Skuladottir Gudrun Valgerdur, Oskarsdottir Harpa, Pisanu Claudia, Sjödin Marcus, Lindberg Johan, Mwinyi Jessica, Schiöth Helgi Birgir
Department of Physiology, Faculty of Medicine, University of Iceland, Reykjavik, Iceland,
Department of Neuroscience, Functional Pharmacology, Uppsala University, Uppsala, Sweden,
Diabetes Metab Syndr Obes. 2018 Oct 9;11:611-618. doi: 10.2147/DMSO.S175730. eCollection 2018.
Dietary macronutrient composition, stearoyl-CoA desaturase (SCD) activity indices, and primary bile acid (BA) concentrations are among the factors that have been associated with lipid metabolism and contributed to obesity. We investigated the association between the polymorphic expression of the fat mass and obesity-associated () gene and its relationship with SCD activity indices and primary BA concentrations after a low-fat meal.
Blood plasma samples were collected from 56 young (20-36 years) healthy subjects with different rs9939609 genotypes. Fasting and post-meal (2 hours after a low-fat breakfast) blood samples were collected on the subsequent morning for the analysis of DNA methylation, SCD activity indices (product-to-precursor fatty acid ratios; 16:1n-7/16:0 and 18:1n-9/18:0), and chenodeoxycholic acid (CDCA) and cholic acid (CA) concentrations. Expression of lipogenic genes was investigated post-meal to assess the relationship between the CDCA and CA concentrations and mRNA levels of lipogenic genes.
The AA (obesity risk) genotype group (n=18) had higher (<0.05) post-meal SCD-16 activity index than the TT (wild type) genotype group (n=26). In both the TT (n=16) and AA (n=8) genotype groups, the post-meal concentrations of CDCA and CA were lower (<0.05) compared with the fasted state. No difference in BA concentrations between the TT and AA genotype groups in both meal states was observed. After adjusting for the body mass index, the highest 50% post-meal concentrations of CA were inversely (=0.010) correlated with the level of mRNA expression.
AA carriers may be at a higher risk for obesity through higher SCD activity in a low-fat diet environment. This effect may be partly pronounced by very low CA concentrations.
膳食常量营养素组成、硬脂酰辅酶A去饱和酶（SCD）活性指标以及初级胆汁酸（BA）浓度是与脂质代谢相关并导致肥胖的因素。我们研究了脂肪量与肥胖相关基因（）的多态性表达之间的关联及其与低脂餐后SCD活性指标和初级BA浓度的关系。
从56名年龄在20 - 36岁、具有不同rs9939609基因型的健康年轻受试者中采集血浆样本。在随后的早晨采集空腹和餐后（低脂早餐后2小时）血样，用于分析DNA甲基化、SCD活性指标（产物与前体脂肪酸比率；16:1n - 7/16:0和18:1n - 9/18:0）以及鹅去氧胆酸（CDCA）和胆酸（CA）浓度。餐后研究生脂基因的表达，以评估CDCA和CA浓度与生脂基因mRNA水平之间的关系。
AA（肥胖风险）基因型组（n = 18）餐后SCD - 16活性指标高于TT（野生型）基因型组（n = 26）（<0.05）。在TT（n = 16）和AA（n = 8）基因型组中，与空腹状态相比，餐后CDCA和CA浓度均较低（<0.05）。在两种进餐状态下，TT和AA基因型组之间的BA浓度均未观察到差异。调整体重指数后，餐后CA最高的50%浓度与mRNA表达水平呈负相关（=0.010）。
在低脂饮食环境中，AA携带者可能因较高的SCD活性而具有更高的肥胖风险。这种影响可能部分由极低的CA浓度所导致。
