Durão C, Oliveira A, Santos A C, Severo M, Guerra A, Barros H, Lopes C
EPIUnit - Institute of Public Health, Universidade do Porto, Porto, Portugal.
Department of Clinical Epidemiology, Predictive Medicine and Public Health, University of Porto Medical School, Universidade do Porto, Porto, Portugal.
Int J Obes (Lond). 2017 Apr;41(4):533-541. doi: 10.1038/ijo.2016.240. Epub 2016 Dec 28.
BACKGROUND/OBJECTIVES: The role of Protein Intake (PI) at preschool age on later adiposity is understudied, and prospective studies also examining Dietary Glycemic Load (GL) are lacking. The current study evaluated the association of PI and GL at 4 years with adiposity and Fasting Serum Insulin (FSI) 3 years later, and examined the possible interaction between PI and GL on these associations, by sex.
This prospective study included 1999 singleton children enrolled in the population-based birth cohort, Generation XXI (Porto, Portugal, 2005-2006). Diet at 4 years was assessed by 3-days food diaries. Energy-adjusted PI and GL (g per day) were converted into sex-specific tertiles (T). At 7 years, Body Mass Index (BMI) z-scores were defined according to the World Health Organization. Sample's sex-specific z-scores were computed for Fat Mass Index (FMI), Waist-to-Height ratio (W/Ht) and FSI. Associations were estimated by linear regression coefficients (β) and 95% confidence intervals (95% CI).
After adjustment for confounders, PI was positively associated with BMI in girls (T2 vs T1: β=0.187; 95% CI: 0.015, 0.359) and boys (T3 vs T1: β=0.205; 95% CI: 0.003, 0.406), being associated with FSI only in boys (T3 vs T1: β=0.207; 95% CI: 0.011, 0.404; P-interaction=0.026). Also, GL was associated with BMI only in boys (T3 vs T1: β=0.362; 95% CI: 0.031, 0.693; P-interaction=0.006), in whom significant interactions between PI and GL were found on the association with FMI (P=0.019) and W/Ht (P=0.039). Boys within the third T of both PI and GL at 4 years had higher FMI (β=0.505; 95% CI: 0.085, 0.925) and W/Ht (β=0.428; 95% CI: 0.022, 0.834) at 7 years.
In both girls and boys, PI at preschool age is positively associated with later BMI, being positively associated with FSI only in boys. Dietary GL is associated with adiposity only in boys, in whom it seems to interact with PI enhancing increased adiposity.
背景/目的：学龄前蛋白质摄入量（PI）对后期肥胖的作用研究不足，且缺乏同时考察膳食血糖负荷（GL）的前瞻性研究。本研究评估了4岁时的PI和GL与3年后肥胖及空腹血清胰岛素（FSI）之间的关联，并按性别检验了PI和GL在这些关联上可能存在的相互作用。
这项前瞻性研究纳入了1999名单胎儿童，他们来自基于人群的出生队列“二十一世纪一代”（葡萄牙波尔图，2005 - 2006年）。通过3天食物日记评估4岁时的饮食情况。将能量调整后的PI和GL（每天克数）转换为按性别划分的三分位数（T）。7岁时，根据世界卫生组织定义体重指数（BMI）z评分。计算样本按性别划分的脂肪量指数（FMI）、腰高比（W/Ht）和FSI的z评分。通过线性回归系数（β）和95%置信区间（95%CI）估计关联。
在对混杂因素进行调整后，PI与女孩的BMI呈正相关（T2 vs T1：β = 0.187；95%CI：0.015，0.359）以及男孩的BMI呈正相关（T3 vs T1：β = 0.205；95%CI：0.003，0.406），且仅与男孩的FSI相关（T3 vs T1：β = 0.207；95%CI：0.011，0.404；P交互作用 = 0.026）。此外，GL仅与男孩的BMI相关（T3 vs T1：β = 0.362；95%CI：0.031，0.693；P交互作用 = 0.006），在男孩中发现PI和GL在与FMI（P = 0.019）和W/Ht（P = 0.039）的关联上存在显著交互作用。4岁时PI和GL均处于第三个三分位数的男孩在7岁时具有更高的FMI（β = 0.505；95%CI：0.085，0.925）和W/Ht（β = 0.428；95%CI：0.022，0.834）。
在女孩和男孩中，学龄前PI与后期BMI呈正相关，且仅与男孩的FSI呈正相关。膳食GL仅与男孩的肥胖相关，在男孩中它似乎与PI相互作用增强了肥胖程度。
