Plasma Free Fatty Acids Metabolic Profile with LC-MS and Appetite-Related Hormones in South Asian and White European Men in Relation to Adiposity, Physical Activity and Cardiorespiratory Fitness: A Cross-Sectional Study

• Main Authors: Simone Benedetti, Naser F. Al-Tannak, Mansour Alzharani, Hannah J. Moir, David J. Stensel, Alice E. Thackray, Declan P. Naughton, Mehmet T. Dorak, Owen Spendiff, Natasha Hill, David G. Watson, Judith Allgrove
• Format: Article
• Language: English
• Published: MDPI AG 2019-04-01
• Series: Metabolites
• Subjects: metabolomics; free fatty acids; cardiovascular disease; Type 2 diabetes; South Asian; physical activity; cardiorespiratory fitness; inflammation; appetite hormones; metabolic markers
• Online Access: https://www.mdpi.com/2218-1989/9/4/71
• ISSN: 2218-1989

South Asians have a greater cardiovascular disease (CVD) and type 2 diabetes (T2D) risk than white Europeans, but the mechanisms are poorly understood. This study examined ethnic differences in free fatty acids (FFAs) metabolic profile (assessed using liquid chromatography-mass spectrometry), appetite-related hormones and traditional CVD and T2D risk markers in blood samples collected from 16 South Asian and 16 white European men and explored associations with body composition, objectively-measured physical activity and cardiorespiratory fitness. South Asians exhibited higher concentrations of five FFAs (laurate, myristate, palmitate, linolenic, linoleate; <i>p</i> &#8804; 0.040), lower acylated ghrelin (ES = 1.00, <i>p</i> = 0.008) and higher leptin (ES = 1.11, <i>p</i> = 0.004) than white Europeans; total peptide YY was similar between groups (<i>p</i> = 0.381). South Asians exhibited elevated fasting insulin, C-reactive protein, interleukin-6, triacylglycerol and ratio of total cholesterol to high-density lipoprotein cholesterol (HDL-C) and lower fasting HDL-C (all ES &#8805; 0.74, <i>p</i> &#8804; 0.053). Controlling for body fat percentage (assessed using air displacement plethysmography) attenuated these differences. Despite similar habitual moderate-to-vigorous physical activity (ES = 0.18, <i>p</i> = 0.675), <inline-formula> <math display="inline"> <semantics> <mrow> <mover> <mi mathvariant="normal">V</mi> <mo>˙</mo> </mover> </mrow> </semantics> </math> </inline-formula>O_2max was lower in South Asians (ES = 1.36, <i>p</i> = 0.001). Circulating FFAs in South Asians were positively correlated with body fat percentage (<i>r</i>² = 0.92), body mass (<i>r</i>² = 0.86) and AUC glucose (<i>r</i>² = 0.89) whereas in white Europeans FFAs were negatively correlated with total step counts (<i>r</i>² = 0.96). In conclusion, South Asians exhibited a different FFA profile, lower ghrelin, higher leptin, impaired CVD and T2D risk markers and lower cardiorespiratory fitness than white Europeans.