Objective To explore the correlation between MTHFR C677T gene polymorphism and hypertension, hyperhomocysteinemia(Hcy), and hyperlipidemia in the Tibetan population of Tibet.

Methods Using a cluster sampling method, participants from high-altitude regions including Ngari Prefecture, Lhasa City, and Nyingchi City in Tibet were enrolled. Differences in MTHFR C677T genotype distribution among individuals with hypertension, HHcy, and hyperlipidemia were analyzed, and multivariate logistic regression was performed to assess the association between these conditions and the TT genotype.

Results A total of 574 eligible subjects were included, with a mean age of 40.64±12.67 years. Males accounted for 46.7%(268/574) and females 53.3%(306/574). Regional distribution was 34.8%(200/574) from Nyingchi City, 33.1%(190/574) from Lhasa City, and 32.1%(184/574) from Ngari Prefecture. Mean systolic and diastolic blood pressures were 117.89±18.98 mm Hg and 79.74±14.88 mm Hg, respectively. The frequency of the TT genotype was significantly higher in the hypertension group than in the non-hypertension group(12.32% vs. 5.96%, P=0.013), and higher in the hyperhomocysteinemia group than in the non-hyperhomocysteinemia group(9.41% vs. 3.31%, P=0.010). No significant difference in TT genotype frequency was observed between the hyperlipidemia and non-hyperlipidemia groups(P > 0.05). Compared with the CC/CT genotypes, the TT genotype was associated with hypertension(OR=2.855, 95% CI: 1.393-5.990) and hyperhomocysteinemia(OR=4.788, 95% CI: 1.617-14.180), but not with hyperlipidemia.

Conclusions The MTHFR C677T TT genotype is significantly associated with hypertension and hyperhomocysteinemia in the Tibetan population, suggesting that this polymorphism may be a genetic risk factor for these diseases in high-altitude regions.