Lactose intolerance and associated factors in a population group in northeastern Brazil

Abstract

INTRODUCTION: The prevalence of lactose intolerance (LI) is still unknown, especially in multi-ethnic populations.

AIM: Evaluate the LI and associated factors in a population group in northeastern Brazil.

METHODS: Ninety-one students and staff at a public university, residents in the Northeast of Brazil, previously healthy, over 18 years, were selected for convenience. The hydrogen breath test (HBT) was performed at a dose of 25 grams lactose 10%, by collecting baseline sample fasted 12 hours, and consecutive samples 60, 90, 120, 150 and 180 minutes after administration of lactose. Increased hydrogen concentrations greater than 20 parts per million (ppm) of the basal sample was considered positive. HBT positive individuals, in the presence of at least one of the symptoms indicative of LI were considered intolerant. The semi-structured questionnaire with information about demographics (gender, age and ethnicity), clinical (gastrointestinal complaints, LI self-perceived) and dietary (dietary restrictions and consumption of dairy products) was applied.

RESULTS: The prevalence of LI was 34.1%, higher among those who declared themselves black (p = 0.005). There was poor correlation between LI self-perceived and diagnosed (Kappa index 0.1615). Individuals with LI self-perceived, independent confirmation of the diagnosis, had a lower intake of lactose, when compared to the group without IL self-perceived (p = 0,00).

CONCLUSION: The prevalence of LI was significant and was associated with ethnicity, even in a multi-racial population. Understanding the actual number of individuals affected with LI provides the proper management of this syndrome