Biomedical subjects

F Gartenberg

Publications and source records attributed to F Gartenberg.

4 recordsLinked to original sources

PubMed1995

Longitudinal measurements of bone density and biochemical indices in untreated primary hyperparathyroidism.

A large number of patients with primary hyperparathyroidism today do not undergo parathyroidectomy. In this prospective study, we evaluated the effect of untreated disease on biochemical and bone densitometric indices. In 66 patients, seven annual measurements showed no change in serum calcium, phosphorus, PTH, vitamin D, or alkaline phosphatase; in urinary calcium, hydroxyproline or hydroxypyridinium cross-link excretion; or lumbar spine, femoral neck, and radial bone mineral density. The subset of postmenopausal women also showed no change in biochemical indices or bone density at any of the three sites. Twenty-four patients met guidelines for surgery as established by the NIH Consensus Conference, 1990. They differed from those who did not meet these guidelines only by being younger (50 +/- 3 vs. 62 +/- 2 yr; P = 0.0005) and by having higher urinary calcium excretion [7.7 +/- 0.9 vs. 5.4 +/- 0.3 mmol/L (310 +/- 37 vs. 215 +/- 14 mg/g creatinine); P < 0.01]. No longitudinal changes in biochemical profile or bone mineral density at any site were noted in this subgroup. Conservative management of patients with mild primary hyperparathyroidism does not lead to progression of disease, as reflected by biochemical indices. Bone density is maintained over 6 yr of observation at sites reflecting both cortical (radius) and cancellous (lumbar spine) bone.

Adult↗

PubMed1995

Increased bone mineral density after parathyroidectomy in primary hyperparathyroidism.

Skeletal involvement in primary hyperparathyroidism is characterized by preferential loss of cortical bone, whereas cancellous bone is relatively spared. Little data are available concerning changes in bone density, particularly at sites containing more cancellous bone, after successful parathyroidectomy. Most patients with primary hyperparathyroidism are asymptomatic, but approximately 50% meet one or more criteria for surgery. In a prospective study of 34 patients who met one or more such criteria, bone density rose at all skeletal sites (lumbar spine, femoral neck, and the radius) in the 4 yr after surgery. The lumbar spine, with most cancellous bone, showed a rapid (mean +/- SE, yr 1, 8.2 +/- 2.0%; P < 0.005) and sustained (yr 4, 12.8 +/- 2.8%; P < 0.001) rise. Post-menopausal patients were similar (by yr 4, 12.5 +/- 2.7%; P < 0.005). At the femoral neck, with intermediate cancellous and cortical composition, a similar increase was noted (12.7 +/- 3.8% by yr 4; P < 0.01). The distal radius, containing mostly cortical bone, rose modestly (4.0 +/- 1.5% by yr 3; P < 0.05), except in patients with lowest preoperative bone density, where the increase was marked (12.3 +/- 2.6% by yr 3; P < 0.05). In patients meeting surgical guidelines, parathyroidectomy is associated with improved bone mineral density.

Adult↗

PubMed1992

Urinary hydroxypyridinium cross-links of collagen in primary hyperparathyroidism.

Urinary concentrations of the collagen cross-links, pyridinoline (PYD) and deoxypyridinoline (DPD), were determined in 87 patients with untreated or surgically treated primary hyperparathyroidism (PHPT). Eighty-four healthy individuals, matched for age and sex, constituted the control group for the excretion of pyridinium cross-links. In addition, a subgroup of 25 patients with PHPT was followed longitudinally for up to 2 yr after successful parathyroidectomy. Mean urinary excretion of PYD (46.8 +/- 2.7 nmol/mmol creatinine) and DPD (17.6 +/- 1.3 nmol/mmol creatinine) was significantly higher in patients with untreated PHPT than in normal subjects (P less than 0.001). In the group undergoing successful parathyroidectomy, mean urinary concentrations of PYD (34 +/- 2.5) and DPD (9.4 +/- 0.8) were similar to those in normal controls and significantly lower than those in the untreated patient population (P less than 0.001). The urinary concentration of both cross-links was significantly correlated with serum levels of both alkaline phosphatase and PTH. Mean urinary concentrations of both cross-link compounds decreased significantly within 6 months in patients followed longitudinally and as early as 2 weeks after surgery in individual patients compared to presurgical baseline values. These changes preceded the reduction in serum alkaline phosphatase and hydroxyproline by approximately 6 months. The results demonstrate that urinary hydroxypyridinium cross-links of collagen are useful indices in the clinical assessment of bone involvement in PHPT.

Alkaline Phosphatase↗

PubMed1990

Nephrolithiasis and bone involvement in primary hyperparathyroidism.

PURPOSE: The purpose of this study was to compare patients with primary hyperparathyroidism with and without nephrolithiasis with regard to (1) biochemical profile, and (2) presence and extent of bone involvement. PATIENTS AND METHODS: Of 70 unselected patients enrolled in a longitudinal study on the natural history of primary hyperparathyroidism, 62 who underwent complete bone densitometry evaluation were considered. The patients had mild hypercalcemia (2.77 +/- 0.02 mmol/L), as well as elevated parathyroid hormone levels by mid-molecule, N-terminal, and immunoradiometric assays. Bone densitometry was assessed by dual-photon absorptiometry of the lumbar spine and femoral neck, and single-photon absorptiometry of the forearm. RESULTS: Eleven of the 62 patients (18%) had nephrolithiasis. There was no difference in serum parathyroid hormone levels, calcium, phosphorus, serum 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D3 between those with and without kidney stones. Total daily urinary calcium excretion was higher among those who formed stones (8.2 +/- 1.0 mmol versus 6.1 +/- 0.4 mmol, p less than 0.05), but not when expressed per mmol of creatinine (0.72 +/- 0.07 versus 0.69 +/- 0.04). Urinary hydroxyproline was also higher in patients who formed stones (58 +/- 11 mg/24 hours versus 37 +/- 2 mg/24 hours; p less than 0.05). Hypercalciuria occurred in 39% of the entire cohort (n = 24), and in 33% (n = 17) of those without stones. Only 29% (n = 7) of those with hypercalciuria had nephrolithiasis. Calcium excretion correlated positively with serum 1,25-dihydroxyvitamin D3 (r = +0.32, p less than 0.05), and negatively with forearm bone mineral density (all patients: r = -0.34, p less than 0.05; hypercalciuric patients: r = -0.53, p less than 0.05). Circulating 1,25-dihydroxyvitamin D3 levels were elevated in a similar proportion of (1) all patients (31%, n = 19); (2) those with nephrolithiasis (27%); and (3) those without stones (31%). Bone mineral density was less than 80% of normal in 61% of patients, but forearm, femoral neck, and lumbar spine density were indistinguishable among those with and without stones. CONCLUSIONS: Cortical bone demineralization occurs to the same extent and frequency in patients with and without nephrolithiasis, and these two subgroups share similar biochemical and bone densitometric profiles. The pathophysiologic events leading to renal and skeletal involvement in primary hyperparathyroidism may be less selective than previously believed, as evidenced by: (1) increased urinary hydroxyproline in patients with nephrolithiasis, and (2) documentation that urinary calcium excretion reflects not only vitamin D status, but bone resorption was well.

Bone Density↗