Schulze Kerry J, O'Brien Kimberly O, Germain-Lee Emily L, Baer David J, Leonard Amanda, Rosenstein Beryl J
Center of Human Nutrition, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205, USA.
Am J Clin Nutr. 2003 Jul;78(1):110-6. doi: 10.1093/ajcn/78.1.110.
Reduced bone mass is common in both children and adults with cystic fibrosis (CF) and may be a consequence of inadequate calcium absorption. The effect of CF on intestinal calcium absorption and retention has not been described in children.
Calcium absorption and urinary losses were characterized in clinically stable girls with CF consuming self-selected diets and following usual pancreatic enzyme regimens.
The percentage of calcium absorption was assessed in 23 girls (aged 7-18 y) with CF by using oral ((44)Ca) and intravenous ((42)Ca) stable isotopes. Girls were grouped according to Tanner stage of breast development. True calcium absorption (V(a)) was determined as the product of percentage calcium absorption and average 4-d daily calcium intake. Calcium balance was estimated by subtracting urinary calcium and estimated endogenous fecal losses from the measure of V(a). Analysis of variance was used to compare outcomes among pubertal groups, and regression analysis was used to describe the relations of percentage and total calcium absorption to calcium intake and of urinary calcium to sodium excretion.
Percentage calcium absorption was inversely related to calcium intake. Percentage absorption and V(a) were similar to values observed in healthy girls in other studies. Total calcium absorption and estimated calcium balance were significantly greater among girls in early puberty (Tanner stages 2-3) than in prepubertal or late-pubertal girls (P < 0.05). Urinary calcium was positively related to urinary sodium excretion (P = 0.02).
The efficiency of calcium absorption was not compromised in clinically stable girls with CF.
骨量减少在患有囊性纤维化（CF）的儿童和成人中都很常见，可能是钙吸收不足的结果。CF对儿童肠道钙吸收和潴留的影响尚未见报道。
对临床稳定、饮食自选且遵循常规胰酶治疗方案的CF女童的钙吸收和尿钙流失情况进行特征描述。
通过口服（（44）Ca）和静脉注射（（42）Ca）稳定同位素评估23名患有CF的女童（7 - 18岁）的钙吸收百分比。女童根据乳房发育的坦纳分期进行分组。真实钙吸收量（V(a)）通过钙吸收百分比与4天平均每日钙摄入量的乘积来确定。通过从V(a)测量值中减去尿钙和估计的内源性粪便钙流失来估算钙平衡。采用方差分析比较青春期各组的结果，采用回归分析描述钙吸收百分比和总钙吸收量与钙摄入量以及尿钙与钠排泄之间的关系。
钙吸收百分比与钙摄入量呈负相关。吸收百分比和V(a)与其他研究中健康女童的观察值相似。青春期早期（坦纳分期2 - 3）女童的总钙吸收量和估计钙平衡显著高于青春期前或青春期后期女童（P < 0.05）。尿钙与尿钠排泄呈正相关（P = 0.02）。
临床稳定的CF女童的钙吸收效率未受影响。
