Reduced plasma glycine concentration in healthy and chronically diseased older adults: a marker of visceral adiposity?

Background: Previous studies have shown that a reduced plasma concentration of the amino acid glycine (Gly) is associated with intra-abdominal obesity, but the mechanism remains unclear.

Objectives: This study aimed to investigate whether lower plasma Gly concentrations in older adults are independently associated with (visceral) adiposity, age, sex, presence of chronic disease, and glucose intolerance, and whether they are caused by a reduced Gly whole-body production (WBP) and/or increased Gly disposal capacity.

Methods: We studied 102 older adults (47 males/55 females, 68.

Females have a different metabolic response to critical illness, measured by comprehensive amino acid flux analysis.

Background: The trajectory from healthy to critical illness is influenced by numerous factors, including metabolism, which differs substantially between males and females. Whole body protein breakdown is substantially increased in critically ill patients, but it remains unclear whether there are sex differences that could explain the different health outcomes. Hence, we performed a secondary analysis of a study, where we used a novel pulse isotope method in critically ill and matched healthy males and females.

Obesity- and sex-related metabolism of arginine and nitric oxide in adults.

Background: There is growing interest in the supplementation of arginine (Arg) and citrulline (Cit) in obesity due to their potential anti-obesogenic and anti-inflammatory properties. However, there is no consensus on the metabolic changes in Arg kinetics in obesity.

Objectives: This exploratory cross-sectional study aimed to investigate the association between obesity, sex, and sex-by-obesity interaction on whole-body Arg kinetics in a large group of human subjects.

Discordance between postprandial plasma glucose measurement and continuous glucose monitoring.

Background: There has been growing interest in studying postprandial glucose responses using continuous glucose monitoring (CGM) in nondiabetic individuals. Accurate measurement of glucose responses to meals can facilitate applications such as precision nutrition and early detection of diabetes.

Objectives: We aimed to quantify the discordance between simultaneous postprandial glucose measurements made using plasma and CGM.

Comprehensive metabolic amino acid flux analysis in critically ill patients.

Amino acid (AA) metabolism is severely disturbed in critically ill ICU patients. To be able to make a more scientifically based decision on the type of protein or AA nutrition to deliver in ICU patients, comprehensive AA phenotyping with measurements of plasma concentrations and whole body production (WBP) is needed. Therefore, we studied ICU patients and matched control subjects using a novel pulse isotope method to obtain in-depth metabolic analysis.