Sylvestre Marie-Pierre, Ahun Marilyn N, O'Loughlin Jennifer
Centre de recherche du centre hospitalier de l`Université de Montréal (CRCHUM) Montréal Quebec Canada.
Department of Social and Preventive Medicine Université de Montréal Montréal Quebec Canada.
Obes Sci Pract. 2021 Jun 25;7(6):711-718. doi: 10.1002/osp4.538. eCollection 2021 Dec.
Body mass index (BMI) is used to identify trajectories of adiposity in youth, but it does not distinguish fat- from fat-free-mass. There are other inexpensive measures of adiposity which might better capture fat-mass in youth The objective of this study is to examine differences between sex-specific trajectories of BMI and other adiposity indicators (subscapular and triceps skinfold thickness, waist circumference, waist-to-height ratio) which may better capture fat-mass in youth.
Data come from four cycles of a longitudinal cohort of 1293 students in Montréal, Canada at ages 12, 15, 17 and 24. Group-based trajectory models identified sex-specific adiposity trajectories among participants with data in ≥3 cycles ( = 417 males; = 445 females).
There were six trajectory groups in males and females for all five indicators, except for waist circumference (seven) in both sexes and triceps skinfold thickness (four) and waist-to-height ratio (five) in females. Most trajectories indicated linear increases; only the skinfold thickness indicators identified a decreasing trajectory. While all indicators identified a trajectory with high levels of adiposity, they differed in the number and relative size of trajectories pertaining to individuals in lower half of the adiposity distribution.
BMI is a satisfactory indicator of adiposity in youth if the aim of the trajectory analysis is to identify youth with excess adiposity, a known risk factor for cardiometabolic outcomes in adulthood.
体重指数（BMI）用于确定青少年肥胖的发展轨迹，但它无法区分脂肪量和去脂体重。还有其他一些低成本的肥胖测量方法，可能能更好地反映青少年的脂肪量。本研究的目的是检验BMI与其他肥胖指标（肩胛下和肱三头肌皮褶厚度、腰围、腰高比）在性别特异性轨迹上的差异，这些指标可能能更好地反映青少年的脂肪量。
数据来自加拿大蒙特利尔一个由1293名学生组成的纵向队列的四个周期，学生年龄分别为12岁、15岁、17岁和24岁。基于群体的轨迹模型在有≥3个周期数据的参与者中确定了性别特异性肥胖轨迹（男性=417人；女性=445人）。
除了腰围（男女均为7个轨迹组）、女性的肱三头肌皮褶厚度（4个轨迹组）和腰高比（5个轨迹组）外，所有五个指标在男性和女性中都有六个轨迹组。大多数轨迹呈线性增加；只有皮褶厚度指标确定了一个下降轨迹。虽然所有指标都确定了一个肥胖水平较高的轨迹，但它们在所涉及的肥胖分布下半部分个体的轨迹数量和相对规模上存在差异。
如果轨迹分析的目的是识别肥胖青少年（肥胖是成年人心血管代谢疾病结局的已知危险因素），那么BMI是青少年肥胖的一个令人满意的指标。
