Elevated Serum Levels of Cysteine and Tyrosine: Early Biomarkers in Asymptomatic Adults at Increased Risk of Developing Metabolic Syndrome

Abstract

As there is effective intervention for delaying or preventing metabolic diseases, which are often present for years before becoming clinically apparent, novel biomarkers that would mark metabolic complications before the onset of metabolic disease should be identified. We investigated the role of fasting serum amino acids and their associations with inflammatory markers, adipokines, and metabolic syndrome (MetS) components in subjects prior to the onset of insulin resistance (IR). Anthropometric measurements, food records, adipokines, biochemical markers, and serum levels of amino acids were determined in 96 asymptomatic subjects aged 25–49 years divided into three groups according to the number of MetS components present. Cysteine and tyrosine were significantly higher already in group with one component of MetS present compared to subjects without MetS components. Serum amino acid levels correlated with markers of inflammation and adipokines. Alanine and glycine explained 10% of insulin resistance variability. The role of tyrosine and cysteine, that were higher already with 1 component of MetS present, should be further investigated as they might point to future insulin disturbances.

Total Serum Antioxidant Capacity in Healthy Normal Weight and Asymptomatic Overweight Adults

“…Therefore, serum Cys imbalances correlate with markers of metabolic dysfunction. We found significant positive correlations between serum Cys and HOMA-IR, CRP, TNF-α, WC and body shape index in recent work [28], and here we present a significant positive correlation between Cys and TAC.…”

Early Programming of Obesity Throughout the Life Course: A Metabolomics Perspective

“…In contrast to several adult studies which related BCAA to IR and obesity [42,46,47] , the results in children are rather inconsistent. Some studies found BCAA or BCAA-associated factors to be related with obesity [48][49][50][51][52] or even predictive for later IR [52] or triglyceride levels [53] in childhood.…”

“…Both studies showing beneficial effects of BCAA were published by the same group and conducted in the same collective. The authors state that the contrast of their beneficial findings of BCAA in adolescents and other studies showing adverse associations in adults, may be due to the adaptive (mitochondrial) mechanisms which are still present in youth but vanish with the progression of obesity [42,46,47] .…”

Excited-state intramolecular proton-transfer (ESIPT) based fluorescence sensors and imaging agents

“…However, abnormal levels of Cys are associated with a number of health problems, including cancer, neurological disorders, and motor neuron diseases. [123][124][125][126][127] Therefore, the development of an analytical tool for the detection of Cys over other thiol-containing biologically important species is highly desirable.…”