The association between vitamin E intake and hypertension: results from the re-analysis of the National Health and Nutrition Survey.
Recently, there has been an increasing concern about noncommunicable diseases (NCDs), in which oxidative damage plays a role. In this paper, we have re-analyzed the data from the National Health and Nutrition Survey (NHNS) 2007 to study the relationship between an NCD (e.g. hypertension) and the dietary intake of vitamin E, a potent anti-oxidative vitamin. The inclusion criteria were those aged 40 and over, excluding pregnant or lactating women, and data from 1,405 males and 2,102 females were analyzed. The mean ages were 63.5 and 62.4, respectively. Nutrients intake was evaluated from a semi-weighted, 1-d household dietary record. When the subjects were categorized into tertiles based on their vitamin E intake, higher vitamin E intake was associated with a lower percentage of subjects with hypertension (p for trend=0.01). Subjects with higher vitamin E intake had higher energy intake-adjusted intake of other nutrients which have been considered to be related to hypertension such as potassium, magnesium, and vitamin C. Logistic regression analysis was done with the low tertile of vitamin E intake as the reference. The medium and high tertiles of vitamin E intake were associated with a significantly lower odds ratio for hypertension, 0.73 (95% CI; 0.62-0.87) for the former and 0.81 (95% CI; 0.69-0.96) for the latter. Additional analyses, one adjusted for the indices associated with hypertension and one excluding the subjects with vitamin E supplementation, have yielded the similar results. In summary, re-analysis of data from NHNS has revealed that higher vitamin E intake was significantly associated with lower prevalence of hypertension.