High parathyroid hormone (PTH) levels in postmenopausal women with vitamin D insufficiency are associated with altered bone geometry, increased bone turnover, and reduced bone mineral density (BMD) in the lumbar spine, investigators concluded.
Lene Langageraard Rødbro, MD, and colleagues at Aarhus University Hospital in Aarhus, Denmark, studied 102 postmenopausal women with low 25-hydroxyvitamin D levels (less than 50 nmol/L) who had either secondary hyperparathyroidism (SHPT) with elevated PTH levels (above 6.9 pmol/L, 51 patients) or normal PTH levels (51 patients).
Levels of 25-hydroxyvitamin D in both groups were 38 nmol/L. PTH levels were 8.5 pmol/L in the SHPT group vs 5.2 pmol/L in women with normal PTH levels, the investigators reported online ahead of print in Osteoporosis International. Both groups were similar with respect to body mass index and estimated glomerular filtration rate.
SHPT was associated with lower total and trabecular bone area, lower cortical perimeter, and increased cortical area in the tibia and radius, Dr Rødbro’s team stated. SHPT was associated with a lower weight-adjusted BMD at the lumbar spine. High vs normal PTH levels were associated with significantly lower plasma levels of 1,25-dihydroxyvitamin D and phosphate, but higher levels of osteocalcin and borderline higher levels of collagen type 1 cross-linked C-telopeptide.
Bone metabolism, density, and geometry in postmenopausal women with vitamin D insufficiency: a cross-sectional comparison of the effects of elevated parathyroid levels. Osteoporos Int. 2018; published online ahead of print. Doi: 10.1007/s00198-4602-x