THURSDAY, Dec. 18 (HealthDay News) -- Central melanocortinergic tone significantly effects blood pressure, and may contribute to the impact of weight loss and obesity on blood pressure, according to data published online Dec. 17 in the New England Journal of Medicine.
Jerry R. Greenfield, M.D., Ph.D., of the University of Cambridge Metabolic Research Laboratories in the United Kingdom, and colleagues evaluated blood pressure, heart rate and urinary catecholamines among overweight or obese individuals who had a mutation in the melanocortin 4 receptor (MC4R) gene. These data were compared with data assessed from equally overweight control individuals without the MC4R gene mutation.
After adjusting for the use of antihypertensive medications, individuals with the MC4R mutation had significantly lower mean systolic blood pressure (123 versus 131 mm Hg) and lower mean diastolic pressure (73 versus 79 mm Hg) compared with those without the mutation, the report indicates. Administration of an MC4R agonist was associated with significant increases in both systolic and diastolic blood pressures, the investigators found. Changes in blood pressure were not impacted by insulin level. Individuals with the MC4R mutation also exhibited a lower increase in waking heart rate, a lower heart rate during euglycemic hyperinsulinemia, and a lower urinary excretion of norepinephrine, the researchers report.
"Results of our genetic and pharmacologic studies implicate melanocortinergic signaling in the control of human blood pressure through an insulin-independent mechanism," the authors conclude.
Support for the study was received from Eli Lilly. Several of the study authors report financial relationships with the pharmaceutical industry.
Abstract
Full Text
