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The determinants of trabecular bone mass in primary hyperparathyroidism
310
Abstracts
metabolic bone disease. The surface area of the histological section suitable for histomorphometric analysis is reduced by the build-up of bone dust and by trabecular fracture, produced by the conventional Bordier bone drill. We describe here a modification of this drill that allows escape of dust from around the cutting edge of the teeth, which greatly reduces bone dust volume and trabecular fracture. The modification consists of a series of grooves extending from between each adjacent pair of teeth for part of the way along the outer surface of the shaft which permit escape of the dust from around the cutting edges of the teeth. Apertures extending through the tube wall allow the escaping dust to pass inwardly distal to the biopsy and outward when the plunger is used to eject the biopsy once it has been obtained. In paired samples, the new drill was shown to reduce significantly the quantity of bone dust (p < 0.03) and trabecular injury (p = 0.05) in the biopsy specimens. The improvement in the quality of the biopsy makes it likely that a smaller drill (i.e., 5 or 6 mm internal diameter) would give a sample of sufficient size to give good repeatability and small sampling variation.
THE DETERMINANTS OF TRABECULAR IN PRIMARY HYPERPARATHYROIDISM B.C. Lalor, A.J.J. Freemont, S. Bogle, and P.H. Adams University Departments Manchester University,
BONE MASS
R. Laite, E.B. Mawer,
of Medicine UK.
and Pathology,
There is an increase in peripheral and vertebral crush fracture in patients with primary hyperparathyroidism (1 HPT), and as a group they have a reduced bone mass in relation to age. However, the precise cause of this and whether it is related to the degree of IHPT are not clear. Transilial biopsies (7 mm) were obtained following tetracycline labeling from 63 patients with biochemically proven 1HPT (13 men, 50 women). Standard histomorphometric assessments were made of trabecular bone volume (TBV), osteoid extent, mineralizing fronts, resorption and osteoelastic activity, and mean wall thickness. Assessments were also made of vitamin D status and parameters of mineral metabolism. All but one biopsy were abnormal, but no mineralization defect was seen in any biopsy. TBV was not different from that obtained for age- and sex-matched controls. Seven patients had osteoporosis (defined as the presence of one or more vertebral crush fractures or an age- and sex-adjusted TBV > 2 SD below the mean). All were postmenopausal women. Three had had a premature menopause (~40). Three (including two with an early menopause) had previously received treatment with corticosteroids. Multivariate analysis of the relevant variables showed that age and cigarette smoking were negatively correlated, and mean wall thickness and bone resorption were positively correlated with TBV. It seems likely that not all patients with IHPT are destined to develop osteoporosis, but that in those who do it is multifactorial.
DETERMINANTS OF SERUM CALCITRIOL PRIMARY HYPERPARATHYROIDISM
IN
B.C. Lalor, G. Lumb, E.B. Mawer, and P.H. Adams Department of Medicine, Manchester Royal Infirmary and Manchester University, UK.
of the Bone and Tooth Society Meeting
Serum concentrations of calcitriol are commonly found to be elevated in patients with primary hyperparathyroidism (1 HPT). Previous work has shown simple positive correlations between serum concentrations of calcitriol, kalcidiol, and parathyroid hormone and with renal function. Sixtythree patients (50 women, 13 men) with IHPT of variable severity were studied to determine the factors likely to influence the serum concentrations of calcitriol. 16 patients had elevated serum calcitriol concentrations (range 66- 104 pgiml). These patients had higher serum calcidiol concentrations (median 22.1 ng/ml in the patients with raised calcitriol, median 17.8 ng/ml in those with normal calcitriol, p < 0.05). No differences were found between serum concentrations of iPTH, calcium, phosphate, or renal function. Multivariate analysis of all the relevant variables using the best subset method for the entire group showed that parathyroid function, calcidiol, and urinary calcium were significant positive determinants of serum calcitriol and that serum calcium was a significant negative determinant.
A NEW COMPUTERIZED METHOD FOR DIRECT MEASUREMENTOFMEANTRABECULARPLATE THICKNESS IN HUMAN ILIAC CREST BIOPSIES R.W.E. Mellish, N.J. Garrahan,
S. Vedi, and J.E. Compston
Dept. of Pathology, University of Wales College of Medicine, Heath Park, Cardif, UK. Measurement of mean trabecular plate thickness (MTPT) provides important information about patterns of bone loss in ageing and osteoporosis. Previously, either direct manual measurements or calculations from area and perimeter measurements have been used. We report a new computerized method for direct measurement of MTPT using an lbas II Image Analyser.,iJndecalcified, von Kossa-stained sections from biopsies of 56 healthy subjects were examined at x 83. There was a strong correlation between values for MTPT obtained using the new method and values calculated from area and perimeter measurements also made by the Image Analyser (r = 0.98); however, correlation between these methods and calculations derived from grid measurements was weaker (r = 0.44). The precision of the new method was 2%. There was a significant decrease in MTPT with ages (p < 0.05) in both sexes. The mean calculated mean trabecular plate density in females decreased after the age of 50 years from 1.032 +- O.l86/mm to 0.841 + 0.212/mm, and plate separation increased from 663 + 126.3 pm to 848.8 ? 242.6 pm; there were no corresponding changes in males. The new method described enables rapid and highly reproducible measurements of MTPT. Our results suggest that MTPT decreases with age in both sexes, but that in females, loss of whole trabecular plates also contributes.
MATERNOFETAL CALCIUM TRANSPORT ACROSS THE IN SITU PERFUSED RAT PLACENTA: RELATION TO MATERNAL 1,25(OH),D, ADMINISTRATION M.Z. Mughal, C.P. Sibley, R.D.H. Boyd, and E.B. Mawer Departments of Child Health and Medicine, Manchester, Manchester, UK
University of
Abstracts
metabolic bone disease. The surface area of the histological section suitable for histomorphometric analysis is reduced by the build-up of bone dust and by trabecular fracture, produced by the conventional Bordier bone drill. We describe here a modification of this drill that allows escape of dust from around the cutting edge of the teeth, which greatly reduces bone dust volume and trabecular fracture. The modification consists of a series of grooves extending from between each adjacent pair of teeth for part of the way along the outer surface of the shaft which permit escape of the dust from around the cutting edges of the teeth. Apertures extending through the tube wall allow the escaping dust to pass inwardly distal to the biopsy and outward when the plunger is used to eject the biopsy once it has been obtained. In paired samples, the new drill was shown to reduce significantly the quantity of bone dust (p < 0.03) and trabecular injury (p = 0.05) in the biopsy specimens. The improvement in the quality of the biopsy makes it likely that a smaller drill (i.e., 5 or 6 mm internal diameter) would give a sample of sufficient size to give good repeatability and small sampling variation.
THE DETERMINANTS OF TRABECULAR IN PRIMARY HYPERPARATHYROIDISM B.C. Lalor, A.J.J. Freemont, S. Bogle, and P.H. Adams University Departments Manchester University,
BONE MASS
R. Laite, E.B. Mawer,
of Medicine UK.
and Pathology,
There is an increase in peripheral and vertebral crush fracture in patients with primary hyperparathyroidism (1 HPT), and as a group they have a reduced bone mass in relation to age. However, the precise cause of this and whether it is related to the degree of IHPT are not clear. Transilial biopsies (7 mm) were obtained following tetracycline labeling from 63 patients with biochemically proven 1HPT (13 men, 50 women). Standard histomorphometric assessments were made of trabecular bone volume (TBV), osteoid extent, mineralizing fronts, resorption and osteoelastic activity, and mean wall thickness. Assessments were also made of vitamin D status and parameters of mineral metabolism. All but one biopsy were abnormal, but no mineralization defect was seen in any biopsy. TBV was not different from that obtained for age- and sex-matched controls. Seven patients had osteoporosis (defined as the presence of one or more vertebral crush fractures or an age- and sex-adjusted TBV > 2 SD below the mean). All were postmenopausal women. Three had had a premature menopause (~40). Three (including two with an early menopause) had previously received treatment with corticosteroids. Multivariate analysis of the relevant variables showed that age and cigarette smoking were negatively correlated, and mean wall thickness and bone resorption were positively correlated with TBV. It seems likely that not all patients with IHPT are destined to develop osteoporosis, but that in those who do it is multifactorial.
DETERMINANTS OF SERUM CALCITRIOL PRIMARY HYPERPARATHYROIDISM
IN
B.C. Lalor, G. Lumb, E.B. Mawer, and P.H. Adams Department of Medicine, Manchester Royal Infirmary and Manchester University, UK.
of the Bone and Tooth Society Meeting
Serum concentrations of calcitriol are commonly found to be elevated in patients with primary hyperparathyroidism (1 HPT). Previous work has shown simple positive correlations between serum concentrations of calcitriol, kalcidiol, and parathyroid hormone and with renal function. Sixtythree patients (50 women, 13 men) with IHPT of variable severity were studied to determine the factors likely to influence the serum concentrations of calcitriol. 16 patients had elevated serum calcitriol concentrations (range 66- 104 pgiml). These patients had higher serum calcidiol concentrations (median 22.1 ng/ml in the patients with raised calcitriol, median 17.8 ng/ml in those with normal calcitriol, p < 0.05). No differences were found between serum concentrations of iPTH, calcium, phosphate, or renal function. Multivariate analysis of all the relevant variables using the best subset method for the entire group showed that parathyroid function, calcidiol, and urinary calcium were significant positive determinants of serum calcitriol and that serum calcium was a significant negative determinant.
A NEW COMPUTERIZED METHOD FOR DIRECT MEASUREMENTOFMEANTRABECULARPLATE THICKNESS IN HUMAN ILIAC CREST BIOPSIES R.W.E. Mellish, N.J. Garrahan,
S. Vedi, and J.E. Compston
Dept. of Pathology, University of Wales College of Medicine, Heath Park, Cardif, UK. Measurement of mean trabecular plate thickness (MTPT) provides important information about patterns of bone loss in ageing and osteoporosis. Previously, either direct manual measurements or calculations from area and perimeter measurements have been used. We report a new computerized method for direct measurement of MTPT using an lbas II Image Analyser.,iJndecalcified, von Kossa-stained sections from biopsies of 56 healthy subjects were examined at x 83. There was a strong correlation between values for MTPT obtained using the new method and values calculated from area and perimeter measurements also made by the Image Analyser (r = 0.98); however, correlation between these methods and calculations derived from grid measurements was weaker (r = 0.44). The precision of the new method was 2%. There was a significant decrease in MTPT with ages (p < 0.05) in both sexes. The mean calculated mean trabecular plate density in females decreased after the age of 50 years from 1.032 +- O.l86/mm to 0.841 + 0.212/mm, and plate separation increased from 663 + 126.3 pm to 848.8 ? 242.6 pm; there were no corresponding changes in males. The new method described enables rapid and highly reproducible measurements of MTPT. Our results suggest that MTPT decreases with age in both sexes, but that in females, loss of whole trabecular plates also contributes.
MATERNOFETAL CALCIUM TRANSPORT ACROSS THE IN SITU PERFUSED RAT PLACENTA: RELATION TO MATERNAL 1,25(OH),D, ADMINISTRATION M.Z. Mughal, C.P. Sibley, R.D.H. Boyd, and E.B. Mawer Departments of Child Health and Medicine, Manchester, Manchester, UK
University of