Department of Pediatrics, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Lifecourse Epidemiology of Adiposity and Diabetes (LEAD) Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
Am J Clin Nutr. 2022 Oct 6;116(4):1010-1018. doi: 10.1093/ajcn/nqac168.
Adiposity is an established risk factor for pediatric nonalcoholic fatty liver disease (NAFLD), but little is known about the influence of body composition patterns earlier in life on NAFLD risk.
We aimed to examine associations of body composition at birth and body composition trajectories from birth to early childhood with hepatic fat in early childhood.
Data were from the longitudinal Healthy Start Study in Colorado. Fat-free mass index (FFMI), fat mass index (FMI), percentage body fat (BF%), and BMI were assessed at birth and/or ∼5 y in >1200 children by air displacement plethysmography and anthropometrics. In a subset (n = 285), hepatic fat was also assessed at ∼5 y by MRI. We used a 2-stage modeling approach: first, we fit body composition trajectories from birth to early childhood using mixed models with participant-specific intercepts and linear slopes (i.e., individual deviations from the population average at birth and rate of change per year, respectively); second, associations of participant-specific trajectory deviations with hepatic fat were assessed by multivariable-adjusted linear regression.
Participant-specific intercepts at birth for FFMI, FMI, BF%, and BMI were inversely associated with log-hepatic fat in early childhood in models adjusted for offspring demographics and maternal/prenatal variables [back-transformed β (95% CI) per 1 SD: 0.93 (0.88, 0.99), 0.94 (0.88, 0.99), 0.94 (0.89, 0.99), and 0.90 (0.85, 0.96), respectively]. Whereas, faster velocities for BF% and BMI from birth to ∼5 y were positively associated with log-hepatic fat [back-transformed β (95% CI) per 1 SD: 1.08 (1.01, 1.15) and 1.08 (1.02, 1.15), respectively]. These latter associations of BF% and BMI velocities with childhood hepatic fat were attenuated to the null when adjusted for participant-specific intercepts at birth.
Our findings suggest that a smaller birth weight, combined with faster adiposity accretion in the first 5 y, predicts higher hepatic fat in early childhood. Strategies aiming to promote healthy body composition early in life may be critical for pediatric NAFLD prevention.This study was registered voluntarily at clinicaltrials.gov as NCT02273297.
肥胖是小儿非酒精性脂肪肝（NAFLD）的既定危险因素，但人们对生命早期的身体成分模式对 NAFLD 风险的影响知之甚少。
本研究旨在探讨出生时的身体成分以及从出生到幼儿期的身体成分轨迹与幼儿期肝内脂肪的关系。
数据来自科罗拉多州的纵向健康启动研究。通过空气置换体描记法和人体测量法，在 1200 多名儿童中评估了脂肪量指数（FMI）、瘦体重指数（FFMI）、体脂百分比（BF%）和 BMI，出生时和（或）＞5 岁时进行了评估。在一个亚组（n=285）中，还通过 MRI 评估了＞5 岁时的肝内脂肪。我们使用两阶段建模方法：首先，使用混合模型拟合从出生到幼儿期的身体成分轨迹，模型具有参与者特异性截距和线性斜率（即出生时个体与人群平均值的偏差和每年的变化率）；其次，通过多变量调整的线性回归评估参与者特异性轨迹偏差与肝内脂肪的关系。
FFMI、FMI、BF%和 BMI 的出生时个体特异性截距与调整后代特征和母婴/产前变量后的幼儿期肝内脂肪的对数呈负相关[每 1 SD 的反转换 β（95%CI）：0.93（0.88，0.99）、0.94（0.88，0.99）、0.94（0.89，0.99）和 0.90（0.85，0.96）]。而从出生到 5 岁时 BF%和 BMI 的较快速度与肝内脂肪的对数呈正相关[每 1 SD 的反转换 β（95%CI）：1.08（1.01，1.15）和 1.08（1.02，1.15）]。当调整出生时的个体特异性截距时，BF%和 BMI 速度与儿童期肝内脂肪的这些关联减弱至接近零。
我们的研究结果表明，出生体重较小，加上前 5 年脂肪量快速增加，预测幼儿期肝内脂肪含量较高。旨在促进生命早期健康身体成分的策略对于预防小儿非酒精性脂肪肝可能至关重要。本研究在 clinicaltrials.gov 上自愿注册为 NCT02273297。
