Flatz G, Howell J N, Doench J, Flatz S D
Hum Genet. 1982;62(2):152-7. doi: 10.1007/BF00282305.
A total of 1805 apparently healthy, adult and adolescent Germans (1572 males and 233 females with a mean age of 20.3 years) were examined for lactose absorption capacity employing a field version of the breath hydrogen (H2) test. The diagnostic parameter, maximal change of breath hydrogen concentration 120 or 150 min after a load of 50 g lactose, showed a bimodal distribution, separating lactose absorbers (n = 1537, 85.2%) and lactose malabsorbers (n = 268, 14.8%). The distribution of the adult lactase phenotypes was independent of age, sex, and educational status. The incidence of gastrointestinal symptoms after lactose administration demonstrated the incongruity of lactose malabsorption and lactose intolerance. In addition to grouping by residence, the probands were classified according to the birthplaces of their grandparents in order to reconstruct the distribution pattern of the lactase phenotypes prior to World War I, a period of relative population stability. Considerable differences in the frequency of lactose malabsorption were found in regions corresponding to traditional ethnic groups within the German population: northwest Germany 6-9%, west and south 13-14%, southwest 23%, east (including formerly German territories east of rivers Oder and Neisse) 22%. These differences are discussed with reference to population history. The present fairly even distribution of the lactase phenotypes in West Germany is the result of internal migrations at the end of World War II.
共对1805名表面健康的德国成年人及青少年（1572名男性和233名女性，平均年龄20.3岁）进行了乳糖吸收能力检测，采用现场呼气氢（H2）测试法。诊断参数为50克乳糖负荷后120或150分钟时呼气氢浓度的最大变化，结果呈双峰分布，区分出乳糖吸收者（n = 1537，85.2%）和乳糖吸收不良者（n = 268，14.8%）。成人乳糖酶表型的分布与年龄、性别和教育程度无关。乳糖摄入后胃肠道症状的发生率表明乳糖吸收不良与乳糖不耐受情况不一致。除按居住地分组外，还根据先证者祖父母的出生地对其进行分类，以重建第一次世界大战前乳糖酶表型的分布模式，当时人口相对稳定。在德国人口中与传统族群相对应的地区，乳糖吸收不良的频率存在显著差异：德国西北部6 - 9%，西部和南部13 - 14%，西南部23%，东部（包括奥得河和尼斯河以东的原德国领土）22%。结合人口历史对这些差异进行了讨论。西德目前乳糖酶表型相当均匀的分布是第二次世界大战末期国内人口迁移的结果。
