Cleaning the Label of Cured Meat; Effect of the Replacement of Nitrates/Nitrites on Nutrients Bioaccessibility, Peptides Formation, and Cellular Toxicity of In Vitro Digested Salami.

Curing salts composed of mixtures of nitrates and nitrites are preservatives widely used in processed meats. Despite many desirable technological effects, their use in meat products has been linked to methemoglobinemia and the formation of nitrosamines. Therefore, an increasing "anti-nitrite feeling" has grown among meat consumers, who search for clean label products. In this view, the use of natural compounds as alternatives represents a challenge for the meat industry. Processing (including formulation and fermentation) induces chemical or physical changes of food matrix that can modify the bioaccessibility of nutrients and the formation of peptides, impacting on the real nutritional value of food. In this study we investigated the effect of nitrate/nitrite replacement with a combination of polyphenols, ascorbate, and nitrate-reducing microbial starter cultures on the bioaccessibility of fatty acids, the hydrolysis of proteins and the release of bioactive peptides after in vitro digestion. Moreover, digested salami formulations were investigated for their impacts on cell proliferation and genotoxicity in the human intestinal cellular model (HT-29 cell line). The results indicated that a replacement of synthetic nitrates/nitrites with natural additives can represent a promising strategy to develop innovative "clean label" salamis without negatively affecting their nutritional value.

Impact of a Shorter Brine Soaking Time on Nutrient Bioaccessibility and Peptide Formation in 30-Months-Ripened Parmigiano Reggiano Cheese.

Reducing the salt content in food is an important nutritional strategy for decreasing the risk of diet-related diseases. This strategy is particularly effective when applied to highly appreciated food having good nutritional characteristics, if it does not impact either upon sensory or nutritional properties of the final product. This work aimed at evaluating if the reduction of salt content by decreasing the brine soaking time modifies fatty acid and protein bioaccessibility and bioactive peptide formation in a 30-month-ripened Parmigiano Reggiano cheese (PRC). Hence, conventional and hyposodic PRC underwent in vitro static gastrointestinal digestion, and fatty acid and protein bioaccessibility were assessed. The release of peptide sequences during digestion was followed by LC-HRMS, and bioactive peptides were identified using a bioinformatic approach. At the end of digestion, fatty acid and protein bioaccessibility were similar in conventional and hyposodic PRC, but most of the bioactive peptides, mainly the ACE-inhibitors, were present in higher concentrations in the low-salt cheese. Considering that the sensory profiles were already evaluated as remarkably similar in conventional and hyposodic PRC, our results confirmed that shortening brine soaking time represents a promising strategy to reduce salt content in PRC.

Including Relative Adrenal Insufficiency in Definition and Classification of Acute-on-Chronic Liver Failure.

BACKGROUND & AIMS: Relative adrenal insufficiency (RAI) is defined by insufficient production of cortisol relative to organ demand. RAI is observed frequently in hospitalized patients with cirrhosis, but there is disagreement over the clinical effects of RAI in these patients. We evaluated the prevalence and the clinical effects of RAI in hospitalized patients with cirrhosis. METHODS: We performed a prospective study of 160 patients admitted to a hospital in Italy for acute decompensation of cirrhosis from May 2011 through September 2016. Patients were followed up until death, liver transplantation, or a maximum of 90 days. Serum and salivary levels of cortisol were measured before and after a 1-hour Short Synacthen Test. A diagnosis of RAI was given to patients with an increase in serum cortisol of less than 9 µg/dL, after Synacthen administration, in patients with baseline serum levels of cortisol less than 35 µg/dL. We collected blood samples before the Synacthen test and analyzed them for blood cell counts, liver and renal function, levels of C-reactive protein, and lipid profiles (total cholesterol, high-density lipoprotein cholesterol, apolipoprotein-A1). RESULTS: A diagnosis of RAI was made for 78 patients (49%). Age (odds ratio [OR], 0.95; P = .030), number of leukocytes (OR, 3.10; P = .006), and levels of high-density lipoprotein cholesterol (OR, 0.30; P = .039) were associated independently with RAI. Patients with RAI had a significantly higher risk of developing bacterial infections (hazard ratio [HR], 1.60; P = .038), sepsis (HR, 2.95; P = .001), septic shock (HR, 4.94; P = .038), new organ failures (HR, 2.45; P = .014), and acute-on-chronic liver failure (HR, 2.27; P = .037) than patients without RAI. RAI was associated independently with death within 90 days of diagnosis (subdistribution HR, 4.83; P = .001). Patients with RAI and mild renal dysfunction or hepatic encephalopathy had no significant difference in cumulative incidence of 28-day mortality vs patients with acute-on-chronic liver failure grade 1 (25% vs 22%). CONCLUSIONS: We found RAI to occur in almost half of patients admitted to a hospital for acute decompensation of cirrhosis. RAI was associated with a deficit of substrates for steroidogenesis and an increase in markers of inflammation. Patients with RAI have a high risk of developing sepsis, septic shock, organ failure, and death within 90 days. RAI has similar prognostic value to nonrenal organ failures.

Diagnostic accuracy of increased urinary cortisol/cortisone ratio to differentiate ACTH-dependent Cushing's syndrome.

BACKGROUND AND AIM: Differential diagnosis between Cushing's Disease (CD) and Ectopic ACTH Syndrome (EAS) may be a pitfall for endocrinologists. The increasing use in clinical practice of chromatography and mass spectrometry improves the measurement of urinary free cortisol (UFF) and cortisone (UFE). We have recently observed that cortisol to cortisone ratio (FEr) was higher in a small series of EAS; in this study we collected a larger number of ACTH-dependent Cushing's Syndrome (CS) to study the role of FEr to characterize the source of corticotropin secretion. MATERIALS AND METHODS: High-pressure liquid chromatography with UV detection (HPLC-UV, n=35) or liquid chromatography-tandem mass spectrometry (LC-MS/MS, n=72) were used to measure UFF, UFE and FEr in 83 patients with CD and 24 with EAS. RESULTS: UFF, UFE and FEr levels were higher in EAS than in CD (UFF: 6671 vs 549 nmol/24 hours; UFE: 2069 vs 464 nmol/24 hours; FEr: 4.13 vs 0.97; all P<.001). FEr >1.15 (the best ROC-based threshold) was able to distinguish CD from EAS with 75% sensitivity (SE) and 75% specificity (SP), AUC 0.811; results were similar between HPLC-UV (SE 73%, SP 79%, AUC 0.708) and LC-MS/MS (SE 77%, SP 73%, AUC 0.834; P=.727). The diagnostic accuracy of FEr was similar to that of CRH test or high-dose dexamethasone suppression test (respectively P=.171 and P=.683), also combined. Finally, FEr was able to increase the number of correct diagnosis in patients with discordant dynamic tests. CONCLUSIONS: Urinary FEr >1.15 was able to suggest EAS, with a diagnostic accuracy similar to that of other dynamic tests proposed to study ACTH-dependent CS.

An approach for estimating measurement uncertainty in medical laboratories using data from long-term quality control and external quality assessment schemes.

BACKGROUND: The present study was prompted by the ISO 15189 requirements that medical laboratories should estimate measurement uncertainty (MU). METHODS: The method used to estimate MU included the: a) identification of quantitative tests, b) classification of tests in relation to their clinical purpose, and c) identification of criteria to estimate the different MU components. Imprecision was estimated using long-term internal quality control (IQC) results of the year 2016, while external quality assessment schemes (EQAs) results obtained in the period 2015-2016 were used to estimate bias and bias uncertainty. RESULTS: A total of 263 measurement procedures (MPs) were analyzed. On the basis of test purpose, in 51 MPs imprecision only was used to estimate MU; in the remaining MPs, the bias component was not estimable for 22 MPs because EQAs results did not provide reliable statistics. For a total of 28 MPs, two or more MU values were calculated on the basis of analyte concentration levels. Overall, results showed that uncertainty of bias is a minor factor contributing to MU, the bias component being the most relevant contributor to all the studied sample matrices. CONCLUSIONS: The model chosen for MU estimation allowed us to derive a standardized approach for bias calculation, with respect to the fitness-for-purpose of test results. Measurement uncertainty estimation could readily be implemented in medical laboratories as a useful tool in monitoring the analytical quality of test results since they are calculated using a combination of both the long-term imprecision IQC results and bias, on the basis of EQAs results.

Verification of examination procedures in clinical laboratory for imprecision, trueness and diagnostic accuracy according to ISO 15189:2012: a pragmatic approach.

Background The International Standard ISO 15189 is recognized as a valuable guide in ensuring high quality clinical laboratory services and promoting the harmonization of accreditation programmes in laboratory medicine. Examination procedures must be verified in order to guarantee that their performance characteristics are congruent with the intended scope of the test. The aim of the present study was to propose a practice model for implementing procedures employed for the verification of validated examination procedures already used for at least 2 years in our laboratory, in agreement with the ISO 15189 requirement at the Section 5.5.1.2. Methods In order to identify the operative procedure to be used, approved documents were identified, together with the definition of performance characteristics to be evaluated for the different methods; the examination procedures used in laboratory were analyzed and checked for performance specifications reported by manufacturers. Then, operative flow charts were identified to compare the laboratory performance characteristics with those declared by manufacturers. Results The choice of performance characteristics for verification was based on approved documents used as guidance, and the specific purpose tests undertaken, a consideration being made of: imprecision and trueness for quantitative methods; diagnostic accuracy for qualitative methods; imprecision together with diagnostic accuracy for semi-quantitative methods. Conclusions The described approach, balancing technological possibilities, risks and costs and assuring the compliance of the fundamental component of result accuracy, appears promising as an easily applicable and flexible procedure helping laboratories to comply with the ISO 15189 requirements.

Performance criteria and quality indicators for the post-analytical phase.

BACKGROUND: Quality indicators (QIs) used as performance measurements are an effective tool in accurately estimating quality, identifying problems that may need to be addressed, and monitoring the processes over time. In Laboratory Medicine, QIs should cover all steps of the testing process, as error studies have confirmed that most errors occur in the pre- and post-analytical phase of testing. Aim of the present study is to provide preliminary results on QIs and related performance criteria in the post-analytical phase. METHODS: This work was conducted according to a previously described study design based on the voluntary participation of clinical laboratories in the project on QIs of the Working Group "Laboratory Errors and Patient Safety" (WG-LEPS) of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). RESULTS: Overall, data collected highlighted an improvement or stability in performances over time for all reported indicators thus demonstrating that the use of QIs is effective in the quality improvement strategy. Moreover, QIs data are an important source for defining the state-of-the-art concerning the error rate in the total testing process. The definition of performance specifications based on the state-of-the-art, as suggested by consensus documents, is a valuable benchmark point in evaluating the performance of each laboratory. CONCLUSIONS: Laboratory tests play a relevant role in the monitoring and evaluation of the efficacy of patient outcome thus assisting clinicians in decision-making. Laboratory performance evaluation is therefore crucial to providing patients with safe, effective and efficient care.

Cortisol and cortisone ratio in urine: LC-MS/MS method validation and preliminary clinical application.

BACKGROUND: The determination of urinary cortisol/cortisone ratio is of clinical utility in cases of Cushing's syndrome, apparent mineralocorticoid excess, and also provides information on 11ß-hydroxysteroid dehydrogenase (11ß-HSD) type 2 activity. It is therefore of utmost importance to ensure accurate cortisol and cortisone measurement and establish appropriate reference ranges. METHODS: After the isotopic dilution of urine, sample cleanups were obtained with on-line solid-phase extraction and cortisol and cortisone, separated using a Zorbax Eclipse XDB-C18 HPLC analytical column, were analyzed by tandem mass spectrometry with an electrospray ionization source in positive ion mode operation. RESULTS: The method was linear, with concentrations of up to 625 and 1125 nmol/L and lower limit of quantitation (LLOQ) of 5 and 6 nmol/L, for cortisol and cortisone, respectively. Within-run and between-run coefficients of variation were <5% and 6% for cortisol and 6% and 8% for cortisone, respectively. No ion suppression was observed. The non-parametric reference range for the cortisol/cortisone ratio was 0.14-1.09. CONCLUSIONS: A simple and sensitive liquid chromatography tandem mass spectrometry method was developed and validated for the measurement of cortisol and cortisone in urine. Our findings indicate that the proposed analytical method is suitable for routine purposes and useful in many pathological conditions.

Clinical and biochemical data for the diagnosis of endogenous hypercortisolism: the "Cushingomic" approach.

CONTEXT: The clinical presentation of Cushing's syndrome (CS) overlaps with common conditions. Recommended screening tests are serum cortisol after 1-mg overnight dexamethasone suppression test (DST), urinary free cortisol (UFC), and late-night salivary cortisol (LNSC). METHODS: We analyzed the diagnostic accuracy of screening tests in 615 patients without CS (263 suspected CS, 319 adrenal and 33 pituitary incidentaloma) and 40 with CS. Principal component analysis, K-means clustering, and neural network were used to compute an integrated analysis among tests, comorbidities, and signs/symptoms of hypercortisolism. RESULTS: The diagnostic accuracy of screening tests for CS was high, DST and UFC were slightly superior to LNSC. The threshold of DST should be adapted to the population considered, especially in adrenal incidentaloma with mild autonomous cortisol secretion: the cutoff to differentiate CS should be increased to 196 nmol/L. Diabetes, hypertension, and obesity were more common in patients without CS: the direction of their vectors was not aligned and their correlation with screening tests was poor. Clustering allowed us to differentiate those patients without CS in cluster one (aged osteoporotic patients with impaired screening tests), cluster two (hypertensive and metabolic phenotype), and cluster three (young subjects with a low likelihood of overt CS). A neural network model that combined screening tests and clinical presentation was able to predict the CS diagnosis in the validation cohort with 99% precision and 86% accuracy. CONCLUSIONS: Despite the high diagnostic accuracy of screening tests to detect CS, cortisol-related comorbidities or adrenal incidentaloma should be considered when interpreting a positive test.

Heat inactivation of SARS-CoV 2 enabled the measurement of salivary cortisol during COVID-19 pandemic.

BACKGROUND AND AIM: Salivary cortisol has become an essential tool in the management of cortisol-related disease. In 2020 the sudden outbreak of COVID-19 pandemic caused several concerns about the use of saliva, due to the risk of contamination, and a European consensus further discourage using salivary cortisol. To decrease infectious risk, we handled specimens by applying a heat treatment to inactivate viral particles, further evaluating the impact of the COVID-19 pandemic on the use of salivary cortisol in clinical practice. MATERIAL AND METHODS: Saliva samples were exposed for 10 min at 70 °C, then cortisol was measured using LC-MS/MS. The number of salivary cortisol examinations from 2013 to 2022 was extracted from the local electronic database: those performed in 2019, 2020, and 2021 were analyzed and compared with the historical data. RESULTS: During 2020 we observed a decrease of 408 (-20%) examinations (p = 0.05) compared to 2019; especially in salivary cortisol daily rhythm and salivary cortisol/cortisone ratio (respectively reduction of 47% and 88%, p = 0.003 and p = 0.001). Analyzing year 2021 compared with 2020 we reported an increase of 420 examinations (+20%, p = 0.01), with a complete recovery of salivary cortisol measurement (considering 2019: p = 0.71). Major differences were observed between morning salivary cortisol (-20%, p = 0.017), LNSC (-21%, p = 0.012) and salivary cortisol rhythm (-22%, p = 0.056). No Sars-Cov2 infections related to working exposure were reported among laboratory's employers. CONCLUSIONS: We speculate that the adoption of an appropriate technique to inactivate viral particles in saliva specimens allowed the safety maintenance of salivary collections, also during the Sars-CoV-2 outbreak.

Toward Sustainable and Healthy Fish Products-The Role of Feeding and Preservation Techniques.

Fish is a fundamental component of the human diet, and in the near future the proportion of aquatic foods originating from aquaculture production is expected to increase to over 56%. The sustainable growth of the aquaculture sector involves the use of new sustainable raw materials as substitutes for traditional fishmeal and fish oil ingredients, but it is crucial that the substitution maintains the nutritional value of the fish meat. In addition, the preservation of the nutritional value should be a mandatory requirement of new technologies that extend the shelf life of fish. In this context, we evaluated the impact of a newly formulated feed and three preservation treatments (brine, pulsed electric field (PEF), and PEF plus brine) on the fatty acid composition and protein and lipid digestibility of sea bass fillets. In non-digested fillets, although slightly reduced by the newly formulated feed (standard = 2.49 ± 0.14; newly formulated = 2.03 ± 0.10) the n-3/n-6 PUFA ratio indicated good nutritional value. The preservation treatments did not modify the fatty acid content and profile of non-digested fillets. Conversely, protein and lipid digestibility were not affected by the different diets but were significantly reduced by brine, with or without PEF, while PEF alone had no effect. Overall, our results indicated that the newly formulated feed containing 50% less fishmeal is a good compromise between the sustainability and nutritional value of cultivated seabass, and PEF is a promising preservation technology deserving of further study.

Association of autoantibodies targeting endothelin type-A receptors with no-reflow in ST-elevation myocardial infarction.

BACKGROUND AND AIMS: No-reflow (NR), where the coronary artery is patent after treatment of ST-elevation myocardial infarction (STEMI) but tissue perfusion is not restored, is associated with worse outcomes. We aimed to investigate the relationship between autoantibodies activating endothelin-1 receptor type A (ETAR-AAs) and NR after primary percutaneous coronary intervention (PPCI) in STEMI. METHODS: We studied 50 patients (age 59 ± 11 years, 40 males) with STEMI who underwent PPCI within 6 h after the onset of symptoms. Blood samples were obtained from all patients within 12 h following PPCI for ETAR-AA level measurement. The seropositive threshold was provided by the manufacturer (>10 U/ml). NR was assessed by cardiac magnetic resonance imaging (MVO, microvascular obstruction). As a control group, 40 healthy subjects matched for age and sex were recruited from the general population. RESULTS: MVO was observed in 24 patients (48%). The prevalence of MVO was higher in patients with ETAR-AAs seropositivity (72% vs. 38%, p = 0.03). ETAR-AAs were higher in patients with MVO (8.9 U/mL (interquartile range [IQR] 6.8-16.2 U/mL) vs. 5.7 U/mL [IQR 4.3-7.7 U/mL], p = 0.003). ETAR-AAs seropositivity was independently associated with MVO (OR 3.2, 95% CI 1.3-7.1; p = 0.03). We identified ≥6.74 U/mL as the best cut-off for prediction of MVO (sensitivity 79%; specificity 65%; NPV 71%; PPV 74%; accuracy 72%). CONCLUSIONS: The ETAR-AAs seropositivity is associated with NR in STEMI patients. These findings may open up new options in the management of myocardial infarction even if confirmation in a larger trial is needed.

Human saliva total protein levels by AV17 pigment based analysis: validation, stability and short-term variation studies.

BACKGROUND: A colorimetric method based on acid violet pigment, namely AV17, to analyse salivary total protein content, was assessed. METHODS: Human saliva sample or standard (50 microL) was added to 1.5 mL of AV17 working solution (1 mg/mL in 75 mmol/L sodium chloride and 1.7 mol/L phosphoric acid). Total protein concentration was measured at 546 nm. Salivary total protein of healthy subjects was analyzed. RESULTS: The standard protein was Human Serum Albumin and the detection range was 38 mg/L - 900 mg/L with a LOD and LOQ of 26 mg/L and 64 mg/L, respectively. Intraday CVs were 3% - 5% and interday CVs were 3%-6%. The dilution test demonstrated a correlation coefficient of 0.999 and the recovery tests ranged from 108% to 111%. Saliva sample stability was also demonstrated. No intra-individual salivary total protein variation was found during the morning. CONCLUSIONS: The method suitability for laboratory diagnostic purposes to analyse human saliva protein content and stability was demonstrated.

Insight on Glucose and Fructose Absorption and Relevance in the Enterocyte Milieu.

Although epidemiological studies indicate a strong correlation between high sugar intake and metabolic diseases, the biological mechanisms underlying this link are still controversial. To further examine the modification and crosstalk occurring in enterocyte metabolism during sugar absorption, in this study we evaluate the diffusion and intestinal metabolism of glucose, fructose and sucrose, which were supplemented in equimolar concentration to Caco-2 cells grown on polyester membrane inserts. At different time points after supplementation, changes in metabolite concentration were evaluated in the apical and basolateral chambers by nuclear magnetic resonance (NMR) and gas-chromatography (GC). Sucrose was only minimally hydrolyzed by Caco-2 cells. Upon supplementation, we observed a faster uptake of fructose than glucose, the pentose sugar being also faster catabolized. Monosaccharide absorption was concomitant to the synthesis/transport of other metabolites, which occurred differently in glucose and fructose supplemented cells. Our results confirm the prominent role of intestinal cells in fructose metabolism and clearance after absorption, representing a further step forward in the understanding of the role of dietary sugars. Future research, including targeted analysis on specific transporters/enzymes and the use of labeled substrates, will be helpful to confirm the present results and their interpretation.

Comparison of Cortisol, Androstenedione and Metanephrines to Assess Selectivity and Lateralization of Adrenal Vein Sampling in Primary Aldosteronism.

Success of adrenal vein sampling (AVS) is verified by the selectivity index (SI), i.e., by a step-up of cortisol levels between the adrenal vein and the infrarenal inferior vena cava samples, beyond a given cut-off. We tested the hypothesis that androstenedione, metanephrine, and normetanephrine, which have higher gradients than cortisol, could increase the rate of AVS studies judged to be bilaterally successful and usable for the clinical decision making. We prospectively compared within-patient, head-to-head, the selectivity index of androstenedione (SIA), metanephrine (SIM), and normetanephrine (SINM), and cortisol (SIC) in consecutive hypertensive patients with primary aldosteronism submitted to AVS. Main outcome measures were rate of bilateral success, SI values, and identification of unilateral PA. We recruited 136 patients (55 + 10 years, 35% women). Compared to the SIC, the SIA values were 3.5-fold higher bilaterally, and the SIM values were 7-fold and 4.4-fold higher on the right and the left side, respectively. With the SIA and the SIM the rate of bilaterally successful AVS increased by 14% and 15%, respectively without impairing the identification of unilateral PA. We concluded that androstenedione and metanephrine outperformed cortisol for ascertaining AVS success, thus increasing the AVS studies useable for the clinical decision making.

Coenzyme Q10 Phytosome Formulation Improves CoQ10 Bioavailability and Mitochondrial Functionality in Cultured Cells.

Coenzyme Q10 (CoQ10) is a lipid-soluble molecule with a dual role: it transfers electrons in the mitochondrial transport chain by promoting the transmembrane potential exploited by the ATPase to synthesize ATP and, in its reduced form, is a membrane antioxidant. Since the high CoQ10 hydrophobicity hinders its bioavailability, several formulations have been developed to facilitate its cellular uptake. In this work, we studied the bioenergetic and antioxidant effects in I407 and H9c2 cells of a CoQ10 phytosome formulation (UBIQSOME®, UBQ). We investigated the cellular and mitochondrial content of CoQ10 and its redox state after incubation with UBQ. We studied different bioenergetic parameters, such as oxygen consumption, ATP content and mitochondrial potential. Moreover, we evaluated the effects of CoQ10 incubation on oxidative stress, membrane lipid peroxidation and ferroptosis and highlighted the connection between the intracellular concentration of CoQ10 and its antioxidant potency. Finally, we focused on the cellular mechanism that regulates UBQ internalization. We showed that the cell lines used in this work share the same uptake mechanism for UBQ, although the intestinal cell line was less efficient. Given the limitations of an in vitro model, the latter result supports that intestinal absorption is a critical step for the oral administration of Coenzyme Q10 formulations.

Low-dose short synacthen test with salivary cortisol in patients with suspected central adrenal insufficiency.

CONTEXT: The low-dose short synacthen test (LDSST) is recommended for patients with suspected central adrenal insufficiency (AI) if their basal serum cortisol (F) levels are not indicative of an intact hypothalamic-pituitary-adrenal (HPA) axis. OBJECTIVE: To evaluate diagnostic threshold for salivary F before and 30 min after administering 1 µg of synacthen, performed before 09:30 h. DESIGN: A cross-sectional study from 2014 to 2020. SETTING: A tertiary referral university hospital. PATIENTS: In this study, 174 patients with suspected AI, 37 with central AI and 137 adrenal sufficient (AS), were included. MAIN OUTCOME MEASURE: The diagnostic accuracy (sensitivity (SE), specificity (SP)) of serum and salivary F levels measured, respectively, by chemiluminescence immunoassay and liquid chromatography-tandem mass spectrometry. RESULTS: Low basal serum or salivary F levels could predict AI. For the LDSST, the best ROC-calculated threshold for serum F to differentiate AI from AS was 427 nmol/L (SE 79%, SP 89%), serum F > 500 nmol/L reached SP 100%. A salivary F peak > 12.1 nmol/L after administering synacthen reached SE 95% and SP 84% for diagnosing central AI, indicating a conclusive reduction in the likelihood of AI. This ROC-calculated threshold for salivary F was similar to the 2.5th percentile of patients with a normal HPA axis, so it was considered sufficient to exclude AI. Considering AS those patients with salivary F > 12.1 nmol/L after LDSST, we could avoid unnecessary glucocorticoid treatment: 99/150 subjects (66%) had an inadequate serum F peak after synacthen, but salivary F was >12.1 nmol/L in 79 cases, who could, therefore, be considered AS. CONCLUSIONS: Salivary F levels > 12.1 nmol/L after synacthen administration can indicate an intact HPA axis in patients with an incomplete serum F response, avoiding the need to start glucocorticoid replacement treatment.

High sodium intake, glomerular hyperfiltration, and protein catabolism in patients with essential hypertension.

AIMS: A blood pressure (BP)-independent metabolic shift towards a catabolic state upon high sodium (Na+) diet, ultimately favouring body fluid preservation, has recently been described in pre-clinical controlled settings. We sought to investigate the real-life impact of high Na+ intake on measures of renal Na+/water handling and metabolic signatures, as surrogates for cardiovascular risk, in hypertensive patients. METHODS AND RESULTS: We analysed clinical and biochemical data from 766 consecutive patients with essential hypertension, collected at the time of screening for secondary causes. The systematic screening protocol included 24 h urine (24 h-u-) collection on usual diet and avoidance of renin-angiotensin-aldosterone system-confounding medications. Urinary 24 h-Na+ excretion, used to define classes of Na+ intake (low ≤2.3 g/day; medium 2.3-5 g/day; high >5 g/day), was an independent predictor of glomerular filtration rate after correction for age, sex, BP, BMI, aldosterone, and potassium excretion [P = 0.001; low: 94.1 (69.9-118.8) vs. high: 127.5 (108.3-147.8) mL/min/1.73 m2]. Renal Na+ and water handling diverged, with higher fractional excretion of Na+ and lower fractional excretion of water in those with evidence of high Na+ intake [FENa: low 0.39% (0.30-0.47) vs. high 0.81% (0.73-0.98), P < 0.001; FEwater: low 1.13% (0.73-1.72) vs. high 0.89% (0.69-1.12), P = 0.015]. Despite higher FENa, these patients showed higher absolute 24 h Na+ reabsorption and higher associated tubular energy expenditure, estimated by tubular Na+/ATP stoichiometry, accordingly [Δhigh-low = 18 (12-24) kcal/day, P < 0.001]. At non-targeted liquid chromatography/mass spectrometry plasma metabolomics in an unselected subcohort (n = 67), metabolites which were more abundant in high versus low Na+ intake (P < 0.05) mostly entailed intermediates or end products of protein catabolism/urea cycle. CONCLUSION: When exposed to high Na+ intake, kidneys dissociate Na+ and water handling. In hypertensive patients, this comes at the cost of higher glomerular filtration rate, increased tubular energy expenditure, and protein catabolism from endogenous (muscle) or excess exogenous (dietary) sources. Glomerular hyperfiltration and the metabolic shift may have broad implications on global cardiovascular risk independent of BP.

Interference of lipemia in samples for routine coagulation testing using a Sysmex CS-5100 coagulometer.

INTRODUCTION: Lipemia in samples can cause analytical errors in coagulation tests using photometric assays. To define the level of this interference, some studies assessed lipemic interferences by in vitro 'spiking' of different types of lipids obtaining interesting information, but spiked samples do not represent a real-world situation as natively lipemic samples do. METHODS: A total of 101 samples flagged as 'lipemic' by a Sysmex CS-5100 coagulometer were analyzed for PT, aPTT, fibrinogen Clauss assay, antithrombin activity, D-dimer concentration, before and after a double high-speed centrifugation procedure to reduce lipemic interference. We evaluated using Bland-Altman test if high-speed centrifugation and retesting are justified, considering that's a resource-consuming procedure; when a statistically significant difference was found, quality specification for imprecision was considered and compared to the observed delta. RESULTS: Statistically significant differences were found for PT, antithrombin activity and fibrinogen. Considering the Bland-Altman plot, fibrinogen results were split into two groups, and statistically significant difference was confirmed only for samples >2 g/L. CONCLUSIONS: For PT and antithrombin activity a mean percentual difference between the two determinations lower than within-subject biologic variation and one of the Fraser's quality specifications can be considered as a confounding 'noise' factor that is neither analytically nor clinically relevant. If the instrument determines a result on the first run, for PT, aPTT, D-dimer concentration and antithrombin activity tests, the double plasma high-speed centrifugation is unnecessary. It is instead necessary if fibrinogen >2 g/L or if the instrument cannot determine a result on the first run.