Antihypertensive effects of oral calcium supplementation may be mediated through the potent vasodilator CGRP.
Alteration of calcium metabolism and changes in the levels of calcium-regulating hormones have been described in essential hypertension. In the majority of the reported clinical trials, calcium supplementation has resulted in a decrease in blood pressure. However, the mechanisms by which such a response would be mediated are entirely unknown. The present study confirmed that daily supplementation with 1.4 g of elemental calcium led to a significant decrease in both systolic and diastolic blood pressures (P < .01). Decrease in blood pressure was negatively correlated with increase in plasma calcitonin gene-related peptide (CGRP), measured with radioimmunoassay and by radioreceptor assay (P < .001), and positively correlated with decrease in intact parathyroid hormone (PHT) (P < .05). Following cessation of calcium supplementation, plasma CGRP levels and the blood pressure both reverted back to the base-line values, suggesting a direct effect of supplemented calcium on these two parameters.
Wimalawansa
S J
SJ
Department of Medicine (Endocrinology), Royal Post-graduate Medical School, London, U.K.
D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015740:Calcitonin Gene-Related Peptide / Q000097:blood / Q000502:physiology*; D002118:Calcium / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D014664:Vasodilation / Q000187:drug effects*
D000959:Antihypertensive Agents; D010281:Parathyroid Hormone; D015740:Calcitonin Gene-Related Peptide; D002118:Calcium