Dual Photon Absorptiometry Research Articles

Relationship between skin collagen and bone changes during aging

There is evidence that skin collagen content and bone mass are influenced by estrogen deficiency, both of them declining in the years following menopause. The aim of our study was to analyze the relationship between changes in skin collagen content and bone mass during aging. A total of 76 nulliparous women who had been admitted for surgery of non-malignant processes were studied. All subjects were arranged into five age-groups (from 20 to 60 years). Bone mineral density was measured by dual photon absorptiometry and expressed in g/cm 2as the mean of the second to fourth lumbar vertebrae. Additionally, in all patients skin biopsies were taken from a non-sun exposed site in the lower abdomen (4 cm above the pubic symphysis) and osteocalcin levels were determined. Collagen decreased significantly with age after the 40s ( P < 0.001) and after menopause ( P < 0.001). Changes in bone mass were closely related to those detected in collagen ( r = 0.586 P < 0.0001). In conclusion, our data suggest that bone mass and skin collagen decline in parallel with aging and that the hypoestrogenism developing in postmenopausal years has a significant effect on skin collagen content. Nevertheless, the question of whether osteoporosis is an intrinsic collagen disorder remains to be demonstrated.

Total body and regional bone mineral content in hemodialysis patients.

Bone mineral content (BMC) in the total body and lumbar spine was evaluated in 126 hemodialysis patients (60 males, 66 females) by dual photon absorptiometry with the Norland DBD 2600. Measurements of: 1) total body BMC divided by lean body mass (BMCTB/LBM), 2) bone mineral density (BMD) of total body, 3) BMD of four regional sections (head, trunk, pelvis, and legs), and 4) BMD of lumbar spine, generally showed a significant decrease in the hemodialysis patients compared to the reference population. However, arm BMD did not show a significant difference between patients and control populations. The z-score of BMCTB/LBM declined significantly throughout the duration of hemodialysis, although that of the lumbar spine BMD did not. It should be noted that the degree of decrease in BMC was more prominent in the total body measurement than in the lumbar spine measurement. There was preferential osteopenia of the total body in the hemodialysis patients. Although the lumbar spine BMD showed a lower value than the control population, the lumbar spine is not the recommended region to monitor the BMD change in hemodialysis patients.

Sex-related changes in the bone mineral content of atrophic mandibles.

In 25 edentulous anatomical mandible specimens (15 female, age range 69-90 years; 10 male, age range 68-88 years), the bone mineral content (BMC) was measured by dual-photon absorptiometry (DPA) and analyzed in a standardized area of the mandibular body. The results of our BMC examinations showed that there was a significant difference (P = 0.05) between the two sexes. Another notable fact was that, with advancing age, the values measured in the male mandibles tended to increase slightly but in a statistically significant way. Those of the female mandibles tended to decrease with age. A possible explanation for this observation may be derived from the fact that a reduction of the mandibular height leads to a reduction of the moment of resistance. As functional adaptation in order to preserve the stability of the atrophic body of the mandible, the amount of inner cortical bone of the male mandibles increases, leading to a reduction of the cancellous portion. In the mandibles of women, postmenopausal osteoporosis seems to prevent an analogous compensation mechanism.

The Bone Density of Female Twins Discordant for Tobacco Use

Smoking is recognized as a risk factor for vertebral, forearm, and hip fractures. Since bone density is an important determinant of bone strength, we conducted a study to ascertain whether a deficit in bone density is associated with tobacco use and, if so, to identify the responsible mechanisms. We conducted a cross-sectional study of bone density at the lumbar spine and the femoral neck and shaft in 41 pairs of female twins (21 monozygotic pairs), 27 to 73 years of age (mean, 49), who were discordant for at least 5 pack-years of smoking (mean, 23; maximum, 64). Bone density was measured by dual-photon absorptiometry. The difference in bone density between the members of a pair was expressed as a percentage of the mean value for the pair. For every 10 pack-years of smoking, the bone density of the twin who smoked more heavily was 2.0 percent lower at the lumbar spine (P = 0.01), 0.9 percent lower at the femoral neck (P = 0.25), and 1.4 percent lower at the femoral shaft (P = 0.04). These results were not confounded by measured lifestyle factors. In the 20 pairs who were discordant by 20 or more pack-years (mean, 35), the (mean +/- SE) within-pair differences in bone density at the three sites were 9.3 +/- 3.1 percent (P = 0.008), 5.8 +/- 2.9 percent (P = 0.06), and 6.5 +/- 3.2 percent (P = 0.05), respectively. Smoking was associated with higher serum concentrations of follicle-stimulating hormone (P = 0.02) and luteinizing hormone (P = 0.03) and lower serum concentrations of parathyroid hormone (P = 0.05). Differences in spinal bone density between members of a pair were associated with differences in the serum concentrations of parathyroid hormone (P = 0.01) and calcium (P = 0.05) and urinary pyridinoline excretion (P = 0.06), a marker of bone resorption. Women who smoke one pack of cigarettes each day throughout adulthood will, by the time of menopause, have an average deficit of 5 to 10 percent in bone density, which is sufficient to increase the risk of fracture.

Effect of Long-Term Administration of Progestogen on Post-Menopausal Bone Loss

Summary OBJECTIVE We determined whether a progestogen given alone to post-menopausal women may prevent bone loss. STUDY DESIGN Thirty-five early post-menopausal women who had not received any form of treatment to prevent bone loss were randomly assigned to a 2-year regimen of 500 μ g/day of a gestagen derived from 19-norprogester-one (Promegestone) or a placebo for 21 days out of a 28-day treatment cycle. Bone mineral density of the spine was measured by dual photon absorptiometry. RESULTS After 2 years of treatment bone mineral density decreased significantly in the placebo group by a mean of 4.5%. In the gestagen group, the rate of bone change was significantly lower as compared to the placebo group (-1.3%± 1.2% vs −4.5%± 2% (mean ± SEM), P & lt; 0.05). There were no changes in the biochemical bone turnover parameters in the placebo group but in the gestagen group a significant decrease was observed in the urinary calcium excretion after 2 years. CONCLUSION The results suggest that a gestagen with no androgenic action can partly counteract early post-menopausal bone loss.

A study of bone mineral density versus age in Omani women and a comparison with normal British women

Dual photon absorptiometry (DPA) of the lumbar spine (2nd, 3rd and 4th lumbar vertebrae) was carried out using a Norland 2600 bone densitometer on 194 Omani women (OW). The exclusion criteria were (1) any medical treatment known to affect calcium metabolism or bone mass, (2) osteomalacia or secondary osteoporosis, (3) the presence of osteophytes or compression fractures of the lumbar vertebrae and (4) the presence of aortic calcifications. The bone mineral density (BMD) results showed a peak value occurring in the 30-35 year old age range (mean 1.1 g cm-2, standard deviation 0.1). The data were compared with a group of 165 normal British women (BW) with a similar age distribution whose peak BMD (obtained with dual X-ray absorptiometry) occurred in the 40-45 year old age range. The two groups were compared in each 10 year age range and the BMD of the OW group was found to be significantly lower in the 40-49 year old age range (P < 0.01) as well as the 50-59 and 60-69 year old age ranges (P < 0.001).

Dual Photon Absorptiometry for Bone Mineral Measurements Using a Gamma Camera

A gamma camera was equipped with a special collimator and arm assembly for bone mineral measurements with dual photon absorptiometry (DPA). The system was evaluated in vitro and in vivo and compared both with a rectilinear DPA and a dual energy X-ray (DEXA) system. All 3 systems showed a linear response in measurements of 4 vials, containing different amounts of hydroxyapatite. Phantom measurements with the gamma camera system showed a precision of 1.6% to 2.8%. Results obtained in 8 healthy volunteers with rectilinear and gamma camera systems were well correlated (R2 = 0.78). With the photon beam directed from posterior to anterior, the separation of vertebrae was easy with the gamma camera system. We conclude that bone mineral measurements can be made with a gamma camera for assessment of fracture risk and in the decision process whether a patient needs treatment or not. For follow-up, the precision of DPA with a gamma camera is inadequate.

Measurement of Bone Mineral Content to Facilitate an Objective Evalution of Limp Function in the Dog

SummaryThe aim of this study was to evaluate the feasibility of using measurements of bone mineral content (BMC) and bone mineral density (BMD) by dual photon absorptiometry (DPA; Gadolinium-153), as an objective measure of limb functional status in the dog. The in vitro accuracy error expressed as the standard error of the estimate (SEE) for BMC and BMD measurements was 3.2% and 1.1% respectively, and the precision in vivo for measurements of BMC and BMD in the distal diaphysis of the tibia and fibula was 2.1% and 1.9% respectively. A significant difference in bone mineral between right and left leg was not found in normal dogs, and in these dogs the average percentage intra-individual difference, between bone mineral in the legs with the highest bone density and the legs with the lowest density, was 2.2% and 3.7% for BMC and BMD respectively. However the BMC and BMD in eight clinical cases of unilateral lameness were significantly decreased in the affected legs, when compared to the healthy contralateral legs, by 20.4% (P = 0.01) and 18.3% (P = 0.01)respectively. Measurements of BMC and BMD by DP A in weight-bearing extremities in the dog showed that bone mineral is highly sensitive to decreased loading of the extremity. This method might well be used not only as an objective measure of limb activity, but also for measurement of prospective changes in bone mineral, following treatment of musculoskeletal diseases and injuries.The feasibility of using bone mineral measurements by dual photon absorptiometry, as an objective measure of limb functional status in the dog, was evaluated. Precision and accuracy were calculated from in vitro and in vivo studies. In eight cases of unilateral lameness bone mineral was significantly decreased (20%) in the affected legs when compared to the healthy contralateral legs.

Pubertal Changes in Bone Mineral Content of The Wrist and Spine in Normal Boys and Girls

We measured the bone mineral content of the wrist and spine using single and dual photon absorptiometry (SPA and DPA) in 165 normal boys and girls to quantitate the contribution of normal pubertal development to the attainment of adult bone mass. We constructed bone density ranges for spine and wrist bone density for each pubertal stage in girls (breast) and boys (pubic hair). Wrist bone density measurements (±SD) for girls and boys, pubertal stages 1 and 5, were 0.41±0.06 and 0.62±0.05gm/cm2 (girls) and 0.46±0.08 and 0.70±0.08gm/cm2 (boys), respectively. Spine bone density measurements (±SD) for girls and boys, pubertal stages 1 and 5, were 0.78±0.09 and 1.18±0.13gm/cm2 (girls) and 0.81±0.10 and 1.22±0.23gm/cm2 (boys), respectively. Thus, bone mineral content of the wrist and spine increased during pubertal development (between stage 1 and 5) by approximately 50% for boys and girls. The wrist bone density of boys was significantly greater than that of girls (p<0.03). Bone mineral content of the spine was similar for boys and girls throughout pubertal development. The bone mineral content of the wrist and spine in girls and boys correlated significantly with chronologic age, bone age, body mass index, height age, height, weight, serum IGF-I, and testosterone (boys), (all p<0.0001). We conclude that bone density of the wrist but not the spine is increased in boys versus girls, that bone mineral content increases by approximately 50% between Tanner stage 1 and 5 for both sexes, and that bone mineral content at both sites correlates with advances in pubertal development.

Effects of oral calcitriol on bone mineral density in patients with end-stage renal failure

Evolution of bone mineral density (BMD) at various skeletal sites and the influence of calcitriol on BMD are still poorly documented in patients with terminal renal failure. Using dual photon absorptiometry, we investigated the changes in BMD at the levels of lumbar spine, femoral neck and midfemoral shaft in 21 patients with end-stage renal failure (ESRF) treated with calcitriol (mean dosage +/- SEM: 0.21 +/- 0.02 microgram/day) and compared them to 25 patients with ESRF but not treated with calcitriol (control group) over a period of 20.3 +/- 1.5 and 17.2 +/- 1.2 months, respectively. Lumbar spine BMD increased by 7.7 +/- 3.2%/year in the treated group and decreased by 2.5 +/- 1.3%/year in the control group (P < 0.005). Femoral shaft BMD increased more in treated than in control group (+ 6.7 +/- 2.3 vs. + 1.4 +/- 2.0%/year; P < 0.05) and femoral neck BMD remained stable. PTH levels increased by 92 +/- 121 and 1033 +/- 254 pmol/year (P < 0.01) in the treated group and the controls, respectively. Osteocalcin changes were -2.7 +/- 3.7 and +20.1 +/- 11.7 micrograms/liter (P < 0.05) per year in the same groups. These results indicate that low doses of oral calcitriol in patients with end-stage renal failure were associated with an increase in BMD at the levels of lumbar spine and femoral shaft, and with a stabilization of serum PTH and osteocalcin concentrations.

A community-based population study of vertebral fractures in 85-year-old men and women.

Radiographic examinations for the presence of vertebral fracture between T4 and L5 were performed in a random sample of 85-year-old women (n = 304) and men (n = 158) who participated in a longitudinal study in Gothenburg. A vertebral fracture was defined as an anterior/posterior (A/P) vertebral height ratio of 0.66 or less. A severe vertebral fracture was defined as a compression of vertebral height of more than 33% both at the anterior and posterior edges compared to the posterior edge of the adjacent vertebral body. Bone mineral density was measured with dual photon absorptiometry in the right calcaneus. The most common site for vertebral fractures was L1 in women and Th12 in men. Bone mineral density in men at the age of 75 showed a significant correlation with vertebral fractures at 85 years of age (p < 0.001). This was not the case for women. Stepwise logistic analysis revealed that women with vertebral fractures at 85 years of age had more significant back pain, shorter stature, and more often a history of another fracture and/or chronic treatment with corticosteroids. In men, muscle strength, marital status and body weight at age 85 were the only factors significantly associated with vertebral fractures.

A study of bone mineral density in postmenopausal and senile osteoporosis with vertebral fractures in female

Bone mineral density of the lumbar vertebrae (L2-4BMD) in involutional osteoporosis was measured by dual photon absorptiometry to investigate its relationship with the incidence of osteoporotic vertebral fractures of the thoracic and lumbar spine. In addition to monitor L2-4BMD, the author also examined the progress of vertebral fractures during drug treatments by means of radiographs. L2-4BMD at the antero-posterior projection was measured in 287 female subjects with involutional osteoporosis ranging from 45 to 91 years of age. Fracture of the vertebrae was determined from lateral radiographs. Low BMD is the most important risk factor in vertebrae fractures. There was a significant difference in L2-4BMD with and without fractures of the vertebrae. L2-4BMD for threshold was 0.633 g/cm2 for 90th percentile with vertebral fractures, and that for breakpoint was 0.532 g/cm2 for 65th percentile with vertebral fractures. The incidence of vertebral fractures with BMD above the threshold was 17.5%, however that between the threshold and the breakpoint was 30.6%. Furthermore that below the breakpoint was 48.9%. Although the incidence of vertebral fractures was affected to some extent by age, height, and weight, the number of vertebral fractures increased with the decrease of L2-4BMD. The progress of vertebral fractures under drug treatments with 1,25-dihydroxyvitamin D3, ipriflavone, and calcitonin was affected by pre-existing vertebral fractures and L2-4BMD at the first visit. Estimation of L2-4BMD and the existence of vertebral fractures is important in predicting new vertebral fractures and the further collapse of pre-existing vertebral fractures.

Bone mineral content of the third lumbar vertebra during 18 months of prednisolone treatment for giant cell arteritis

Altogether forty-four patients with giant cell arteritis (GCA) were randomly allocated to either daily morning or alternate-day administration of prednisolone. The BMC of the third lumbar vertebra was determined using dual photon absorptiometry. At least ten measurements were performed in each patient during a period of 18 months. During the course of treatment there was no significant change of the mean BMC in either group compared to the pre-treatment value. The changes of BMC were independent of such potentially explanatory variables as cumulative dose of prednisolone, initial BMC, sex and body weight. Corticosteroid treatment in patients with GCA, in the doses used by us, does not appear to cause excessive bone loss.

Apparent velocity of ultrasound (AVU) at the patella in comparison to bone mineral density at the lumbar spine in normal males and females

It has been reported that apparent velocity of ultrasound (AVU) at the patella discriminates as well between osteoporotic and normal subjects as measurement of bone mineral density (BMD) using dual photon absorptiometry. To investigate the relationship between AVU and peak bone mass, we compared AVU (Signet™, Osteo-Technology, Framingham, MA) at the patella and BMD (QDR 1000™, Hologic, Waltham, MA) at the lumbar spine in a large sample of healthy males and females. The study population consisted of 153 males (aged 20–60 years) and 129 premenopausal females (aged 20–52 years). Vertebral BMD showed no significant difference between males and females (1.03 ± 0.16 g/cm 2 for males vs. 1.07 ± 0.14 g/cm 2 for females, NS), while AVU values were significantly higher in males compared with females (1967 ± 64 m/s vs. 1938 ± 76 m/s, P < 0.05). In men there was a significant decrease in BMD with aging ( r = −0.27, P < 0.05), in premenopausal females we found no age-related change in BMD. Similarly in males AVU decreased significantly with age ( r = −0.2, P < 0.05), whereas in females AVU values showed relative stability over the age range. There was a significant correlation between AVU and BMD ( r = 0.36 for males, r = 0.34 for females, P < 0.05). Our study demonstrates only a weak correlation between AVU at that patella and BMD at the lumbar spine, supporting the view that AVU not only reflects bone quantity but possibly also qualitative properties of bone structure. The sex difference in AVU but not in BMD suggests that the trabecular bone at the patella differs significantly from axial trabecular bone. The identical peak BMD at the lumbar spine for young males and females underscores the importance of the menopause for later manifestation of vertebral fractures.

Low-dose gallium nitrate for prevention of osteolysis in myeloma: results of a pilot randomized study.

Since osteolysis is a major cause of morbidity in myeloma, we conducted a pilot study to evaluate whether the addition of gallium nitrate to standard antimyeloma treatment could preserve or increase bone mass in patients with osteolytic disease. Patients stabilized on cytotoxic therapy were randomized to treatment with gallium nitrate for 6 months, or to observation only for the first 6 months followed by gallium nitrate treatment during the subsequent 6 months. Gallium nitrate was administered in monthly cycles by daily subcutaneous injections (30 mg/m2/d) for 2 weeks, followed by 2 weeks with no therapy, supplemented by an intravenous infusion (100 mg/m2/d) for 5 days every other month. Paired 6-month comparisons were available for seven observation periods and 13 gallium nitrate treatment periods. Total-body calcium assessed by delayed-gamma neutron activation (DGNA) decreased in four of seven patients during observation, but increased in nine of 13 patients during gallium nitrate treatment; the mean difference in total-body calcium (TBCa) between the two groups at 6 months was 3%. Median regional bone density assessed by dual-photon absorptiometry (DPA) declined by 1.4% in patients under observation (range, +6.7% to -18.3%), but was unchanged during gallium nitrate treatment (median change, 0%; range, -10.5% to +14.4%). The group mean vertebral fracture index assessed by lateral spine x-rays decreased by 27% during observation compared with 2% during gallium nitrate treatment. Mean body height decreased by 0.57 inches in the observation group and .06 inches in the gallium nitrate group. Patient self-assessment of bone pain showed that seven of 12 gallium nitrate-treated patients rated themselves as experiencing major reductions in bone pain, compared with zero of seven patients who were observed. One episode of hypercalcemia occurred in a patient under observation. Adjuvant treatment with low-dose gallium nitrate attenuates the rate of bone loss in myeloma and may be useful for ameliorating the consequences of skeletal morbidity in patients with cancer-related osteolysis.

Predictors of axial and peripheral bone mineral density in healthy children and adolescents, with special attention to the role of puberty

The role of various physical and lifestyle factors in determining axial bone mineral density (BMD) at the lumbar segment of the spine, as measured by dual-photon absorptiometry, and peripheral BMD at the distal third of the radius, as measured by single-photon absorptiometry, was assessed in 299 healthy white children of both sexes, aged 6 to 18 years. The BMD measurements were correlated with age, height, weight, body mass index, and pubertal status. Peripheral and axial BMD were highly correlated with age, height, weight, and pubertal stage, and more weakly with body mass index. Approximately 76% of the observed changes in peripheral BMD were accounted for by age, height, weight, and pubertal stage, with weight being the single strongest predictor. Up to 80% of the variation in axial BMD was explained by weight and pubertal stage, with pubertal stage being the strongest single predictor. After adjustment for weight, the effect of puberty on axial BMD in both sexes was greatest between middle and late puberty. These data indicate that a large amount of the observed changes on BMD is accounted for by standard measures of growth and development, which are largely genetically determined. Peripheral BMD rose steadily with age. Axial BMD increased steadily before puberty, followed by accelerated increases during puberty, beginning at 10 years of age in girls and 13 years of age in boys. A significant positive effect of dietary calcium intake on peripheral BMD and of physical activity on axial BMD indicated a potentially important impact of physical activity and calcium intake on peak bone mass.

Relationship between quadriceps strength and bone mineral density of the proximal tibia and distal forearm in women.

It is well known that there is a relationship between muscle strength and bone density, but it is uncertain whether this relationship is site specific. The aim of this study was to assess the relationship of quadriceps strength to site-specific bone mineral density (BMD) of the tibia and to BMD of the forearm. In 66 healthy women, aged 21-78 years, BMD was measured in the proximal tibia and the distal forearm by dual-photon absorptiometry. Isometric and isokinetic strength of the quadriceps was measured using an isokinetic dynamometer (Cybex II). Highly significant correlations between BMD of the proximal tibia and quadriceps strength were found (RS ranging from 0.79 to 0.84, p < 0.0001). Also, BMD of the distal forearm was correlated with quadriceps strength (RS ranging from 0.59 to 0.62, p < 0.0001). In a stepwise multiple regression analysis, quadriceps strength was a better predictor of tibial BMD than age, body height, or weight. However, age, height, and weight were more predictive of forearm BMD than quadriceps strength. When studying the pre- and postmenopausal women separately, quadriceps strength was correlated with BMD of the proximal tibia but not to forearm BMD. In conclusion, the study provides support for a site-specific relationship between muscle and bone.

Osteoporosis, Metabolic Aberrations, and Increased Risk for Vertebral Fractures After Partial Gastrectomy

A case-control study compared 129 men with earlier partial gastrectomy (operation during the period 1952-1961) with 216 men from a community-based population study. All were born 1910-1915 and the mean age was 72 years. Men with a previous partial gastrectomy had vertebral fractures in 19% compared with 4% (P < 0.01) in the control population. Bone mineral density (BMD) in the right calcaneus measured with dual energy photon absorptiometry was 20% lower in men with a Billroth II operation (P < 0.001) and 8% lower with a Billroth I operation (ns). In comparison with the controls, the men subjected to partial gastrectomy had higher serum concentrations of osteocalcin and alkaline phosphatase activity, a lower serum concentration of 25-hydroxyvitamin D (25OHD) and a lower body mass index (BMI). There were no difference in serum concentrations of free calcium, intact parathyroid hormone (PTH), or free thyroxine. The smoking prevalence was significantly higher in men with partial gastrectomy than in controls. Smokers had significantly lower serum concentrations of intact PTH and 25OHD than nonsmokers and also lower BMD and BMI. The relationships between intact PTH on one hand, and ionized calcium (inverse relationship) and osteocalcin (direct relationship) on the other were preserved in smokers, however. Gastroscopy was performed in 78 men with multiple biopsies in the gastric remnant and also in the small intestine. All but two subjects had chronic gastritis. Examination of sternal bone marrow smears showed that 40% of the Billroth-operated men lacked bone marrow reticular iron.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Composition Study in The Elderly: Comparison Between Tritium Dilution Method and Dual Photon Absorptiometry

The methods commonly employed in body composition study in elderly persons derive fat-free mass (FFM) by measures of total body water (TBW); these methods assume FFM hydration constant (TBW/FFM = 0.732). The aim of our study was to verify the accuracy of the TBW method in FFM estimation and to study the variability of fat-free mass hydration (TBW/FFM) in healthy elderly subjects. We assessed FFM in 27 healthy old subjects (76 +/- 7 yrs) by dual photon absorptiometry (DPA) and by TBW measured by 3H2O. Furthermore, to verify the accuracy in FFM estimation by our methods, we measured resting metabolic rate (RMR) by indirect calorimetry. FFM hydration was 71.9 +/- 4.9 (range 63.6-80.4%), a range larger than that reported by direct chemical analysis in adults. The FFM hydration measured in our subjects was not different from the 73.2 value currently used in healthy adults. FFM values derived by TBW (assuming TBW/FFM = 0.732) were not significantly different from FFM measured by DPA. We correlated FFM with resting metabolic rate and found a similar correlation between RMR and FFM-DPA (r = .89, p < .001) and FFM-TBW (r = .85, p < .001). Both methods employed in our study have proved to be accurate in estimating FFM in elderly persons; particularly, the value of 0.732 assigned to FFM hydration to derive fat-free mass in adults can be employed also in body composition study of the elderly.

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.