Accuracy in 24-hour Urine Collection at a Tertiary Center

Influence of sex and functional status on the value of serum steroid profiling in discriminating adrenocortical carcinoma from adrenocortical adenoma

Background

It is challenging for clinicians to distinguish adrenocortical carcinoma (ACC) from benign adrenocortical adenomas (ACA) in their early stages. This study explored the value of serum steroid profiling as a complementary biomarker for malignancy diagnosis of ACC other than diameter and explored the influence of sex and functional status.

Methods

In this retrospective study, a matched cohort of patients diagnosed with either ACC or ACA based on histopathology was meticulously paired in a 1:1 ratio according to sex, age, and functional status. Eight serum steroids including 11-deoxycortisol, 11-deoxycorticosterone, progesterone, androstenedione, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), 17-hydroxyprogesterone, and estradiol, were quantified by liquid chromatography tandem mass spectrometry. We conducted a comparative analysis of the clinical characteristics and serum steroid profiles of patients with ACC and ACA, with further subgroup analysis.

Results

The study included 31 patients with ACC and 31 matched patients with ACA. Patients with ACC exhibited significantly larger tumor diameters, lower body mass index (BMI), and higher levels of 11-deoxycortisol, progesterone, and androstenedione than those with ACA. 11-deoxycortisol was the only valuable index for discriminating ACC from ACA, regardless of functional status and sex. Progesterone, DHEA, and DHEAS levels were higher in the functional ACC group than in the non-functional ACC group. Female ACC patients, especially in postmenopausal female exhibited higher levels of androstenedione than male patients. The area under the curve of tumor diameter, 11-deoxycortisol, and BMI was 0.947 (95% CI 0.889-1.000), with a sensitivity of 96.8% and specificity of 90.3%.

Conclusion

Serum steroid profiling serves as a helpful discriminative marker for ACC and ACA, with 11-deoxycortisol being the most valuable marker. For other steroid hormones, consideration of sex differences and functional status is crucial.

The effect of a low renal acid load diet on blood pressure, lipid profile, and blood glucose indices in patients with type 2 diabetes: a randomized clinical trial

BACKGROUND

Observational studies have reported that dietary renal acid load has an important role in insulin resistance and metabolic factors. The aim of the present study was to assess the effect of a low renal acid load diet (LRALD) on blood pressure, lipid profile, and blood glucose indices in patients with type 2 diabetes.

METHODS

In this parallel randomized clinical trial, 80 patients with type 2 diabetes were randomly assigned to the LRALD (n = 40) or control (n = 40) groups, for 12 weeks. Both groups received a balanced diet and a list of nutritional recommendations based on healthy eating behaviors. In the LRALD group, food items with low renal acid load were prescribed. Primary outcomes including: fasting blood glucose (FBG), hemoglobin A1c (HbA1c), fasting serum insulin, quantitative insulin sensitivity check index (QUICKI), homeostatic model assessment for insulin resistance (HOMA) and secondary outcomes including: weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), and high-density lipoprotein (HDL). were measured at baseline and end of the study. The present trial was registered at IRCT.ir (IRCT20130903014551N5).

RESULTS

Seventy subjects completed the study (n = 35 in control group and n = 36 in LRALD). Weight (P < 0.001), body mass index (P < 0.001), FBG (P < 0.001), HbA1c (P < 0.001), SBP (P = 0.004), and TG (P = 0.049) were reduced and HDL (P = 0.002) was increased in both groups, compared with baseline. After adjusting for baseline values, DBP (P = 0.047) was reduced in the LRALD group compared with control group. Results had no changes after using intention to treat analysis.

CONCLUSION

A LRALD may decrease DBP in type 2 diabetic patients. However, it elicited no significant effect on lipid profile compared with a healthy diet.

TRIAL REGISTRATION

This randomized clinical trial was registered at IRCT.ir (IRCT20130903014551N5).

The ABCs of personalized incremental dialysis start, Le Mans style

Thrice weekly hemodialysis (HD) is considered the standard of care for patients with end-stage chronic kidney disease (CKD) on extracorporeal renal replacement therapy. However, recent evidence has shown that up to one third of patients start dialysis with a residual kidney function that could allow a reduced frequency/dialysis dose. Interest towards HD schedules other than thrice weekly and the lessons learned from peritoneal dialysis, in addition to growing attention to patients' quality of life, have promoted renewed attention towards incremental HD (iHD). iHD comprises once and twice weekly schedules, makes it possible to soften the "dialysis shock" at the inception of therapy and is patient-friendly. Moreover, it might contribute to preserving residual kidney function longer. Nevertheless, iHD is performed differently in different settings and no guidelines exist on this subject. Taking advantage of the experience accrued with regard to the treatment of advanced CKD both in the outpatient clinic and in the dialysis unit in Le Mans, where two thirds of incident HD patients start in an incremental way, we aimed to present the practical aspects of iHD and discuss its advantages and drawbacks.

Use of Salivary Iodine Concentrations to Estimate the Iodine Status of Adults in Clinical Practice

BACKGROUND

Measurement of the 24-h urinary iodine concentration or urinary iodine excretion (UIE) is the gold standard to determine iodine status; however, this method is inconvenient. The use of salivary iodine could be a possible alternative since salivary glands express the sodium-iodine symporter.

OBJECTIVES

We aimed to establish the correlation between the salivary iodine secretion and UIE, to evaluate the clinical applicability of the iodine saliva measurement.

METHODS

We collected 24-h urine and saliva samples from 40 participants ≥18 y: 20 healthy volunteers with no specific diet (group 1), 10 patients with differentiated thyroid cancer with a low dietary intake (<50 μg/d, group 2), and 10 patients with a high iodine status as the result of the use of amiodarone (group 3). Urinary and salivary iodine were measured using a validated inductively coupled plasma MS method. To correct for differences in water content, the salivary iodine concentration (SIC) was corrected for salivary protein and urea concentrations (SI/SP and SI/SU, respectively). The intra- and inter-individual CVs were calculated, and the Kruskal-Wallis test and Spearman's correlation were used.

RESULTS

The intra-individual CVs for SIC, SI/SP, and SI/SU were 63.8%, 37.7%, and 26.9%, respectively. The inter-individual CVs for SIC, SI/SP, and SI/SU were 77.5%, 41.6% and 47.0%, respectively. We found significant differences (P < 0.01) in urinary and salivary iodine concentrations between all groups [the 24-h UIE values were 176 μg/d (IQR, 96.1-213 μg/d), 26.0 μg/d (IQR, 22.0-37.0 μg/d), and 10.0*103 μg/d (IQR, 7.57*103-11.4*103 μg/d) in groups 1-3, respectively; the SIC values were 136 μg/L (IQR, 86.3-308 μg/L), 71.5 μg/L (IQR, 29.5-94.5 μg/L), and 14.3*103 μg/L (IQR, 10.6*103-25.6*103 μg/L) in groups 1-3, respectively]. Correlations between the 24-h UIE and SIC, SI/SP, and SI/SU values were strong (ρ = 0.80, ρ = 0.90, and ρ = 0.86, respectively; P < 0.01).

CONCLUSIONS

Strong correlations were found between salivary and urinary iodine in adults with different daily iodine intakes. A salivary iodine measurement can be performed to assess the total iodine body pool, with the recommendation to correct for salivary protein or urea.

Urinary extracellular vesicles: A position paper by the Urine Task Force of the International Society for Extracellular Vesicles

Urine is commonly used for clinical diagnosis and biomedical research. The discovery of extracellular vesicles (EV) in urine opened a new fast-growing scientific field. In the last decade urinary extracellular vesicles (uEVs) were shown to mirror molecular processes as well as physiological and pathological conditions in kidney, urothelial and prostate tissue. Therefore, several methods to isolate and characterize uEVs have been developed. However, methodological aspects of EV separation and analysis, including normalization of results, need further optimization and standardization to foster scientific advances in uEV research and a subsequent successful translation into clinical practice. This position paper is written by the Urine Task Force of the Rigor and Standardization Subcommittee of ISEV consisting of nephrologists, urologists, cardiologists and biologists with active experience in uEV research. Our aim is to present the state of the art and identify challenges and gaps in current uEV-based analyses for clinical applications. Finally, recommendations for improved rigor, reproducibility and interoperability in uEV research are provided in order to facilitate advances in the field.

False elevations in urinary metanephrines: under-recognised pitfall with 24-hour urinary volume collection

One pitfall in 24-hour urine collection is the input of incorrect urinary volume by the reference laboratory. This may lead to an incorrect diagnosis of pheochromocytoma or paraganglioma. A 48-year-old African-American woman was seen in the clinic for an elevated 24-hour urine metanephrine screen during workup for secondary hypertension. Urine volume was found to be incorrectly inputted by the lab as 9750 mL rather than 975 mL. The urinary metanephrines were then recalculated and the 24-hour urinary metanephrines resulted within normal limits. This case highlights this unique and potentially under-recognised error in testing with 24-hour urine volume collection.

Steroid profiling in the diagnosis of mild and overt Cushing's syndrome

In this review, we provide a comprehensive overview of the utility of steroid profiling for diagnosis of management of overt Cushing syndrome and mild autonomous cortisol secretion. A diagnosis of Cushing syndrome is made through a multistep process that includes confirmation of endogenous hypercortisolism, followed by determination of its cause. Steroid metabolomic testing applied to serum or urine steroids and their metabolites can provide additional and novel insights into alterations of steroid biosynthesis and metabolism and its causes. In particular, increased availability and advances in mass spectrometry-based steroid analysis, coupled with machine learning-based algorithms, have facilitated the development of tailored diagnostic and subtyping approaches for autonomous cortisol secretion and might be useful for detecting low grade autonomous glucocorticoid secretion and in predicting and monitoring of disease severity and associated comorbidities.

Correlation between urine ACR and 24-h proteinuria in a real-world cohort of systemic AL amyloidosis patients

A 24-h urine protein collection (24hUP), the gold standard for measuring albuminuria in systemic AL amyloidosis, is cumbersome and inaccurate. We retrospectively reviewed 575 patients with systemic AL amyloidosis to assess the correlation between a urine albumin to creatinine ratio (uACR) and the 24hUP. The uACR correlated strongly with 24hUP at diagnosis (Pearson’s r = 0.87, 95% CI 0.83–0.90) and during the disease course (Pearson’s r = 0.88, 95% CI 0.86–0.90). A uACR ≥300 mg/g estimated a 24hUP ≥ 500 mg with a sensitivity of 92% and specificity of 97% (area under the receiver operating curve = 0.938, 95% CI 0.919–0.957). A uACR cutoff of 3600 mg/g best predicted a 24hUP > 5000 g (sensitivity 93%, specificity 94%), and renal stage at diagnosis was strongly concordant using either 24hUP or uACR as the proteinuria measure (k = 0.823, 95% CI 0.728–0.919). In patients with serial urine collections, a > 30% decrease in uACR predicted a > 30% decrease in 24hUP with a sensitivity of 94%. In conclusion, the uACR is a reliable and convenient method for ruling out proteinuria >500 mg per day, prognosticating renal outcomes, and assessing renal response to therapy. Further studies are needed to validate the uACR cutoffs proposed in this study.

Comparison of CYP2C9 Activity in Ethiopian and Non-Ethiopian Jews Using Phenytoin as a Probe

The pharmacokinetics of CYP2C9 substrates is characterized by substantial interethnic variability. The objective of the study was to compare CYP2C9 activity by using Phenytoin Metabolic Ratio (PMR) between Ethiopian and non-Ethiopian Jews. PMR was derived from the ratio of p-HPPH in 24 h urine collection to plasma phenytoin, 12 h (PMR24/12) or 24 h (PMR24/24) after the administration of 300 mg phenytoin. Analysis of CYP2C9*2, *3, *5, *6, *8, and *11 was carried by direct sequencing. PMR was significantly correlated with CYP2C9 genotype in both groups (p < 0.002). Mean PMR values were similar among Ethiopians and non-Ethiopians despite the fact that the fraction of non-carriers of CYP2C9 variant alleles was significantly different (85 vs. 53%, respectively, p < 0.001). However, among non-carriers of CYP2C9*2, *3, *5, *6, *8, and *11 variant alleles, PMR24/12 and PMR24/24 values were 30 and 34% greater respectively in the non-Ethiopians group (p < 0.001). In conclusion-CYP2C9 activity as measured by PMR is similar in Ethiopian and non-Ethiopian Jews. However, among non-carriers of CYP2C9 variant alleles accounting for 85% of Ethiopian Jews, CYP2C9 activity is decreased by approximately one third as compared with non-Ethiopian Jews. Unique genetic CYP2C9 polymorphisms occurring only in Ethiopians may account for this difference.

Impact of Demographic Factors and Systemic Disease on Urinary Stone Risk Parameters Amongst Stone Formers

This article examines via multivariate analysis the associations between demographic factors and systemic diseases on stone risk parameters in a stone-forming population. A retrospective chart review of adult stone formers who completed 24-hour urine collections from April 2004 through August 2015 was performed. Data was collected on age, sex, race, body mass index (BMI), and diagnoses of diabetes and hypertension. CT imaging and renal/abdominal ultrasonography (within ± 66 mo) were reviewed for diagnosis of fatty liver disease. Statistical analysis included Pearson and Spearman correlation analysis, and linear and logistic regression analyses, both univariate and multivariate. Five hundred eighty-nine patients were included. Numerous urinary parameters were significant in association with demographic factors or systemic diseases in a multivariate analysis. Older age was associated with decreased calcium (Ca) excretion (P = 0.0214), supersaturation of calcium oxalate (SSCaOx; P = 0.0262), supersaturation of calcium phosphate (SSCaP; P < 0.0001), and urinary pH (P = 0.0201). Men excreted more Ca (P = 0.0015) and oxalate (Ox; P = 0.0010), had lower urine pH (P = 0.0269), and higher supersaturation of uric acid (SSUA; P < 0.0001) than women. Blacks had lower urine volume (P = 0.0023), less Ca excretion (P = 0.0142), less Ox excretion (P = 0.0074), and higher SSUA (P = 0.0049). Diabetes was associated with more Ox excretion (P < 0.0001), lower SSCaP (P = 0.0068), and lower urinary pH (P = 0.0153). There were positive correlations between BMI and Ca excretion (P = 0.0386), BMI and Ox excretion (P = 0.0177), and BMI and SSUA (P = 0.0045). These results demonstrate that demographic factors and systemic disease are independently associated with numerous risk factors for kidney stones. The mechanisms responsible for these associations and disparities (racial differences) need to be further elucidated.