Regional Variations of Blood Pressure in the United States Are Associated with Regional Variations in Dietary Intakes: The NHANES-III Data

Compared with other regions in the United States, the southern region has had the highest stroke mortality rate and a more prevalent and resistant hypertension. We designed this analysis of the data obtained from the National Health and Nutritional Examination Survey III (NHANES-III), which is a community-based cross-sectional survey, to describe regional variations in blood pressure and the reported consumption of nutrients, focusing on those linked to blood pressure, in the United States. We selected the following variables from the NHANES-III data for this analysis: systolic and diastolic blood pressures, protein, carbohydrates, total fatty acids, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, cholesterol, fiber, sodium, potassium, calcium, magnesium, zinc, copper, iron, riboflavin, niacin, thiamin, alcohol and vitamins C, E, B-6 and B-12. Of the 17,752 participants in the survey who were 18 y of age or older, the south had the highest systolic and diastolic blood pressures (P < 0.005 for each) and reported the highest consumption of monounsaturated fatty acids, polyunsaturated fatty acids and cholesterol (P < 0.05 for all) and the least amount of fiber in the multivariate analysis (P < 0.005). The highest reported sodium consumption was in the south region (3.4 +/- 0.02 g), and the lowest was in the west (3.2 +/- 0.03 g; P < 0.05). The south also consumed the least potassium, calcium, phosphorous, magnesium, copper, riboflavin, niacin, iron and vitamins A, C and B-6 (P < 0.005). There was no difference among the four regions in frequency of "adding salt on the table." The region of the United States that includes the "stroke belt" has dietary patterns that may contribute to the high prevalence of hypertension and cardiovascular disease.