Ghrelin and Bone Mass in Postmenopausal Hypertensive Women

Abstract

Background: Ghrelin, a recently discovered peptide mainly secreted by the stomach, has an orexigenic effect which stimulates secretion of the growth hormone. It also has vasodilator effects which reduce blood pressure and stimulate in vitro, bone formation. Objectives: To evaluate the effect of ghrelin on bone mass and bone remodeling markers in postmenopausal hypertensive women. Material and Methods: 25 postmenopausal hypertensive women, light to moderate based on the JNC-VII criteria, were studied. They had a mean age of 58 ± 8 years, a body mass index of 28 ± 6 and a hypertension development time of 65 ± 84 months. Osteocalcin, PTHi, 25-vitamin D, ghrelin in serum and deoxypiridinoline in urine were determined in all patients. A lumbar spine densitometer was made (DXP Lunar, Madison, Wisc., USA). Results: Diminished levels of ghrelin were observed in the osteoporotic group (40 ± 19 vs. 78 ± 40, p = 0.027). When the patients were separated according to ghrelin tertiles, a greater bone mass was observed in the upper tertiles, which was associated with a decrease in the urinary deoxypiridinoline. When the total population was analyzed, no relation between the ghrelin and bone mass was found, nor with any of the parameters of calcium metabolism. Only a statistically significant relation between ghrelin and deoxypiridinoline was observed (r = –0.428, p = 0.026). Conclusions: In postmenopausal hypertensive women, ghrelin may produce a protecting effect over bone mass through an anticatabolic mechanism manifested by a decrease of bone resorption.