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

Plasma copeptin and markers of arterial disorder in patients with type 2 diabetes, a cross-sectional study

OBJECTIVES

There is currently limited understanding of the relationship between copeptin, the midregional portion of proadrenomedullin (MRproADM) and the midregional fragment of the N-terminal of proatrial natriuretic peptide (MRproANP), and arterial disorders. Toe brachial index (TBI) and aortic pulse wave velocity (aPWV) are established parameters for detecting arterial disorders. This study evaluated whether copeptin, MRproADM, and MRproANP were associated with TBI and aPWV in patients with type 2 diabetes with no history of cardiovascular disease (CVD).

METHODS

In the CARDIPP study, a cross-sectional analysis of 519 patients with type 2 diabetes aged 55-65 years with no history of CVD at baseline, had complete data on copeptin, MRproADM, MRproANP, TBI, and aPWV was performed. Linear regression analysis was used to investigate the associations between conventional CVD risk factors, copeptin, MRproADM, MRproANP, TBI, and aPWV.

RESULTS

Copeptin was associated with TBI (β-0.0020, CI-0.0035- (-0.0005), p = 0.010) and aPWV (β 0.023, CI 0.002-0.044, p = 0.035). These associations were independent of age, sex, diabetes duration, mean 24-hour ambulatory systolic blood pressure, glycated hemoglobin A1c, total cholesterol, estimated glomerular filtration rate, body mass index, and active smoking.

CONCLUSIONS

Plasma copeptin may be a helpful surrogate for identifying individuals at higher risk for arterial disorders.

TRIAL REGISTRATION

 ClinicalTrials.gov identifier NCT010497377.

Food intake, plasma copeptin and cardiovascular risk in patients with type 2 diabetes: A cross-sectional analysis

BACKGROUND AND AIM

Increased consumption of ultra-processed foods has been linked to both mortality and cardiovascular risk. Copeptin levels may serve as potential risk markers for cardiovascular death and events. This cross-sectional analysis seeks to assess the potential correlation between the intake of ultra-processed foods and copeptin levels in outpatients diagnosed with type 2 diabetes, based on estimates of cardiovascular risk.

METHODS AND RESULTS

Outpatients underwent clinical and nutritional assessments. Dietary information was gathered using a validated quantitative food frequency questionnaire, and the consumption of all foods, beverages, and food products was assessed according to the NOVA food classification system. Fasting plasma-EDTA samples were collected and preserved at -80 °C. Plasma copeptin measurements were analyzed using an enzyme-linked immunosorbent assay based on the competition principle. Participants were categorized into two groups: high risk and very high risk, based on cardiovascular risk calculated by the HEARTS calculator. A total of 190 participants were included in the evaluation, with an average age of 60 ± 9 years, glycated hemoglobin of 8.4 ± 1.4%, and a diabetes duration of 11 (5-19) years. Patients at a very high cardiovascular risk exhibited higher plasma copeptin levels compared to those at high cardiovascular risk. Notably, 92.1% of patients reported consuming more than 10% of total energy intake from ultra-processed foods, although this proportion did not differ between the two groups.

CONCLUSION

This patient sample reported elevated consumption of ultra-processed foods; nevertheless, the correlation between ultra-processed foods and plasma copeptin has not been substantiated.

Association of serum copeptin and urinary uromodulin with kidney function, blood pressure and albuminuria at 6 weeks post-partum in pre-eclampsia

Background

Preeclampsia (PE) is associated with subsequent higher risk of cardiovascular and kidney disease. Serum copeptin, as a proxy for vasopressin, and urinary uromodulin, were associated with PE physiopathology and kidney functional mass respectively. We describe concentrations of these proteins in the post-partum period and characterize their association with persistent hypertension (HTN) or albuminuria.

Methods

Patients with PE and healthy controls with uncomplicated pregnancy were prospectively included at two teaching hospitals in Switzerland. Clinical parameters along with serum copeptin and urinary uromodulin were measured at 6 weeks post-partum. PE patients were further characterized based on presence of HTN (defined as either systolic BP (SBP) ≥140 mmHg or diastolic (BP) ≥90 mmHg) or albuminuria [defined as urinary albumin to creatinine ratio (ACR) ≥3 mg/mmol].

Results

We included 226 patients with 35 controls, 120 (62.8%) PE with persistent HTN/albuminuria and 71 (37.1%) PE without persistent HTN/albuminuria. Median serum copeptin concentration was 4.27 (2.9-6.2) pmol/L without differences between study groups (p > 0.05). Higher copeptin levels were associated with higher SBP in controls (p = 0.039), but not in PE (p > 0.05). Median urinary uromodulin concentration was 17.5 (7.8-28.7) mg/g with lower levels in PE patients as compared to healthy controls (p < 0.001), but comparable levels between PE patients with or without HTN/albuminuria (p > 0.05). Higher uromodulin levels were associated with lower albuminuria in PE as well as control patients (p = 0.040).

Conclusion

Serum copeptin levels at 6 weeks post-partum are similar between PE patients and healthy controls and cannot distinguish between PE with or without residual kidney damage. This would argue against a significant pathophysiological role of the vasopressin pathway in mediating organ damage in the post-partum period. On the opposite, post-partum urinary uromodulin levels are markedly lower in PE patients as compared to healthy controls, potentially reflecting an increased susceptibility to vascular and kidney damage that could associate with adverse long-term cardiovascular and kidney outcomes.

Plasma Citrate Levels Are Associated with an Increased Risk of Cardiovascular Mortality in Patients with Type 2 Diabetes (Zodiac-64)

Circulating citrate may represent a proxy of mitochondrial dysfunction which plays a role in the development of vascular complications in type 2 diabetes (T2D). Here, we determined the associations between plasma citrate levels and cardiovascular (CV) mortality in T2D patients. In this prospective cohort study, 601 patients were included who participated in the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC). Plasma citrate levels were measured by nuclear magnetic resonance spectroscopy. Cox proportional hazards regression models were used to evaluate the associations between plasma citrate and the risk of CV mortality. Over a median follow-up of 11.4 years, 119 (19.8%) of the 601 patients died from a CV cause. In multivariable Cox proportional hazards regression models, adjusting for conventional risk factors, plasma citrate was associated with an increased risk of CV mortality (the hazard ratio (HR) per 1-SD increment was 1.19 (95%CI: 1.00-1.40), p = 0.048). This association was prominent in males (n = 49 with CV mortality) (HR 1.52 (95%CI: 1.14-2.03), p = 0.005), but not in females (n = 70 with CV mortality) (HR 1.11 (95%CI: 0.90-1.37), p = 0.319) (age-adjusted Pinteraction = 0.044). In conclusion, higher plasma citrate levels are associated with an increased risk of CV mortality in patients with established T2D. Future studies are warranted to unravel the potential role of citrate-related pathways in the pathogenesis of T2D-related vascular complications.

Rethinking Vasopressin: New Insights into Vasopressin Signaling and Its Implications

Vasopressin is a highly conserved peptide hormone that has been traditionally associated with water homeostasis. There is accumulating evidence in both humans and animal models that vasopressin is implicated in the regulation of metabolism. This review focuses on the effects that vasopressin exerts on the regulation of glucose and fatty acids with a particular emphasis on the potential repercussions of metabolic dysregulation in kidney disease.

Heart Failure And Type 2 Diabetes Mellitus: Neurohumoral, Histological And Molecular Interconnections

Heart failure (HF) is a global healthcare burden and a leading cause of morbidity and mortality worldwide. Type 2 diabetes mellitus (T2DM) appears to be one of the major risk factors that significantly worsen HF prognosis and increase the risk of fatal cardiovascular outcomes. Despite a great knowledge of pathophysiological mechanisms involved in HF development and progression, hospitalization rates in patients with HF and concomitant T2DM remain elevated. In this review, we discuss the complex interplay between systemic neurohumoral regulation and local cardiac mechanisms participating in myocardial remodeling and HF development in T2DM with special attention to cardiomyocyte energy metabolism, mitochondrial function and calcium metabolism, cardiomyocyte hypertrophy and death, extracellular matrix remodeling.

Association of Serum Homocysteine with Cardiovascular and All-Cause Mortality in Adults with Diabetes: A Prospective Cohort Study

Background

Homocysteine (Hcy) was implicated in oxidative stress and diabetes biologically. However, the clinical evidence on the link between Hcy level and diabetes is limited and controversial. This study is aimed at investigating the association of serum Hcy with all-cause and cardiovascular mortality in diabetic patients.

Methods

Serum Hcy was measured among 2,286 adults with type 2 diabetes in NHANES 1999-2006. Cox proportional hazard regression was used to estimate hazard ratios (HR) and 95% CIs for the association of Hcy with all-cause and cause-specific mortality.

Results

Over a median follow-up of 11.0 (interquartile range, 8.9-13.4) years, 952 of the 2286 patients with diabetes died, covering 269 (28.3%) cardiovascular deaths and 144 (15.2%) cancer deaths. Restricted cubic spline showed the linear relationship between Hcy and all-cause mortality risk. After multivariate adjustment, higher serum Hcy levels were independently associated with increased risk of all-cause and cardiovascular mortality. Compared with participants in the bottom tertile of Hcy, the multivariate-adjusted HRs and 95% CI for participants in the top quartile were 2.33 (1.64-3.30) for all-cause mortality (p_trend < 0.001), 2.24 (1.22-4.10) for CVD mortality (p_trend = 0.017), and 2.05 (0.90-4.69) for cancer mortality (p_trend = 0.096). The association with total mortality was especially stronger among patients with albuminuria. Serum Hcy significantly improved reclassification for 10-year mortality in diabetic patients (net reclassification index = 0.253 and integrated discrimination improvement = 0.011).

Conclusions

Serum Hcy was associated with risks of all-cause and cardiovascular mortality in diabetic adults. Our results suggested that Hcy was a promising biomarker in risk stratification among diabetic patients.

Associations of Nutritional, Environmental, and Metabolic Biomarkers with Diabetes-Related Mortality in U.S. Adults: The Third National Health and Nutrition Examination Surveys between 1988-1994 and 2016

Background: Nutritional, environmental, and metabolic status may play a role in affecting the progression and prognosis of type 2 diabetes. However, results in identifying prognostic biomarkers among diabetic patients have been inconsistent and inconclusive. We aimed to evaluate the associations of nutritional, environmental, and metabolic status with disease progression and prognosis among diabetic patients. Methods: In a nationally representative sample in the NHANES III (The Third National Health and Nutrition Examination Survey, 1988−1994), we analyzed available data on 44 biomarkers among 2113 diabetic patients aged 20 to 90 years (mean age: 58.2 years) with mortality data followed up through 2016. A panel of 44 biomarkers from blood and urine specimens available from NHANES III were included in this study and the main outcomes as well as the measures are mortalities from all-causes. We performed weighted logistic regression analyses after controlling potential confounders. To assess incremental prognostic values of promising biomarkers beyond traditional risk factors, we compared c-statistics of the adjusted models with and without biomarkers, separately. Results: In total, 1387 (65.2%) deaths were documented between 1988 and 2016. We observed an increased risk of all-cause mortality associated with higher levels of serum C-reactive protein (p for trend = 0.0004), thyroid stimulating hormone (p for trend = 0.04), lactate dehydrogenase (p for trend = 0.02), gamma glutamyl transferase (p for trend = 0.02), and plasma fibrinogen (p for trend = 0.03), and urine albumin (p for trend < 0.0001). In contrast, higher levels of serum sodium (p for trend = 0.005), alpha carotene (p for trend = 0.006), and albumin (p for trend = 0.005) were associated with a decreased risk of all-cause mortality. In addition, these significant associations were not modified by age, sex, or race. Inclusion of thyroid stimulating hormone (p = 0.03), fibrinogen (p = 0.01), and urine albumin (p < 0.0001), separately, modestly improved the discriminatory ability for predicting all-cause mortality among diabetic patients. Conclusions: Our nationwide study findings provide strong evidence that some nutritional, environmental, and metabolic biomarkers were significant predictors of all-cause mortality among diabetic patients and may have potential clinical value for improving stratification of mortality risk.

Copeptin and renal function decline, cardiovascular events and mortality in type 1 diabetes

BACKGROUND

Plasma copeptin is a surrogate of arginine vasopressin (AVP) secretion and is associated with a risk of renal and cardiovascular disease. We investigated associations between copeptin and renal events, cardiovascular events and mortality in type 1 diabetes (T1D).

METHODS

We conducted a prospective cohort study on 658 individuals with T1D from Steno Diabetes Center Copenhagen. Plasma copeptin concentrations and conventional risk factors were assessed at baseline. The five endpoints were traced through national registries and electronic laboratory records.

RESULTS

Baseline mean age was 55 ± 13 years and estimated glomerular filtration rate (eGFR) was 81 ± 26 mL/min/1.73 m2. The median follow-up was 6.2 years (interquartile range 5.8-6.7); 123 participants reached a combined renal endpoint [decline in eGFR ≥30%, end-stage kidney disease (ESKD) or all-cause mortality], 93 had a decrease in eGFR ≥30%, 21 developed ESKD, 94 experienced a combined cardiovascular endpoint and 58 died from all causes. Higher copeptin was associated with all endpoints in unadjusted Cox regression analyses. Upon adjustment for baseline eGFR, the associations were attenuated and remained significant only for the combined renal endpoint and decrease in eGFR ≥30%. Results were similar upon further adjustment for other risk factors, after which hazard ratios for the two renal endpoints were 2.27 (95% confidence interval 1.08-4.74) and 4.49 (1.77-11.4), respectively, for the highest versus the lowest quartile of copeptin.

CONCLUSIONS

Higher copeptin was an independent risk marker for a combined renal endpoint and decline in renal function. AVP may be a marker of renal damage or a factor whose contribution to renal and cardiovascular risk is partially mediated by renal damage.

Novel Cardiovascular Risk Factors in Patients with Diabetic Kidney Disease

Patients with diabetic kidney disease (DKD) are at very high risk for cardiovascular events. Only part of this increased risk can be attributed to the presence of diabetes mellitus (DM) and to other DM-related comorbidities, including hypertension and obesity. The identification of novel risk factors that underpin the association between DKD and cardiovascular disease (CVD) is essential for risk stratification, for individualization of treatment and for identification of novel treatment targets.In the present review, we summarize the current knowledge regarding the role of emerging cardiovascular risk markers in patients with DKD. Among these biomarkers, fibroblast growth factor-23 and copeptin were studied more extensively and consistently predicted cardiovascular events in this population. Therefore, it might be useful to incorporate them in risk stratification strategies in patients with DKD to identify those who would possibly benefit from more aggressive management of cardiovascular risk factors.

Circulating Trimethylamine N-Oxide Is Associated with Increased Risk of Cardiovascular Mortality in Type-2 Diabetes: Results from a Dutch Diabetes Cohort (ZODIAC-59)

Trimethylamine N-oxide (TMAO), a novel cardiovascular (CV) disease and mortality risk marker, is a gut microbiota-derived metabolite as well. Recently, plasma concentrations of branched-chain amino acids (BCAA) have been reported to be affected by microbiota. The association of plasma TMAO with CV mortality in Type 2 Diabetes (T2D) and its determinants are still incompletely described. We evaluated the association between plasma BCAA and TMAO, and the association of TMAO with CV mortality in T2D individuals. We used data of 595 participants (mean age 69.5 years) from the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) cohort were analyzed. Plasma TMAO and BCAA were measured with nuclear magnetic resonance spectroscopy. CV mortality risk was estimated using multivariable-adjusted Cox regression models. Cross-sectionally, TMAO was independently associated with BCAA standardized (Std) β = 0.18 (95% Confidence Interval (CI) 0.09; 0.27), p <0.001. During a median follow-up of 10 years, 113 CV deaths were recorded. In Cox regression analyses, adjusted for multiple clinical and laboratory variables including BCAA, TMAO was independently associated with CV mortality: adjusted hazard ratio (_adjHR) 1.93 (95% CI 1.11; 3.34), p = 0.02 (for the highest vs. the lowest tertile of the TMAO distribution). The same was true for analyses with TMAO as continuous variable: _adjHR 1.32 (95% CI 1.07; 1.63), p = 0.01 (per 1 SD increase). In contrast, BCAAs were not associated with increased CV mortality. In conclusion, higher plasma TMAO but not BCAA concentrations are associated with an increased risk of CV mortality in individuals with T2D, independent of clinical and biochemical risk markers.

Serum IRAP, a Novel Direct Biomarker of Prediabetes and Type 2 Diabetes?

Insulin resistance (IR), currently called prediabetes (PD), affects more than half of the adult population worldwide. Type 2 diabetes (T2D), which often follows in the absence of treatment, affects more than 475 million people and represents 10–20% of the health budget in industrialized countries. A preventive public health policy is urgently needed in order to stop this constantly progressing epidemic. Indeed, early management of prediabetes does not only strongly reduce its evolution toward T2D but also strongly reduces the appearance of cardiovascular comorbidity as well as that of associated cancers. There is however currently no simple and reliable test available for the diagnosis or screening of prediabetes and it is generally estimated that 20–60% of diabetics are not diagnosed. We therefore developed an ELISA for the quantitative determination of serum Insulin-Regulated AminoPeptidase (IRAP). IRAP is associated with and translocated in a stoechiometric fashion to the plasma membrane together with GLUT4 in response to insulin in skeletal muscle and adipose tissue which are the two major glucose storage sites. Its extracellular domain (IRAPs) is subsequently cleaved and secreted in the blood stream. In T2D, IRAP translocation in response to insulin is strongly decreased. Our patented sandwich ELISA is highly sensitive (≥10.000-fold “normal” fasting concentrations) and specific, robust and very cost-effective. Dispersion of fasting plasma concentration values in a healthy population is very low (101.4 ± 15.9 μg/ml) as compared to those of insulin (21–181 pmol/l) and C-peptide (0.4–1.7 nmol/l). Results of pilot studies indicate a clear correlation between IRAPs levels and insulin sensitivity. We therefore think that plasma IRAPs may be a direct marker of insulin sensitivity and that the quantitative determination of its plasma levels should allow large-scale screening of populations at risk for PD and T2D, thereby allow the enforcement of a preventive health policy aiming at efficiently reducing this epidemic.

Copeptin as a Biomarker of Atherosclerosis in Type 1 Diabetic Patients

AIM:

To evaluate copeptin as an early marker of atherosclerosis in adolescent type 1 diabetics.

METHODS:

Sixty-two type 1 diabetic patients and 50 healthy volunteers were enrolled in the study. Serum copeptin, glycosylated haemoglobin (HbA1c), lipid profile, oxidised low-density lipoprotein (OxLDL), urinary albumin/creatinine ratio, carotid intimal medial thickness (cIMT), aortic intimal medial thickness (aIMT) and resistivity index were assessed for all participants in the study.

RESULTS:

HbA1c, albumin/creatinine ratio, lipid profile, OxlDL, copeptin, cIMT and aIMT were significantly higher in diabetic patients. Copeptin was higher in patients with positive cIMT and aIMT. Copeptin correlated with cIMT and aIMT. Stepwise multiple regression analysis found that copeptin correlated with aIMT. ROC curve showed that copeptin had 100 % specificity with aIMT and cIMT and 95.2 and 60,7 sensitivity with aIMT and cIMT respectively.

CONCLUSION:

Copeptin can be used as a marker for early detection of atherosclerosis of type 1 diabetic patients.

Hydration for health hypothesis: a narrative review of supporting evidence

PURPOSE

An increasing body of evidence suggests that excreting a generous volume of diluted urine is associated with short- and long-term beneficial health effects, especially for kidney and metabolic function. However, water intake and hydration remain under-investigated and optimal hydration is poorly and inconsistently defined. This review tests the hypothesis that optimal chronic water intake positively impacts various aspects of health and proposes an evidence-based definition of optimal hydration.

METHODS

Search strategy included PubMed and Google Scholar using relevant keywords for each health outcome, complemented by manual search of article reference lists and the expertise of relevant practitioners for each area studied.

RESULTS

The available literature suggest the effects of increased water intake on health may be direct, due to increased urine flow or urine dilution, or indirect, mediated by a reduction in osmotically -stimulated vasopressin (AVP). Urine flow affects the formation of kidney stones and recurrence of urinary tract infection, while increased circulating AVP is implicated in metabolic disease, chronic kidney disease, and autosomal dominant polycystic kidney disease.

CONCLUSION

In order to ensure optimal hydration, it is proposed that optimal total water intake should approach 2.5 to 3.5 L day^-1 to allow for the daily excretion of 2 to 3 L of dilute (< 500 mOsm kg^-1) urine. Simple urinary markers of hydration such as urine color or void frequency may be used to monitor and adjust intake.

The role of IL-1 in the regulation of copeptin in patients with metabolic syndrome

Arginine vasopressin (AVP) was suggested to contribute to cardiovascular risk and type 2 diabetes in patients with metabolic syndrome. The proinflammatory cytokine interleukin (IL)-1 is able to induce AVP secretion and plays a causal role in cardiovascular mortality and type 2 diabetes. We investigated in two studies whether copeptin levels - the surrogate marker for AVP - are regulated by IL-1-mediated chronic inflammation in patients with metabolic syndrome. Study A was a prospective, interventional, single-arm study (2014-2016). Study B was a randomized, placebo-controlled, double-blind study (2016-2017). n = 73 (Study A) and n = 66 (Study B) adult patients with metabolic syndrome were treated with 100 mg anakinra or placebo (only in study B) twice daily for 1 day (study A) and 28 days (study B). Fasting blood samples were drawn at day 1, 7, and 28 of treatment for measurement of serum copeptin. Patients with chronic low-grade inflammation (C-reactive protein levels ≥2 mg/L) and BMI >35 kg/m2 had higher baseline copeptin levels (7.7 (IQR 4.9-11.9) vs 5.8 (IQR 3.9-9.3) pmol/L, Pinflamm = 0.009; 7.8 (IQR 5.4-11.7) vs 4.9 (IQR 3.7-9.8) pmol/L, PBMI = 0.008). Copeptin levels did not change either in the anakinra or in the placebo group and remained stable throughout the treatment (P = 0.44). Subgroup analyses did not reveal effect modifications. Therefore, we conclude that, although IL-1-mediated inflammation is associated with increased circulating copeptin levels, antagonizing IL-1 does not significantly alter copeptin levels in patients with metabolic syndrome.

Distinguishing Low and High Water Consumers-A Paradigm of Disease Risk

A long-standing body of clinical observations associates low 24-h total water intake (TWI = water + beverages + food moisture) with acute renal disorders such as kidney stones and urinary tract infections. These findings prompted observational studies and experimental interventions comparing habitual low volume (LOW) and high volume (HIGH) drinkers. Investigators have learned that the TWI of LOW and HIGH differ by 1-2 L·d-1, their hematological values (e.g., plasma osmolality, plasma sodium) are similar and lie within the laboratory reference ranges of healthy adults and both groups appear to successfully maintain water-electrolyte homeostasis. However, LOW differs from HIGH in urinary biomarkers (e.g., reduced urine volume and increased osmolality or specific gravity), as well as higher plasma concentrations of arginine vasopressin (AVP) and cortisol. Further, evidence suggests that both a low daily TWI and/or elevated plasma AVP influence the development and progression of metabolic syndrome, diabetes, obesity, chronic kidney disease, hypertension and cardiovascular disease. Based on these studies, we propose a theory of increased disease risk in LOW that involves chronic release of fluid-electrolyte (i.e., AVP) and stress (i.e., cortisol) hormones. This narrative review describes small but important differences between LOW and HIGH, advises future investigations and provides practical dietary recommendations for LOW that are intended to decrease their risk of chronic diseases.

Oxytocin and Vasopressin Systems in Obesity and Metabolic Health: Mechanisms and Perspectives

PURPOSE OF REVIEW

The neurohypophysial endocrine system is identified here as a potential target for therapeutic interventions toward improving obesity-related metabolic dysfunction, given its coinciding pleiotropic effects on psychological, neurological and metabolic systems that are disrupted in obesity.

RECENT FINDINGS

Copeptin, the C-terminal portion of the precursor of arginine-vasopressin, is positively associated with body mass index and risk of type 2 diabetes. Plasma oxytocin is decreased in obesity and several other conditions of abnormal glucose homeostasis. Recent data also show non-classical tissues, such as myocytes, hepatocytes and β-cells, exhibit responses to oxytocin and vasopressin receptor binding that may contribute to alterations in metabolic function. The modulation of anorexigenic and orexigenic pathways appears to be the dominant mechanism underlying the effects of oxytocin and vasopressin on body weight regulation; however, there are apparent limitations associated with their use in direct pharmacological applications. A clearer picture of their wider physiological effects is needed before either system can be considered for therapeutic use.

Unexplained Variance in Hydration Study

With the collection of water-intake data, the National Health and Nutrition Examination Survey (NHANES) is becoming an increasingly popular resource for large-scale inquiry into human hydration. However, are we leveraging this resource properly? We sought to identify the opportunities and limitations inherent in hydration-related inquiry within a commonly studied database of hydration and nutrition. We also sought to critically review models published from this dataset. We reproduced two models published from the NHANES dataset, assessing the goodness of fit through conventional means (proportion of variance, R²). We also assessed model sensitivity to parameter configuration. Models published from the NHANES dataset typically yielded a very low goodness of fit R² < 0.15. A reconfiguration of variables did not substantially improve model fit, and the goodness of fit of models published from the NHANES dataset may be low. Database-driven inquiry into human hydration requires the complete reporting of model diagnostics in order to fully contextualize findings. There are several emergent opportunities to potentially increase the proportion of explained variance in the NHANES dataset, including novel biomarkers, capturing situational variables (meteorology, for example), and consensus practices for adjustment of co-variates.

Elevated plasma copeptin levels identify the presence and severity of non-alcoholic fatty liver disease in obesity

INTRODUCTION

Copeptin is the stable surrogate marker of vasopressin (VP), which is released in response to elevated plasma osmolality or low blood pressure. Elevated plasma copeptin levels are associated with higher risk of insulin resistance-related disorders, such as type 2 diabetes (T2DM), metabolic syndrome (MS), and cardiovascular disease, and experimental reduction of circulating VP levels is shown to significantly decrease hepatic fat content in obese rats, independently from body adiposity. However, the association between copeptin and non-alcoholic fatty liver disease and steatohepatitis (NAFLD/NASH) in humans has not been explored yet. The aim of this study was to explore the relationship between plasma copeptin and the presence/severity of NAFLD/NASH.

METHODS

For this study, we recruited 60 obese patients candidate to bariatric surgery for clinical purposes in which intraoperative liver biopsies were performed for diagnosing NAFLD/NASH. Circulating copeptin levels were also assessed in 60 age- and sex-comparable non-obese individuals without NAFLD at liver ultrasonography. Plasma copeptin was measured by sandwich immunoluminometric assay (Thermo Fisher Scientific).

RESULTS

Obese patients with biopsy-proven NAFLD (53%) had significantly higher copeptin levels than both obese individuals without NAFLD and non-obese subjects (ob/NAFLD+ 9.5 ± 4.9; ob/NAFLD- 6.4 ± 2.6; and non-ob/NAFLD- 7.4 ± 5.1 pmol/L; p = 0.004 and p = 0.01 respectively). Plasma copeptin concentration positively correlated with hepatic macro- and micro-vesicular steatosis (r = 0.36, p = 0.026; r = 0.31, p = 0.05), lobular inflammation (r = 0.37, p = 0.024) and significantly increased throughout degrees of NASH severity, as expressed as absence, borderline, and overt NASH at the liver biopsy (r = 0.35, p = 0.01). Greater circulating copeptin predicted the presence of NASH with OR = 1.73 (95% CI = 1.02-2.93) after multivariate adjustment for age, sex, renal function and presence of T2DM and MS components.

CONCLUSIONS

Increased plasma copeptin is independently associated with the presence and severity of NAFLD and NASH, pointing to a novel mechanism behind human fatty liver disease potentially modifiable by pharmacological treatment and lifestyle intervention.

Copeptin and Estimated Insulin Sensitivity in Adults With and Without Type 1 Diabetes: The CACTI Study

OBJECTIVES

Copeptin, a surrogate marker for vasopressin, is elevated in participants with insulin resistance (IR) and type 2 diabetes. Whereas adults with type 1 diabetes also demonstrate elevated copeptin concentrations and IR compared to controls without diabetes, the relationship between copeptin and IR in type 1 diabetes is unclear.

METHODS

Participants with (n=209) and without (n=244) type 1 diabetes in the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study were assessed for serum copeptin, vitals, estimated glomerular filtration rate, urinary albumin-to-creatinine ratio, glycated hemoglobin and lipid panels. Estimated insulin sensitivity (eIS) was calculated by validated equations in participants with and without type 1 diabetes. The relationships among copeptin, IR, waist circumference (WC) and body mass index (BMI) were examined with unadjusted and adjusted linear regression models.

RESULTS

Copeptin was correlated with eIS (R=-0.17, R2=0.029), WC (R=0.16, R2=0.026) and BMI (R=0.22, R2=0.048) for type 1 diabetes and with eIS (R=-0.37, R2=0.14), WC (R=0.40, R2=0.16) and BMI (R=0.25, R2=0.063) in non-type 1 diabetes. In multivariable analysis, copeptin correlated with total cholesterol (beta±SE: -0.12±0.04, p=0.008) and low-density lipoprotein (beta±SE: -0.11±0.04, p=0.01) in type 1 diabetes. In non-type 1 diabetes, copeptin was associated with WC (beta±SE: 0.14±0.04, p=0.0024), BMI (beta±SE: 0.13±0.04, p=0.007) and eIS (beta±SE: -0.14±0.04, p=0.0013).

CONCLUSIONS

Copeptin does not correlate with markers of IR in type 1 diabetes but strongly correlates in non-type 1 diabetes. Thus, elevated vasopressin activity and IR appear to be independent risk factors for vascular complications in type 1 diabetes.

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.

Effects of liraglutide on cardiovascular risk biomarkers in patients with type 2 diabetes and albuminuria: A sub-analysis of a randomized, placebo-controlled, double-blind, crossover trial

We assessed the effects of liraglutide treatment on five cardiovascular risk biomarkers, reflecting different pathophysiology: tumour necrosis factor (TNF)-α; soluble urokinase plasminogen activator receptor (suPAR); mid-regional pro-adrenomedullin (MR-proADM); mid-regional pro-atrial natriuretic peptide (MR-proANP); and copeptin, in people with type 2 diabetes with albuminuria. In a randomized, double-blind, placebo-controlled, crossover trial we enrolled people with type 2 diabetes and persistent albuminuria (urinary albumin-to-creatinine ratio [UACR] >30 mg/g) and estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m² . Participants received liraglutide (1.8 mg/d) and matched placebo for 12 weeks, in random order. The primary endpoint was change in albuminuria; this was a prespecified sub-study. A total of 32 participants were randomized, of whom 27 completed the study. TNF-α level was 12% (95% confidence interval [CI] 3; 20) lower after liraglutide treatment compared with placebo (P = .012); MR-proADM level was 4% (95% CI 0; 8) lower after liraglutide treatment compared with placebo (P = .038), and MR-proANP level was 13% (95% CI 4; 21) lower after liraglutide treatment compared with placebo (P = .006). In the present study, we showed anti-inflammatory effects of liraglutide treatment, reflected in reductions in levels of TNF-α and MR-proADM, while the reduction in MR-proANP levels may represent a clinically relevant benefit with regard to heart failure.

Copeptin and NT-proBNP for prediction of all-cause and cardiovascular death in ischemic stroke

OBJECTIVE

To evaluate long-term mortality in patients with acute ischemic stroke (AIS) by exploring the correlation between death and plasma concentrations of copeptin and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in a cohort study.

METHODS

In a prospective, multicenter observational study of 4,215 patients with AIS, copeptin and NT-proBNP levels were measured with a standardized method when patients were admitted to hospital. The primary endpoint was all-cause mortality or cardiovascular disease (CVD) mortality within 1 year.

RESULTS

During a follow-up period, 906 patients (20.1%, 95% confidence interval [CI] 18.9-21.2) died, including 589 cases of CVD mortality (13.1%, 95% CI 12.1-14.0). With the use of a multivariate analysis, both markers were found to have prognostic value in the same model (CVD mortality: odds ratio [OR] for fourth quartile of copeptin and NT-proBNP 1.68 and 2.58, 95% CI 1.22-2.49 and 1.76-4.05, respectively; all-cause mortality: OR for fourth quartile of copeptin and NT-proBNP 1.48 and 2.47, 95% CI 1.22-2.03 and 1.68-3.95, respectively). In a receiver operating characteristics analysis of CVD mortality, the area under the curve varied from 0.80 to 0.83 (95% CI 0.79-0.87) when the index of NT-proBNP was added and increased to 0.86 (95% CI 0.83-0.90) when both markers were added.

CONCLUSIONS

Copeptin and NT-proBNP may be useful independent prognostic markers of all-cause or CVD mortality in Chinese patients with AIS.

B-type natriuretic peptide overexpression ameliorates hepatorenal fibrocystic disease in a rat model of polycystic kidney disease

Polycystic kidney disease (PKD) involves progressive hepatorenal cyst expansion and fibrosis, frequently leading to end-stage renal disease. Increased vasopressin and cAMP signaling, dysregulated calcium homeostasis, and hypertension play major roles in PKD progression. The guanylyl cyclase A agonist, B-type natriuretic peptide (BNP), stimulates cGMP and shows anti-fibrotic, anti-hypertensive, and vasopressin-suppressive effects, potentially counteracting PKD pathogenesis. Here, we assessed the impacts of guanylyl cyclase A activation on PKD progression in a rat model of PKD. Sustained BNP production significantly reduced kidney weight, renal cystic indexes and fibrosis, in concert with suppressed hepatic cystogenesis in vivo. In vitro, BNP decreased cystic epithelial cell proliferation, suppressed fibrotic gene expression, and increased intracellular calcium. Together, our data demonstrate multifaceted effects of sustained activation of guanylyl cyclase A on polycystic kidney and liver disease. Thus, targeting the guanylyl cyclase A-cGMP axis may provide a novel therapeutic strategy for hepatorenal fibrocystic diseases.

Elevated plasma levels of copeptin linked to diabetic retinopathy in type 2 diabetes

BACKGROUND

The arginine vasopressin (AVP) system has been postulated to play a role in glucose homeostasis, insulin resistance, and diabetes mellitus in human and animal studies. The aim of this study was to evaluate the role of plasma copeptin in Chinese patients with type 2 diabetes mellitus (T2DM) with and without diabetic retinopathy (DR).

METHOD

Plasma copeptin concentrations were determined in 281 patients with T2DM. At baseline, demographic and clinical information including presence of DR and vision-threatening DR (VTDR) was collected. The relationship between copeptin and DR or VTDR was investigated using logistic regression.

RESULTS

T2DM participants with DR or VTDR had significantly higher plasma copeptin concentrations on admission (P < 0.0001). Receiver operating characteristics to predict DR and VDTR demonstrated areas under the curve for copeptin of 0.784 (95% confidence interval [CI] 0.724-0.844) and 0.834 (95% CI 0.781-0.904), respectively, which were superior to those for the homeostasis model assessment of insulin resistance (DR AUC 0.736, 95% CI 0.676-0.797; VTDR AUC 0.754, 95% CI 0.703-0.828; P < 0.01). Multivariate logistic regression analysis adjusted for common DR risk factors showed plasma copeptin concentrations ≥28.6 pmol/L (>3rd quartile) to be an independent marker of DR (OR 3.68, 95% CI 2.04-6.79; P < 0.0001) and VTDR (OR 4.32, 95% CI 2.12-8.14; P < 0.0001).

CONCLUSIONS

We found that increased plasma copeptin concentrations were an independent marker of DR and VDTR in Chinese patients with T2DM, suggesting a possible role of copeptin in the pathogenesis of DR complications.

Urinary Sodium Concentration Is an Independent Predictor of All-Cause and Cardiovascular Mortality in a Type 2 Diabetes Cohort Population

OBJECTIVE

Sodium intake is associated with cardiovascular outcomes. However, no study has specifically reported an association between cardiovascular mortality and urinary sodium concentration (UNa). We examined the association of UNa with mortality in a cohort of type 2 diabetes (T2D) patients.

METHODS

Patients were followed for all-cause death and cardiovascular death. Baseline UNa was measured from second morning spot urinary sample. We used Cox proportional hazard models to identify independent predictors of mortality. Improvement in prediction of mortality by the addition of UNa to a model including known risk factors was assessed by the relative integrated discrimination improvement (rIDI) index.

RESULTS

Participants (n = 1,439) were followed for a median of 5.7 years, during which 254 cardiovascular deaths and 429 all-cause deaths were recorded. UNa independently predicted all-cause and cardiovascular mortality. An increase of one standard deviation of UNa was associated with a decrease of 21% of all-cause mortality and 22% of cardiovascular mortality. UNa improved all-cause and cardiovascular mortality prediction beyond identified risk factors (rIDI = 2.8%, P = 0.04 and rIDI = 4.6%, P = 0.02, resp.).

CONCLUSIONS

In T2D, UNa was an independent predictor of mortality (low concentration is associated with increased risk) and improved modestly its prediction in addition to traditional risk factors.

Albuminuria is associated with greater copeptin concentrations in men with type 1 diabetes: A brief report from the T1D exchange Biobank

Vasopressin exerts important cardio-renal effects, but remains problematic to measure. Copeptin is a more stable peptide derived from the same precursor molecule. In this case-control study from the Type 1 Diabetes Exchange (T1DX) Biobank registry, men with T1D and albuminuria had greater copeptin concentrations than men with normoalbuminuria.

Cross-Sectional Positive Association of Serum Lipids and Blood Pressure With Serum Sodium Within the Normal Reference Range of 135-145 mmol/L

OBJECTIVE

Serum sodium concentration is maintained by osmoregulation within normal range of 135 to 145 mmol/L. Previous analysis of data from the ARIC study (Atherosclerosis Risk in Communities) showed association of serum sodium with the 10-year risk scores of coronary heart disease and stroke. Current study evaluated the association of within-normal-range serum sodium with cardiovascular risk factors.

APPROACH AND RESULTS

Only participants who did not take cholesterol or blood pressure medications and had sodium within normal 135 to 145 mmol/L range were included (n=8615), and the cohort was stratified based on race, sex, and smoking status. Multiple linear regression analysis of data from ARIC study was performed, with adjustment for age, blood glucose, insulin, glomerular filtration rate, body mass index, waist to hip ratio, and calorie intake. The analysis showed positive associations with sodium of total cholesterol, low-density lipoprotein cholesterol, and total cholesterol to high-density lipoprotein cholesterol ratio; apolipoprotein B; and systolic and diastolic blood pressure. Increases in lipids and blood pressure associated with 10 mmol/L increase in sodium are similar to the increases associated with 7 to 10 years of aging. Analysis of sodium measurements made 3 years apart demonstrated that it is stable within 2 to 3 mmol/L, explaining its association with long-term health outcomes. Furthermore, elevated sodium promoted lipid accumulation in cultured adipocytes, suggesting direct causative effects on lipid metabolism.

CONCLUSIONS

Serum sodium concentration is a cardiovascular risk factor even within the normal reference range. Thus, decreasing sodium to the lower end of the normal range by modification of water and salt intake is a personalizable strategy for decreasing cardiovascular risks.

Copeptin and the risk of incident stroke, CHD and cardiovascular mortality in older men with and without diabetes: The British Regional Heart Study

AIMS/HYPOTHESIS

This study aimed to examine the association between copeptin (a surrogate marker of arginine vasopressin) and incident stroke, CHD and cardiovascular mortality in older men with and without diabetes.

METHODS

We conducted a prospective study of 3536 men aged 60-79 years who were followed for an average of 13 years. During this period, there were 437 major CHD events (fatal and non-fatal myocardial infarction [MI]), 323 stroke events (fatal and non-fatal) and 497 cardiovascular disease (CVD) deaths. Prevalent diabetes was defined on the basis of a history of doctor-diagnosed diabetes or fasting blood glucose ≥7.0 mmol or HbA1c ≥6.5% (48 mmol/mol) (n = 428).

RESULTS

No association was seen between copeptin and incident stroke or CVD mortality in men without diabetes after adjustment for conventional cardiovascular risk factors, renal dysfunction, and insulin and N-terminal pro B-type natriuretic peptide levels. In contrast, elevated copeptin levels were associated with an increased risk of stroke and CVD mortality in men with diabetes after these adjustments. Compared with those in the lowest tertile of copeptin, men in the top tertile had adjusted relative HRs for stroke and CVD death of 2.34 (95% CI 1.04, 5.27) and 2.21 (1.12, 4.36), respectively. The risk of stroke and CVD mortality remained increased after the exclusion of men with prevalent stroke or MI. Higher levels of copeptin were associated with increased risk of CHD in the diabetic and non-diabetic groups, but these associations were attenuated after exclusion of individuals with a previous stroke or MI.

CONCLUSIONS/INTERPRETATION

Copeptin was independently associated with an increased risk of incident stroke and CVD mortality in men with diabetes, but not in men without diabetes. Targeting the arginine vasopressin system might have beneficial effects on CVD mortality and stroke risk in older men with diabetes.

Elevated copeptin is associated with atherosclerosis and diabetic kidney disease in adults with type 1 diabetes

BACKGROUND

Vasopressin exerts important cardio-renal effects, but remains problematic to measure. Copeptin is a more stable peptide derived from the same precursor molecule. We examined the associations between copeptin, coronary artery calcium (CAC), albuminuria and impaired glomerular filtration rate (GFR) in adults with type 1 diabetes (T1D).

METHODS

Participants with (n=209) and without T1D (n=244) in the Coronary Artery Calcification in Type 1 Diabetes (CACTI) study were assessed for serum copeptin, CAC measured using 128-slice spiral CT, urinary albumin-to-creatinine ratio (UACR) and eGFR calculated by CKD-EPI creatinine. Impaired GFR was defined as eGFR <60mL/min/1.73m(2), albuminuria as UACR ≥30mg/g, high and very high CAC score as ≥100 and ≥300AU, and elevated copeptin as >13pmol/L (>97.5th percentile for healthy adults). Unadjusted and adjusted (age, sex, HbA1c, SBP and LDL-C) logistic models were applied to examine the relationships.

RESULTS

Participants with T1D had greater ultrasensitive copeptin concentrations than non-diabetics (3.5 [95% CI 2.3-3.8] vs. 2.8 [2.7-3.1], p=0.003). In participants with T1D, elevated copeptin was associated with greater odds of impaired eGFR (OR: 18.52, 95% CI 4.03-85.02), albuminuria (10.55, 2.24-49.62), high CAC (6.61, 1.39-31.31) and very high CAC (6.24, 1.51-25.90) in multivariable models. Similar linear relationships were obtained with ultrasensitive copeptin, eGFR, UACR, CAC volume and CAC score in adjusted models.

CONCLUSION

In this cross-sectional analysis, copeptin was strongly associated with diabetic kidney disease and coronary atherosclerosis in adults with T1D. Further research is needed to determine whether these relationships hold true longitudinally in people with T1D.

Increased Levels of Copeptin, a Surrogate Marker of Arginine Vasopressin, Are Associated with an Increased Risk of Chronic Kidney Disease in a General Population

BACKGROUND

Our aim was to test if plasma copeptin, a stable surrogate marker of arginine vasopressin, predicts decline of glomerular filtration rate (GFR) and risk of chronic kidney disease (CKD).

METHODS

We measured copeptin and renal function at the Malmö Diet and Cancer Cardiovascular Cohort baseline exam and reassessed renal function after a follow-up time of 16.6 ± 1.5 years (n = 3,186). Furthermore, we defined CKD based on an estimated GFR (eGFR) calculated by the Modification of Diet in Renal Disease (MDRD) <60 (CKD_60MDRD), <45 (CKD_45MDRD) and <30 (CKD_30MDRD) ml/min/1.73 m2.

RESULTS

After multivariate adjustment (gender, age, baseline eGFR, smoking status, systolic blood pressure, antihypertensive treatment and follow-up time), copeptin (beta-coefficient per 1 SD increment of copeptin) was independently associated with significantly greater annual decline of eGFR (ml/min/1.73 m2) according to the MDRD formula (OR 0.057, 95% CI 0.022-0.093; p = 0.001) as well as according to the CKD Epidemiology Collaboration (CKD-EPI) formula (OR 0.050, 95% CI 0.022-0.077; p < 0.001). Each SD increment of copeptin independently predicted incident CKD_60MDRD (OR 1.19, 95% CI 1.04-1.36; p = 0.010), CKD_45MDRD (OR 1.33, 95% CI 1.04-1.71; p = 0.026) and CKD_30MDRD (OR 3.69, 95% CI 1.41-9.66; p = 0.008). The relationship between copeptin and CKD defined by CKD-EPI gave similar results.

CONCLUSION

Our data suggest that increased levels of copeptin independently predict decline in eGFR and greater risk of new-onset CKD.

Diabetic Kidney Disease in Adolescents With Type 2 Diabetes: New Insights and Potential Therapies

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease (ESRD) and dialysis in the Western world. Early DKD, including microalbuminuria and renal hyperfiltration, is common in adolescents with type 2 diabetes (T2D). Furthermore, youth-onset T2D carries a higher risk of progressive DKD than adult-onset T2D of similar diabetes duration. DKD is characterized by a long clinically silent period without signs of disease. Therefore, a major challenge in preventing DKD is the difficulty in identifying high-risk T2D patients at an early stage. The Type 2 Diabetes in Adolescents and Youth (TODAY) study demonstrated a high initial prevalence that increased over time, irrespective of treatment arm. This key observation underscores the importance of discovering new therapeutic targets to supplement conventional management, in order to reduce DKD risk. In this review, we focus on early DKD in T2D and summarize potential novel biomarkers and therapeutic targets.

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.

Copeptin: Pathophysiology and potential clinical impact

Copeptin, a C-terminal part of the precursor pre-provasopressin is a novel biomarker of arginine-vasopressin (AVP) system. Measurements of AVP concentration are not used in clinical practice because of technical difficulties. Copeptin is synthesized in stoichiometric ratio with AVP, hence it reflects vasopressin concentration in human plasma and serum. This review outlines current research concerning the role of copeptin as a prognostic marker in different diseases and its potential clinical value.

Is the association of serum sodium with mortality in patients with type 2 diabetes explained by copeptin or NT-proBNP? (ZODIAC-46)

BACKGROUND AND AIMS

Hyponatremia has been associated with an increased mortality risk in the general population. Diabetes is a condition predisposing for elevated levels of arginine vasopressin (AVP) and heart failure, both common causes of hyponatremia. These factors, however, are also associated with an increased mortality risk. We aimed to investigate whether serum sodium is associated with cardiovascular and all-cause mortality in type 2 diabetes and whether these associations could be explained by copeptin, a surrogate for AVP, or NT-proBNP, a marker for heart failure.

METHODS

Patients with type 2 diabetes participating in the observational ZODIAC study were included. Cox regression analyses were used to investigate the association of serum sodium with mortality.

RESULTS

We included 1068 patients (age 67 ± 12 years, 45% male, serum sodium 142 ± 3 mmol/L). After 15 years of follow-up, 519 patients (49%) died, with 225 cardiovascular deaths (21%). In univariable analyses, serum sodium, copeptin, and NT-proBNP were all significantly associated with cardiovascular and all-cause mortality. These associations remained significant after combination of these markers in a multivariable model. Serum sodium and NT-proBNP remained significantly associated with mortality after further adjustment for potential confounders, whereas copeptin lost significance after adjustment for SCr and ACR.

CONCLUSION

Low serum sodium was associated with an increased risk of cardiovascular and all-cause mortality in type 2 diabetes. Moreover, these associations were not explained by copeptin and NT-proBNP. Whether low serum sodium itself leads to poor outcome or is a marker for (unidentified) co-morbidity severity or use of specific medications remains to be elucidated.

Copeptin testing in acute myocardial infarction: ready for routine use?

Suspected acute myocardial infarction is one of the leading causes of admission to emergency departments. In the last decade, biomarkers revolutionized the management of patients with suspected acute coronary syndromes. Besides their pivotal assistance in timely diagnosis, biomarkers provide additional information for risk stratification. Cardiac troponins I and T are the most sensitive and specific markers of acute myocardial injury. Nonetheless, in order to overcome the remaining limitations of these markers, novel candidate biomarkers sensitive to early stage of disease are being extensively investigated. Among them, copeptin, a stable peptide derived from the precursor of vasopressin, emerged as a promising biomarker for the evaluation of suspected acute myocardial infarction. In this review, we summarize the currently available evidence for the usefulness of copeptin in the diagnosis and risk stratification of patients with suspected acute myocardial infarction in comparison with routine biomarkers.

The relationship between N-terminal prosomatostatin, all-cause and cardiovascular mortality in patients with type 2 diabetes mellitus (ZODIAC-35)

BACKGROUND

The hormone somatostatin inhibits growth hormone release from the pituitary gland and is theoretically linked to diabetes and diabetes related complications. This study aimed to investigate the relationship between levels of the stable somatostatin precursor, N-terminal prosomatostatin (NT-proSST), with mortality in type 2 diabetes (T2DM) patients.

METHODS

In 1,326 T2DM outpatients, participating in this ZODIAC prospective cohort study, Cox proportional hazards models were used to investigate the independent relationship between plasma NT-proSST concentrations with all-cause and cardiovascular mortality.

RESULTS

Median concentration of NT-proSST was 592 [IQR 450-783] pmol/L. During follow-up for 6 [3-10] years, 413 (31%) patients died, of which 176 deaths (43%) were attributable to cardiovascular causes. The age and sex adjusted hazard ratios (HRs) for all-cause and cardiovascular mortality were 1.48 (95%CI 1.14 - 1.93) and 2.21 (95%CI 1.49 - 3.28). However, after further adjustment for cardiovascular risk factors there was no independent association of log NT-proSST with mortality, which was almost entirely attributable to adjustment for serum creatinine. There were no significant differences in Harrell's C statistics to predict mortality for the models with and without NT-proSST: both 0.79 (95%CI 0.77 - 0.82) and 0.81 (95%CI 0.77 - 0.84).

CONCLUSIONS

NT-proSST is unsuitable as a biomarker for cardiovascular and all-cause mortality in stable outpatients with T2DM.

Diabetes Complications in Childhood Diabetes-New Biomarkers and Technologies

A major challenge in preventing vascular complications in diabetes is the inability to identify high-risk patients at an early stage, emphasizing the importance of discovering new risk factors, technologies and therapeutic targets to reduce the development and progression of complications. Promising biomarkers which may improve risk stratification and serve as therapeutic targets, include: uric acid, insulin sensitivity, copeptin, SGLT-2 and Klotho/FGF-23. Non-invasive measures of macrovasuclar disease in youth, include: 1) pulse wave velocity to examine arterial stiffness; 2) carotid intima-media thickness to evaluate arterial thickness; 3) cardiac MRI to investigate cardiac function and structure. Novel microvascular measures include: GFR by iohexol clearance using filter paper to directly measure GFR, retinal vascular geometry to predict early retinal changes and corneal confocal microscopy to improve detection of early nerve loss to better predict diabetic neuropathy. Herein we will review technologies, novel biomarkers, and therapeutic targets in relation to vascular complications of diabetes.

Renal function is associated with peak exercise capacity in adolescents with type 1 diabetes

OBJECTIVE

Diabetic nephropathy and cardiovascular disease are strongly related in adults with type 1 diabetes, yet little is known about this relationship in adolescents prior to the onset of detectable clinical disease. We hypothesized that cardiopulmonary fitness would be directly associated with albumin-to-creatinine ratio (ACR) and inversely related to estimated glomerular filtration rate (eGFR) in adolescents with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Sixty-nine adolescents with type 1 diabetes and 13 nondiabetic control subjects of similar pubertal stage and BMI had insulin sensitivity (glucose infusion rate [GIR]), measured by hyperinsulinemic-euglycemic clamp, and lean body mass, measured by DEXA. Cardiopulmonary fitness was measured by cycle ergometry to obtain peak volume of oxygen (VO2peak), and renal function was measured by eGFR using the Bouvet equation (measuring creatinine and cystatin C levels) and ACR.

RESULTS

Adolescents (15.5 ± 2.2 years of age) with type 1 diabetes (6.3 ± 3.8 years diabetes duration) had reduced VO2peak (31.5 ± 6.3 vs. 36.2 ± 7.9 mL/kg ⋅ min, P = 0.046) and VO2peak/lean kg (43.7 ± 7.0 vs. 51.0 ± 8.6 mL/lean kg ⋅ min, P = 0.007) compared with nondiabetic control subjects. eGFR was inversely associated with VO2peak and VO2peak/lean kg after adjusting for sex, Tanner stage, GIR, HbA1c level, systolic blood pressure, and LDL cholesterol level (β ± SE, VO2peak: -0.19 ± 0.07, P = 0.02; VO2peak/lean kg: -0.19 ± 0.09, P = 0.048). Moreover, participants in the highest tertile for eGFR had significantly lower sex- and Tanner-adjusted VO2peak and VO2peak/lean kg compared with participants in the lowest tertile.

CONCLUSIONS

Adolescents with type 1 diabetes had reduced exercise capacity, which was strongly associated with renal health, independent of insulin sensitivity. Future studies should examine the underlying interrelated pathophysiology in order to identify probable targets for treatment to reduce cardiovascular and renal complications.

Plasma copeptin as marker of cardiovascular disease in asymptomatic type 2 diabetes patients

Recently, copeptin was found associated with cardiovascular disease (CVD) and all-cause mortality in type 2 diabetes mellitus (T2DM) patients treated in primary care. This study aimed to evaluate whether plasma copeptin correlated to CVD in asymptomatic T2DM patients intensively investigated for sub-clinical CVD. A total of 302 T2DM patients referred to the Diabetes Clinic at Odense University Hospital, Denmark, entered the study. None of the patients had known or suspected CVD. As a control group, 30 healthy adults were recruited from the DanRisk study - a random sample of middle-aged Danes. A variety of clinical investigations were performed, including blood pressure measurements, carotid intima media thickness evaluation and myocardial perfusion scintigraphy. Blood sample analyses included copeptin measurements. Median plasma copeptin concentrations were similar in the T2DM group and the control group. However, men had significantly higher copeptin concentrations than women in the T2DM group (p < 0.001), and also, T2DM men had significantly higher copeptin concentrations than men without T2DM (p = 0.038). Copeptin correlated significantly with a number of variables, but the strongest correlation was with creatinine (R = 0.432, p < 0.001), and in multiple regression analysis, only this correlation remained significant. When association with clinical scores were investigated, plasma copeptin remained significantly associated with peripheral arterial disease (PAD) (p = 0.01). We found correlations between creatinine, copeptin levels and PAD in T2DM patients, and if confirmed, plasma copeptin combined with plasma creatinine could be a candidate for PAD screening in T2DM patients.

Postoperative plasma copeptin levels independently predict delirium and cognitive dysfunction after coronary artery bypass graft surgery

Copeptin can reflect individual's stress state and are correlated with poor outcome of critical illness. The occurrence of postoperative delirium (POD) and cognitive dysfunction (POCD) is associated with worse outcome after coronary artery bypass graft (CABG) surgery. The present study aimed to investigate the ability of postoperative plasma copeptin level to predict POD and POCD in patients undergoing CABG surgery. Postoperative plasma copeptin levels of 108 patients were measured by an enzyme-linked immunosorbent assay. It was demonstrated that plasma copeptin levels were substantially higher in patients with POD than without POD (1.8±0.6 ng/mL vs. 1.1±0.3 ng/mL; P<0.001) and in patients with POCD than without POCD (1.9±0.6 ng/mL vs. 1.1±0.4 ng/mL; P<0.001). Plasma copeptin level and age were identified as independent predictors for POD [odds ratio (OR), 67.386; 95% confidence interval (CI), 12.031-377.426; P<0.001 and OR, 1.202; 95% CI, 1.075-1.345; P=0.001] and POCD (OR, 28.814; 95% CI, 7.131-116.425; P<0.001 and OR, 1.151; 95% CI, 1.030-1.285; P=0.003) using a multivariate analysis. For prediction of POD, the area under receiver operating characteristic curve (AUC) of the copeptin concentration (AUC, 0.883; 95% CI, 0.807-0.937) was markedly higher than that of age (AUC, 0.746; 95% CI, 0.653-0.825; P=0.020). For prediction of POCD, the AUC of the copeptin concentration (AUC, 0.870; 95% CI, 0.792-0.927) was markedly higher than that of age (AUC, 0.735; 95% CI, 0.641-0.815; P=0.043). Thus, postoperative plasma copeptin level may be a useful, complementary tool to predict POD and POCD in patients undergoing CABG surgery.

Early diabetic nephropathy in type 1 diabetes: new insights

PURPOSE OF REVIEW

Despite improvements in glycemic and blood pressure control in patients with type 1 diabetes, diabetic nephropathy remains the most common cause of chronic kidney disease worldwide. A major challenge in preventing diabetic nephropathy is the inability to identify high-risk patients at an early stage, emphasizing the importance of discovering new therapeutic targets and implementation of clinical trials to reduce diabetic nephropathy risk.

RECENT FINDINGS

Limitations of managing patients with diabetic nephropathy with renin-angiotensin-aldosterone system blockade have been identified in recent clinical trials, including the failure of primary prevention studies in T1D and the demonstration of harm with dual renin-angiotensin-aldosterone system blockade. Fortunately, several new targets, including serum uric acid, insulin sensitivity, vasopressin, and sodium-glucose cotransporter-2 inhibition, are promising in the prevention and treatment of diabetic nephropathy.

SUMMARY

Diabetic nephropathy is characterized by a long clinically silent period without signs or symptoms of disease. There is an urgent need for improved methods of detecting early mediators of renal injury, to ultimately prevent the initiation and progression of diabetic nephropathy. In this review, we will focus on early diabetic nephropathy and summarize potential new therapeutic targets.

Plasma copeptin levels are inversely associated with intima-media-thickness in men: the population-based KORA F4 study

Background

Elevated plasma preprovasopressin (copeptin) levels are associated with cardiovascular complications as well as with an increased risk for type 2 diabetes (T2D). Here, we studied, whether plasma copeptin is related to carotid intima-media thickness (IMT), a measure of early atherosclerosis, and may thus be one explanation for the high cardiovascular risk in T2D.

Methods

Plasma concentrations of copeptin and IMT of the common carotid artery were determined in 1275 participants of the population-based KORA F4 study. We used linear regression models to investigate associations between copeptin levels and IMT.

Results

In the whole study group, copeptin levels were not significantly associated with IMT after adjustment for age and sex. Copeptin and IMT were significantly inversely associated after multivariable adjustment in the total cohort (β = -0.020 mm, 95% CI: -0.037 mm; -0.003 mm), in men (β = -0.035 mm, 95% CI: -0.061 mm; -0.009 mm) and in study participants with prediabetes (β = -0.041 mm, 95% CI: -0.078 mm; -0.005 mm) comparing quartile 4 vs quartile 1. The negative association of copeptin and IMT in men was present after adjustment for age alone. In women and patients with T2D, copeptin was not significantly associated with IMT.

Conclusions

Plasma copeptin was not associated with an increased IMT in our study cohort. In contrast, copeptin levels were related to a lower IMT in men and subjects with prediabetes, suggesting that elevated copeptin concentrations do not exert proatherogenic effects on carotid arteries.