背景:呼吸碳同位素比(CIR)最近被确定为短期添加糖(AS)摄入量的非侵入性候选生物标志物。
目的:本研究旨在更好地了解呼吸CIR作为膳食生物标志物的潜力。我们评估了短期和长期摄入AS的影响,动物蛋白(AP),以及呼吸CIR上的相关变量,在典型的饮食摄入模式的背景下。
方法:我们对100名成年人(年龄18-70岁,55%女性)在凤凰城,AZ.为参与者提供了与习惯性食物摄入量近似的个性化饮食,并记录了食物消耗的时间。三个呼吸样本(禁食,中午,和晚上)在3个非连续研究日的每一天收集。我们用线性混合模型模拟了采集呼吸样本前8小时饮食摄入对呼吸CIR的影响,其中还包括15-d平均摄入量,性别,年龄,BMI。
结果:我们研究中AS和AP的中位数(IQR)摄入量为65(38)和67(33)g/d,分别。中午和晚上呼吸CIRs彼此密切相关(0.80),与空腹呼吸CIR(分别为0.77和0.68)。在我们的线性混合模型中,呼吸CIR在样品收集前1-4小时因AS消耗而增加,AP在样品收集前3-6小时消耗,和15天AS和AP的摄入量,都具有相似的效果大小。呼吸CIR也与15天内在糖和植物蛋白的摄入量呈负相关;因此,当按AS比率(添加糖/总糖)和AP比率(动物蛋白/总蛋白)成比例表示时,与15d摄入量的关联特别强。
结论:呼吸CIR是衡量AS和AP长期摄入量的有希望的指标,尤其是成比例的摄入量。增加特异性的方法将有利于该生物标志物的进一步发展。
BACKGROUND: The breath carbon isotope ratio (CIR) was recently identified as a noninvasive candidate biomarker of short-term added sugars (AS) intake.
OBJECTIVE: This study aimed to better understand the potential of the breath CIR as a dietary biomarker. We evaluated the effects of short-term and long-term intakes of AS, animal protein (AP), and related variables on breath CIR, in the context of typical dietary intake patterns.
METHODS: We conducted a 15-d controlled feeding study of 100 adults (age 18-70 y, 55% females) in Phoenix, AZ. Participants were provided individualized diets that approximated habitual food intakes and recorded the timing of food consumption. Three breath samples (fasting, midday, and evening) were collected on each of 3 nonconsecutive study days. We modeled the effects of dietary intake in each of 8 h preceding collection of the breath sample on breath CIR with a linear mixed model, which also included 15-d mean intakes, sex, age, and BMI.
RESULTS: Median (IQR) intakes of AS and AP in our study were 65 (38) and 67 (33) g/d, respectively. Midday and evening breath CIRs correlated strongly with each other (0.80) and with fasting breath CIR (0.77 and 0.68, respectively). In our linear mixed models, breath CIR increased by AS consumed 1-4 h before sample collection, AP consumed 3-6 h before sample collection, and 15-d intakes of AS and AP, all with similar effect sizes. The breath CIR was also inversely associated with 15-d intakes of intrinsic sugars and plant protein; thus, associations with 15-d intakes were particularly strong when expressed proportionally as the AS ratio (added sugars/total sugars) and AP ratio (animal protein/total protein).
CONCLUSIONS: The breath CIR is a promising measure of long-term intakes of AS and AP, especially as proportional intakes. Approaches to increase specificity would benefit the further development of this biomarker.