Total and regional bone mineral content in relation to menopause

Changes in serum leptin levels during GnRH agonist therapy

The purpose of the present study was to investigate changes in serum leptin levels during GnRH agonist therapy. Twenty regularly menstruating women with uterine leiomyomas were enrolled. These subjects were given GnRH agonist (leuprorelin acetate, 3.75 mg) monthly for 4 months. Serum leptin and estradiol (E2) levels were measured at the two time points of day 1 or 2 of the menstrual cycle and the end of GnRH agonist therapy. Weight, total body fat mass, percentage of body fat, and total body lean mass were measured by whole body scanning with dual-energy X-ray absorptiometry. The ratio of serum leptin levels to total body fat mass (leptin-fat mass ratio), and the ratio of serum leptin levels to total body lean mass (leptin-lean mass ratio) were calculated. All subjects became amenorrheic after the initial administration of GnRH agonist. Baseline E2 levels were 45.4 +/- 21.0 pg/mL, which significantly decreased after GnRH agonist therapy (13.3 +/- 4.2 pg/mL, p<0.01). Baseline leptin levels were 8.7 +/- 8.1 ng/mL, which did not differ from the values after 4 months of GnRH agonist administration (8.9 +/- 6.8 ng/mL). Total body fat mass significantly increased from 20.0 +/- 10.4 to 21.0 +/- 9.4 kg (p<0.05), while total body lean mass significantly decreased (34.5 +/- 4.2 kg to 33.3 +/- 3.9 kg, p<0.01). However, leptin-fat mass ratio after GnRH agonist therapy did not differ from the baseline values (0.39 +/- 0.16 ng/mL/kg vs 0.38 +/- 0.16 ng/mL/kg). Hypogonadism does not have a major impact on circulating leptin levels.

Changes in body composition in women treated with gonadotropin-releasing hormone agonists

OBJECTIVE

The changes that agonists of gonadotropin-releasing hormone (GnRH) produce in mineral bone mass are known, but, as far as we know, those produced by these agents in other body compartments are unknown.

METHODS

We studied these changes using dual-energy X-ray absorptiometry in 50 eugonadal women treated with decapeptyl (Triptoreline), 3.75 mg injected intramuscularly, at 28-day intervals for 6 months.

RESULTS

There were significant increases in fat content (9.5%, P < 0.0005) and weight (1.3%, P < 0.01), and significant decreases in fat-free mass (-1.9%, P < 0.0001) and water content (-1.8%, P < 0.0002). Bone mass was lost in the axial skeleton (-3.6%, P < 0.0001) but not in the peripheral skeleton.

CONCLUSIONS

The changes induced in body composition by the GnRH agonists are similar to those of natural menopause.

Vertebral and metacarpal morphometry as indicators of nutritional improvement

Because of the importance of nutrition in the development of bone mass, we studied the nutritional state, and bone state by means of metacarpal radiogrammetric measurements and vertebral morphometry in a group of 40 premenopausal women born between 1960 and 1970, mean age 29 +/- 5 years, and in another group of 40 postmenopausal women born between 1934 and 1944, mean age 55 +/- 4 years. Both groups were considered normal, the main characteristic distinguishing them being that the women born between 1934 and 1944 grew up in a period of widespread malnutrition in Spain and the women born between 1960 and 1970 grew up in a period of normal nutrition. Protein, carbohydrate and fat intake in these two periods differed significantly (p < 0.0001 in the three cases by Fischer's exact test). The values of the metacarpal measurements, anterior height of the dorsal vertebrae from T-4 to T-12, and posterior height from L-1 to L-4 between the premenopausal and postmenopausal groups of women were significantly different (p < 0.001) (Anova test). These findings show the importance of nutrition in the development of bone mass during childhood.

Behavior of bone mass measurements. Dual energy x-ray absorptiometry total body bone mineral content, ultrasound bone velocity, and computed metacarpal radiogrammetry, with age, gonadal status, and weight in healthy women

RATIONALE AND OBJECTIVES

Bone mass as measured by dual energy x-ray absorptiometry varies with body weight. The authors studied the behavior of bone mass measurements made by ultrasound bone velocity and metacarpal radiogrammetry in relation to body weight.

METHODS

Eighty healthy women were studied: 40 post-menopausal and 40 premenopausal (mean age 60 +/- 6 and 38 +/- 8 years, respectively). The authors performed in every subject the following studies: a radiograph of the nondominant hand for metacarpal cortical thickness, a study of the 2nd to 5th proximal phalanges for ultrasound bone velocity, and total bone mineral content by dual energy x-ray absorptiometry.

RESULTS

The measurements obtained with the three methods correlated significantly with each other (P < 0.0001). The only parameter related significantly with weight were total bone mineral content (P < 0.0001). In the premenopausal women, age did not correlate with any measurement. In the postmenopausal women, age correlated significantly with the three measured parameters (P < 0.0058 to P < 0.0001).

CONCLUSIONS

Weight did not influence ultrasound bone velocity and metacarpal cortical thickness measurements.

Total and regional bone mineral content in Spanish professional ballet dancers

Total body bone mineral content (TBBMC) and regional bone mineral content (BMC) was measured in the members of the Spanish National Dance Company (15 female, mean age 25.1 +/- 3.8 years, and 15 male, mean age 28.2 +/- 2.1 years) and in 30 controls (15 women, mean age 26.1 +/- 1.8 years, and 15 men, mean age 28.0 +/- 1.5 years). Ca, P, and Mg intake were greater in the group of ballet dancers than in controls analysis of variance (ANOVA, all P < 0.0001). BMC was similar in the group of ballet dancers and controls except in the trunk without pelvis (P < 0.001). Both male and female dancers weighed less than controls (P < 0.05). The BMC of the male dancers was less than that of male controls only in the trunk (P < 0.05) and in the trunk without pelvis (P < 0.005); BMC was lower in female dancers than in female controls only in the arms and in the trunk without pelvis (P < 0.05 and P < 0.005, respectively). TBBMC, adjusted for weight and age, was correlated partially with caloric intake (kcal/day) and with Ca, P, Mg, and Zn intake (g/day), and yielded significant differences between the dancers and controls only in P intake (P < 0.01), and between male dancers and male controls only in caloric intake and in Ca, P, and Zn intake (all P < 0.01, except for Ca, P < 0.05). The lower trunk bone mass observed in the female dancers is a risk factor for eventual osteoporosis.

Evidence that the loss of bone mass induced by GnRH agonists is not totally recovered

There is disagreement as to whether the loss of bone mass induced by GnRH agonists is reversible. In part, the differences of opinion might be attributed to the fact that the influence of weight and seasonal changes on bone mass is often overlooked. Taking into consideration weight and seasonal changes in bone mass, total (TBBMC) and regional body bone mineral content were measured in 38 women treated with GnRH agonists for 6 months for endometriosis or leiomyomata. Measurements were made at the onset of treatment, at 6 months of treatment and at 6 months after finishing treatment. TBBMC was corrected for body weight. Body weight had increased significantly at 6 months of treatment (P = 0.0175). Regional bone mineral content showed the following: limbs, no changes; head, significantly lower at 12 months than at baseline (P = 0.0036) and at 6 months (P = 0.0343) of therapy; trunk, significantly lower at 6 months (P = 0.0002) compared to baseline, but the values at 1 year were not significantly different from either the baseline or the 6-month values; pelvis, the same pattern of change as in the trunk (P = 0.0349). TBBMC was significantly lower at 6 months of treatment (P < 0.0001) and at 1 year (P = 0.0162). TBBMC adjusted for weight experienced the same changes as unadjusted bone mineral content (P < 0.0001 and P < 0.0009 at 6 months and 1 year, respectively). Our findings indicate that the bone mass lost with GnRH treatment had not been restored 6 months after discontinuing treatment.

Postmenopausal bone loss in Japanese women

OBJECTIVES

Our purpose was to detect anatomic variations in postmenopausal bone loss and to determine the risk factors most affecting bone mass in Japanese women.

METHODS

One hundred sixty-six Japanese women (54 premenopausal and 112 postmenopausal), aged 40-68 years, were enrolled in the study. Bone mineral densities (BMD) of the lumbar spine (L2-4) and total body were measured by dual energy X-ray absorptiometry and the results were subjected to statistical analysis.

RESULTS

Among the various sites studied, the lumbar spine (L2-4) showed the fastest bone loss after menopause. Multiple regression analysis indicated that two factors, number of years since the menopause and body mass index (BMI), affected lumbar spine (L2-4) BMD.

CONCLUSION

Measurement of lumbar spine (L2-4) BMD is suitable for evaluating postmenopausal osteoporosis. The risk factors for postmenopausal bone loss were a long period after menopause and a low BMI.

Longitudinal study of the effect of calcium pidolate on bone mass in eugonadal women

Seventy-two eugonadal women, mean age 39 +/- 4 years, with a z score for total body bone mineral content (BMC) of less than -1.5 (mean -1.80 +/- 0.12) were selected from a previous screening study of normal values of total body and regional BMC in women using dual-energy X-ray absorptiometry. The women were distributed into two groups: 36 women undergoing treatment with 1 g/day of elemental calcium in the form of calcium pidolate and 36 women not treated. One year later, total body BMC, regional BMC in arms, legs and trunk, 24-hour urinary calcium excretion (Ca 24 hour), fasting urinary calcium/creatinine ratio, and serum tartrate-resistant acid phosphatase concentration were measured in both groups. There was a significant increase in total body and regional BMC (P < 0.001) in the group taking calcium pidolate. The increase was greater in arms and legs (2.5%) than in trunk (1.7%), being 2.6% for total body BMC. The z score increased from -1.81 +/- 0.13 to -1.52 +/- 0.12 (16%, P < 0.001). The corporal index did not change, and total body BMC corrected for fat-free body mass increased by 6.7% (P < 0.001). These changes were accompanied by an increase in 24-hour urinary calcium excretion and a decrease in urinary calcium/creatinine ratio and serum tartrate-resistant acid phosphatase concentration (P < 0.05 for all). There was a correlation between cumulative calcium dose at the end of treatment and gain in total body BMC (r2 = 0.925, P < 0.001). The untreated group showed no changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of weight and seasonal changes on radiogrammetry and bone densitometry

We studied the behavior of radiogrammetric and densitometric measurements in relation to season and body weight in a group of 30 healthy premenopausal women. Measurements were made at 6-month intervals, in summer/fall when bone density increases and in winter/spring when bone density declines. Total body bone mineral content (TBBMC) and regional bone mineral content (RBMC) were measured using dual-energy X-ray absorptiometry (DXA). Metacarpal radiogrammetry was carried out with computed radiography. Weight and body mass index increased significantly in winter (P < 0.05) and total body and RBMC decreased (P < 0.001). The opposite occurred in summer: weight and body mass index decreased significantly (P < 0.05) and total body and regional bone mineral content increased (P < 0.001). Differences in TBBMC persisted when the measurement was corrected for weight (TBBMC/W) (P < 0.001), but not for metacarpal cortical thickness corrected for weight. In the first measurement made there were significant relations between weight and both TBBMC (P < 0.001) and metacarpal cortical thickness (P < 0.005). The relation between weight and TBBMC remained significant in later measurements, but the relation between weight and metacarpal cortical thickness ceased to be significant in the second and fourth measurements. Our results show that there is an important seasonal variation in bone mass and that DXA is more sensitive than radiogrammetry in registering these changes.

Quantitative peripheral computed tomodensitometric study of cortical and trabecular bone mass in relation with menopause

Changes in total, cortical and trabecular bone mass were studied using quantitative peripheral computed tomodensitometry on the forearm of 58 normal eugonadal premenopausal women and 116 normal postmenopausal women to evaluate the evolution of bone components with age. In premenopausal women, no changes were seen in any bone component. In postmenopausal women, only trabecular bone mass diminished in the first 5 years after menopause (P < 0.05). It continued to decrease in the next 5 years (P < 0.05), but not later. Cortical bone mass experienced a significant loss 6-10 years after menopause (P < 0.001), and more than 15 years after menopause (P < 0.0005). These results are similar to those obtained with other techniques, and document the differing behavior of the cortical and trabecular bone components with years of menopause.

Total and regional bone mineral content in women treated with GnRH agonists

Changes in bone mineral content induced by GnRH agonists were investigated by measuring total body bone mineral content (TBBM) and regional bone mineral content (BMC) (arms, legs, trunk, pelvis) and densities with dual energy X-ray absorptiometry in 25 premenopausal women before and after a 6-month treatment with gonadotropin-releasing hormone (GnRH) agonists. Biological markers of bone remodeling, estrogens, luteinizing hormone, and follicle-stimulating hormone were also measured. Weight and body mass index increased significantly after treatment (P < 0.05), and TBBM, corrected for weight (TBBM/W), decreased (P < 0.001). The changes in BMC that we observed ranged from +2.5% to -6.9%. The greatest decrease in regional BMC occurred in the trunk (4.4%, P < 0.001), with TBBM decreasing by 2.1% (P < 0.001). No significant changes were observed in the limbs. Tartrate-resistant acid phosphatase (TRAP) increased significantly after treatment (P < 0.001) and a significant negative correlation between TRAP and TBBM (P < 0.001) and between TRAP and estradiol (P < 0.001) were observed before treatment. The lack of changes observed in the BMC of the limbs indicate that GnRH agonists cause a preferential loss of BMC in trunk osseous structures, a situation similar to that of the first years of menopause.