Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares (CIBERCV) and Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Translational Research Unit, Hospital Universitario Miguel Servet, Universidad de Zaragoza, Zaragoza, Spain
Centro de Investigación Biomédica en Red Epidemiología y Salud Pública (CIBERESP), Department of Preventive Medicine and Public Health, School of Medicine, Universidad Autónoma de Madrid/Instituto de Investigación del Hospital La Paz (IDIPAZ), Madrid, Spain.
Diabetes Care. 2018 Oct;41(10):2195-2201. doi: 10.2337/dc18-0372. Epub 2018 Jul 30.
Elevated LDL cholesterol (LDLc) is not strongly associated with obesity or metabolic syndrome (MS), but this relationship repeatedly has been examined assuming a linear association. This study aimed to assess the dose-response relationship between body mass index (BMI) or waist circumference (WC) and LDLc and to evaluate its link to metabolic impairment.
Participants in the continuous National Health and Nutrition Examination Survey (NHANES, 1999-2010) ( = 12,383) and the Study on Nutrition and Cardiovascular Risk (ENRICA, 2008-2010) ( = 11,765), representative samples of U.S. and Spanish noninstitutionalized populations, were cross-sectionally investigated. LDLc was modeled with age- and sex-adjusted regressions, with BMI and/or WC as explanatory variables included in models as two-segment linear and natural cubic splines.
In NHANES and ENRICA, slopes of the BMI-LDLc association changed ( < 0.001) at BMI 27.1 and 26.5 kg/m, respectively, forming an inverted U shape. Below these BMI inflection points, LDLc rose 2.30 and 2.41 mg/dL per kg/m (both < 0.001). However, above said points, LDLc declined -0.37 and -0.38 mg/dL per kg/m (both < 0.001). The WC-LDLc relationship was similar to the BMI-LDLc relationship. Accumulation of MS traits was associated with a weakening of the positive BMI-LDLc association among lean participants (below the BMI inflection point). Aging shifted the inflection point of the BMI-LDLc relationship to lower BMI values.
The BMI- and WC-LDLc relationships have inverted U shapes. Diminishing associations between BMI and LDLc might indicate metabolic impairment as a result of aging or other metabolic diseases. In lean individuals, small weight losses might help to lower LDLc for cardiovascular prevention.
升高的低密度脂蛋白胆固醇（LDLc）与肥胖或代谢综合征（MS）并无强烈关联，但该关联在反复评估时都假设为线性关系。本研究旨在评估体重指数（BMI）或腰围（WC）与 LDLc 之间的剂量-反应关系，并评估其与代谢损伤的关联。
本研究纳入了连续的美国国家健康和营养检查调查（NHANES，1999-2010 年）（n=12383）和营养与心血管风险研究（ENRICA，2008-2010 年）（n=11765）中的参与者，这两项研究分别代表了美国和西班牙非住院人群的样本。采用年龄和性别校正回归模型来对 LDLc 进行建模，将 BMI 和/或 WC 作为解释变量纳入模型，采用两段线性和自然三次样条进行分析。
在 NHANES 和 ENRICA 中，BMI 与 LDLc 关联的斜率（P<0.001）分别在 BMI 为 27.1kg/m² 和 26.5kg/m² 时发生变化，呈倒 U 型。在这些 BMI 拐点以下，LDLc 每增加 1kg/m² 会升高 2.30 和 2.41mg/dL（均 P<0.001）。然而，在这些点以上，LDLc 每增加 1kg/m² 会降低 0.37 和 0.38mg/dL（均 P<0.001）。WC 与 LDLc 的关系与 BMI 与 LDLc 的关系相似。随着代谢综合征特征的积累，在偏瘦的参与者中（BMI 拐点以下），BMI 与 LDLc 之间的正相关关系减弱。随着年龄的增长，BMI 与 LDLc 关系的拐点向更低的 BMI 值移动。
BMI 和 WC 与 LDLc 的关系呈倒 U 型。BMI 与 LDLc 之间的关联减弱可能表明随着衰老或其他代谢性疾病的发生而出现代谢损伤。在偏瘦的个体中，较小的体重减轻可能有助于降低 LDLc 以预防心血管疾病。
