Phosphatidylcholine (PC), the most abundant of the phospholipids, has several metabolic functions in organs such as the liver and the intestine, important structural- and signaling functions in biological membranes, and might have a role in the effects of Roux-en-Y gastric bypass (RYGB), an operation known to ameliorate metabolic diseases, including type 2 diabetes. We hypothesized that serum PC, as a reflection of phospholipid metabolism, changes after RYGB, and that changes are related to weight loss and possibly to changes in glucose metabolism (reflected in the HbA1c-level) as well as to changes in serum Apo A1, Apo B and Apo B/Apo A1 ratio. In a cohort of 220 RYGB patients, we studied changes in serum PC after RYGB in relation to serum Apo A1 and Apo B, the main apolipoproteins in HDL- and LDL/VLDL-particles, respectively, up to 2 years following RYGB-surgery. Serum PC reached its lowest levels 3 months postoperatively to later rebound to preoperative levels 24 months after RYGB. No difference was seen between patients with or without type 2 diabetes. Serum Apo A1 showed a similar pattern whereas serum Apo B concentrations stayed low after the initial decrease after RYGB. As a result, the Apo B / Apo A1 ratio constantly decreased during follow-up. There was a strong positive correlation between PC and Apo A1, and between PC and Apo B, but none between Apo A1 and Apo B. After RYGB surgery, both PC and Apo A1, but not Apo B, correlated positively to weight loss. In relation to total cholesterol, the molar ratio between serum PC and plasma cholesterol increased steadily after RYGB. We conclude that changes in PC and apolipoproteins after RYGB are highly dynamic, reflecting a large plasticity and capability of accommodating lipid metabolism including PC-, cholesterol- and apolipoprotein metabolism imposed by RYGB surgery, independent of glucose tolerance. We suggest that after RYGB and major weight loss, PC and Apo A1 might have a special role in the altered metabolism of lipoproteins.

中文翻译：

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Roux-en-Y胃绕道手术后磷脂酰胆碱及其与载脂蛋白A-1和B变化的关系：一项队列研究

磷脂酰胆碱（PC）是最丰富的磷脂，在肝脏和肠道等器官中具有多种代谢功能，在生物膜中具有重要的结构和信号传导功能，并且可能在Roux-en-Y的作用中起作用胃旁路手术（RYGB），一种可改善包括2型糖尿病在内的代谢性疾病的手术。我们假设RYGB后血清PC作为磷脂代谢的变化而发生变化，并且该变化与体重减轻有关，并且可能与葡萄糖代谢的变化（反映在HbA1c水平上）以及血清Apo A1的变化有关， Apo B和Apo B / Apo A1的比率。在一组220名RYGB患者中，我们研究了RYGB后血清PC相对于血清Apo A1和Apo B（分别是HDL和LDL / VLDL颗粒中的主要载脂蛋白）的变化，RYGB手术后最长2年。RYGB术后24个月，血清PC达到最低水平，随后反弹至术前水平。患有或未患有2型糖尿病的患者之间均未见差异。RYGB最初降低后，血清Apo A1表现出相似的模式，而血清Apo B浓度保持较低。结果，在随访期间，Apo B / Apo A1比率不断下降。PC与Apo A1之间，PC与Apo B之间存在很强的正相关，但Apo A1与Apo B之间没有正相关。RYGB手术后，PC和Apo A1与Apo B都与体重减轻呈正相关。关于总胆固醇，RYGB后血清PC和血浆胆固醇之间的摩尔比稳定增加。我们得出结论，RYGB后PC和载脂蛋白的变化是高度动态的，反映了RYGB手术所具有的可塑性和适应脂质代谢的能力，包括PC，胆固醇和载脂蛋白代谢，与葡萄糖耐量无关。我们建议在RYGB和主要减肥后，PC和Apo A1可能在脂蛋白代谢改变中具有特殊作用。