Limitations of our study
hypertensive
REGRESSION
Our study also has several limitations. First, as an observational study, although a number of covariates have been adjusted for in the regression models, we cannot exclude the possibility of residual confounding from other unmeasured or unknown factors, such as detailed information on antioxidant dietary intakes, dietary habits, and physical activity. Second, Se was only measured at a single time point. More frequent measurements of Se would have provided more information. Third, due to a lack of relatively high levels of Se in this study population, we were unable to further investigate the potentially U-shaped relationship of Se with renal function. Moreover, this sample size was not large enough to explore the 3-way interactions of selenium, folate, and tHcy on renal outcomes. Fourth, the study population consisted of hypertensive adults from China; the generalizability of the results to a general population or to other ethnicities remains to be verified. Owing to the study limitations, confirmation of our findings in an independent study is necessary.