Year: 2018
Type: article
Abstract: The storage of lipids in the form of triglycerides (TGs) and the de novo synthesis (lipogenesis) of fatty acids from nonlipid precursors [de novo lipogenesis (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 African-American and 25 Caucasian; 29.7 ± 5.5 years; BMI 32.2 ± 2.8 kg/m2; 44.3 ± 4.0% body fat) were enrolled in the study. In vivo synthesis (or replacement) of TGs (fTG) as well as the synthesis of the fatty acid, palmitate [a measure of adipose DNL (fDNL)], were assessed using an 8 week incorporation of deuterium into lipids (glycerol and palmitate moieties of TGs) in subcutaneous abdominal (scABD) and subcutaneous femoral (scFEM) AT. We report, for the first time, significant race differences in both TG synthesis and absolute DNL, with Caucasians having higher fTG and fDNL as compared with African-Americans. The DNL contribution to newly synthesized TG (corrected fDNL) 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 (fTG) 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. The storage of lipids in the form of triglycerides (TGs) and the de novo synthesis (lipogenesis) of fatty acids from nonlipid precursors [de novo lipogenesis (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 African-American and 25 Caucasian; 29.7 ± 5.5 years; BMI 32.2 ± 2.8 kg/m2; 44.3 ± 4.0% body fat) were enrolled in the study. In vivo synthesis (or replacement) of TGs (fTG) as well as the synthesis of the fatty acid, palmitate [a measure of adipose DNL (fDNL)], were assessed using an 8 week incorporation of deuterium into lipids (glycerol and palmitate moieties of TGs) in subcutaneous abdominal (scABD) and subcutaneous femoral (scFEM) AT. We report, for the first time, significant race differences in both TG synthesis and absolute DNL, with Caucasians having higher fTG and fDNL as compared with African-Americans. The DNL contribution to newly synthesized TG (corrected fDNL) 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 (fTG) 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. Adipose tissue (AT) is a vital organ that is a significant regulator of whole-body energy metabolism and energy balance (1.Danforth Jr., E. Failure of adipocyte differentiation causes type II diabetes mellitus?.Nat. Genet. 2000; 26: 13Crossref PubMed Scopus (367) Google Scholar, 2.Cinti S. The adipose organ at a glance.Dis. Model. Mech. 2012; 5: 588-594Crossref PubMed Scopus (239) Google Scholar). An important function of AT is the storage of lipids in the form of triglycerides (TGs) to maintain lipid and glucose homeostasis. Evidence suggests that a decreased capacity to synthesize and store TGs in subcutaneous AT may result in increased lipid circulation and deposition in ectopic tissues, such as skeletal muscle, liver, heart, and pancreas, contributing to the development of the metabolic syndrome and T2D (3.Roden M. Price T.B. Perseghin G. Petersen K.F. Rothman D.L. Cline G.W. Shulman G.I. Mechanism of free fatty acid-induced insulin resistance in humans.J. Clin. Invest. 1996; 97: 2859-2865Crossref PubMed Scopus (1237) Google Scholar, 4.Ravussin E. Smith S.R. Increased fat intake, impaired fat oxidation, and failure of fat cell proliferation result in ectopic fat storage, insulin resistance, and type 2 diabetes mellitus.Ann. N. Y. Acad. Sci. 2002; 967: 363-378Crossref PubMed Scopus (384) Google Scholar, 5.McQuaid S.E. Hodson L. Neville M.J. Dennis A.L. Cheeseman J. Humphreys S.M. Ruge T. Gilbert M. Fielding B.A. Frayn K.N. et al.Downregulation of adipose tissue fatty acid trafficking in obesity: a driver for ectopic fat deposition?.Diabetes. 2011; 60: 47-55Crossref PubMed Scopus (247) Google Scholar). The majority of published studies utilized in vitro and indirect methods to estimate the synthesis of TGs in humans (6.McLaughlin T. Sherman A. Tsao P. Gonzalez O. Yee G. Lamendola C. Reaven G.M. Cushman S.W. Enhanced proportion of small adipose cells in insulin-resistant vs insulin-sensitive obese individuals implicates impaired adipogenesis.Diabetologia. 2007; 50: 1707-1715Crossref PubMed Scopus (269) Google Scholar, 7.McLaughlin T. Lamendola C. Liu A. Abbasi F. Preferential fat deposition in subcutaneous versus visceral depots is associated with insulin sensitivity.J. Clin. Endocrinol. Metab. 2011; 96: E1756-E1760Crossref PubMed Scopus (303) Google Scholar), while only limited investigations have applied an in vivo approach to measure TG kinetics (8.Strawford A. Antelo F. Christiansen M. Hellerstein M.K. Adipose tissue triglyceride turnover, de novo lipogenesis, and cell proliferation in humans measured with 2H2O.Am. J. Physiol. Endocrinol. Metab. 2004; 286: E577-E588Crossref PubMed Scopus (271) Google Scholar, 9.Arner P. Bernard S. Salehpour M. Possnert G. Liebl J. Steier P. Buchholz B.A. Eriksson M. Arner E. Hauner H. et al.Dynamics of human adipose lipid turnover in health and metabolic disease.Nature. 2011; 478: 110-113Crossref PubMed Scopus (264) Google Scholar). Recent studies reported that in vivo rates of TG synthesis in adipose cells were significantly lower in insulin-resistant as compared with insulin-sensitive subjects (10.Tuvdendorj D. Chandalia M. Batbayar T. Saraf M. Beysen C. Murphy E.J. Abate N. Altered subcutaneous abdominal adipose tissue lipid synthesis in obese, insulin-resistant humans.Am. J. Physiol. Endocrinol. Metab. 2013; 305: E999-E1006Crossref PubMed Scopus (22) Google Scholar, 11.Allister C.A. Liu L.F. Lamendola C.A. Craig C.M. Cushman S.W. Hellerstein M.K. McLaughlin T.L. In vivo 2H2O administration reveals impaired triglyceride storage in adipose tissue of insulin-resistant humans.J. Lipid Res. 2015; 56: 435-439Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar), providing evidence that TG kinetics in subcutaneous AT plays a significant role in metabolism. To date, no studies have assessed in vivo TG kinetics in human populations of different races. Another function of AT is the ability to synthesize de novo fatty acids from nonlipid precursors. Although the liver has been implicated as the primary site for de novo lipogenesis (DNL) in humans, recent long-term labeling studies have demonstrated a significant contribution from adipose DNL to adipose lipid stores (8.Strawford A. Antelo F. Christiansen M. Hellerstein M.K. Adipose tissue triglyceride turnover, de novo lipogenesis, and cell proliferation in humans measured with 2H2O.Am. J. Physiol. Endocrinol. Metab. 2004; 286: E577-E588Crossref PubMed Scopus (271) Google Scholar, 12.Guo Z.K. Cella L.K. Baum C. Ravussin E. Schoeller D.A. De novo lipogenesis in adipose tissue of lean and obese women: application of deuterated water and isotope ratio mass spectrometry.J. Int. J. Obes. Relat. Metab. Disord. 2000; 24: 932-937Crossref PubMed Scopus (45) Google Scholar). The role of DNL in human metabolic health and diseases is not established. Studies in subjects with obesity have shown that insulin resistance and hepatic steatosis are positively correlated with liver DNL, but negatively correlated with the expression of DNL genes in AT (13.Diraison F. Dusserre E. Vidal H. Sothier M. Beylot M. Increased hepatic lipogenesis but decreased expression of lipogenic gene in adipose tissue in human J. Physiol. Endocrinol. Metab. 2002; PubMed Google Scholar, L. T. A. et novo lipogenesis in human fat and liver is to and metabolic 2013; PubMed Scopus Google Scholar). studies have shown expression of adipose DNL genes in human obesity and T2D (13.Diraison F. Dusserre E. Vidal H. Sothier M. Beylot M. Increased hepatic lipogenesis but decreased expression of lipogenic gene in adipose tissue in human J. Physiol. Endocrinol. Metab. 2002; PubMed Google Scholar, L. T. A. et novo lipogenesis in human fat and liver is to and metabolic 2013; PubMed Scopus Google Scholar, D. J. E. et gene expression of the lipogenic is in visceral adipose tissue of obese PubMed Scopus Google Scholar), in with in vivo studies DNL in the AT of insulin-resistant versus insulin-sensitive subjects (10.Tuvdendorj D. Chandalia M. Batbayar T. Saraf M. Beysen C. Murphy E.J. Abate N. Altered subcutaneous abdominal adipose tissue lipid synthesis in obese, insulin-resistant humans.Am. J. Physiol. Endocrinol. Metab. 2013; 305: E999-E1006Crossref PubMed Scopus (22) Google Scholar, 11.Allister C.A. Liu L.F. Lamendola C.A. Craig C.M. Cushman S.W. Hellerstein M.K. McLaughlin T.L. In vivo 2H2O administration reveals impaired triglyceride storage in adipose tissue of insulin-resistant humans.J. Lipid Res. 2015; 56: 435-439Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar). an role for adipose Yet, studies using in vivo of adipose DNL in humans We assessed in vivo cell kinetics of subcutaneous AT using an 8 week incorporation of deuterium as into the of adipose cells in women with obesity Hellerstein M.K. Ravussin E. in in vivo kinetics in abdominal and femoral subcutaneous adipose tissue in PubMed Scopus Google Scholar, Hellerstein M.K. Ravussin E. of in vivo adipose tissue kinetics with of metabolic health in humans.J. Clin. Endocrinol. Metab. PubMed Scopus Google Scholar). In of have applied to measure the in vivo synthesis of TGs (fTG) the incorporation of 2H2O in the of as well as the synthesis of the fatty acid, providing a measure of adipose DNL in subcutaneous abdominal (scABD) and subcutaneous femoral (scFEM) AT. Our findings significant differences in TG replacement (synthesis and breakdown) and palmitate synthesis with Caucasians having higher fTG and fDNL as compared with African-Americans. Our also show that the scFEM adipose depot had higher TG replacement rates relative to the scABD. Finally, fTG was negatively correlated with changes in body weight in women with with were to the of BMI glucose of organ and and liver weight for and no significant changes in activity in the a of liver of with glucose lipid of that causes weight with were as were and subjects in the of 2H2O were in were to for week and for body 2H2O the 8 S. A. J. D. Antelo F. A. et in vivo of proliferation rates of turnover cells by 2H2O labeling of the of Acad. Sci. 2002; PubMed Scopus Google Scholar). with 2H2O was of for and to measure in body water were measured by isotope ratio were using and was with an to a mass 2H2O were by to by 2H2O with 2H2O in The the to 2H2O for was as the the for using the metabolic were at the of the study. and were the 8 week were to maintain body weight and with the small weight changes were and body weight was as weight weight was using the to body were with AT and were and with using a by from the of the liver to the were by a of and AT were to mass using an of AT abdominal AT the of abdominal fat that is and was as AT lipid and lipid in the and skeletal as well as lipid were measured with a body and using a body and was with A. C. M. C. de D. for the PubMed Google as L.K. S. Smith S.R. A. Ravussin E. of with insulin fat cell and ectopic lipid in PubMed Scopus Google Scholar, Smith S.R. L.K. Ravussin E. triglyceride measured by and PubMed Scopus Google Scholar, L.K. J. Smith S.R. M. D.A. Ravussin E. of and and liver lipids and of liver PubMed Scopus Google Scholar). and are relative to the of a of as G. P. De F. E. A. C. A. G. G. A. et triglyceride is a of in vivo insulin resistance in a in of type 2 PubMed Scopus Google Scholar). was assessed by a 2 glucose and insulin by the of glucose glucose M. from glucose with the insulin PubMed Scopus Google Scholar). AT were with a and a and were from the between and of the from the to the and from the scFEM the of the to of the from the to the The tissue was in and in for The were the and the were for AT lipids were using the and TGs were Adipose TG was with acid were from The the was to the for S.M. Murphy E.J. Antelo F. T. A. C. Hellerstein M.K. of TG synthesis and turnover in vivo by 2H2O incorporation into the and application of J. Physiol. Endocrinol. Metab. PubMed Scopus Google Scholar). of the were measured by and using a in of and and as S.M. Murphy E.J. Antelo F. T. A. C. Hellerstein M.K. of TG synthesis and turnover in vivo by 2H2O incorporation into the and application of J. Physiol. Endocrinol. Metab. PubMed Scopus Google Scholar). were by using a with as and and for and as M. G.M. Hellerstein M.K. of cell proliferation by water 2007; PubMed Scopus Google Scholar). were measured to for The of the in the was by the in the from the in the The in was using M.K. a for and turnover of J. Physiol. PubMed Google the body 2H2O over the 8 week period. synthesized the 2H2O administration was using the fTG is the of newly synthesized TG in the is the mass for and is the mass of a The was using the body water that the of in the labeling is S.M. Murphy E.J. Antelo F. T. A. C. Hellerstein M.K. of TG synthesis and turnover in vivo by 2H2O incorporation into the and application of J. Physiol. Endocrinol. Metab. PubMed Scopus Google Scholar). of metabolic balance fTG both synthesis and of TGs replacement turnover of The of palmitate synthesized from the DNL was from body water and using as (8.Strawford A. Antelo F. Christiansen M. Hellerstein M.K. Adipose tissue triglyceride turnover, de novo lipogenesis, and cell proliferation in humans measured with 2H2O.Am. J. Physiol. Endocrinol. Metab. 2004; 286: E577-E588Crossref PubMed Scopus (271) Google Scholar). the of newly adipose that from the DNL was by fDNL by as (8.Strawford A. Antelo F. Christiansen M. Hellerstein M.K. Adipose tissue triglyceride turnover, de novo lipogenesis, and cell proliferation in humans measured with 2H2O.Am. J. Physiol. Endocrinol. Metab. 2004; 286: E577-E588Crossref PubMed Scopus (271) Google Scholar). for the of TG that was in AT the 8 week labeling for the not have from the DNL measured the study. was to estimate the of TGs (fTG) and DNL over 8 and to the associated with and from the were to for of for of the have been Hellerstein M.K. Ravussin E. of in vivo adipose tissue kinetics with of metabolic health in humans.J. Clin. Endocrinol. Metab. PubMed Scopus Google Scholar). for TG were no race differences in of the at to of the and of was the of the with the of lower a the results from between fTG and fDNL with the were using differences in the for ± ± ± ± ± ± weight ± ± weight ± ± body ± ± ± ± AT ± ± ± ± ± ± fat ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± are as ± in a are as ± The and 25 and of women in the have been reported Hellerstein M.K. Ravussin E. of in vivo adipose tissue kinetics with of metabolic health in humans.J. Clin. Endocrinol. Metab. PubMed Scopus Google Scholar). The that the for fTG the body body of and depot fTG was significantly associated with depot location race and body weight The that the for fDNL body body of and depot fDNL was significantly associated with race body fat and body weight and of by between fTG and fDNL and the to are significantly shown in newly synthesized adipose TG (fTG) was significantly higher in Caucasians versus that TG replacement was significantly higher in the scFEM depot compared with the 2 that newly synthesized palmitate was significantly higher in Caucasians versus the contribution of DNL to was not different between the not TG synthesis was significantly correlated with DNL in the and scFEM adipose depots not We in vivo TG synthesis and DNL rates were associated with and using that fTG was negatively associated with body weight in both and scFEM adipose body and were also but of correlated with fTG in The fDNL was also negatively associated with 8 week body weight in the and scFEM depots not DNL rates in the depot but not the scFEM depot were negatively correlated with body fat not and were also but not significantly associated with fDNL in The of was to the in vivo synthesis of TGs (fTG) and DNL both of subcutaneous AT lipid in a of women with Our findings significant differences in both TG replacement and DNL, with Caucasians having higher fTG and fDNL as compared with African-Americans. fDNL was not different between our also show that the scFEM adipose depot had higher TG replacement rates relative to the adipose Finally, fTG and fDNL were negatively correlated with changes in body weight over the 8 week higher lipid kinetics in women that Our estimates of both fTG ± in the ± in the scFEM and fDNL ± in the ± in the scFEM are to reported of TG synthesis and absolute DNL rates (8.Strawford A. Antelo F. Christiansen M. Hellerstein M.K. Adipose tissue triglyceride turnover, de novo lipogenesis, and cell proliferation in humans measured with 2H2O.Am. J. Physiol. Endocrinol. Metab. 2004; 286: E577-E588Crossref PubMed Scopus (271) Google Scholar, 11.Allister C.A. Liu L.F. Lamendola C.A. Craig C.M. Cushman S.W. Hellerstein M.K. McLaughlin T.L. In vivo 2H2O administration reveals impaired triglyceride storage in adipose tissue of insulin-resistant humans.J. Lipid Res. 2015; 56: 435-439Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar). Our findings also estimate the contribution from DNL to newly TG (corrected fDNL) to in the depot and in the scFEM to estimates of (8.Strawford A. Antelo F. Christiansen M. Hellerstein M.K. Adipose tissue triglyceride turnover, de novo lipogenesis, and cell proliferation in humans measured with 2H2O.Am. J. Physiol. Endocrinol. Metab. 2004; 286: E577-E588Crossref PubMed Scopus (271) Google Scholar). for the first time, a significant between versus Caucasians in in vivo TG replacement in AT depots of women with with higher rates synthesis and breakdown) in studies have reported race differences in with to have increased abdominal and insulin resistance compared with Caucasians C.M. and the of type 2 diabetes in and the in 2002; PubMed Scopus Google Scholar, in the between and 2002; PubMed Scopus Google Scholar, insulin but lower in in the Metab. Res. 2002; PubMed Scopus Google Scholar, M. M. A. differences in the of triglycerides with metabolic syndrome the of Relat. Disord. 2011; PubMed Scopus Google Scholar). investigations have race differences in lipid P. M. Lipid and in The Lipid PubMed Scopus Google Scholar, in and with diabetes in the PubMed Scopus Google Scholar, M. differences in and by the in J. PubMed Scopus Google Scholar). to our is the first to differences in in vivo adipocyte lipid kinetics races. of evidence that the impaired capacity for TG storage in subcutaneous AT may whole-body metabolism and to the development of P. Bernard S. Salehpour M. Possnert G. Liebl J. Steier P. Buchholz B.A. Eriksson M. Arner E. Hauner H. et al.Dynamics of human adipose lipid turnover in health and metabolic disease.Nature. 2011; 478: 110-113Crossref PubMed Scopus (264) Google Scholar, D. Chandalia M. Batbayar T. Saraf M. Beysen C. Murphy E.J. Abate N. Altered subcutaneous abdominal adipose tissue lipid synthesis in obese, insulin-resistant humans.Am. J. Physiol. Endocrinol. Metab. 2013; 305: E999-E1006Crossref PubMed Scopus (22) Google Scholar, 11.Allister C.A. Liu L.F. Lamendola C.A. Craig C.M. Cushman S.W. Hellerstein M.K. McLaughlin T.L. In vivo 2H2O administration reveals impaired triglyceride storage in adipose tissue of insulin-resistant humans.J. Lipid Res. 2015; 56: 435-439Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar). Recent studies in humans reported that the AT of insulin-resistant subjects had impaired in vivo TG synthesis (fTG) relative to insulin-sensitive subjects (10.Tuvdendorj D. Chandalia M. Batbayar T. Saraf M. Beysen C. Murphy E.J. Abate N. Altered subcutaneous abdominal adipose tissue lipid synthesis in obese, insulin-resistant humans.Am. J. Physiol. Endocrinol. Metab. 2013; 305: E999-E1006Crossref PubMed Scopus (22) Google Scholar, 11.Allister C.A. Liu L.F. Lamendola C.A. Craig C.M. Cushman S.W. Hellerstein M.K. McLaughlin T.L. In vivo 2H2O administration reveals impaired triglyceride storage in adipose tissue of insulin-resistant humans.J. Lipid Res. 2015; 56: 435-439Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar). suggests that higher TG associated with metabolic is important to the fTG both synthesis and of adipose TG stores as were in our study. fTG as our show higher fTG and higher TG in with Although our not significant differences in and associated with metabolic health between and with the of higher TGs in the the first to that the in vivo synthesis of TG in adipose depots varies by race in women with investigations are to the of in vivo TG kinetics in AT may associated with the development of metabolic health in different the between (scABD) versus (scFEM) adipose with metabolic health is a to depot differences in adipocyte Interestingly, the first evidence that in vivo TG synthesis varies by depot location in humans and suggests that scFEM AT has a higher capacity for TG with our higher in vivo fat cell in the scFEM depot Hellerstein M.K. Ravussin E. in in vivo kinetics in abdominal and femoral subcutaneous adipose tissue in PubMed Scopus Google Scholar), that the as a depot to and lipid K.N. F. Frayn K.N. body fat as a of metabolic J. Obes. PubMed Scopus Google Scholar, differences in human adipose the of 2012; 13Crossref PubMed Scopus Google Scholar). The by DNL in AT is in human obesity and insulin resistance is in adipose DNL has been by recent studies in that is from adipose DNL, is an fatty acid H. S.M. of a a lipid adipose tissue to Full Text Full Text PDF PubMed Scopus Google Scholar, H. A. administration of acid insulin resistance and hepatic lipid in with type 2 2011; PubMed Scopus Google Scholar), a role for AT DNL in glucose homeostasis. studies in humans that the AT of insulin-resistant individuals had rates of in vivo DNL relative to insulin-sensitive subjects (10.Tuvdendorj D. Chandalia M. Batbayar T. Saraf M. Beysen C. Murphy E.J. Abate N. Altered subcutaneous abdominal adipose tissue lipid synthesis in obese, insulin-resistant humans.Am. J. Physiol. Endocrinol. Metab. 2013; 305: E999-E1006Crossref PubMed Scopus (22) Google Scholar, 11.Allister C.A. Liu L.F. Lamendola C.A. Craig C.M. Cushman S.W. Hellerstein M.K. McLaughlin T.L. In vivo 2H2O administration reveals impaired triglyceride storage in adipose tissue of insulin-resistant humans.J. Lipid Res. 2015; 56: 435-439Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar). recent studies a significant role for adipose DNL in humans. investigations not race differences in adipose DNL rates Z.K. Cella L.K. Baum C. Ravussin E. Schoeller D.A. De novo lipogenesis in adipose tissue of lean and obese women: application of deuterated water and isotope ratio mass spectrometry.J. Int. J. Obes. Relat. Metab. Disord. 2000; 24: 932-937Crossref PubMed Scopus (45) Google Scholar). Our findings show significantly higher in vivo adipose DNL in Caucasians versus African-Americans. the of newly palmitate in adipose TG that from the DNL (corrected fDNL) is not different between Caucasians and African-Americans. fDNL is a measure for palmitate turnover that for palmitate and that also the The of significant race differences in fDNL that the higher fDNL storage of in Caucasians may to higher TG turnover, a contribution of DNL to our between fatty acids that are synthesized by AT from that are synthesized by the liver and to the adipose has been that hepatic DNL contribution to adipose DNL is fatty acids over an 8 week labeling (8.Strawford A. Antelo F. Christiansen M. Hellerstein M.K. Adipose tissue triglyceride turnover, de novo lipogenesis, and cell proliferation in humans measured with 2H2O.Am. J. Physiol. Endocrinol. Metab. 2004; 286: E577-E588Crossref PubMed Scopus (271) Google Scholar). is the rate of by the liver the of palmitate in fatty acids and the of from the DNL a contribution from hepatic DNL of hepatic DNL were in 8 of labeling result in of AT palmitate of adipose TG of is a small of the of adipose palmitate measured as studies are to the role of adipose DNL in human metabolism and the was weight the of the of the small changes in body weight and Interestingly, our a between fTG and body higher TG synthesis and DNL in women that TG replacement rates both synthesis and may increased in subjects that in increased to newly synthesized our show higher fTG as well as higher TG in We also reported a between in vivo adipose cell and body higher in women that weight Hellerstein M.K. Ravussin E. of in vivo adipose tissue kinetics with of metabolic health in humans.J. Clin. Endocrinol. Metab. PubMed Scopus Google Scholar). body weight in subjects over the 8 week was small to only a in body fat of body was no significant of in vivo lipid synthesis (fTG) and body fat in the the scFEM investigations are to significant changes in body weight and body fat may in vivo adipose We not between in vivo adipocyte kinetics and of metabolic demonstrated that fTG was associated with of the metabolic insulin resistance and lipid (10.Tuvdendorj D. Chandalia M. Batbayar T. Saraf M. Beysen C. Murphy E.J. Abate N. Altered subcutaneous abdominal adipose tissue lipid synthesis in obese, insulin-resistant humans.Am. J. Physiol. Endocrinol. Metab. 2013; 305: E999-E1006Crossref PubMed Scopus (22) Google Scholar, D. G. Chandalia M. M. Murphy E.J. Abate N. In vivo triglyceride synthesis in subcutaneous adipose tissue of humans with Full Text Full Text PDF PubMed Scopus Google Scholar). our only women were investigations populations to the of in vivo AT lipid kinetics influence metabolic health in humans. We subjects with fat mass to TG replacement in the body fat fat were significantly associated with demonstrated that the of fat AT and fat (or fat in the not the In addition, race differences in the replacement of TG significant with changes in the in and Caucasians relative to the reported our findings not the of lower TG turnover in subjects with higher fat mass and may that TG turnover of AT is in of of our is the of the to measure in vivo TG synthesis and DNL in the is different from methods that indirect utilized for the of both and scFEM depots is an as depot differences in AT function and metabolism are are also to study. Although have a our only women with results applied to women to In addition, the only that are are and is important to that our and not and In the first evidence that in vivo adipose kinetics replacement rates and in women with obesity by with higher rates in Caucasians versus African-Americans. our that the scFEM AT may have a higher capacity for TG storage and relative to the The for adipose tissue de novo lipogenesis lipid deuterium lipid lipid glucose subcutaneous abdominal subcutaneous femoral abdominal adipose tissue triglyceride visceral adipose tissue
Source: Journal of Lipid Research
DOI: 10.1194/jlr.p082628
Language: English
Subfield: Biochemistry
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
Awards: Depot-specific adipose cell size distributions and metabolic health markers, The Regulation and Metabolic Effects of gp130 Cytokines in Human White Adipose Ti, Cellular Dynamics of Subcutaneous Fat Distribution in Obese Women, Louisiana Clinical and Translational Science Center, Pennington/Louisiana NORC
OpenAlex ID: W2808448640