Relationship of American Indian blood quantum with osteoporosis risk: a cross-sectional study of American Indian women in Oklahoma.

Information regarding the prevalence and risk of osteoporosis among American Indian (AI) women is limited. This study showed that with increasing AI blood quantum, the prevalence of osteoporosis at the hip based on BMD T-scores decreased and this appeared to be independent of other risk factors. INTRODUCTION: This study was designed to investigate the effects of AI blood quantum (BQ) on osteoporosis prevalence and risk in a cohort of AI women in Oklahoma. METHODS: Women (n = 301), aged 50 years and older, were recruited to participate in the Oklahoma American Indian Women's Osteoporosis Study. Baseline bone density, fracture history, bone biochemical markers, and potential risk factors were assessed. Participants were stratified by AI BQ into BQ1 ≤ 25%, BQ2 = 25-49%, BQ3 = 50-74%, and BQ4 = 75-100%. The effects of BQ on the prevalence and risk of osteoporosis were evaluated. RESULTS: Based on T-scores, one in approximately eight women in the study was osteoporotic at one or more sites. The prevalence of osteoporosis decreased (p < 0.05) with increasing BQ, especially at the hip, trochanteric, and intertrochanter regions. No differences in bone-specific alkaline phosphatase and C-telopeptide were observed across BQ that could account for the differences in bone density. 25-OH vitamin D decreased with increasing BQ, but mean for each BQ1-4 was > 40 ng/mL. Fracture history did not differ across BQ, and though 52% of the population consumed less than the RDA for calcium, no effect of BQ was observed. CONCLUSIONS: In this cohort of women who identified as AI, greater Indian BQ was associated with a decrease in the prevalence of osteoporosis.

Non-surgical therapy of primary hyperparathyroidism.

BACKGROUND: Primary hyperparathyroidism is a commonly encountered illness that can usually be treated successfully with surgery. However, non-surgical ablation by either infusion of contrast media via angiography or percutaneous injection of ethanol has been reported from a few medical centers. METHODS: All patients undergoing non-surgical treatment of primary hyperthyroidism at the University of Oklahoma Health Sciences Center were identified and their records reviewed. RESULTS: We have used non-surgical techniques to treat three patients with primary hyperparathyroidism. The patients were considered poor surgical candidates or had persistent hypercalcemia after neck exploration. Hypercalcemia was improved or cured in each of the patients without recurrence. CONCLUSIONS: Our application of these techniques indicates that centers without extensive experience can successfully employ angiographic or ethanol ablation of parathyroid adenomas.

An open-label extension study of alendronate treatment in elderly women with osteoporosis.

We have recently reported the results of a 24-month, double-blind, placebo-controlled study in 359 elderly osteoporotic women who were treated with daily oral alendronate (ALN) 1, 2.5, or 5 mg or placebo (PBO). We report the results of a 12-month, open-label, extension study during which 246 patients from the original study were treated with ALN 10 mg/day. Significant increases in lumbar spine bone mineral density (BMD) were observed in patients who had previously received PBO or ALN 1 and 2.5 mg/day for 24 months. Significant gains in trochanter BMD were seen in all treatment groups. Small changes were observed in femoral neck, total body, and forearm BMD during the course of this extension study. In general, the greatest increases in BMD during the open-label extension year occurred in patients who received either PBO or the lower doses of ALN during the previous 2-year blinded study. The frequencies of all categories of upper gastrointestinal adverse experiences (AEs) were less during months 25-36 (open-label extension) than during months 0-24 (original study). In conclusion, treatment with ALN 10 mg/day for 12 months in elderly women with osteoporosis who were previously treated for 24 months with PBO or ALN 1, 2.5, or 5 mg/day increased or maintained BMD of the spine, trochanter, and forearm, and was generally safe and well tolerated, especially in the upper gastrointestinal tract.

The effect of aging on bone mineral metabolism and bone mass in Native American women.

OBJECTIVE: To examine the effect of age on mineral metabolism and bone mineral density (BMD) of the hip and spine in Native American women. DESIGN: A cross-sectional study. SETTING: The Sac and Fox Nation in rural Oklahoma MEASUREMENTS: Serum measurements were made of 25 hydroxyvitamin D (25OHD), osteocalcin, and immunoreactive parathyroid hormone. Bone mineral density of the hip and spine was assessed by dual energy X-ray absorptiometry. PARTICIPANTS: A total of 77 Native American women aged 19 to 85 years. RESULTS: Serum 25 hydroxyvitamin D was related inversely to age (r = -0.32; P < .05) and was less than 15 ng/mL in 7% of the subjects. Serum osteocalcin was higher (P < .001) in postmenopausal than in premenopausal subjects. In postmenopausal subjects, serum osteocalcin was related to age (r = .59, P < .001). BMD was lower (P < .001) in postmenopausal than in premenopausal subjects. There was no evidence of bone loss before age 50 in either the femur or the spine. Age (r > or = -0.48, P < .001) and body mass index (BMI) (r > or = 0.41, P < .005) were independent determinants of both femoral and lumbar BMD. Serum 25OHD was a significant independent determinant of both lumbar (r = .26, P < .05) and femoral (r = .41, P < .01) BMD. Age, BMI, and serum 25OHD together accounted for 70% of the variance in BMD at these sites. The use of t scores indicated femoral bone density was higher (P < .05) in premenopausal Native American women, and lower (P < 0.05) in postmenopausal subjects, compared with white women. CONCLUSIONS: In Native American women, there is a reduction in bone density and a sustained increase in bone turnover postmenopausally. BMI and serum 25OHD are significant determinants of BMD. Peak BMD may be higher, and the postmenopausal rate of bone loss greater, than that in white women.

Educational needs of internal medicine residency graduates: general internist versus subspecialists.

Residency training is inadequate with respect to the needs of general internal medicine doctors in several areas. We undertook this study to determine the practice habits and educational requirements of general versus subspecialty internists. A survey was mailed to 138 doctors who had completed at least a three-year university-based internal medicine post-graduate training. Sixty-three (46%) responded, of whom 32 completed additional training in a subspecialty of internal medicine. Many (14 of 32) subspecialists described their practice as general internal medicine (GIM) with a subspecialty emphasis. GIM was as important to their practice as it was to the general internists. General internists saw non-internal medicine disciplines as important but subspecialists did not. General internists frequently performed procedures that were not formally taught during training, while subspecialists rarely if ever performed a procedure outside the scope of their fellowship training. Internal medicine training programmes should be able to individualize training based on the career choices of trainees such that training will more fully prepare trainees for practice.

Effect of adrenergic and muscarinic cholinergic agonists on atrial natriuretic peptide secretion by isolated rat atria. Potential role of the autonomic nervous system in modulating atrial natriuretic peptide secretion.

Stretching of the atrial wall is a known stimulant for atrial natriuretic peptide (ANP) secretion. Little is known about other factors that may influence ANP secretion. We examined the effects of the neurotransmitters of the autonomic nervous system on ANP secretion from isolated rat left atria. Superfusion with 10 muM norepinephrine produced a biphasic rise in ANP secretion with a peak response 2.5-fold above baseline secretion. To determine whether the response to norepinephrine primarily reflected alpha- or beta-adrenergic receptor stimulation, atria were superfused with 0.1 muM isoproterenol or 10 muM phenylephrine and 1 muM propranolol. ANP secretion in response to isoproterenol was biphasic, similar to the response to norepinephrine. Phenylephrine evoked a monophasic ANP secretory response, which was delayed in onset relative to that of isoproterenol or norepinephrine. Superfusion with 10 muM methacholine alone had no effect on ANP secretion, but rapidly attenuated norepinephrine-stimulated secretion by 67%. From these observations we conclude: (a) Both alpha- and beta-adrenergic agonists directly and distinctively stimulate ANP secretion; (b) Norepinephrine stimulates ANP secretion by both alpha- and beta-adrenergic mechanisms, however the secretory response pattern of norepinephrine reflects a predominence of beta-adrenergic activity; (c) Under basal conditions, methacholine does not influence ANP secretion; and (d) Methacholine inhibits norepinephrine-stimulated ANP secretion. Thus, in vivo, activation of the sympathetic nervous system may enhance ANP secretion, whereas a rise in parasympathetic tone may lower ANP secretion.