Journal Article

Serum metabolic biomarkers distinguish metabolically healthy peripherally obese from unhealthy centrally obese individuals

Zhang, Weidong, Cahill, Farrell, Gao, Xiang, Randell, Edward, Gulliver, Wayne, Sun, Guang, Zhai, Guangju, Wang, Yongbo, Pedram, Pardis

2016

Overview

Background Metabolic abnormalities are more associated with central obesity than peripheral obesity, but the underlying mechanisms are largely unknown. The present study was to identify serum metabolic biomarkers which distinguish metabolically unhealthy centrally obese (MUCO) from metabolically healthy peripherally obese (MHPO) individuals. Methods A two-stage case–control study design was employed. In the discovery stage, 20 individuals (10 MHPO and 10 MUCO) were included and in the following validation stage, 79 individuals (20 normal weight (NW), 30 MHPO, 29 MUCO) were utilized. Study groups were matched for age, sex, physical activity and total dietary calorie intake with MHPO and MUCO additionally matched for BMI. Metabolic abnormality was defined as: 1) HOMA-IR > 4.27 (90 th percentile), 2) high-density lipoprotein cholesterol < 1.03 mmol/L in men and < 1.30 mmol/L in women, 3) fasting blood glucose ≥ 5.6 mmol/L, and 4) waist circumference > 102 cm in men and > 88 cm in women. MUCO individuals had all of these abnormalities whereas MHPO and NW individuals had none of them. A targeted metabolomics approach was performed on fasting serum samples, which can simultaneously identify and quantify 186 metabolites. Results In the discovery stage, serum leucine, isoleucine, tyrosine, valine, phenylalanine, alpha-aminoadipic acid, methioninesulfoxide and propionylcarnitine were found to be significantly higher in MUCO, compared with MHPO group after multiple testing adjustment. Significant changes of five metabolites (leucine, isoleucine, valine, alpha-aminoadipic acid, propionylcarnitine) were confirmed in the validation stage. Conclusions Significantly higher levels of serum leucine, isoleucine, valine, alpha-aminoadipic acid, propionylcarnitine are characteristic of metabolically unhealthy centrally obese patients. The finding provides novel insights into the pathogenesis of metabolic abnormalities in obesity.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V
• Subject: Biological markers / biomarkers / blood glucose / blood serum / body mass index / Branched chain amino acids / Carnitine / case-control studies / Clinical Nutrition / energy intake / experimental design / Health aspects / high density lipoprotein cholesterol / isoleucine / leucine / Medicine / Medicine & Public Health / men / Metabolic Diseases / Metabolism / Metabolites / metabolomics / Nutrition / Obesity / pathogenesis / patients / phenylalanine / physical activity / Physiological aspects / tyrosine / valine / waist circumference / women