What they observed was an acute, dose-dependent increase in blood pressure upon drug treatment, Farooqi said. "So, basically what this means is that both our own data on the patients with the MC4R gene problem, and the data from Lilly giving the drug, show that this gene is important in controlling blood pressure."
Most people, of course, are not missing the MC4R gene. What normally happens in obese individuals, Farooqi explained, is this: "As people gain weight, they make more fat. And your fat produces a hormone called leptin, and levels of leptin then increase. 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."
Dr. Daniel Marks, of the Oregon Health & Science University in Portland, said, "It is a well-done study and teaches us something about the fundamental physiology of blood pressure regulation in humans."
Yet Marks also cautioned that MC4R is not likely the only link between obesity and blood pressure.
"There's a difference between being statistically significant and clinically significant," he said. "Those are two different issues, and I think the issue of clinical significance is still pretty unknown here."
Dr. George Bakris, of the University of Chicago Pritzker School of Medicine, called the study a "really big deal."
"I think this paper is going to become a real classic," Bakris said, "because it is the first time this kind of characterization has been done in such a very clean way and provides a way of identifying people who may not have a blood pressure problem, even though they may have a weight problem."
All rights reserved