To further investigate the relationship between calcitonin deficiency and osteoporosis, we have measured bone mineral content (BMC) by single photon absorptiometry in patients made iatrogenically calcitonin deficient by prior total thyroidectomy for thyroid cancer. Compared to sex-, age-, height-, and weight-matched normal controls, male patients had a significantly lower mean BMC at the midradius (1.162 +/- 0.02 vs. 1.301 +/- 0.05 g/cm; P less than 0.02) and the distal radius (1.180 +/- 0.04 vs. 1.338 +/- 0.04 g/cm; P less than 0.01). Female patients also had a significantly lower BMC at the midradius compared to those of a similarly matched group of normal controls and a group of patients on L-T4 suppression for nodular goiters (0.791 +/- 0.04 vs. 0.896 +/- 0.05 vs. 0.891 +/- 0.03 g/cm; P less than 0.025). We conclude that calcitonin deficiency from surgical thyroidectomy is associated with significant decreases in bone mineral content in both sexes. This lends further support to the concept that calcitonin deficiency may be an important causative factor in the development of osteoporosis.

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A method has been developed to estimate glomerular filtration rate using computer evaluation of images obtained during routine renal scanning. The technique requires less than 40 minutes of imaging time, requires only a single blood sample, and correlates highly with 24 hour creatinine clearance.

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It has been suggested that calcium-channel blockers may delay gastric emptying by inhibiting gastric smooth muscle contraction. Most reports in man, however, reveal no significant delay in gastric emptying after using nifedipine; other calcium-channel blockers have not been studied in humans to date. We studied the effects of verapamil and diltiazem on solid-phase gastric emptying in 10 healthy volunteers. Each subject underwent a radionuclide gastric emptying determination (1) without preadministered medication, (2) after verapamil 80 mg orally every 6 hr for 10 doses, and (3) after diltiazem 60 mg by mouth given as one dose. Results revealed no significant difference in gastric emptying rates after pretreatment with verapamil or diltiazem when compared with no premedication (P greater than 0.37). We conclude that verapamil and diltiazem do not significantly delay gastric emptying in normal subjects. These data may be of clinical significance when prescribing calcium-channel blockers to patients with diseases associated with altered gastric emptying.