The relationship between riboflavin and hypertension with MTHFR C677T in older adults in northern China: a case-control study.

The incidence of hypertension is higher in individuals with the methylenetetra-hydrofolate reductase (MTHFR) 677TT genotype. Riboflavin serves as a coenzyme of MTHFR, but its role in hypertension prevalence is poorly understood. This study aimed to explore the relationship between riboflavin levels and hypertension and the impact of genotype on this relationship. The case-control study used data from the Tianjin Elderly Nutrition and Cognition study, with 200 hypertensive patients and 200 matched non-hypertensive controls. It collected questionnaires, clinical data, and measured blood riboflavin levels using the dried blood spot technique. Conditional logistic regression analyzed varia-bles related to hypertension prevalence, with effects assessed by odds ratios (ORs) and 95% confidence intervals (CIs). The hypertensive group had significantly lower riboflavin concentration than the non-hypertensive group (p<0.001). The regression analysis indicated that regardless of adjustment for sociodemographic characteristics, riboflavin concentration was negatively associated with the prevalence of hypertension. In the multivariable model, the OR was 0.607 [95%CI, 0.507-0.727], p<0.001. Additionally, we found an interaction between MTHFR genotype and riboflavin status. Compared with the combined TT genotype and below-median riboflavin levels as the reference category, the CC genotype and above-median riboflavin levels decreased the prevalence of hypertension (OR, 0.189 [95%CI, 0.071-0.501], p=0.001). In conclusion, riboflavin status impacts the development of hypertension. There is also interaction between the MTHFR genotype and riboflavin. Specifically, low riboflavin status increases the prevalence of hypertension when combined with the MTHFR 677TT genotype.