Moore Lori B, Liu Sarah V, Halliday Tanya M, Neilson Andrew P, Hedrick Valisa E, Davy Brenda M
Departments of Human Nutrition, Foods, and Exercise and.
Food Science and Technology, Virginia Tech, Blacksburg, VA.
J Nutr. 2017 Dec;147(12):2364-2373. doi: 10.3945/jn.117.256875. Epub 2017 Sep 20.
Objective indicators of dietary intake (e.g., biomarkers) are needed to overcome the limitations of self-reported dietary intake assessment methods in adolescents. To our knowledge, no controlled feeding studies to date have evaluated the validity of urinary sodium, nitrogen, or sugar excretion as dietary biomarkers in adolescents. This investigation aimed to evaluate the validity of urinary sodium, nitrogen, and total sugars (TS) excretion as biomarkers for sodium, protein, and added sugars (AS) intake in nonobese adolescents. In a crossover controlled feeding study design, 33 adolescents [12-18 y of age, 47 ± 25th percentile (mean ± SD) of body mass index (BMI; in kg/m) for age] consumed 5% AS [low added sugars (LAS)] and 25% AS [high added sugars (HAS)] isocaloric, macronutrient-matched (55% carbohydrate, 30% fat, and 15% protein) diets for 7 d each, in a randomly assigned order, with a 4-wk washout period between diets. On the final 2 d of each diet period, 24-h urine samples were collected. Thirty-two adolescents completed all measurements (97% retention). Urinary sodium was not different from the expected 90% recovery (mean ± SD: 88% ± 18%, = 0.50). Urinary nitrogen was correlated with protein intake ( = 0.69, < 0.001), although it was below the 80% expected recovery (62% ± 7%, < 0.001). Urinary TS values were correlated with AS intake during the HAS diet ( = 0.77, < 0.001) and had a higher value of 0.28 than did AS intake ( = 0.36). TS excretion differed between LAS (0.226 ± 0.09 mg/d) and HAS (0.365 ± 0.16 mg/d) feeding periods ( < 0.001). Urinary sodium appears to be a valid biomarker for sodium intake in nonobese adolescents. Urinary nitrogen is associated with protein intake, but nitrogen excretion rates were less than previously reported for adults, possibly owing to adolescent growth rates. TS excretion reflects AS at 25% AS intake and was responsive to the change in AS intake. Thus, urinary biomarkers are promising objective indicators of dietary intake in adolescents, although larger-scale feeding trials are needed to confirm these findings. This trial was registered at clinicaltrials.gov as NCT02455388.
为克服青少年自我报告饮食摄入量评估方法的局限性，需要饮食摄入量的客观指标（如生物标志物）。据我们所知，迄今为止尚无对照喂养研究评估尿钠、氮或糖排泄作为青少年饮食生物标志物的有效性。本研究旨在评估非肥胖青少年尿钠、氮和总糖（TS）排泄作为钠、蛋白质和添加糖（AS）摄入量生物标志物的有效性。在一项交叉对照喂养研究设计中，33名青少年[年龄12 - 18岁，年龄别体重指数（BMI；kg/m²）处于第47±25百分位（均值±标准差）]，以随机分配的顺序，分别食用5% AS[低添加糖（LAS）]和25% AS[高添加糖（HAS）]的等热量、宏量营养素匹配（55%碳水化合物、30%脂肪和15%蛋白质）饮食各7天，饮食之间有4周的洗脱期。在每个饮食期的最后2天，收集24小时尿液样本。32名青少年完成了所有测量（保留率97%）。尿钠与预期的90%回收率无差异（均值±标准差：88%±18%，P = 0.50）。尿氮与蛋白质摄入量相关（r = 0.69，P < 0.001），尽管低于预期的80%回收率（62%±7%，P < 0.001）。在HAS饮食期间，尿TS值与AS摄入量相关（r = 0.77，P < 0.001），且其r值（0.28）高于AS摄入量的r值（0.36）。LAS（0.226±0.09 mg/d）和HAS（0.365±0.16 mg/d）喂养期的TS排泄存在差异（P < 0.001）。尿钠似乎是非肥胖青少年钠摄入量的有效生物标志物。尿氮与蛋白质摄入量相关，但氮排泄率低于先前报道的成年人，这可能归因于青少年的生长速度。TS排泄反映了25% AS摄入量时的AS情况，并且对AS摄入量的变化有反应。因此，尿生物标志物有望成为青少年饮食摄入量的客观指标，尽管需要更大规模的喂养试验来证实这些发现。本试验已在clinicaltrials.gov注册，注册号为NCT02455388。
