Introduction: Single nucleotide polymorphic variants of the methylenetetrahydrofolate reductase (MTHFR) gene have been related with a tendency to gain weight according to recent studies. The aetiology of atypical anorexia nervosa remains under investigation and might be associated with the genetic background. The aim of this study was to evaluate the association between the presence of A1298C or C677T polymorphisms of the MTHFR gene and weight status in a sample of adolescent girls diagnosed with anorexia nervosa.
Patients and methods: This cross-sectional study evaluated a total of 40 adolescent girls diagnosed with anorexia nervosa aged 1319 years. We recorded anthropometric parameters and calculated BMI z-scores adjusted for age, as well as duration of amenorrhea. Blood samples were obtained for genotyping and hormonal assessment.
Results: Mean values of BMI were 16.25±1.41 kg/m2, while the mean BMI adjusted for age was −2.10±1.31. The prevalence of the MTHFR A1298C polymorphic variant differed, almost significantly, between quartiles of BMI z-scores (CA+CC vs AA genotype, Q1 vs Q2 vs Q3 vs Q4: 70% vs 50% vs 25% vs 20%, Chi-square P-value=0.092). Multivariate regression analysis showed that girls with BMI z-scores within the top quartile had significantly lower risk of carrying the MTHFR A1298C polymorphic variant compared to the lowest quartile (CA+CC genotype vs AA genotype: OR 0.047, P-value=0.032), adjusted for age, estrogen levels and duration of amenorrhea. The prevalence of MTHFR C677T polymorphic variant or the combined prevalence of either MTHFR polymorphic variant (C677T or A1298C) did not differ between quartiles of BMI z-score adjusted for age.
Conclusions: We observed a significantly lower prevalence of the polymorphic variant A1298C of the MTHFR gene in adolescent girls with BMI z-score in the highest quartile compared to the lowest quartile, indicating a possible association between the presence of MTHFR wild type genotype and the tendency to lose weight.
18 - 21 May 2019
European Society of Endocrinology