The effect of phlebotomy and placement of an intravenous catheter on plasma catecholamine and serum copeptin concentrations.

Objectives: Limited data are available on the hormonal response of children to venepuncture or intravenous cannulation (IVC). Catecholamines [epinephrine (E) and norepinephrine (NE)] have been traditionally recognized as stress hormones. Copeptin, the carboxyl-terminus of the arginine vasopressin (AVP) precursor peptide, is also a known marker for stressful stimuli, including myocardial infarction, critical illness, and sepsis.

Fasting intact insulin by mass spectrometry is associated with metabolic dysfunction-associated steatotic liver disease in youth.

Background: Fasting intact insulin concentrations can predict metabolic dysfunction-associated steatotic liver disease (MASLD) in adults without diabetes; however, research in youth is limited. We sought to determine whether fasting intact insulin, measured by liquid chromatography-tandem mass spectrometry, is associated with MASLD in children.

Methods: This retrospective cross-sectional analysis used data and samples from children who participated in studies across 3 universities between 2014 and 2022.

Biomarkers of glucose-insulin homeostasis and incident type 2 diabetes and cardiovascular disease: results from the Vitamin D and Omega-3 trial.

Background: Dysglycemia and insulin resistance increase type 2 diabetes (T2D) and cardiovascular disease (CVD) risk, yet associations with specific glucose-insulin homeostatic biomarkers have been inconsistent. Vitamin D and marine omega-3 fatty acids (n-3 FA) may improve insulin resistance. We sought to examine the association between baseline levels of insulin, C-peptide, HbA1c, and a novel insulin resistance score (IRS) with incident cardiometabolic diseases, and whether randomized vitamin D or n-3 FA modify these associations.

Comparing ARR Versus Suppressed PRA as Screening Tests for Primary Aldosteronism.

Background: In many practices, the screening for primary aldosteronism relies on a single-blood draw for plasma aldosterone concentration (PAC) and plasma renin activity (PRA) to establish an aldosterone-to-renin ratio (ARR). ARR levels vary between expert centers and repeated assays in the same individual, emphasizing the potential variability of this screening approach. A suppressed PRA to <1 ng/mL per h has been proposed as an alternative test to the ARR.

Associations of an HDL apolipoproteomic index with cardiometabolic risk factors before and after exercise training in the HERITAGE Family Study.

Background And Aims: Previous studies have derived and validated an HDL apolipoproteomic score (pCAD) that predicts coronary artery disease (CAD) risk. However, the associations between pCAD and markers of cardiometabolic health in healthy adults are not known, nor are the effects of regular exercise on pCAD.

Methods: A total of 641 physically inactive adults free of cardiovascular disease from the HERITAGE Family Study completed 20 weeks of exercise training.

Copeptin Stimulation by Combined Intravenous Arginine and Oral LevoDopa/Carbidopa in Healthy Short Children and Children with the Polyuria-Polydipsia Syndrome.

Introduction: Stimulated copeptin may provide an alternative to water deprivation testing (WDT) in the evaluation of polyuria-polydipsia syndrome (PPS). Though best studied, arginine stimulation alone produces a modest copeptin response in children. We investigated the effectiveness of the arginine + LevoDopa/Carbidopa stimulation test (ALD-ST) for copeptin.

Glucose ingestion does not lower testosterone concentrations in men on testosterone therapy.

Oral calorie intake causes an acute and transient decline in serum testosterone concentrations. It is not known whether this decline occurs in men on testosterone therapy. In this study, we evaluated the change in testosterone concentrations following oral glucose ingestion in hypogonadal men before and after treatment with testosterone therapy.

Predictors of lack of glycemic control in persons with type 2 diabetes.

Background: Professional guidelines recommend an HbA1c < 7% for most people with diabetes and < 8.5% for those with relaxed glycemic goals. However, many people with type 2 diabetes mellitus (T2DM) are unable to achieve the desired HbA1c goal.

Very elevated serum copeptin concentrations occur in a subset of healthy children in the minutes after phlebotomy.

Objectives: Although AVP and its surrogate, copeptin, are mainly regulated by osmotic and volume stimuli, their secretion is also elicited by stress and growth hormone (GH) stimulating agents. The aim of this report is to describe unusual patterns of copeptin response in a subset of children undergoing GH stimulation tests (GH-ST).

Methods: We conducted a secondary analysis of a cohort of 93 healthy short children with no polydipsia, polyuria or fluid/electrolyte abnormalities, undergoing GH-ST with intravenous arginine, insulin, oral clonidine, or L-Dopa/carbidopa in various combinations.

Proteomic Determinants of Variation in Cholesterol Efflux: Observations from the Dallas Heart Study.

High-density lipoproteins (HDLs) are promising targets for predicting and treating atherosclerotic cardiovascular disease (ASCVD), as they mediate removal of excess cholesterol from lipid-laden macrophages that accumulate in the vasculature. This functional property of HDLs, termed cholesterol efflux capacity (CEC), is inversely associated with ASCVD. HDLs are compositionally diverse, associating with >250 different proteins, but their relative contribution to CEC remains poorly understood.

Prognostic value of insulin resistance and hyperglycemia biomarkers for long-term risks of cardiometabolic outcomes.

We found that individuals in the top tertile of HOMA-IR and with HbA1c-defined prediabetes have elevated risk of cardiometabolic outcomes.

Insulin resistance probability score and incident cardiovascular disease.

Background: Insulin resistance (IR) is associated with cardiovascular disease (CVD). However, insulin immunoassay variability and scarce research of the elderly have hindered the adoption of IR assessment for CVD prevention. We asked whether the probability of having IR [p(IR)]-derived from insulin and C-peptide mass-spectrometry assays-was associated with CVD in the elderly.

The relationship between insulin resistance and ion mobility lipoprotein fractions.

Objective: Insulin resistance (IR) increases risk of type 2 diabetes and atherosclerotic cardiovascular disease and is associated with lipid and lipoprotein abnormalities including high triglycerides (TG) and low high-density lipoprotein cholesterol (HDL-C). Lipoprotein size and lipoprotein subfractions (LS) have also been used to assist in identifying persons with IR. Associations of LS and IR have not been validated using both direct measures of IR and direct measures of LS.

Combined Arginine and Insulin Stimulation Elicits a Robust and Consistent Copeptin Response in Short Children.

Introduction: Copeptin, co-secreted with arginine vasopressin, is regulated by osmotic and volume stimuli but also responds to intravenous arginine and insulin-induced hypoglycemia. The serum copeptin response to the latter agents has been studied in adults but only to a limited extent in children. The objective of this study was to describe the copeptin response to combined arginine and insulin in children with normal posterior pituitary function.

Differences in HDL-Bound Apolipoproteins in Patients With Advanced Liver Fibrosis Due to Nonalcoholic Fatty Liver Disease.

Context: The mechanisms leading to increased cardiovascular disease in patients with nonalcoholic fatty liver disease (NAFLD) and advanced liver fibrosis remain incompletely understood.

Objective: This study assessed HDL-bound proteins in patients with NAFLD with or without advanced fibrosis.

Methods: This cross-sectional study at a university hospital included 185 patients with or without type 2 diabetes (T2D).

Quantitation of Free Thyroxine by Equilibrium Dialysis and Liquid Chromatography-Tandem Mass Spectrometry.

A method for free thyroxine measurement in human serum using equilibrium dialysis followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) is described. Free thyroxine in serum is first separated from protein-bound thyroxine by equilibrium dialysis and then measured by LC-MS/MS.

High prevalence of subnormal testosterone in obese adolescent males: reversal with bariatric surgery.

Objective: Obesity in adolescent males is associated with the lowering of total and free testosterone concentrations. Weight loss may increase testosterone concentrations.

Design And Methods: We evaluated the changes in sex hormones following bariatric surgery in 34 males (age range: 14.

Antibody-Free Quantification of Serum Chromogranin A by Targeted Mass Spectrometry.

Background: Chromogranin A (CgA) is a 48 kDa protein that serves as a diagnostically sensitive, but nonspecific, serum biomarker for neuroendocrine tumors. Immunoassays for CgA are not standardized and have a narrow dynamic range, which requires dilution of concentrated specimens. We developed and validated an antibody-free, liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method for CgA without these limitations.