Activation of the calcium sensing receptor stimulates gastrin and gastric acid secretion in healthy participants.

UNLABELLED: In 17 adults on a fixed metabolic diet, an 11-day course of cinacalcet increased serum gastrin and basal gastric acid output, but not maximal gastric acid output, compared with a placebo. These findings indicate that the calcium sensor receptor plays a role in the regulation of gastric acid. INTRODUCTION: Gastric acid secretion is a complex process regulated by neuronal and hormonal pathways. Ex vivo studies in human gastric tissues indicate that the calcium sensing receptor (CaR), expressed on the surface of G and parietal cells, may be involved in this regulation. We sought to determine whether cinacalcet, a CaR allosteric agonist, increases serum gastrin and gastric acid secretion. METHODS: Seventeen healthy adults with normal gastric acid output were placed on an 18-day metabolic diet. On day 8 (baseline), participants were given cinacalcet (15 then 30 mg/day) or placebo for 11 days. Changes in gastric acid output, serum gastrin, and other measures were compared in the two groups. RESULTS: Changes in serum gastrin and basal acid output (adjusted for baseline body weight) were significantly more positive in the cinacalcet group compared with placebo (P = 0.004 and P = 0.039 respectively). Change in maximal acid output was similar in the two groups (P = 0.995). As expected, cinacalcet produced significant decreases in serum PTH (P < 0.001) and ionized calcium levels (P = 0.032), and increases in serum phosphorus levels (P = 0.001) and urinary calcium (P = 0.023). CONCLUSIONS: This study provides in vivo evidence that activation of the CaR increases serum gastrin levels and basal gastric acid secretion in healthy adults.

Benefits and costs of medical nutrition therapy by registered dietitians for patients with hypercholesterolemia. Massachusetts Dietetic Association.

The Massachusetts Dietetic Association implemented a statewide retrospective quality assurance audit to determine the effectiveness and cost of medical nutrition therapy in patients with hypercholesterolemia (> 5.20 mmol/L). Hypercholesterolemia is a major risk factor for coronary artery disease (CAD). Data were collected at 23 sites from 285 outpatients seen by a registered dietitian for a minimum of two visits. Patients taking lipid-lowering medications were excluded. Of the 285 patients, 108 (38%) were men and 177 (62%) were women. The mean age was 51.4 years (range = 22 to 79 years). Results showed that the mean reduction in serum cholesterol level was 8.6%, which translates to a decrease of approximately 17.2% in risk of CAD. Forty-five percent of the total population showed an 11% or greater reduction in serum cholesterol levels. Reduction in serum cholesterol levels correlated with increased time spent with a dietitian (r = .188, P < .001). The mean cost for nutrition intervention with a dietitian was $163 (a mean of four visits). In contrast, the estimated annual cost of treatment for patients with hypercholesterolemia using drug therapy is $1,450. A 1993 report calculated the annual cost of treating heart disease in the United States to be $80 billion. Medical nutrition therapy should be considered the initial, effective, and low-cost approach in the management of patients with mild to moderate hypercholesterolemia.