Racial differences in in vivo adipose lipid kinetics in humans

Abstract

The storage of lipids in the form of triglycerides (TG) and the de novo synthesis (lipogenesis) of fatty acids from non-lipid precursors (DNL) are important functions of adipose tissue (AT) that influence whole-body metabolism. Yet, few studies have reported in vivo estimates of adipose lipid kinetics in humans. Fifty-two women with obesity (27 AfricanAmerican; 25 Caucasian; 29.7 ± 5.5 years; BMI 32.2 ± 2.8 kg/m 2 ; 44.3 ± 4.0 % body fat) were enrolled in the study. In vivo synthesis (or replacement) of triglycerides (f TG ), as well as the synthesis of the fatty acid palmitate (a measure of adipose de novo lipogenesis (f DNL )) were assessed using an 8-week incorporation of deuterium ( 2 H) into lipids (glycerol and palmitate moieties of TGs) in subcutaneous abdominal (scABD) and femoral (scFEM) AT. We report for the first time significant race differences in both TG synthesis and absolute DNL, with Caucasians having higher f TG and f DNL as compared to AfricanAmericans. The DNL contribution to newly synthesized TG (corrected f DNL ) was not different between races. Interestingly, our findings also show that the scFEM adipose depot had higher TG replacement rates relative to the scABD. Finally, the replacement rate of TG (f TG ) was negatively correlated with changes in body weight over the 8-week labeling period. Our results provide the first evidence that in vivo TG replacement (synthesis and breakdown) rates differ by ethnicity. In addition, TG turnover varies by depot location in humans, implying an increased capacity for TG storage and higher lipolytic activity in the scFEM AT.ClinicalTrials.gov Identifier-NCT01748994

Hyperinsulinemia: An Early Indicator of Metabolic Dysfunction

“…Black women with obesity have a lower rate of TG turnover in adipose tissue and lower rates of adipose de novo lipogenesis (DNL) compared with white women with obesity [151]. DNL was originally thought to make only minor contributions to hepatic and adipose tissue lipid contents based on small studies in lean subjects [152].…”

The association of prostatic lipids with progression, racial disparity and discovery of biomarkers in prostate cancer

“…This study first revealed that prostatic lipid profiling are different between AA and CA patients with PCa. While the mechanism underlying racial difference in prostatic lipid composition has not fully understood, studies suggest that AA individuals, as compared with CA individuals have lower serum TG concentration [36] , lower rate in de novo synthesis (lipogenesis) of fatty acids from non-lipid precursors [37] , and greater risk for recurrence of PCa with elevated serum level of cholesterol [38] . Our data would add new avenues to study the association of racial difference in prostatic lipid composition with all aspects of racial disparity of PCa.…”

Investigation of Plasma Metabolic and Lipidomic Characteristics of a Chinese Cohort and a Pilot Study of Renal Cell Carcinoma Biomarker

“…Large molecular lipids, such as TGs and DGs, were found to be gender-associated in whites [6, 7], but they were not significant in Chinese or Japanese. It was reported that TGs synthesis and lipid metabolism showed racial differences, with Caucasians having higher TG synthesis as compared with African-Americans ( 35 ). Additionally, preferences for high-lipid diets, such as hamburgers, among white people could partly contribute to these changes.…”