Department of Epidemiology, School of Public Health and Tropical Medicine, Tulane University, 1440 Canal Street, Suite 1724, 70112, New Orleans, LA, USA.
Clinical and Translational Epidemiology Unit and Division of Gastroenterology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Eur J Nutr. 2022 Apr;61(3):1353-1362. doi: 10.1007/s00394-021-02713-x. Epub 2021 Nov 19.
L-Carnitine is abundant in animal source foods, particularly red meat, and circulating L-carnitine may be related to the incidence of coronary heart disease (CHD). We investigated whether long-term changes in plasma L-carnitine over 10 years were associated with the CHD incidence and also examined joint associations of carnitine-rich red meat consumption and L-carnitine changes on the subsequent risk of CHD.
This prospective nested case-control study included 772 healthy women at baseline (386 incident CHD cases and 386 healthy controls). Plasma L-carnitine levels were measured both at the first (1989-90) and second blood collections (2000-02). Incident cases of CHD were prospectively followed from the date of the second blood collection through 2016.
Overall, a greater increase in L-carnitine from the first to the second time point was related to a higher risk of CHD, regardless of the initial L-carnitine levels (relative risk: 1.36 (95% CI 0.999, 1.84) per 1-SD increase). The 10-year changes in L-carnitine were positively associated with red meat consumption over time, and women with higher red meat intake (≥ 36 g/day) and with greater increases in L-carnitine had a 1.86 (95% CI 1.13, 3.09) times increased risk of CHD, as compared to those with lower red meat intake and lesser increases in L-carnitine.
Long-term increases in L-carnitine levels were associated with the subsequent incidence of CHD, especially among women with higher intake of red meat. Our results suggest the importance of atherogenic L-carnitine changes and dietary intakes over time in the prevention of CHD.
左旋肉碱大量存在于动物源性食物中，特别是红色肉类，循环中的左旋肉碱可能与冠心病（CHD）的发病率有关。我们研究了 10 年内血浆左旋肉碱的长期变化是否与 CHD 的发病率有关，还检查了富含肉碱的红色肉类消费和左旋肉碱变化对随后 CHD 风险的联合影响。
这项前瞻性嵌套病例对照研究包括 772 名基线时健康的女性（386 例 CHD 病例和 386 名健康对照者）。分别在第一次（1989-1990 年）和第二次采血（2000-2002 年）时测量血浆左旋肉碱水平。从第二次采血日期开始，通过 2016 年对 CHD 病例进行前瞻性随访。
总体而言，从第一次到第二次采血点左旋肉碱的增加幅度越大，CHD 的风险越高，而不论初始左旋肉碱水平如何（相对风险：每增加 1-SD 为 1.36（95%CI 0.999，1.84））。左旋肉碱 10 年变化与随时间推移的红色肉类消费呈正相关，与红色肉类摄入量较高（≥36g/天）和左旋肉碱增加幅度较大的女性相比，CHD 的风险增加 1.86 倍（95%CI 1.13，3.09），而摄入量较低且左旋肉碱增加幅度较小的女性则风险较低。
左旋肉碱水平的长期升高与 CHD 的后续发病有关，尤其是在红色肉类摄入量较高的女性中。我们的研究结果表明，在预防 CHD 方面，左旋肉碱的致动脉粥样硬化变化和随时间推移的饮食摄入很重要。
