A study published in the New England Journal of Medicine identified the molecular pathway linking obesity and hypertension (high blood pressure). The melanocortin-4 receptor (MC4R) helps regulate blood pressure in humans.
 
Researchers examined obese individuals who were missing the MC4R gene and compared them to obese individuals who had two normal copies of the gene. Individuals without the MC4R gene tended to have slightly lower blood pressure values than did the control group, and less hypertension overall.
 
As people gain weight, they make more fat. Fat produces a hormone called leptin, and levels of leptin then increase when weight is gained. Leptin then circulates in the bloodstream and goes to the brain, where it triggers MC4R, which then triggers the sympathetic system and drives up your blood pressure.
 
Researchers of the study also suggest MC4R is probably not the only link between blood pressure and obesity.
 
Hypertension is a leading cause of kidney disease.

This article originally appeared in the January 2009 issue of Kidney Beginnings: The Electronic Newsletter.