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PubMed2002

Jumping exercises with and without raloxifene treatment in healthy elderly women.

Several meta-analyses confirm that physical exercise can slow down postmenopausal bone loss, but it is not clear whether physical exercise alone can increase bone mass. Our intent was to evaluate high-impact exercises (including jumping) and combined balance and leg-strength training, with and without raloxifene treatment, in three healthy elderly women, age 68-71 years. The 40-week study period consisted of two 17-week exercise periods with a 6-week rest period in between. The jumping exercises were performed both vertically and in different directions. Effects were measured in bone mineral density (BMD), balance, maximal gait speed, and leg extensor strength. BMD (g/cm(2)) was measured with dual-energy X-ray photon absorptiometry (DXA) at the proximal femur, lumbar spine, and total body. After the first exercise period, large losses of trochanteric BMD (8.1%-10.8%) were seen in all subjects. After both 6 weeks of rest and the second exercise period, which included both exercise and raloxifene, BMD increased in all subjects. During both exercise periods, the balance, gait speed, and leg extensor strength increased in all subjects. The results show that this kind of high-impact exercise had limited effects on BMD, but had large positive effects on balance, gait speed, and leg extensor strength. In conclusion, high-impact exercise in elderly women improves their fall risk factors, but, at least without raloxifene treatment, the trochanteric fracture risk might even increase because of reduction in the regional bone mass.

Absorptiometry, Photon↗

PubMed1993

Bone density is not reduced during the short-term administration of levothyroxine to postmenopausal women with subclinical hypothyroidism: a randomized, prospective study.

PURPOSE: Controversy exists as to whether patients with subclinical hypothyroidism benefit from treatment. Two randomized trials reported that hypothyroid symptoms improved following thyroid hormone replacement therapy. However, during the initial treatment of overt hypothyroidism with levothyroxine, three studies have demonstrated short-term (6 to 12 months) 5% to 13% reductions in bone density. The current study measures bone density during the initial treatment of subclinical hypothyroidism. PATIENTS: Seventeen postmenopausal women with subclinical hypothyroidism (elevated serum thyrotropin [TSH] and normal serum free thyroxine concentrations) and no prior history of thyroid disease were randomly assigned to levothyroxine treatment or no treatment and followed prospectively. Patients in the treatment group had similar initial serum TSH concentrations (9.8 +/- 3.3 versus 8.4 +/- 2.7 microU/mL) but were slightly older (68 +/- 7 years versus 60 +/- 5 years [p < 0.02]). The average dose of levothyroxine needed to normalize serum TSH concentration was 0.072 +/- 0.027 mg. RESULTS: Bone density determinations were not significantly different between the two groups at baseline. After 14 +/- 1 months, single-photon absorptiometry of the wrist decreased by 1.8% +/- 3.2% in the untreated patients and 0.5% +/- 4.1% in the levothyroxine-treated patients (p = NS). Dual-energy X-ray absorptiometry of the lumbar spine decreased by 0.7% +/- 2.9% in the untreated patients and rose 0.1% +/- 4.75% in the levothyroxine-treated patients (p = NS). CONCLUSIONS: Unlike the early treatment of overt hypothyroidism, there is no short-term reduction of bone density with levothyroxine treatment of subclinical hypothyroidism in postmenopausal women. These data suggest that potentially symptomatic women with subclinical hypothyroidism should be given a trial of levothyroxine therapy without concern about adverse effects on skeletal integrity.

Absorptiometry, Photon↗

PubMed1989

Monitoring skeletal response to estrogen.

Estrogen replacement therapy at accepted doses is not fully effective in preventing bone loss and fractures in postmenopausal women. Bone densitometry is useful for monitoring estrogen replacement therapy to assess dose, foster compliance, and check for secondary bone loss. The most appropriate site for bone loss monitoring is probably the spine because it shows larger decreases at the menopause than appendicular sites, it shows larger increases with therapy, and it has clinical import in terms of fracture. Both dual-photon absorptiometry (or dual-energy x-ray absorptiometry) and computed tomography are the preferred monitoring methods. The precision of these densitometry methods is generally adequate to permit interim decisions with regard to continuing therapy, as well as conclusive decisions on therapeutic efficacy after 1 to 2 years of monitoring. Judicious use of densitometry in combination with biochemical determinations can enhance therapeutic control and provide both patient and physician confidence in long-term estrogen replacement therapy.

Absorptiometry, Photon↗

PubMed1990

Effects on bone of surgical menopause and estrogen therapy with or without progesterone replacement in cynomolgus monkeys.

The influence of estrogen replacement therapy on bone loss of surgically postmenopausal cynomolgus macaques was evaluated histomorphometrically using the first (L-1) lumbar vertebra and ex vivo dual photon absorptiometry of the third (L-3) lumbar vertebra. The animals were a subgroup of a larger study on the effects of estrogen replacement therapy on diet-induced coronary artery atherosclerosis. The three experimental conditions were as follows: untreated females with oophorectomy, females with oophorectomy treated with continuous estrogen replacement therapy plus cyclic progesterone, and females with oophorectomy treated with estrogen replacement therapy. Bone mineral density (grams per square centimeter) of L-3, when covaried for body mass index (body mass index, body weight/(trunk length/100)2), was significantly lower for the oophorectomy group compared with the group treated by estrogen replacement therapy plus progesterone and estrogen replacement therapy groups (p = 0.018). When covaried for body mass index, trabecular bone volume percentage of a midsagittal section of L-1 was not significantly different between groups, but the adjusted mean was greatest in the estrogen replacement therapy plus progesterone group, followed closely by the estrogen replacement therapy group, and was least in the oophorectomy group. When covaried for body mass index, trabecular plate number was significantly lower (p = 0.022) and mean trabecular plate separation was significantly higher (p = 0.033) in the oophorectomy group. Thus both estrogen replacement therapy and estrogen replacement therapy plus progesterone provided overall protection against surgical menopause--associated bone mass loss. Cynomolgus macaques are an extremely useful animal model for estrogen replacement therapy use in prevention of postmenopausal bone loss.

Absorptiometry, Photon↗

PubMed1995

Is tubal ligation a risk factor for low bone density and increased risk of fracture?

OBJECTIVE: Osteoporosis is a major women's health problem, because it is responsible for about 1.3 million fractures in the United States each year. Estrogen deficiency is a major risk factor in the pathogenesis of osteoporosis. Recent evidence has indicated that tubal ligation may cause menstrual dysfunction and estrogen deficiency. This study examined the association between tubal ligation and bone mass in a group of elderly postmenopausal women. STUDY DESIGN: Subjects were 2215 white women > or = 65 years old participating in the Baltimore center of the Study of Osteoporotic Fractures. Bone mineral density of the proximal and distal radius and the calcaneus was measured by single photon absorptiometry. Multiple regression analysis was performed to determine whether tubal ligation had an independent effect on bone density. The effect of tubal ligation on the risk of hip and osteoporotic fractures was estimated by Cox proportional hazards model. RESULTS: Women who reported a tubal ligation had lower, although not statistically significant, bone density of the radius and calcaneus. The relative risk of hip (1.05, 95% confidence limit 0.84 to 1.32) and osteoporotic fractures (1.01, 0.80 to 1.29) was not significantly increased in women with tubal ligation. CONCLUSION: We conclude that elderly women who had a tubal ligation have small changes in bone density that are not of sufficient magnitude to increase their risk of osteoporotic fractures.

Absorptiometry, Photon↗

PubMed1995

Effects of weight gain and resumption of menses on reduced bone density in patients with anorexia nervosa.

The bone mineral density (BMD) of the lumbar vertebrae (L2-L4) and of the whole body were measured in cross-sectional and longitudinal studies in female patients with eating disorders, using dual photon absorptiometry before and after weight gain with or without resumption of menses. In the cross-sectional study, the low-body-weight anorectic patients, with or without bulimia nervosa, were found to have lower BMD of the lumbar vertebrae associated with severe weight loss, low physical activity, and earlier onset and longer duration of amenorrhea. In the longitudinal study, 11 patients attained subnormal body weight (70%SBW < or = approximately < 85% SBW), 10 patients attained normal body weight (> or = 85%SBW, 6 patients of them resumed regular menses) after treatment. The BMD of the lumbar vertebrae was found to increase with weight gain, but not to the control level. The BMD was further increased with the resumption of menses in patients with anorexia nervosa. These results suggest that resumption of menses, in addition to weight gain, is essential to normalize reduced bone mineral density.

Absorptiometry, Photon↗

PubMed1993

Bone metabolism in young women taking a monophasic pill containing 20 mcg ethinylestradiol: a prospective study.

The present one-year prospective study was performed to evaluate the effects of an oral contraceptive containing 20 mcg ethinylestradiol plus 0.150 mg desogestrel on bone metabolism in young women. Nineteen women aged 20 to 30 years completed the trial. Bone density was measured in the distal radius by dual photon absorptiometry before starting pill use and at the 3rd, 6th and 12th cycle. At the same time intervals, urinary hydroxyproline-to-creatinine ratio and serum alkaline phosphatase were evaluated. Bone density showed a slight, but not significant, increase at the end of the trial. Both urinary hydroxyproline-to-creatinine ratio and serum alkaline phosphatase showed a significant decrease. The results suggest that bone resorption is reduced, although bone density in the distal radius is not significantly increased in young women using an oral contraceptive containing only 20 mcg ethinylestradiol for one year.

Absorptiometry, Photon↗

PubMed1995

Bone mass and metabolism in patients with celiac disease.

BACKGROUND & AIMS: Several aspects of the pathogenesis of osteopenia in celiac disease are still unclear. Therefore, bone mass and metabolism were evaluated in adults with celiac disease in a cross-sectional study. METHODS: Bone mineral density (BMD), assessed by total body dual-photon absorptiometry, and serum indices of bone metabolism and remodeling were evaluated in 17 patients with untreated celiac disease, 14 with celiac disease on a gluten-free diet, and 24 healthy volunteers. RESULTS: BMD, expressed as a z score, was significantly lower in patients with untreated celiac disease than in patients with treated celiac disease and volunteers and lower in patients with treated celiac disease than in volunteers. Similar changes were observed in serum calcium level, whereas intact parathyroid hormone level was significantly higher in untreated than in treated patients with celiac disease and volunteers, and no difference was found between the latter two groups. 25-Vitamin D level was significantly lower and 1,25-vitamin D level significantly higher in untreated celiac disease than in treated celiac disease and volunteers. Indices of bone remodeling were significantly higher in untreated than in treated patients and volunteers and significantly and positively correlated with iPTH in untreated patients with celiac disease. CONCLUSIONS: BMD is almost invariably low in patients with untreated celiac disease. Results in treated patients suggest that gluten-free diet improves but does not normalize BMD. Untreated celiac disease is characterized by high levels of 1,25-vitamin D and by increased bone turnover, caused by the increase in intact parathyroid hormone level.

Absorptiometry, Photon↗

PubMed1989

Relation of body fat distribution to serum lipids and lipoproteins in elderly women.

Fat distribution measured by dual photon absorptiometry, serum lipids and lipoproteins were determined in 95 elderly women with mild osteoporosis. Increasing obesity, determined anthropometrically as body mass index (BMI) = body weight/(height)2, was associated with a more central fat distribution (P less than 0.001) Central fat distribution correlated positively and independently of BMI and body weight to serum cholesterol, low density lipoprotein-cholesterol (LDL-C), triglycerides and the ratio LDL-C/HDL-C (P less than 0.05), whereas the correlation between central fat distribution and high density lipoprotein-cholesterol (HDL-C) was negative (P less than 0.05). We conclude that the increased risk of cardiovascular disease observed in subjects with central fat distribution might be partly mediated through changes in the lipoprotein profile.

Absorptiometry, Photon↗

PubMed1995

Osteopenia in genetically diabetic DB/DB mice and effects of 1alpha-hydroxyvitamin D3 on the osteopenia. Basic Research Group.

To explore the pathogenesis of non-insulin-dependent diabetes mellitus associated osteopenia, we examined age-related changes of the femur metaphyseal bone mineral density in genetically diabetic (db/db) mice and non-diabetic (+/+) mice of the same strain using single photon absorptiometry and characterized the osteopenia pharmacologically and biochemically. Bone mineral density increased with age in the +/+ mice from 5 to 16 weeks of age, but reached a plateau in the db/db mice at 8 weeks of age, and significant differences between the two groups were observed after 12 weeks of age. Ash weight (A) and dry weight (D) of the femur and A/D ratio were significant lower in the db/db mice than in the +/+ mice after 8 weeks of age. Significant elevations of serum calcium and parathyroid hormone (PTH) were observed after 8 weeks and 12 weeks of age, respectively. Serum 1alpha,25-dihydroxyvitamin D levels were significantly decreased in the db/db mice compared to the +/+ mice. Daily oral treatment with 1alpha-hydroxyvitamin D3 (1alpha-(OH)D3) for 4 weeks starting from 8 weeks of age significantly attenuated the bone loss in the db/db mice. These results suggest that an impaired bone mineralization probably by insufficient vitamin D activity and high PTH levels are involved in the osteopenia in the db/db mice. 1alpha-(OH)D3 exerted beneficial effects on the bone loss.

Absorptiometry, Photon↗

PubMed1990

Aging bone loss from the femur, spine, radius, and total skeleton.

In order to establish a comprehensive model for involutional bone loss, the following measurements were made of healthy white women: total body calcium by neutron activation analysis, bone density of the distal radius by single-photon absorptiometry, and dual-photon absorptiometry of the lumbar spine and femur (neck, Ward's triangle, and intertrochanteric areas). Longitudinal measurements were made for each of these skeletal sites except the femur. Evidence for a curvilinear component to the pattern of bone loss with aging was found for total body calcium and bone density of the radius, but not for the other measurements on analysis of cross-sectional data. Longitudinal studies confirmed that substantial bone loss begins only after menopause for the radius, whereas there is substantial premenopausal loss of bone from the lumbar spine. Prevention of vertebral osteoporosis requires maximizing bone mass before menopause. If longitudinal data confirm the model of linear rates of bone loss for the femur, there will be important implications for prevention of hip fractures.

Adult↗

PubMed1991

Contributions of regional adipose tissue depots to plasma lipoprotein concentrations in overweight men and women: possible protective effects of thigh fat.

Anthropometry and dual-photon absorptiometry (DPA) were used to examine associations of regional adiposity with plasma lipid, lipoprotein, and lipoprotein subfraction mass concentrations in moderately overweight men and women. Among 130 women, waist to thigh girth ratio (WTR) correlated with triglycerides (TG) (r = .33, P less than .0001) and negatively with high-density lipoprotein (HDL)-cholesterol (HDL-C) (r = -.37, P less than .0001) concentration, as expected. While WTR did not correlate with low-density lipoprotein (LDL)-cholesterol (LDL-C) it correlated positively with the mass subfraction of small (Sfo, 0 to 7) LDL (r = .38, P less than .0001), and negatively with large (Sfo, 7 to 12) LDL (r = -.31, P less than .01). Among 133 men, similar though weaker relationships were found. Thigh girth correlated positively with HDL and HDL2-C and mass, and with LDL particle size among women. Multivariate analysis suggests that association of WTR with lipoprotein values known to carry risk of coronary heart disease (CHD) are due at least as much to effects of thigh girth as to deleterious effects of waist girth. Estimates of fat weight in thigh and abdominal regions by DPA support thigh fat as contributing to these effects of thigh girth. Thigh fat may contribute to lipoprotein profiles that predict lower risk of cardiovascular disease.

Absorptiometry, Photon↗

PubMed1992

Composition of weight loss in severely obese women: a new look at old methods.

Seven severely obese, outpatient dieters lost weight (mean +/- SEM, 14 +/- 1 kg), and the composition of weight lost was determined by six different models. Total body water (TBW), total body potassium (TBK), and body density, bone mineral content, and fat as determined by dual photon absorptiometry (DPA) were measured while subjects were weight-stable, before and after weight loss. Fat loss was calculated by three two-compartment models (2C-TBW, 2C-TBK, and hydrodensitometry [2C-HD]), one three-compartment model (HD with correction for water content of fat-free mass [FFM], 3C), and one four-compartment model (HD with correction for water and mineral content of FFM, 4C), and was measured directly by DPA. Mean composition of weight loss was similar for all models (mean weight lost as fat: 89% for DPA, 91.5% for 4C, 89% for 3C, 88.6% for 2C-HD, and 87% for 2C-TBW) except 2C-TBK (weight lost as fat, 66%). There was a much wider range of individual values for the 2C-TBW and 2C-TBK models (17% to 138% and 18% to 93%, respectively) than for the multicompartment models (63% to 112%) and DPA (76% to 107%). Almost opposite results were obtained for the same individual when using the 2C-TBK and 2C-TBW models. The discrepancy between these models was due to the inverse relationship between changes in TBW and TBK in the group as a whole (r = -.34, NS). In addition, TBK loss was found to be dependent on the initial level of hyperinsulinemia, calculated as the area under the 2-hour oral glucose tolerance curve.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗

PubMed1992

Non-invasive densitometry.

Several non-invasive methods are available to measure bone density in different regions of the skeleton. Bedrest and microgravity both lead to bone loss, which is more marked in the lower parts of the skeleton. The bone loss can be monitored by non-invasive techniques in longitudinal studies when precision (i.e. the ability to produce repeated measurements with the same value) is adequate. Bone mineral density (BMD) can be measured with single photon absorptiometry in the lower forearm and calcaneus and with dual energy X-ray absorptiometry (DXA) in almost any region of the skeleton. The latter technique pairs good precision with very low radiation exposure. With peripheral quantitative computed tomography very precise measurements of the lower forearm and tibia are feasible with low radiation dose. It has the additional option of separate measurement of cortical and trabecular bone. This could be of particular importance in microgravity studies, as trabecular bone loss is more severe in this condition. A new development is the measurement of ultrasound velocity or attenuation which depends on bone density and structure. Ultrasound data of the calcaneus correlate well with bone mineral density in spine and hip. The advantage of this technique is that it operates without radiation. However, the clinical value has to be established. The ultimate choice of technique and skeletal region for bone densitometry will depend on specific requirements.

Absorptiometry, Photon↗

PubMed1990

Effects of transdermal versus oral hormone replacement therapy on bone density in spine and proximal femur in postmenopausal women.

66 early postmenopausal women were randomised to 28-day cycles of either transdermal hormone replacement therapy--continuous oestradiol 17-beta 0.05 mg daily, with norethisterone acetate 0.25 mg daily for 14 of each 28 days--or oral therapy--continuous conjugated equine oestrogens 0.625 mg daily, with dl-norgestrel 0.15 mg daily for 12 of each 28 days. An untreated reference group of 30 women were studied concurrently. Bone density was measured in the lumbar spine and proximal femur by dual photon absorptiometry at 6-month intervals for 18 months. Skeletal turnover was assessed by serum measurements of calcium, phosphate, and alkaline phosphatase, and by urine estimations of hydroxyproline/creatinine and calcium/creatinine excretion. In both treatment groups by comparison with the untreated groups by comparison with the untreated group, bone density increased in the vertebrae and proximal femur and biochemical measurements indicated a significant reduction in bone turnover.

Absorptiometry, Photon↗

PubMed1992

A controlled trial of prednisolone treatment in primary biliary cirrhosis. Three-year results.

The results of a 3-year, placebo-controlled trial of prednisolone treatment in primary biliary cirrhosis (PBC) are presented. The active (n = 19) and placebo (n = 17) arms were initially well matched for age, menopausal status and disease severity. At 3 years hepatic symptoms were relatively improved in the prednisolone group. Hepatic mortality was 3/19 (prednisolone), 5/17 (placebo) (p = n.s.). For all liver blood tests the trend favoured prednisolone treatment, though the differences were only significant for alkaline phosphatase and protein. All immunoglobulins fell significantly. Quantitative ELISA determination of antimitochondrial antibody showed a significant fall in the prednisolone group compared with placebo (p less than 0.001 at 1 year, p less than 0.05 at 3 years). Deterioration in histology (appearance of cirrhosis) was more common in the placebo group. Overall hepatic function (hepatic mortality, doubling in bilirubin, 6 milligrams fall in albumin, de novo appearance of cirrhosis or symptoms of portal hypertension) was significantly worse in the placebo group (p less than 0.01). After 3 years no significant differences could be detected in bone mineral content (single photon absorptiometry of radius and femur) between the two groups or in comparison with other PBC patients. Thus, after 3 years, prednisolone treatment was associated with a better overall hepatic outcome and little evidence of increased bone loss.

Absorptiometry, Photon↗

PubMed1992

Sodium fluoride prevents bone loss in primary biliary cirrhosis.

Low-bone-turnover osteoporosis is a common complication of primary biliary cirrhosis (PBC). Since sodium fluoride stimulates bone formation we assessed the effect of this drug on bone mass in a 2-year, prospective, double-blind trial including 22 women with PBC who were randomly assigned to receive sodium fluoride (50 mg/day) or placebo. All received calcium supplements and low doses of vitamin D. Bone mineral density of the lumbar spine was measured by dual-photon absorptiometry initially and every 6 months. Vertebral fractures were evaluated in thoracic and lumbar spine initially, and after 1 and 2 years. Seven patients in the fluoride group and eight in the placebo group completed the trial. In the fluoride group, bone mineral density did not change after 2 years (initial 1.05 +/- 0.07, final 1.07 +/- 0.06 g/cm2; p = n.s.). In the placebo group, however, bone mineral density decreased significantly (initial 1.00 +/- 0.07, final 0.93 +/- 0.06 g/cm2; p = 0.03). Moreover, in the fluoride group bone mineral density increased by 2.9 +/- 3.6%, and in the placebo group decreased by 6.6 +/- 2.6% (p = 0.04). None of the patients developed new vertebral or non-vertebral fractures. Treatment with sodium fluoride did not impair liver function or cholestasis in PBC. These results indicate that sodium fluoride prevents bone loss in PBC and therefore might be considered as a possible therapeutic agent for osteoporosis associated with this liver disease. Since a small number of patients completed the trial, further studies are required.

Absorptiometry, Photon↗

PubMed1991

Bone mineral content of British and rural Gambian women aged 18-80+ years.

The bone mineral content (BMC) of the mid-shaft radius was measured in 446 rural Gambian and 349 British women aged 18-80+ years using single-photon absorptiometry. The two groups of women differed substantially in habitual calcium intake, calcium requirements for reproduction, physical activity and incidence of minimal-trauma fractures. The relationships of BMC with bone width (BW) and with body weight and height were explored using stepwise multiple regression analysis. The pattern of BMC with age was similar in The Gambia and Britain; BMC increased slightly to a peak at the end of the fourth decade followed by a decrease of about 30% between 40 and 70+ years. Gambian women had significantly lower BMC than British women of the same age (-5.6%, P less than 0.001) but after adjusting for weight, height and BW, the BMC of Gambian women was shown to be slightly higher than that of British women (+2.1%, P less than 0.05).

Absorptiometry, Photon↗