title: [Frequency and clinical overview of hypolactasia among children, adolescents and students of Szczecin schools].
abstract: BACKGROUND
  Adult type hypolactasia is the most common non allergic abnormal reaction to food. Its frequency increases with age. Hypolactasia creates the risk of decreased milk consumption, which could be the cause of lowered bone density, osteoporosis and fractures. The aim of the research was to estimate the frequency of hypolactasia among Szczecin's citizens.
  
  
  METHODS
  200 randomly chosen people aged between 10-23, divided into three groups: 10-14 years old (36 children), 15-19 years old (77 adolescents) as well as 20-23 (87 students) were examined. The study protocol included the completion of a questionnaire, a breath hydrogen test, as well as the evaluation of the occurrence of intestinal ailments during the test.
  
  
  RESULTS
  Hypolactasia was diagnosed in 48 (24%) subjects, regardless of sex, including 11% of the children, 22% of the adolescents, and 31% of the students (p = 0.055). Lactose intolerance was observed in 65% of the subjects with hypolactasia, including over 47% of the adolescents and 85% of the students.
  
  
  CONCLUSIONS
  During BHT, hydrogen concentration in the expired air was the highest in the group of students and the lowest in the children, indicating an age-dependent decline in intestinal lactase activity among people with hypolactasia, which explains the increasing proportions of subjects with lactose intolerance increasing with age.
authors.forename: Agata
authors.initials: A
authors.lastname: Marasz
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D006801:Humans; D007787:Lactose Intolerance / Q000453:epidemiology*; D011044:Poland / Q000453:epidemiology; D015995:Prevalence; D012737:Sex Factors; D013334:Students / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D055815:Young Adult