Tavares Edelweiss F, Vieira-Filho João P B, Andriolo Adagmar, Perez Ana B A, Vergani Naja, Sañudo Adriana, Gimeno Suely G A, Franco Laércio J
Endocrinology Section, Federal University of São Paulo, São Paulo--SP, Brazil.
Ethn Dis. 2004 Winter;14(1):49-56.
Hyperhomocysteinemia is a risk factor for cardiovascular disease. C677T mutation at the MTHFR gene and deficiencies of folic acid and vitamin B-12 may account for elevation of total homocysteine (tHcy). Ninety Brazilian Parkatêjê Indians (90.0% of the population without admixture, aged > or = 20 years) were studied. Hyperhomocysteinemia was observed in 26.7% of the Indians. No case of vitamin B-12 deficiency was detected. Folic acid deficiency was found in 43.3% of the subjects. Rates of mutated allele 677T and TT genotype were 40.7% and 14.0%, respectively. Prevalence of hypertension, dyslipidemia, smoking, WHR > or = 0.9, BMI > or = 25 kg/m2 and chronic alcohol use were 4.4%, 44.4%, 25.6%, 72.2%, 67.8%, and 0.0%, respectively. All creatinine values were normal. Natural logarithmic (ln) tHcy showed no correlation with age, but was positively correlated with systolic (r = 0.22) and diastolic (r = 0.21) blood pressure and triglycerides (r = 0.39) and inversely correlated with folic acid (r = -0.40) adjusted for age and sex. Total homocysteine (tHcy) was higher among TT genotype (P < .001). The multiple linear regression model, containing variables for sex, folic acid, TT genotype, and triglycerides, explained 50.0% of the variation of the ln tHcy. In summary, high rates of cardiovascular risk factors were discovered. C667T mutation and folic acid deficiency can explain, at least in part, the observed hyperhomocysteinemia.
高同型半胱氨酸血症是心血管疾病的一个风险因素。亚甲基四氢叶酸还原酶（MTHFR）基因的C677T突变以及叶酸和维生素B12缺乏可能导致总同型半胱氨酸（tHcy）升高。对90名巴西帕卡泰耶印第安人（占无混血人群的90.0%，年龄≥20岁）进行了研究。在26.7%的印第安人中观察到高同型半胱氨酸血症。未检测到维生素B12缺乏病例。43.3%的受试者存在叶酸缺乏。突变等位基因677T和TT基因型的发生率分别为40.7%和14.0%。高血压、血脂异常、吸烟、腰臀比≥0.9、体重指数≥25kg/m²和长期饮酒的患病率分别为4.4%、44.4%、25.6%、72.2%、67.8%和0.0%。所有肌酐值均正常。自然对数（ln）tHcy与年龄无相关性，但与收缩压（r = 0.22）、舒张压（r = 0.21）、甘油三酯（r = 0.39）呈正相关，与经年龄和性别校正后的叶酸（r = -0.40）呈负相关。TT基因型的总同型半胱氨酸（tHcy）更高（P <.001）。包含性别、叶酸、TT基因型和甘油三酯变量的多元线性回归模型解释了ln tHcy变异的50.0%。总之，发现心血管风险因素的发生率很高。C667T突变和叶酸缺乏至少可以部分解释观察到高同型半胱氨酸血症。
