title: Association of the European lactase persistence variant (LCT-13910 C>T polymorphism) with obesity in the Canary Islands.
abstract: BACKGROUND
  European lactose tolerance genotype (LCT -13910 C>T, rs4988234) has been positively associated to body mass indexes (BMI) in a meta-analysis of 31,720 individuals of northern and central European descent. A strong association of lactase persistence (LP) with BMI and obesity has also been traced in a Spanish Mediterranean population. The aim of this study was to analyze a potential association of LP compared to lactase non-persistence (LNP) with BMI in inhabitants of the Canary Islands of Spain using Mendelian randomization.
  
  
  METHODS
  A representative, randomly sampled population of adults belonging to the Canary Islands Nutrition Survey (ENCA) in Spain, aged 18-75 years (n = 551), was genotyped for the LCT - 13910 C>T polymorphism. Milk consumption was assessed by a validated questionnaire. Anthropometric variables were directly measured. WHO classification of BMI was used.
  
  
  RESULTS
  LP individuals were significantly more obese than LNP subjects (χ(2) = 10.59; p<0.005). LP showed in a multivariate linear regression analysis showed a positive association of LP with BMI compared to LNP, (β = 0.96; 95% CI: 0.08-1.85, p = 0.033). In a multinomial logistic regression analysis normal range weight LP subjects showed an odds ratio for obesity of 2.41; 95%CI 1.39-418, (p = 0.002) compared to LNP.
  
  
  CONCLUSIONS
  The T-13910 of the allele LCT-13910 C>T polymorphism is positively associated with BMI. LP increases significantly the risk to develop obesity in the studied population. The LCT-13910 C>T polymorphism stands proxy for the lifetime exposure pattern, milk intake, that may increase susceptibility to obesity and to obesity related pathologies.
authors.affiliation: Family Medicine Research Centre, School of Health and Medical Sciences, Örebro University, Örebro, Sweden. ricardo.almon@orebroll.se
authors.forename: Ricardo
authors.initials: R
authors.lastname: Almon
authors.forename: Eva Elisa
authors.initials: EE
authors.lastname: Álvarez-León
authors.forename: Lluís
authors.initials: L
authors.lastname: Serra-Majem
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D000818:Animals; D015992:Body Mass Index; D001835:Body Weight / Q000235:genetics; D004327:Drinking Behavior; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D043322:Lactase / Q000235:genetics*; D007787:Lactose Intolerance / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D008892:Milk; D009765:Obesity / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D013030:Spain; D011795:Surveys and Questionnaires
chemical_list: D043322:Lactase