Genomic Study Links Potassium Levels to Regulation of BP

A recent paper described a study designed to examine different points of the human genome to determine where the genetic sequence linked serum potassium levels to modulation of blood pressure (BP).

Investigators at the University of Georgia (Athens, USA) performed genome-wide analyses to identify genomic loci that interacted with potassium to influence BP using single-marker and gene-based tests on Chinese participants of the GenSalt study (Genetic Epidemiology Network of Salt Sensitivity).

The initial GenSalt study, which was designed to evaluate gene-diet (sodium and potassium) interactions on BP regulation, was performed in rural areas in northern China from October 2003 to July 2005. The overall objective of the study was to identify susceptibility genes that influenced individual BP responses to dietary sodium and potassium intake in human populations. The specific aims were: (1) To localize and identify novel genes related to variation in BP responses to a low dietary sodium intake and a high dietary sodium intake; (2) To localize and identify novel genes related to variations in BP responses to oral potassium supplementation; and (3) To localize and identify novel genes related to BP responses to a cold pressor test. In addition, the GenSalt study localized and identified genes related to usual BP level and the risk of hypertension.

For the current study, the investigators analyzed data from1876 GenSalt participants. The average results of three urine samples were used to estimate potassium excretion, while nine BP measurements were taken using a random-zero sphygmomanometer. A total of 2.2 million single nucleotide polymorphisms were imputed using Affymetrix (Santa Clara, CA, USA) 6.0 genotype data and the Chinese Han of Beijing and Japanese of Tokyo HapMap reference panels.

Results published in the December 6, 2017, online edition of the journal Circulation: Cardiovascular Genetics revealed two genomic loci - one of which had never been identified - and six individual genes, all significantly associated with the regulation of blood pressure in the body.

“One of the major drawbacks of previous genetic studies of hypertension is that these studies did not explore the interactions between genes and environmental factors,” said senior author Dr. Changwei Li, assistant professor of biostatistics and epidemiology at the University of Georgia. “For example, some genes’ effect on blood pressure only manifests under certain environments. If environmental factors are not taken into account, these genes will not be identified for hypertension.”

“Findings from our study help to identify individuals who are particularly sensitive to dietary potassium as a way to reduce blood pressure, based on their genomic profiles,” said Dr. Li. “Subsequently, we could provide personalized suggestions to prevent disease based on their genotypes.”

Related Links:
University of Georgia
Affymetrix