Circulating glutamate level as a potential biomarker for abdominal obesity and metabolic risk

Nutr Metab Cardiovasc Dis. 2019 Dec;29(12):1353-1360. doi: 10.1016/j.numecd.2019.08.015. Epub 2019 Aug 31.

Abstract

Background and aim: Circulating level of glutamate, a by-product of the catabolism of branched-chain amino acids, has been positively correlated with visceral adipose tissue accumulation and waist circumference (WC). The aim of the present study was to assess the potential of using glutamate level to identify individuals with abdominal obesity and a high cardiometabolic risk.

Methods and results: The study sample included 99 men and 99 women. Fasting serum glutamate was measured using the Biocrates p180 kit. Anthropometric and metabolic variables were used to identify individuals with abdominal obesity (WC ≥ 95 cm in both sexes), the hypertriglyceridemic waist (HTW) phenotype and the metabolic syndrome (MetS). Mean (±SD) age was 34.1 ± 10.1 years, mean BMI was 29.0 ± 6.2 kg/m2 and mean WC was 92.7 ± 16.5 cm. Glutamate was strongly correlated with WC (r = 0.66 for men; r = 0.76 for women, both p < 0.0001) and multiple markers of metabolic dysfunction, particularly fasting triglyceride level (r = 0.59 for men; r = 0.57 for women, both p < 0.0001), HDL-cholesterol level (r = -0.45, p < 0.0001 in both sexes) and the HOMA-IR index (r = 0.65 for men; r = 0.60 for women, both p < 0.0001). Logistic regressions showed that glutamate had an excellent accuracy to identify individuals with abdominal obesity (ROC_AUC: 0.90 for both sexes), a good accuracy to identify those with the HTW phenotype (ROC_AUC: 0.82 for men; 0.85 for women) and fair-to-good accuracy for the MetS (ROC_AUC: 0.78 for men; 0.89 for women).

Conclusion: Glutamate level may represent an interesting potential biomarker of abdominal obesity and metabolic risk.

Keywords: Branched-chain amino acid; Glutamate; Hypertriglyceridemic waist; Men; Metabolic syndrome; Metabolomics; Women.

MeSH terms

  • Adiposity
  • Adolescent
  • Adult
  • Biomarkers / blood
  • Cholesterol, HDL / blood
  • Cross-Sectional Studies
  • Fasting / blood
  • Female
  • Glutamic Acid / blood*
  • Humans
  • Male
  • Metabolic Syndrome / blood*
  • Metabolic Syndrome / diagnosis
  • Metabolic Syndrome / etiology
  • Middle Aged
  • Obesity, Abdominal / blood*
  • Obesity, Abdominal / complications
  • Obesity, Abdominal / diagnosis
  • Predictive Value of Tests
  • Reproducibility of Results
  • Risk Assessment
  • Risk Factors
  • Sex Factors
  • Triglycerides / blood
  • Up-Regulation
  • Waist Circumference
  • Young Adult

Substances

  • Biomarkers
  • Cholesterol, HDL
  • Triglycerides
  • Glutamic Acid