Prevalence of MTHFR C677T polymorphism and its association with serum homocysteine and blood pressure among different ethnic groups: insights from a cohort study of Nepal.

BACKGROUND: The risk of hypertension varies based on ethnicity, environmental factors, and genetic predispositions. Studies have reported a higher risk of cardiovascular diseases (CVD) and hypertension among the Newar ethnic groups in Nepal. However, the genetic analysis for Methylenetetrahydrofolate reductase (MTHFR C677T) gene mutations, serum homocysteine, and high-sensitivity C-reactive protein (hs-CRP) levels across different ethnicities remains unexplored.

METHODS: Sociodemographic information and baseline data of 489 participants were obtained from the first phase of the Dhulikhel Heart Study. Preserved blood samples were analyzed for MTHFR C677T polymorphism using real-time polymerase chain reaction (TaqMan assay), and serum homocysteine was measured through immunoassay techniques. Descriptive analysis, the Hardy-Weinberg equilibrium test, and multinomial regression were performed.

RESULTS: The prevalence of homozygous mutation (TT) was 19.8% in the Newar group and 12.5% in the Brahmin/Chhetri ethnicity. The highest mean value of homocysteine (19.4 µmol/L) was observed in homozygous participants, followed by the heterozygous mutant group (17.4 µmol/L). A statistically significant association (P = < 0.001) was found between homocysteine levels and blood pressure.

CONCLUSIONS: The Dhulikhel Heart Study reveals a significant prevalence of the MTHFR C677T gene mutation among the Newar ethnicity compared to other groups. Elevated levels of homocysteine and high-sensitivity C-reactive protein (hs-CRP) were associated with increased blood pressure.

CLINICAL TRIAL NUMBER: Not applicable.