Association of soil potassium and sodium concentrations with spatial disparities of prevalence and mortality rates of hypertensive diseases in the USA.

Crop available soil potassium is generally low and on the decline in the southeastern states of the USA because of the increasing crop and runoff removal and decreasing application of potassium fertilizer. Hypertension-related mortality rates are also high in the southeastern states and are on the rise. Among 41 elements analyzed from 4856 sites across all 48 states, potassium is identified as the only independent element whose soil concentration has significant association with spatial disparities of essential hypertension and hypertension-related mortality rates in the 48 states between 1999 and 2014. Essential hypertension and hypertension-related mortality rates of the 6 states with the lowest soil potassium concentration are about 50-26% higher than that of the 6 states with the highest soil potassium concentration in the 48 states (RR: 1.50, 1.26, low CI 95% 1.47, 1.25 and upper CI 95% 1.53, 1.27, respectively). Though sodium was not identified as an independent factor, an apparent significant inverse correlation exists between hypertension prevalence rates and soil sodium concentration in the 48 states (r = - 0.66, p = 0.00). There likely has been a decline of potassium in USA produces per unit weight over time and a likely association between this decline and increasing hypertension rate, particularly in the southeastern states. Hence, results of this study suggest the need of increasing potassium intakes for reducing hypertension-related mortality rates in the southeastern states. Results of this study also support further examination of potential benefits of sodium from mixture of non-chloride salts in natural produces.