P3566Ambulatory blood pressure response to riboflavin supplementation in adults with the C677T polymorphism in the folate metabolising enzyme methylenetetrahydrofolate reductase (MTHFR)

Abstract Background Epidemiological evidence suggests that the C677T polymorphism in the folate metabolising enzyme MTHFR is associated with a 24–87% increased risk of hypertension. Riboflavin (a cofactor for MTHFR) can modify this phenotype, as demonstrated in a series of RCTs, at this centre. ABPM measures BP over 24hrs and provides a more reliable assessment of an individual's BP compared to clinic BP. Aim To investigate the effect of riboflavin supplementation on BP (by ABPM) in adults with the MTHFR 677TT genotype. Methods Adults (n=3462) were recruited and screened for the MTHFRTT genotype and those eligible (n=81), were stratified by baseline SBP and randomised to receive riboflavin (10mg/day/16weeks) or placebo. Riboflavin status was measured using the erythrocyte glutathione reductase activation coefficient (EGRac) assay and clinic and ABPM were measured in accordance with clinical guidelines. Results Mean 24hr, daytime and night-time SBP was 6mmHg higher (p<0.05) in adults with the TT v CC genotype. BP response to riboflavin was strongly dependent on baseline BP. In participants with a baseline SBP≥125mmHg, riboflavin resulted in a significant BP lowering in daytime SBP (Table). Day-time SBP response to riboflavin Treatment Placebo P-value Age 48.6 (11.3) 47.8 (12.0) 0.823 Male n (%) 17 (73.9) 12 (46.2) 0.093 BMI 28.8 (3.8) 27.2 (3.1) 0.131 Riboflavin status (EGRac)† Pre 1.33 (1.28–1.38) 1.29 (1.24–1.34) Post 1.20 (1.14–1.25) 1.31 (1.25–1.36) <0.001 Change −0.12 0.02 Daytime BP (mmHg)‡ Pre 137.1 (132.7–141.3) 134.7 (130.3–139.1) Post 133.0 (128.9–138.1) 134.8 (130.6–139.1) 0.036 Change −3.8 −0.2 ANCOVA, adjusting for sex. †Higher EGRac values indicate lower riboflavin status; ‡mean of participant daytime/awake hrs personalised for each participant. Conclusion This is the first study to show, using ABPM, that riboflavin supplementation, targeted at adults with the MTHFR 677TT genotype, results in significant lowering of mean, day and night BP. Given the frequency of this genotype worldwide (approximately 10%, but as high as 30% in some populations) these findings could offer a personalised approach for BP management in at-risk sub-populations. Acknowledgement/Funding This work was supported by DSM Nutritional Products, Ltd and Wellcome Trust-Wolfston Northern Ireland Clinical Research Facility are acknowledged