidney function measures, such as glomerular filtration rate (GFR), are not suitable for monitoring disease progression in ADPKD, particularly in its early stages. Since polycystic kidney enlargement usually precedes the decline in GFR, height-adjusted total kidney volume (ht-TKV) has been accepted as an early biomarker for assessing disease severity in ADPKD patients. However, since measuring ht-TKV is time-consuming and observer-dependent, the identification of a sensitive and quickly measurable biomarker is of a great interest for everyday clinical practice. Throughout the last decade, due to development of proteomic and metabolomic techniques and the enlightenment of multiple molecular pathways involved in the ADPKD pathogenesis, a number of urine and serum protein biomarkers have been investigated in ADPKD patients, some of which seem worth of further exploring. These include copeptin, angiotensinogen, monocyte chemoattractant protein 1, kidney injury molecule-1 and urine-to-plasma urea ratio among many others. The aim of the current review is to provide an overview of all of the published evidence on potentially clinically valuable serum and urine biomarkers that could be used for predicting disease progression or response to therapy in patients with ADPKD. Hopefully, this review will encourage future longitudinal prospective clinical studies evaluating proposed biomarkers as prognostic tools to improve management and outcome of ADPKD patients in everyday clinical practice.

The role of copeptin in kidney disease

Copeptin is a 39-amino acid glycopeptide that is secreted equimolecularly with arginine-vasopressin (AVP) from the prepro-hormone AVP in the posterior pituitary. While AVP is a very unstable molecule and is accompanied by significant technical troubles in its quantification, copeptin is a stable and easily quantifiable molecule. For this reason, circulating copeptin is currently used as a surrogate for AVP in different pathological conditions, including renal diseases. In recent years it has been shown that copeptin is associated with an increased risk of developing chronic kidney disease in the general population. In addition, copeptin has also been associated with multiple renal diseases with relevant clinical consequences and potential therapeutic implications. In the present review, we update and summarize the clinical significance of copeptin as a surrogate marker for AVP concentrations in different kidney diseases, as well as in renal replacement therapy (hemodialysis and peritoneal dialysis) and renal transplantation.

Clinical significance of copeptin as an early predictor of renal graft dysfunction in renal transplant recipients

Background: Copeptin is the carboxyl-terminal part of the vasopressin precursor protein, and its concentration is an independent predictor of the onset of chronic kidney disease and a rapid decline in the glomerular filtration rate. The glomerular filtration rate is regarded as the best indicator of kidney transplant function and is a predictor of graft and patient survival. We investigated the clinical significance of copeptin as an early predictor of renal graft dysfunction in renal transplant recipients.Methods: We measured serum creatinine, cystatin C, and copeptin concentrations in renal transplant recipients on the day of their operation, as well as on postoperative days 3, 7, 30, and 365. Acute rejection was defined as a sudden decrease in renal function accompanied by histological changes.Results: Eight renal transplant recipients were enrolled in the study from July 2018 to December 2019. Four patients experienced histologically confirmed transplant rejection. All four cases involved acute T-cell rejection. No significant correlation was found between the copeptin level and the presence or absence of rejection at any time point. In subgroup analyses, changes in creatinine, the estimated glomerular filtration rate, cystatin, and copeptin did not show statistical significance.Conclusions: We anticipated that copeptin would be useful to identify individuals at high risk of transplant rejection; however, our study failed to show an association. Further research will be needed to overcome the limitations of this study.

Copeptin (CTproAVP) - A Biomarker of a Circulatory Impairment in Liver Transplant Recipients? A Prospective, Observational Study

BACKGROUND

Copeptin, an easily measured and stable surrogate marker of arginine vasopressin, is a biomarker of a homeostasis disorder and a circulatory impairment in a wide spectrum of morbidities. The aim of this study was to evaluate the potential of copeptin as a biomarker of a circulatory impairment in patients undergoing liver transplantation (LT).

METHODS

This was a prospective, observational study. Blood samples were obtained from 38 patients undergoing LT. Serum copeptin level was measured by means of a sandwich immunoassay pre-, intra-, and postoperatively up to 21 days after the operation.

RESULTS

The mean concentration of copeptin remained in the range of values slightly below 1000 pg/mL during the analyzed observation period and remained higher than the values observed in healthy individuals. Intraoperative and immediately postoperative copeptin levels did not correlate with hemodynamic parameters. There was also no correlation between preoperative copeptin levels (C1) and preoperative Model for End-Stage Liver Disease scores, serum creatinine levels, plasma transaminase levels, international normalized ratio, or hematocrit (Spearman ρ, P > .05).

CONCLUSIONS

Preoperative copeptin levels are elevated in most LT recipients and remain elevated for 21 days after surgery. There was no correlation between the concentration of copeptin and the Model for End-Stage Liver Disease-Sodium score or the cause of a hepatic failure. It cannot be concluded that copeptin is a biomarker of a circulatory impairment in patients with transplanted liver in the perioperative period. The secretion of vasopressin, as measured by copeptin concentration during and after LT, requires further study.

Preservation of kidney function irrelevant of total kidney volume growth rate with tolvaptan treatment in patients with autosomal dominant polycystic kidney disease

Background

Tolvaptan slowed the rates of total kidney volume (TKV) growth and renal function decline over a 3-year period in patients with autosomal dominant polycystic kidney disease (ADPKD) enrolled in the Tolvaptan Efficacy and Safety in Management of Autosomal Dominant Polycystic Kidney Disease and Its Outcomes (TEMPO) 3:4 trial (NCT00428948). In this post hoc analysis of Japanese patients from TEMPO 3:4, we evaluated whether the effects of tolvaptan on TKV and on renal function are interrelated.

Methods

One hundred and forty-seven Japanese patients from TEMPO 3:4 were included in this analysis (placebo, n = 55; tolvaptan, n = 92). Tolvaptan-treated patients were stratified into the responder group (n = 37), defined as tolvaptan-treated patients with a net decrease in TKV from baseline to year 3, and the non-responder group (n = 55), defined as tolvaptan-treated patients with a net increase in TKV.

Results

Mean changes during follow-up in the placebo, responder, and non-responder groups were 16.99%, − 8.33%, and 13.95%, respectively, for TKV and − 12.61, − 8.47, and − 8.58 mL/min/1.73 m², respectively, for estimated glomerular filtration rate (eGFR). Compared with the placebo group, eGFR decline was significantly slowed in both the responder and non-responder groups (P < 0.05).

Conclusion

Tolvaptan was effective in slowing eGFR decline, regardless of TKV response, over 3 years in patients with ADPKD in Japan. Treatment with tolvaptan may have beneficial effects on slowing of renal function decline even in patients who have not experienced a reduction in the rate of TKV growth by treatment with tolvaptan.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10157-020-02009-0.

Antidiuretic Hormone and Serum Osmolarity Physiology and Related Outcomes: What Is Old, What Is New, and What Is Unknown?

CONTEXT

Although the physiology of sodium, water, and arginine vasopressin (AVP), also known as antidiuretic hormone, has long been known, accumulating data suggest that this system operates as a more complex network than previously thought.

EVIDENCE ACQUISITION

English-language basic science and clinical studies of AVP and osmolarity on the development of kidney and cardiovascular disease and overall outcomes.

EVIDENCE SYNTHESIS

Apart from osmoreceptors and hypovolemia, AVP secretion is modified by novel factors such as tongue acid-sensing taste receptor cells and brain median preoptic nucleus neurons. Moreover, pharyngeal, esophageal, and/or gastric sensors and gut microbiota modulate AVP secretion. Evidence is accumulating that increased osmolarity, AVP, copeptin, and dehydration are all associated with worse outcomes in chronic disease states such as chronic kidney disease (CKD), diabetes, and heart failure. On the basis of these pathophysiological relationships, an AVP receptor 2 blocker is now licensed for CKD related to polycystic kidney disease.

CONCLUSION

From a therapeutic perspective, fluid intake may be associated with increased AVP secretion if it is driven by loss of urine concentration capacity or with suppressed AVP if it is driven by voluntary fluid intake. In the current review, we summarize the literature on the relationship between elevated osmolarity, AVP, copeptin, and dehydration with renal and cardiovascular outcomes and underlying classical and novel pathophysiologic pathways. We also review recent unexpected and contrasting findings regarding AVP physiology in an attempt to explain and understand some of these relationships.

Osmoregulation Performance and Kidney Transplant Outcome

BACKGROUND

Kidney transplant recipients have an impaired ability to dilute urine but seldom develop baseline hyponatremia before ESRD. Although hyponatremia is a risk factor for adverse events in CKD and in kidney transplant recipients, it remains unclear whether subtler alterations in osmoregulation performance are associated with outcome.

METHODS

We studied a single-center prospective cohort of 1258 kidney transplant recipients who underwent a water-loading test 3 months after transplant to determine osmoregulation performance. Measured GFR (mGFR) was performed at the same visit. A group of 164 healthy candidates for kidney donation served as controls. We further evaluated the association of osmoregulation performance with transplantation outcomes and subsequent kidney function.

RESULTS

Unlike controls, most kidney transplant recipients failed to maintain plasma sodium during water loading (plasma sodium slope of -0.6±0.4 mmol/L per hour in transplant recipients versus -0.12±0.3 mmol/L per hour in controls; P<0.001). Steeper plasma sodium reduction during the test independently associated with the composite outcome of all-cause mortality and allograft loss (hazard ratio [HR], 1.73 per 1 mmol/L per hour decrease in plasma sodium; 95% confidence interval [95% CI], 1.23 to 2.45; P=0.002) and allograft loss alone (HR, 2.04 per 1 mmol/L per hour decrease in plasma sodium; 95% CI, 1.19 to 3.51; P=0.01). The association remained significant in a prespecified sensitivity analysis excluding patients with hyperglycemia. In addition, a steeper plasma sodium slope 3 months after transplantation independently correlated with lower mGFR at 12 months (β=1.93; 95% CI, 0.46 to 3.41; P=0.01).

CONCLUSIONS

Reduced osmoregulation performance occurs frequently in kidney transplant recipients and is an independent predictor of renal outcome.

Dialysate copeptin and peritoneal transport in incident peritoneal dialysis patients

Purpose

Systemic and intraperitoneal inflammation are characteristic features of patients with end-stage renal disease undergoing chronic peritoneal dialysis (PD). Arginine vasopressin (AVP) and its surrogate marker copeptin play important roles in many pathophysiological processes in chronic kidney disease. The aim of this study was to assess if copeptin concentrations in plasma and dialysate were related to peritoneal transport parameters and residual renal function (RRF) in incident PD patients.

Methods

In 37 clinically stable incident PD patients (mean age 50 years, 68% women, 32% diabetes), a 4 h peritoneal equilibration test (PET) was performed 4–6 weeks after the onset of PD. Plasma (at 2 h of PET) and dialysate (at 4 h) concentrations of copeptin, high-sensitivity C-reactive protein and interleukin-6 (IL-6) were determined.

Results

Plasma (80.7 ± 37.3 pg/mL) and dialysate (33.2 ± 18.0 pg/mL) concentrations of copeptin were correlated (Rs = 0.52, p = 0.001). Plasma and dialysate copeptin concentrations were negatively correlated with renal function as assessed by renal Kt/V (Rs = − 0.38; p = 0.021 and Rs = − 0.33; p = 0.047, respectively). At PET, dialysate copeptin negatively correlated with D/P creatinine (Rs = − 0.35, p = 0.033), and positively with D/D0 glucose (Rs = 0.33, p = 0.045) and ultrafiltration (Rs = 0.37, p = 0.024). Multivariate analysis showed that low dialysate copeptin (β = –0.30, p = 0.049) and high dialysate IL-6 (β = + 0.40, p = 0.012) were independent determinants of higher D/P creatinine.

Conclusions

Dialysate copeptin was negatively associated with D/P creatinine in incident PD patients suggesting a potential influence of copeptin or AVP on peritoneal solute transport rate that might involve vasoactive mechanisms.

Urinary extracellular vesicular release of aquaporins in patients with renal transplantation

BACKGROUND

Diuresis has been observed within a week following renal transplantation, suggesting that the procedure causes acute disturbance of renal water homeostasis. Aquaporin (AQP) 1 and AQP2, important proteins for renal water reabsorption, have been identified in urinary extracellular vesicles (uEV-AQP1 and -AQP2), and experimental studies have shown that the presence of uEV-AQP1 and -AQP2 may be an indicator of their levels of expression in the kidney. However, the release patterns of uEV-AQP1 and -AQP2 during the acute phase following renal transplantation are largely unknown.

METHODS

In this study, we examined the release of uEV-AQP1 and -AQP2 in recipients until 6 days (day 6) after renal transplantation. At Miyazaki prefectural Miyazaki Hospital, Japan, uEVs were obtained from 7 recipients, all of whom had received renal allografts from living donors. uEVs were isolated by differential centrifugation.

RESULTS

Immunoblotting analysis showed that the release of uEV-AQP2 was significantly decreased on day 1 in comparison with a control sample (from 3 healthy volunteers), accompanied by high urine output and low urine osmolality. Thereafter, the level increased gradually to the control level by day 6. The release pattern of uEV-AQP1 was similar to that of uEV-AQP2, but the levels did not reach statistical significance in comparison with the control level at any of the time points examined. Evaluation of the relationship between urinary osmolality and uEV-AQPs revealed a significant correlation for uEV-AQP2, but not for uEV-AQP1.

CONCLUSION

These results indicate that acute diuresis after renal transplantation might be due to a decrease in the renal expression of AQP2, whose level can be estimated from the amount released in uEVs.

Salt, water and nephron: Mechanisms of action and link to hypertension and chronic kidney disease

Our knowledge on sodium and water homeostasis and regulation continues to evolve. A considerable amount of new information in this area has emerged in recent years. This review summarizes existing and new literature and discusses complex multi-organ effects of high-salt and low-water intake and role of arginine vasopressin in this process, as well as the potential clinical significance of non-osmotic sodium storage pool and rhythmicity of urine sodium excretion. It has become clear that sodium and water dysregulation can exert profound effects on kidney and vascular health, far greater than previously recognized. Maladaptation to a combined high-salt and low-water intake can be linked to the growing epidemic of hypertension and chronic kidney disease.

Plasma copeptin, kidney disease, and risk for cardiovascular morbidity and mortality in two cohorts of type 2 diabetes

Background

Cardiovascular disease and kidney damage are tightly associated in people with type 2 diabetes. Experimental evidence supports a causal role for vasopressin (or antidiuretic hormone) in the development of diabetic kidney disease (DKD). Plasma copeptin, the COOH-terminal portion of pre-provasopressin and a surrogate marker of vasopressin, was shown to be positively associated with the development and progression of DKD. Here we assessed the association of plasma copeptin with the risk of cardiovascular events during follow-up in two prospective cohorts of type 2 diabetic patients, and we examined if this association could be mediated by deleterious effects of vasopressin on the kidney.

Methods

We studied 3098 and 1407 type 2 diabetic patients from the French cohorts DIABHYCAR and SURDIAGENE, respectively. We considered the incidence during follow-up (median: 5 years) of a combined end point composed of myocardial infarction, coronary revascularization, hospitalization for congestive heart failure, or cardiovascular death. Copeptin concentration was measured in baseline plasma samples by an immunoluminometric assay.

Results

The cumulative incidence of cardiovascular events during follow-up by sex-specific tertiles of baseline plasma copeptin was 15.6% (T1), 18.7% (T2) and 21.7% (T3) in DIABHYCAR (p = 0.002), and 27.7% (T1), 34.1% (T2) and 47.6% (T3) in SURDIAGENE (p < 0.0001). Cox proportional hazards survival regression analyses confirmed the association of copeptin with cardiovascular events in both cohorts: hazard ratio with 95% confidence interval for T3 vs. T1 was 1.29 (1.04–1.59), p = 0.02 (DIABHYCAR), and 1.58 (1.23–2.04), p = 0.0004 (SURDIAGENE), adjusted for sex, age, BMI, duration of diabetes, systolic blood pressure, arterial hypertension, HbA1c, total cholesterol, HDL-cholesterol, triglycerides, estimated glomerular filtration rate (eGFR), urinary albumin concentration (UAC), active tobacco smoking, and previous history of myocardial infarction at baseline. No interaction was observed between plasma copeptin and eGFR (p = 0.40) or UAC (p = 0.61) categories on the risk of cardiovascular events in analyses of pooled cohorts.

Conclusions

Plasma copeptin was positively associated with major cardiovascular events in people with type 2 diabetes. This association cannot be solely accounted for by the association of copeptin with kidney-related traits.

Electronic supplementary material

The online version of this article (10.1186/s12933-018-0753-5) contains supplementary material, which is available to authorized users.

Plasma copeptin and chronic kidney disease risk in 3 European cohorts from the general population

BACKGROUND

The prevalence of chronic kidney disease (CKD) is increasing worldwide. The identification of factors contributing to its progression is important for designing preventive measures. Previous studies have suggested that chronically high vasopressin is deleterious to renal function. Here, we evaluated the association of plasma copeptin, a surrogate of vasopressin, with the incidence of CKD in the general population.

METHODS

We studied 3 European cohorts: DESIR (n = 5,047; France), MDCS-CC (n = 3,643; Sweden), and PREVEND (n = 7,684; the Netherlands). Median follow-up was 8.5, 16.5, and 11.3 years, respectively. Pooled data were analyzed at an individual level for 4 endpoints during follow-up: incidence of stage 3 CKD (estimated glomerular filtration rate [eGFR] < 60 ml/min/1.73 m2); the KDIGO criterion "certain drop in eGFR"; rapid kidney function decline (eGFR slope steeper than -3 ml/min/1.73 m2/yr); and incidence of microalbuminuria.

RESULTS

The upper tertile of plasma copeptin was significantly and independently associated with a 49% higher risk for stage 3 CKD (P < 0.0001); a 64% higher risk for kidney function decline, as defined by the KDIGO criterion (P < 0.0001); a 79% higher risk for rapid kidney function decline (P < 0.0001); and a 24% higher risk for microalbuminuria (P = 0.008).

CONCLUSIONS

High copeptin levels are associated with the development and the progression of CKD in the general population. Intervention studies are needed to assess the potential beneficial effect on kidney health in the general population of reducing vasopressin secretion or action.

FUNDING

INSERM and Danone Research Centre for Specialized Nutrition.

Effect of Chronic Kidney Disease on Changes in Vasopressin System Expression in the Kidney Cortex in Rats with Nephrectomy

It is believed that the vasopressinergic system plays an important role in the pathogenesis of chronic kidney disease (CKD). The aim of this study was to evaluate the effect of CKD on changes in vasopressin system expression in the kidney cortex in rats with nephrectomy. The study was performed on 4 groups of Sprague Dawley (SPRD) rats: a control group (CN), 1/2 nephrectomy (N1/2), 2/3 nephrectomy (N2/3), and 5/6 nephrectomy (N5/6). Blood and the kidney cortex were collected to evaluate plasma copeptin concentrations and mRNA expressions of V1a vasopressin receptors (V1aR) and V2 vasopressin receptors (V2R) and V1aR, V2R, and aquaporin 2 (AQP2) protein levels. V1aR and V2R mRNA expression in the kidney cortex was significantly lower in the CN group compared with the other groups. In contrast, the V1aR, V2R, and AQP2 protein levels were significantly higher in the CN group compared with all of the nephrectomized groups. Plasma copeptin concentration was significantly lower in the CN group than in the nephrectomized groups. CKD caused significant changes in the expression of the vasopressinergic system. Further research is needed to explain the mechanisms of the impact of the vasopressinergic system on the kidney in CKD.

Copeptin, a surrogate marker for arginine vasopressin, is associated with disease severity and progression in IgA nephropathy patients

Background

Besides its essential role for water homeostasis, arginine vasopressin (AVP) may have deleterious effects on the kidney. Copeptin, a surrogate marker for AVP, has been shown to be related to renal outcome in patients with diabetic nephropathy and polycystic kidney disease. We investigated the association of copeptin with disease severity and progression in immunoglobulin A nephropathy (IgAN).

Methods

We included a prospective cohort of 59 patients with biopsy proven IgAN. Urinary excretion of α1 microglobulin (α1m), β 2 microglobulin (β2m), kidney injury molecule-1, neutrophil gelatinase-associated lipocalin and total protein were measured at baseline. Plasma copeptin was determined from stored baseline serum samples. Cox regression was performed for the composite renal outcome defined as doubling of serum creatinine, end-stage renal disease (ESRD) or start of immunosuppressive therapy, and for the individual components during 5-year follow-up.

Results

In IgAN patients [male: 72%, age: 42 ± 13 years, mean arterial pressure (MAP): 101 ± 12 mmHg, proteinuria: 1.4 (0.7-2.3) g/day, estimated glomerular filtration rate (eGFR): 48 ± 21 mL/min/1.73 m 2 ] median copeptin was 9.4 (5.3-18.4) pmol/L. At baseline, copeptin was associated with α1m [standardized beta (St. β) = 0.34, P = 0.009], β2m (St. β = 0.33, P = 0.01) and proteinuria (St. β = 0.36, P = 0.053), adjusted for sex and eGFR. During follow-up, the highest tertile of baseline copeptin was positively associated with the incidence of the composite renal outcome as well as with the individual components of doubling of creatinine, ESRD and start of immunosuppressive therapy. In Cox regression models, copeptin showed prognostic value over MAP, proteinuria and eGFR for the composite renal outcome.

Conclusions

Copeptin is associated with disease severity and prognosis in IgAN patients and may have additional prognostic value besides established risk markers.

The Chronic Kidney Disease Water Intake Trial: Protocol of a Randomized Controlled Trial

Background:

In observational studies, drinking more water associates with a slower rate of kidney function decline; whether the same is true in a randomized controlled trial is unknown.

Objective:

To examine the 1-year effect of a higher vs usual water intake on estimated glomerular filtration rate (eGFR) in patients with chronic kidney disease.

Design:

Parallel-group randomized controlled trial.

Setting:

Nine centers in Ontario, Canada. Enrollment and randomization occurred between May 2013 and May 2016; follow-up for the primary outcome will continue until June 2017.

Participants:

Adults (n = 631) with stage 3 chronic kidney disease (eGFR 30-60 mL/min/1.73 m²) and microalbuminuria.

Intervention:

The high water intake group was coached to increase their oral water intake by 1.0 to 1.5 L/day (depending on sex and weight), over and above usual consumed beverages, for a period of 1 year. The control group was coached to maintain their usual water intake during this time.

Measures:

Participants provided 24-hour urine samples at baseline and at 6 and 12 months after randomization; urine samples were analyzed for volume, creatinine, osmolality, and the albumin-to-creatinine ratio. Blood samples were obtained at baseline and at 3- to 6-month intervals after randomization, and analyzed for creatinine, copeptin, osmolality, and electrolytes. Other measures collected included health-related quality of life, blood pressure, body mass index, and diet.

Primary outcome:

The between-group change in eGFR from baseline (prerandomization) to 12 months after randomization.

Secondary outcomes:

Change in plasma copeptin concentration, 24-hour urine albumin-to-creatinine ratio, measured creatinine clearance, estimated 5-year risk of kidney failure (using the 4-variable Kidney Failure Risk Equation), and health-related quality of life.

Planned analysis:

The primary analysis will follow an intention-to-treat approach. The between-group change in eGFR will be compared using linear regression. Supplementary analyses will examine alternative definitions of eGFR change, including annual percentage change, rate of decline, and rapid decline (a P value <0.05 will be interpreted as statistically significant if there is concordance with the primary outcome).

Trial Registration:

This randomized controlled trial has been registered at www.clinicaltrials.gov; government identifier: NCT01766687.

Pathophysiology of copeptin in kidney disease and hypertension

Copeptin is derived from the cleavage of the precursor of arginine vasopressin (AVP), produced in an equimolar ratio in hypothalamus and processed during axonal transport AVP is an unstable peptide and has a short half-life of 5-20 min. Unlike AVP, copeptin is a stable molecule and can easily be measured. Recent evidence suggest that increased copeptin levels have been associated with worse outcomes in various clinical conditions including chronic kidney disease (CKD) and hypertension. In this review, the data regarding copeptin with kidney function (evaluated as glomerular filtration rate, increased albumin/protein excretion or both) and hypertension with regard to performed studies, prognosis and pathogenesis was summarised.

Effect of increased water intake on plasma copeptin in healthy adults

PURPOSE

Inter-individual variation in median plasma copeptin is associated with incident type 2 diabetes mellitus, progression of chronic kidney disease, and cardiovascular events. In this study, we examined whether 24-h urine osmolality was associated with plasma copeptin and whether increasing daily water intake could impact circulating plasma copeptin.

METHODS

This trial was a prospective study conducted at a single investigating center. Eighty-two healthy adults (age 23.6 ± 2.9 years, BMI 22.2 ± 1.5 kg/m², 50% female) were stratified based upon habitual daily fluid intake volumes: arm A (50-80% of EFSA dietary reference values), arm B (81-120%), and arm C (121-200%). Following a baseline visit, arms A and B increased their water intake to match arm C for a period of 6 consecutive weeks.

RESULTS

At baseline, plasma copeptin was positively and significantly associated with 24-h urine osmolality (p = 0.002) and 24-h urine specific gravity (p = 0.003) but not with plasma osmolality (p = 0.18), 24-h urine creatinine (p = 0.09), and total fluid intake (p = 0.52). Over the 6-week follow-up, copeptin decreased significantly from 5.18 (3.3;7.4) to 3.90 (2.7;5.7) pmol/L (p = 0.012), while urine osmolality and urine specific gravity decreased from 591 ± 206 to 364 ± 117 mOsm/kg (p < 0.001) and from 1.016 ± 0.005 to 1.010 ± 0.004 (p < 0.001), respectively.

CONCLUSIONS

At baseline, circulating levels of copeptin were positively associated with 24-h urine concentration in healthy young subjects with various fluid intakes. Moreover, this study shows, for the first time, that increased water intake over 6 weeks results in an attenuation of circulating copeptin.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02044679.

Renocardiovascular Biomarkers: from the Perspective of Managing Chronic Kidney Disease and Cardiovascular Disease

Mortality among the patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) remains high because of the very high incidence of cardiovascular disease (CVD) such as coronary artery disease, cardiac hypertrophy, and heart failure. Identifying CVD in patients with CKD/ESRD remains a significant hurdle and the early diagnosis and therapy for CVD is crucial in these patients. Therefore, it is necessary for the better management to identify and utilize cardiovascular (CV) biomarkers in profiling CVD risk and enabling stratification of early mortality. This review summarizes current evidence about renocardiovascular biomarkers: CV biomarkers in patients with CKD as well as with ESRD, emphasizing on the emerging biomarkers: B-type natriuretic peptide, cardiac troponins, copeptin, the biomarker of renal injury (neutrophil gelatinase-associated lipocalin), and the mineral and bone disorder hormone/marker (fibroblast growth factor-23). Furthermore, it discusses their potential roles especially in ESRD and in future diagnostic and therapeutic strategies for CVD in the context of managing cardiorenal syndrome.

Increased Serum Sodium and Serum Osmolarity Are Independent Risk Factors for Developing Chronic Kidney Disease; 5 Year Cohort Study

Background

Epidemics of chronic kidney disease (CKD) not due to diabetes mellitus (DM) or hypertension have been observed among individuals working in hot environments in several areas of the world. Experimental models have documented that recurrent heat stress and water restriction can lead to CKD, and the mechanism may be mediated by hyperosmolarity that activates pathways (vasopressin, aldose reductase-fructokinase) that induce renal injury. Here we tested the hypothesis that elevated serum sodium, which reflects serum osmolality, may be an independent risk factor for the development of CKD.

Methods

This study was a large-scale, single-center, retrospective 5-year cohort study at Center for Preventive Medicine, St. Luke’s International Hospital, Tokyo, Japan, between 2004 and 2009. We analyzed 13,201 subjects who underwent annual medical examination of which 12,041 subjects (age 35 to 85) without DM and/or CKD were enrolled. This analysis evaluated age, sex, body mass index, abdominal circumference, hypertension, dyslipidemia, hyperuricemia, fasting glucose, BUN, serum sodium, potassium, chloride and calculated serum osmolarity.

Results

Elevated serum sodium was an independent risk factor for development of CKD (OR: 1.03, 95% CI, 1.00–1.07) after adjusted regression analysis with an 18 percent increased risk for every 5 mmol/L change in serum sodium. Calculated serum osmolarity was also an independent risk factor for CKD (OR: 1.04; 95% CI, 1.03–1.05) as was BUN (OR: 1.08; 95% CI, 1.06–1.10) (independent of serum creatinine).

Conclusions

Elevated serum sodium and calculated serum osmolarity are independent risk factors for developing CKD. This finding supports the role of limiting salt intake and preventing dehydration to reduce risk of CKD.

Plasma Copeptin, Kidney Outcomes, Ischemic Heart Disease, and All-Cause Mortality in People With Long-standing Type 1 Diabetes

OBJECTIVE

Plasma copeptin, a surrogate for vasopressin, has been associated with a decline in renal function and albuminuria in population-based studies as well as with progression of diabetic nephropathy in people with type 2 diabetes. We assessed the risk of kidney and coronary events and all-cause mortality associated with plasma copeptin in people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Plasma copeptin was measured in baseline samples of the GENEDIAB (n = 398; 56% male; mean ± SD age 45 ± 12 years and diabetes duration 28 ± 10 years) and GENESIS (n = 588; 52% male; age 42 ± 11 years; diabetes duration 27 ± 9 years) cohorts. Follow-up data were available for 218 GENEDIAB and 518 GENESIS participants. Median duration of follow-up was 10.2 and 5.0 years, respectively.

RESULTS

Upper sex-specific tertiles of copeptin were associated with a higher incidence of end-stage renal disease (ESRD) during follow-up (hazard ratio [HR] for third vs. first tertile 26.5 [95% CI 8.0-163.3; P < 0.0001]; analysis in pooled cohorts adjusted for age, sex, duration of diabetes, and cohort membership). The highest tertile of copeptin was also associated with incidence of myocardial infarction or coronary revascularization (HR 2.2 [95% CI 1.2-4.0]; P = 0.01) and all-cause mortality (HR 3.3 [95% CI 1.8-6.5]; P < 0.0001) during follow-up.

CONCLUSIONS

Plasma copeptin is a predictor for the risk of ESRD, coronary heart disease, and all-cause mortality in people with type 1 diabetes. Results are consistent with data from experimental and epidemiological studies, suggesting that high circulating levels of vasopressin are deleterious to renal function.

Serum levels of copeptin are associated with type 2 diabetes and diabetic complications in Chinese population

PURPOSE

The aim of this study was to investigate copeptin levels in serum, and assess their associations with type 2 diabetes (T2DM) and diabetic complications.

METHODS

In this post hoc analysis, serum levels of copeptin were tested in 306 patients with T2DM. Clinical information including diabetic retinopathy (DR) and diabetic nephropathy (DN) were collected. The relation of serum copeptin with DR and DN were investigated with the use of logistic regression models according to equal quartiles of the distributions of serum copeptin.

RESULTS

We found that serum copeptin levels were significantly higher in diabetes as compared to normal controls [9.4(IQR, 7.4-12.5) pmol/L vs. 4.1(IQR, 2.5-6.2) pmol/L; P<0.0001]. In multivariate analysis, there was an increased risk of T2DM associated with copeptin levels (OR 1.312, 95% CI: 1.204-1.403; P<0.0001) after adjusting for possible confounders. After adjustment for possible confounders, serum copeptin levels were positively associated with the DR (odds ratio [OR], 1.117; 95% confidence interval [CI], 1.072-1.241; P<0.001) and DN (OR, 1.259; 95% CI, 1.198-1.323; P<0.001). Compared with the first quartile of serum copeptin levels, the ORs for DR and DN were as follows: second quartile, 1.19 (95% CI, 0.94-1.51, P=0.12) and 1.37 (95% CI, 0.78-2.37, P=0.28); third quartile, 1.61 (95% CI, 1.18-2.43, P=0.005) and 2.12 (95% CI, 1.32-3.27, P=0.003); fourth quartile, 2.83 (95% CI, 2.04-4.93; P<0.001) and 3.48 (95% CI, 1.77-7.03; P<0.001), respectively.

CONCLUSIONS

Using a post-hoc analysis our data show that elevated serum levels of copeptin are associated with type 2 diabetes and diabetic complications in Chinese population, suggesting a potential role of the AVP system (copeptin) in the pathophysiology of diabetes.

Chronic recurrent dehydration associated with periodic water intake exacerbates hypertension and promotes renal damage in male spontaneously hypertensive rats

Epidemiological evidence links recurrent dehydration associated with periodic water intake with chronic kidney disease (CKD). However, minimal attention has been paid to the long-term impact of periodic water intake on the progression of CKD and underlying mechanisms involved. Therefore we investigated the chronic effects of recurrent dehydration associated with periodic water restriction on arterial pressure and kidney function and morphology in male spontaneously hypertensive rats (SHR). Arterial pressure increased and glomerular filtration rate decreased in water-restricted SHR. This was observed in association with cyclic changes in urine osmolarity, indicative of recurrent dehydration. Additionally, water-restricted SHR demonstrated greater renal fibrosis and an imbalance in favour of pro-inflammatory cytokine-producing renal T cells compared to their control counterparts. Furthermore, urinary NGAL levels were greater in water-restricted than control SHR. Taken together, our results provide significant evidence that recurrent dehydration associated with chronic periodic drinking hastens the progression of CKD and hypertension, and suggest a potential role for repetitive bouts of acute renal injury driving renal inflammatory processes in this setting. Further studies are required to elucidate the specific pathways that drive the progression of recurrent dehydration-induced kidney disease.

Elevated copeptin is a prognostic factor for mortality even in patients with renal dysfunction

BACKGROUND

Copeptin has turned out to give valuable prognostic information for future cardiovascular events. However, since its plasma concentration directly depends on renal function, the value of copeptin as a predictor for outcome also in patients with chronic kidney disease (CKD) is unknown.

METHODS

In this single-center substudy of the German Coronary Artery Disease-REnal Failure (CAD-REF) registry, 301 patients with an angiographically diagnosed stenosis ≥50% in at least one major coronary vessel were included. Estimated glomerular filtration rate (eGFR) was determined using the MDRD formula and patients were classified according to their CKD stage. Copeptin concentrations were measured before initial angiography. Follow-up was performed at 180days, study endpoint was all-cause mortality.

RESULTS

Of the 301 included patients, 35 (11.6%) patients had no CKD, 113 (37.5%) had CKD stage 1 or 2, 117 (38.9%) had CKD stage 3, and 36 (12.0%) had CKD stage 4 or 5. Copeptin was elevated (≥14pmol/L) in 81 (26.9%) patients and normal (<14pmol/L) in 220 (73.1%) patients. Copeptin values significantly increased with decreasing eGFR (p<0.001) and were strongly correlated with creatinine values (r=0.567, p<0.001). During 180days of follow-up, 15 patients (5.0%) died, 10 of them with elevated copeptin values. Multivariate Cox regression analysis showed that copeptin was the sole predictor for mortality (HRR 5.317 (95% CI 1.653-17.098), p=0.005), independent of serum creatinine.

CONCLUSION

Elevated copeptin can be used as a valuable prognostic factor for intermediate-term mortality in patients with both coronary artery and renal disease.

Copeptin in Heart Failure

Heart failure (HF) is one of the most common causes of hospitalization and mortality in the modern Western world and an increasing proportion of the population will be affected by HF in the future. Although HF management has improved quality of life and prognosis, mortality remains very high despite therapeutic options. Medical management consists of a neurohormonal blockade of an overly activated neurohormonal axis. No single marker has been able to predict or monitor HF with respect to disease progression, hospitalization, or mortality. New methods for diagnosis, monitoring therapy, and prognosis are warranted. Copeptin, a precursor of pre-provasopressin, is a new biomarker in HF with promising potential. Copeptin has been found to be elevated in both acute and chronic HF and is associated with prognosis. Copeptin, in combination with other biomarkers, could be a useful marker in the monitoring of disease severity and as a predictor of prognosis and survival in HF.

Effect of increased water intake on plasma copeptin in patients with chronic kidney disease: results from a pilot randomised controlled trial

OBJECTIVES

Increased water intake may have a beneficial effect on the kidney through suppression of plasma vasopressin. We examined the effect of increased water intake on plasma copeptin (a marker of vasopressin) over 6 weeks in patients with chronic kidney disease.

DESIGN

Secondary analysis of a randomised controlled parallel-group pilot trial.

SETTING

Canada, 2012-2013.

PARTICIPANTS

28 patients with stage 3 chronic kidney disease randomised (2:1) to a hydration (n=17) or control group (n=11).

INTERVENTION

The hydration group was coached to increase water intake by up to 1.5 L/day for 6 weeks. The control group was asked to maintain regular water intake.

MEASURES AND OUTCOMES

Participants provided blood and 24 h urine samples at baseline and 6 weeks. Change in plasma copeptin was compared within and between study groups.

RESULTS

Participants were 64% male with a mean age of 62 years and an estimated glomerular filtration rate of 40 mL/min/1.73 m(2). Between baseline and 6 weeks, 24 h urine volume increased by 0.7 L/day in the hydration group, rising from 2.3 to 3.0 L/day (p=0.01), while decreasing by 0.3 L/day among controls, from 2.0 to 1.7 L/day (p=0.07); between-group difference: 0.9 L/day (95% CI 0.37 to 1.46; p=0.002). In the hydration group, median copeptin decreased by 3.6 pmol/L, from 15.0 to 10.8 pmol/L (p=0.005), while remaining stable among controls at 19 pmol/L (p=0.76; p=0.19 for the between-group difference in median change); the between-group difference in mean change was 5.4 pmol/L (95% CI -1.2 to 12.0; p=0.11).

CONCLUSIONS

Adults with stage 3 chronic kidney disease can be successfully randomised to drink approximately 1 L more per day than controls. This increased water intake caused a significant decrease in plasma copeptin concentration. Our larger 12-month trial will examine whether increased water intake can slow renal decline in patients with chronic kidney disease.

TRIAL REGISTRATION NUMBER

NCT01753466.

Association between copeptin and declining glomerular filtration rate in people with newly diagnosed diabetes. The Skaraborg Diabetes Register

AIMS

Copeptin has shown association with development of chronic kidney disease (CKD) in people with diabetes. Early detection of individuals having the highest risk could help avoid this complication. Therefore we decided to study copeptin concentrations and estimated glomerular filtration rate (eGFR) retrospectively in people with newly diagnosed diabetes.

METHODS

People with newly diagnosed type 2 diabetes in 1996-1998 from Skaraborg Diabetes Register (SDR) were reinvestigated in 2008-2010. Copeptin concentration at the time of diagnosis was determined. Creatinine and cystatin C were used for determination of eGFR at baseline and at reinvestigation (n=161). Data on cardiovascular complications were extracted from national registers. Analyzes were done with logistic regression.

RESULTS

From baseline to follow up eGFR decreased with 33ml. Twenty-nine individuals (18.1%) developed CKD stage 3. There was a significant association between elevated copeptin concentrations and development of CKD stage 3 (OR=1.78, 95% CI=1.01-3.16). When adjusting for GFR at baseline the association between copeptin and GFR decline was borderline significant (OR=1.79, 95% CI=0.99-3.25, p=0.055).

CONCLUSIONS

Determination of copeptin may early identify people with diabetes and high risk for CKD. To prevent complications for these individuals aggressive treatment should be discussed.

Risk stratification of normotensive pulmonary embolism: prognostic impact of copeptin

The prognostic value of copeptin, the C-terminal fragment of the precursor protein of vasopressin which is released upon stress, and hypotension in pulmonary embolism is unknown, especially if combined with biomarkers reflecting different pathophysiological axes such as myocardial injury (high-sensitivity troponin T (hsTnT)) and stretch (N-terminal pro-brain natriuretic peptide (NT-proBNP)).

We prospectively studied 268 normotensive pulmonary embolism patients included in a single-centre cohort study.

Patients with an adverse 30-day outcome (5.6%) had higher copeptin levels than patients with a favourable course (median (interquartile range) 51.8 (21.6–90.8) versus 13.2 (5.9–39.3) pmol·L−1; p=0.020). Patients with copeptin levels above the calculated optimal cut-off value of 24 pmol·L−1 had a 5.4-fold increased risk for an adverse outcome (95% CI 1.68–17.58; p=0.005). We developed a strategy for risk stratification based on biomarkers. None of 141 patients (52.6%) with hsTnT <14 pg·mL−1 or NT-proBNP <600 pg·mL−1 had an adverse outcome (low risk). Copeptin ≥24 pmol·L−1 stratified patients with elevated hsTnT and NT-proBNP as intermediate–low and intermediate–high risk (5.6% and 20.0% adverse outcome, respectively). Compared to the algorithm proposed by the 2014 European Society of Cardiology guideline, more patients were classified as low risk (52.8% versus 17.5%, p<0.001) and more patients in the intermediate–high risk group had an adverse outcome (20.0% versus 11.6%).

Copeptin might be helpful for risk stratification of normotensive patients with pulmonary embolism, especially if integrated into a biomarker-based algorithm.

Plasma Copeptin and Decline in Renal Function in a Cohort from the Community: The Prospective D.E.S.I.R. Study

BACKGROUND/AIMS

In recent days, chronic kidney disease (CKD) is becoming an increasing public health problem. Identification of factors contributing to its progression is crucial for designing preventive interventions. Previous studies suggested that chronically high vasopressin is deleterious to the renal function. We evaluated plasma copeptin, a surrogate of vasopressin, as a predictor for renal function decline in a community cohort.

METHODS

Plasma copeptin was measured at baseline in 1,234 participants from the D.E.S.I.R. study, a prospective cohort from the French general population. All participants were followed for 9 years. Progression towards CKD during follow-up was defined as an estimated glomerular filtration rate (eGFR) below 60 ml/min/1.73 m2 on at least one follow-up visit. We have also considered the criterion 'Certain Drop in eGFR' proposed by the Kidney Disease Improving Global Outcomes (KDIGO) group.

RESULTS

Progression towards CKD was observed in 86 (7.0%) participants. Factors like age, female gender, plasma copeptin and use of angiotensin converting enzyme inhibitor or angiotensin 2 receptor blocker at baseline were positively associated, and eGFR inversely associated with CKD progression during follow-up. The hazard ratio per unit of log10-transformed plasma copeptin was 1.65 (95% CI 1.06-2.54) and p=0.02. Copeptin was similarly associated with CKD and this was observed when we considered the KDIGO criterion: OR 3.03 (95% CI 1.21-7.57), p=0.02.

CONCLUSION

The plasma copeptin level was independently and positively associated with progression towards CKD in a community-based cohort. Our results add to the available evidence for a deleterious effect of high vasopressin on renal health not only in selected groups of patients with CKD but also in the general population.

Urine Osmolarity and Risk of Dialysis Initiation in a CKD Cohort

Background: Several experimental studies in rats and a few association studies in humans suggest that the antidiuretic action of vasopressin may accelerate the progression of chronic kidney disease. We undertook a retrospective analysis in a monocentric cohort of 273 patients with chronic kidney disease stages 1-4, focusing on a strong variable of interest, urinary osmolarity, and a strong endpoint, dialysis initiation. Data was analyzed in a multivariate proportional sub-distribution hazards model for competing risk data with appropriate co-variates. Main Results: Over a median follow-up period of 92 months, dialysis was initiated in 105 patients. After adjustments for baseline creatinine clearance, and other confounding factors, a higher risk for initiation of dialysis was found in patients with higher urinary osmolarity. After 72 months, the estimated adjusted cumulative incidence probability for dialysis initiation was 15, 24, and 34% in patients with baseline urinary osmolarity of 315, 510, and 775 mosm/l, respectively (p = 0.033). Key Messages: In this retrospective, longitudinal study, a higher baseline urinary osmolarity was strongly associated with a higher risk of end-stage renal disease (after appropriate adjustments). Further, prospective studies are required to evaluate the possible benefit of interventions aiming at reducing urinary osmolarity as a potential treatment for slowing chronic kidney disease progression.

Copeptin is associated with kidney length, renal function, and prevalence of simple cysts in a population-based study

Arginine vasopressin (AVP) has a key role in osmoregulation by facilitating water transport in the collecting duct. Recent evidence suggests that AVP may have additional effects on renal function and favor cyst growth in polycystic kidney disease. Whether AVP also affects kidney structure in the general population is unknown. We analyzed the association of copeptin, an established surrogate for AVP, with parameters of renal function and morphology in a multicentric population-based cohort. Participants from families of European ancestry were randomly selected in three Swiss cities. We used linear multilevel regression analysis to explore the association of copeptin with renal function parameters as well as kidney length and the presence of simple renal cysts assessed by ultrasound examination. Copeptin levels were log-transformed. The 529 women and 481 men had median copeptin levels of 3.0 and 5.2 pmol/L, respectively (P<0.001). In multivariable analyses, the copeptin level was associated inversely with eGFR (β=-2.1; 95% confidence interval [95% CI], -3.3 to -0.8; P=0.002) and kidney length (β=-1.2; 95% CI, -1.9 to -0.4; P=0.003) but positively with 24-hour urinary albumin excretion (β=0.11; 95% CI, 0.01 to 0.20; P=0.03) and urine osmolality (β=0.08; 95% CI, 0.05 to 0.10; P<0.001). A positive association was found between the copeptin level and the presence of renal cysts (odds ratio, 1.6; 95% CI, 1.1 to 2.4; P=0.02). These results suggest that AVP has a pleiotropic role in renal function and may favor the development of simple renal cysts.

Copeptin is an independent predictor of diabetic heart disease and death

BACKGROUND

We previously discovered that high copeptin is associated with incidence of diabetes mellitus (diabetes), abdominal obesity, and albuminuria. Furthermore, copeptin predicts cardiovascular events after myocardial infarction in diabetic patients, but whether it is associated with heart disease and death in individuals without diabetes and prevalent cardiovascular disease is unknown. In this study, we aim to test whether plasma copeptin (copeptin), the C-terminal fragment of arginine vasopressin prohormone, predicts heart disease and death differentially in diabetic and nondiabetic individuals.

METHODS

We related plasma copeptin to a combined end point composed of coronary artery disease (CAD), heart failure (HF), and death in diabetes (n = 895) and nondiabetes (n = 4187) individuals of the Malmö Diet and Cancer Study-Cardiovascular cohort.

RESULTS

Copeptin significantly interacted with diabetes regarding the combined end point (P = .006). In diabetic individuals, copeptin predicted the combined end point (hazard ratio [HR] 1.32 per SD, 95% CI 1.10-1.58, P = .003) after adjustment for conventional risk factors, prevalent HF and CAD, and remained significant after additional adjustment for either fasting glucose (P = .02) or hemoglobin A1c (P = .02). Furthermore, in diabetic individuals, copeptin predicted CAD (HR 1.33 per SD, 95% CI 1.04-1.69, P = .02), HF (HR 1.62 per SD, 95% CI 1.09-2.41, P = .02), and death (HR 1.32 per SD, 95% CI 1.04-1.68, P = .02). Interestingly, among nondiabetic individuals, copeptin was not associated with any of the end points.

CONCLUSIONS

Copeptin predicted heart disease and death, specifically in diabetes patients, suggesting copeptin and the vasopressin system as a prognostic marker and therapeutic target for diabetic heart disease and death.

Association of arginine vasopressin surrogate marker urinary copeptin with severity of autosomal dominant polycystic kidney disease (ADPKD)

BACKGROUND

Experimental studies suggest a detrimental role for cyclic adenosine monophosphate (cAMP) and vasopressin in the pathogenesis of autosomal dominant polycystic kidney disease (ADPKD). It is unknown, however, whether urinary cAMP and copeptin concentration are associated with disease severity in patients with ADPKD.

METHODS

Urinary cAMP (u-cAMP) and copeptin concentration (u-copeptin) were measured by immunoassay in ADPKD patients with CKD stage ≤4. We compared our measurements with clinical parameters including estimated glomerular filtration rate (eGFR), total kidney volume (TKV), and height-adjusted TKV (htTKV). Logarithmic transformation of all variables was performed to fulfill the requirement of equal distribution of the residuals.

RESULTS

We included 50 patients in this study (24 females and 26 males; mean age: 49.3 years). The median eGFR and TKV were 53.2 ml/min/1.73 m(2) (interquartile range: IQR; 29.4-68.45) and 1138.1 ml (IQR; 814.7-2065.0), respectively. The median u-copeptin level was 12.19 (IQR; 6.91-22.32) ng/ml. Although u-cAMP/u-Cr was not significantly correlated with TKV (R = -0.006, p = 0.967) and eGFR (R = 0.077, p = 0.602), urinary copeptin/u-Cr was statistically associated with the various markers of disease severity in ADPKD [positively with TKV (R = 0.351, p = 0.014), htTKV (R = 0.383, p = 0.008) and negatively with eGFR (R = -0.304, p = 0.036)].

CONCLUSIONS

In ADPKD subjects, a higher u-copeptin is associated with disease progression, suggesting that u-copeptin may be a new surrogate marker to predict renal prognosis in ADPKD.

Failure of renal biomarkers to predict worsening renal function in high-risk patients presenting with oliguria

PURPOSE

Oliguria is a common symptom in critically ill patients and puts patients in a high risk category for further worsening renal function (WRF). We performed this study to explore the predictive value of biomarkers to predict WRF in oliguric intensive care unit (ICU) patients.

PATIENTS AND METHODS

Single-center prospective observational study. ICU patients were included when they presented a first episode of oliguria. Plasma and urine biomarkers were measured: plasma and urine neutrophil gelatinase-associated lipocalin (pNGAL and uNGAL), urine α1-microglobulin, urine γ-glutamyl transferase, urine indices of tubular function, cystatin C, C terminal fragment of pro-arginine vasopressin (CT-ProAVP), and proadrenomedullin (MR-ProADM).

RESULTS

One hundred eleven patients formed the cohort, of whom 41 [corrected] had worsening renal function. Simplified Acute Physiology Score (SAPS) II was 41 (31-51). WRF was associated with increased mortality (hazard ratio 8.65 [95 % confidence interval (CI) 3.0-24.9], p = 0.0002). pNGAL, MR-ProADM, and cystatin C had the best odds ratio and area under the receiver-operating characteristic curve (AUC-ROC: 0.83 [0.75-0.9], 0.82 [0.71-0.91], and 0.83 [0.74-0.90]), but not different from serum creatinine (Screat, 0.80 [0.70-0.88]). A clinical model that included age, sepsis, SAPS II, and Screat had AUC-ROC of 0.79 [0.69-0.87]; inclusion of pNGAL increased the AUC-ROC to 0.86 (p = 0.03). The category-free net reclassification index improved with pNGAL (total net reclassification index for events to higher risk 61 % and nonevents to lower 82 %).

CONCLUSIONS

All episodes of oliguria do not carry the same risk. No biomarker further improved prediction of WRF compared with Screat in this selected cohort of patients at increased risk defined by oliguria.

Modifiable factors associated with copeptin concentration: a general population cohort

BACKGROUND

Vasopressin plays an important role in maintaining volume homeostasis. However, recent studies suggest that vasopressin also may play a detrimental role in the progression of chronic kidney disease. It therefore is of interest to identify factors that influence vasopressin concentration, particularly modifiable ones.

STUDY DESIGN

Cross-sectional analyses.

SETTING & PARTICIPANTS

Data used are from participants in a large general-population cohort study (Prevention of Renal and Vascular Endstage Disease [PREVEND]). Patients with a missing copeptin value (n=888), nonfasting blood sample (n=495), missing or assumed incorrect 24-hour urine collection (n=388), or heart failure (n=20) were excluded, leaving 6,801 participants for analysis.

FACTOR

Identification of lifestyle- and diet-related factors that are associated with copeptin concentration.

OUTCOMES

Copeptin concentration as surrogate for vasopressin.

MEASUREMENTS

Copeptin was measured by an immunoluminometric assay as a surrogate for vasopressin. Associations were assessed in uni- and multivariable linear regression analyses.

RESULTS

Median copeptin concentration was 4.7 (IQR, 2.9-7.6) pmol/L. When copeptin was studied as a dependent variable, the final stepwise backward model revealed associations with higher copeptin concentrations for lower 24-hour urine volume (P < 0.001), higher sodium excretion (P < 0.001), higher systolic blood pressure (P < 0.001), current smoking (P < 0.001), higher alcohol use (P < 0.001), higher urea excretion (P = 0.003), lower potassium excretion (P = 0.002), use of glucose-lowering drugs (P = 0.02), higher body mass index (P < 0.001), and higher plasma glucose level (P < 0.001). No associations with copeptin concentration were found for C-reactive protein or use of diuretics or nondiuretic antihypertensives.

LIMITATIONS

The cross-sectional study design does not allow firm conclusions on cause-effect relationships.

CONCLUSIONS

Important lifestyle- and diet-related factors associated with copeptin concentration are current smoking, alcohol use, protein and potassium intake, and particularly fluid and sodium intake. These data form a rationale to investigate whether intervening on these factors results in a lower vasopressin concentration with concomitant beneficial renal effects.

Serum copeptin level predicts a rapid decrease of overhydration after kidney transplantation

BACKGROUND

The assessment of proper hydration status in hemodialysis patients is difficult. None of currently available markers or measures is clinically relevant. Recently, human pre-pro-vasopressin (1-164) split product [copeptin (CPP)] - a new surrogate marker of hydration status - was introduced. The aim of the study was to analyze body weight changes in the early post-transplant period in relation to serum CPP levels before kidney transplantation.

METHODS

Serum CPP and NT-proBNP concentrations and osmolality were measured in 130 kidney recipients directly prior to transplantation and, additionally, in 78 of them at 14th day post-transplant. Hydration status at transplantation was calculated from the difference in the patient's body weight before transplantation and at the discharge.

RESULTS

During the post-transplant hospitalization, the average weight change was -1.6 kg, varying from 10.5 kg loss to weight gain of 5 kg. The overall weight loss was significantly related to pretransplant serum concentration of CPP (r=0.238), but not of NT-proBNP or osmolality. Patients with the lowest initial CPP level (first tertile) had smaller post-transplant weight loss. The early kidney graft function was unrelated to pretransplant CPP. Multivariate regression model revealed that variability of post-transplant weight loss is explained by the number of antihypertensive drugs used prior to transplantation [β=0.213 (0.049-0.377)] and pretransplant CPP values [β=0.233 (0.069-0.397)].

CONCLUSIONS

Elevated serum CPP level predicts a rapid weight loss after kidney transplantation and seems to characterize the subgroup of patients with the greatest overhydration. These results suggest the dysregulation of physiological mechanisms of CPP secretion in hemodialysis patients.

Urine osmolarity and risk of dialysis initiation in a chronic kidney disease cohort--a possible titration target?

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.

Plasma copeptin and renal outcomes in patients with type 2 diabetes and albuminuria

OBJECTIVE

Plasma copeptin, a surrogate for vasopressin, was associated with albuminuria in population-based studies. These associations are consistent with the effect of vasopressin on albuminuria observed in humans and rodents. The objective of this study was to determine whether plasma copeptin is an independent marker of risk of renal events in people with type 2 diabetes and albuminuria.

RESEARCH DESIGN AND METHODS

We studied 3,101 participants of the DIABHYCAR trial (6-year follow-up) with type 2 diabetes and albuminuria. A renal event was defined as doubling of serum creatinine or development of end-stage renal disease.

RESULTS

During follow-up, 86 renal events occurred in 76 subjects (2.45%). Incidences by tertiles of baseline plasma copeptin were 1.06% (T1), 1.45% (T2), and 4.84% (T3). They were 2.43% (T1), 5.11% (T2), and 11.81% (T3) for the subset of subjects with macroalbuminuria at baseline (n = 729). Hazard ratio for plasma copeptin tertiles as a risk for renal events was 4.79 (95% CI, 2.48-9.24; P < 0.0001; for T3 vs. T1). In a stepwise regression analysis, urinary albumin excretion and plasma copeptin remained positively associated and HDL cholesterol and estimated glomerular filtration rate were inversely associated with the incidence of renal events. These independent predictors explained ∼18% of the variance of the outcome. The yearly variations of estimated glomerular filtration rate by copeptin tertiles were -1.43 ± 0.51 (T1), -2.29 ± 0.49 (T2), and -3.52 ± 0.44 mL/min/1.73 m2 per year (T3) (P = 0.005) in subjects with macroalbuminuria.

CONCLUSIONS

Plasma copeptin may help to identify subjects with diabetic chronic kidney disease who are at high risk for renal function decline.

Copeptin, a surrogate marker for arginine vasopressin, is associated with cardiovascular and all-cause mortality in patients with type 2 diabetes (ZODIAC-31)

OBJECTIVE

Copeptin, a surrogate marker for arginine vasopressin, has been associated with cardiovascular (CV) events and mortality in patients with type 2 diabetes complicated by end-stage renal disease or acute myocardial infarction. For stable outpatients, these associations are unknown. Our aim was to investigate whether copeptin is associated with CV and all-cause mortality in patients with type 2 diabetes treated in primary care.

RESEARCH DESIGN AND METHODS

Patients with type 2 diabetes participating in the observational Zwolle Outpatient Diabetes Project Integrating Available Care (ZODIAC) study were included. Cox regression analyses with age as time scale were used to assess the relationship of baseline copeptin with CV and all-cause mortality.

RESULTS

We included 1,195 patients (age 67±12 years, 44% male). Median baseline copeptin concentration was 5.4 (interquartile range [IQR] 3.1-9.6) pmol/L. After a median follow-up of 5.9 (IQR 3.2-10.1) years, 345 patients died (29%), with 148 CV deaths (12%). Log2 copeptin was associated with CV (hazard ratio 1.17 [95% CI 0.99-1.39]; P=0.068) and all-cause mortality (1.22 [1.09-1.36]; P=0.001) after adjustment for age, sex, BMI, smoking, systolic blood pressure, total cholesterol to HDL ratio, duration of diabetes, HbA1c, treatment with ACE inhibitors and angiotensin receptor blockers, history of CV diseases, log serum creatinine, and log albumin to creatinine ratio; however, copeptin did not substantially improve risk prediction for CV (integrated discrimination improvement 0.14% [IQR -0.27 to 0.55%]) and all-cause mortality (0.77% [0.17-1.37%]) beyond currently used clinical markers.

CONCLUSIONS

We found copeptin to be associated with CV and all-cause mortality in patients with type 2 diabetes treated in primary care. Intervention studies should show whether the high CV risk in type 2 diabetes can be reduced by suppression of vasopressin, for example by reducing salt intake.

Copeptin, a surrogate marker for arginine vasopressin, is associated with declining glomerular filtration in patients with diabetes mellitus (ZODIAC-33)

AIM/HYPOTHESIS

Arginine vasopressin (AVP), the hormone important for maintaining fluid balance, has been shown to cause kidney damage in rodent models of diabetes. We investigated the potential role of AVP in the natural course of kidney function decline in diabetes in an epidemiological study.

METHODS

Plasma copeptin, a surrogate for AVP, was measured in baseline samples from patients with type 2 diabetes treated in primary care and included in the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) cohort.

RESULTS

Samples from 1,328 patients were available; 349 were analysed separately because they used renin-angiotensin-aldosterone system inhibition (RAASi), which influences albumin/creatinine ratio (ACR) and estimated (e)GFR. In the other 979 patients (46% men, age 68 years [58-75], ACR 1.8 mg/mmol [0.9-5.7], eGFR 67 ± 14 ml min(-1) 1.73 m(-2)) baseline copeptin (5.3 pmol/l [3.2-9.5]) was significantly associated with log e [ACR] and eGFR, even after adjustment for sex, age and risk factors for kidney function decline (standardised [std] β 0.13, p < 0.001, std β -0.20, p < 0.001 respectively). Follow-up data were available for 756 patients (6.5 years [4.1-9.6]). Baseline copeptin was associated with increase in ACR (std β 0.09, p = 0.02), but lost significance after adjustment (std β 0.07, p = 0.08). Copeptin was associated with a decrease in eGFR after adjustment (std β -0.09, p = 0.03). The strength of the association of copeptin with change in eGFR was stronger than that of established risk factors for kidney function decline (e.g. BMI, HbA1c). In patients who used RAASi there was a significant association between baseline copeptin and ACR and eGFR, but not with change in ACR and eGFR.

CONCLUSIONS/INTERPRETATION

In patients with diabetes not using RAASi a higher baseline copeptin concentration is significantly associated with higher baseline ACR and lower eGFR values and with a decline in eGFR during follow-up. This last association is independent of, and stronger than, most traditional risk factors for kidney function decline.

Association between water intake, chronic kidney disease, and cardiovascular disease: a cross-sectional analysis of NHANES data

BACKGROUND

Evidence from animal and human studies suggests a protective effect of higher water intake on kidney function and cardiovascular disease (CVD). Here the associations between water intake, chronic kidney disease (CKD) and CVD were examined in the general population.

METHODS

We conducted a cross-sectional analysis of the 2005-2006 National Health and Nutrition Examination Survey. Non-pregnant adults with an estimated glomerular filtration rate (eGFR) ≥30 ml/min/1.73 m(2) who were not taking diuretics were included. Total water intake from foods and beverages was categorized as low (<2.0 l/day), moderate (2.0-4.3 l/day) and high (>4.3 l/day). We examined associations between low total water intake and CKD (eGFR 30-60 ml/min/1.73 m(2)) and self-reported CVD.

RESULTS

Of 3,427 adults (mean age 46 (range 20-84); mean eGFR 95 ml/min/1.73 m(2) (range 30-161)), 13% had CKD and 18% had CVD. CKD was higher among those with the lowest (<2.0 l/day) vs. highest total water intake (>4.3 l/day) (adjusted odds ratio (OR) 2.52; 95% confidence interval (CI) 0.91-6.96). When stratified by intake of (1) plain water and (2) other beverages, CKD was associated with low intake of plain water: adjusted OR 2.36 (95% CI 1.10-5.06), but not other beverages: adjusted OR 0.87 (95% CI 0.30-2.50). There was no association between low water intake and CVD (adjusted OR 0.76; 95% CI 0.37-1.59).

CONCLUSIONS

Our results provide additional evidence suggesting a potentially protective effect of higher total water intake, particularly plain water, on the kidney.

Vasopressin: a novel target for the prevention and retardation of kidney disease?

After several decades during which little attention was paid to vasopressin and/or urine concentration in clinical practice, interest in vasopressin has renewed with the availability of new, potent, orally active vasopressin-receptor antagonists--the vaptans--and with the results of epidemiological studies evaluating copeptin (a surrogate marker of vasopressin) in large population-based cohorts. Several experimental studies in rats and mice had previously shown that vasopressin, acting via vasopressin V2 antidiuretic receptors, contributes to the progression of chronic kidney disease; in particular, to autosomal dominant polycystic kidney disease. New epidemiological studies now suggest a role for vasopressin in the pathogenesis of diabetes mellitus and metabolic disorders via activation of hepatic V1a and/or pancreatic islet V1b receptors. The first part of this Review describes the adverse effects of vasopressin, as revealed by clinical and experimental studies in kidney diseases, hypertension, diabetes and the metabolic syndrome. The second part provides insights into vasopressin physiology and pathophysiology that may be relevant to the understanding of these adverse effects and that are linked to the excretion of concentrated nitrogen wastes and associated hyperfiltration. Collectively, the studies reviewed here suggest that more attention should be given to the vasopressin-thirst-urine concentration axis in clinical investigations and in patient care. Whether selective blockade of the different vasopressin receptors may provide therapeutic benefits beyond their present indication in hyponatraemia requires new clinical trials.