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Biomedical subjects

M Alvarez del Buergo

Publications and source records attributed to M Alvarez del Buergo.

11 recordsLinked to original sources
PubMed1994

Determinants of total-body and regional bone mineral content and density in postpubertal normal women.

Some investigators consider body fat the main determinant of bone mass in women, and others, weight. Although genetics may be the primary determinant of peak bone mass, modifiable secondary factors such as nutrition and hormone exposure may significantly affect bone mass accretion during the second decade of life. To determine the principal determinants of bone mass, we analyzed total and regional bone mass (by dual-energy x-ray absorptiometry), weight, height, percentage body fat, and lean body mass in a group of 50 young women ranging in age from 14 to 18 years. Total-body bone mineral content, total-body bone mineral density, and total-body bone mineral density corrected for height, analyzed by multiple correlation, were not related to percentage body fat, although percentage body fat did correlate with the regional bone mineral content of the trunk (P < .001), legs (P < .01), and pelvis (P < .001). Lean body mass correlated with total-body bone mineral content and density, total-body bone mineral density corrected for height (P < .001), and regional bone mineral content of the trunk (P < .05), arms (P < .01), and legs (P < .001), but not with regional bone mineral content of the pelvis and head. Weight correlated significantly (P < .001) with all bone mass measurements except regional bone mineral content of the head, where the significance was P less than .05. Similar results were obtained by multiple regression analysis. These results indicate that weight, not body fat, is the main determinant of bone mass in postpubertal women.

Absorptiometry, Photon↗
PubMed1993

The relationship of total body bone mineral (TBBMC) to anthropometric variables in postmenopausal women, and contribution of chronological age and years since menopause to TBBMC loss.

Dual energy X-ray absorptiometry measurements of total body bone mineral content (TBBMC), fat body mass (FBM) and fat mass percentage (%FM), lean body mass (LBM) and body weight (BW) were performed on 168 normal postmenopausal females. They were matched regarding life style and habits and had body mass index under 30. Their TBBMCs were correlated with these measurements, with chronological age (CA) and with the number of years since menopause (YSM). There was no correlation between TBBMC and %FM and LBM, but there was with BW (p < 0.001). There was a significant and negative correlation (r = -0.453, p < 0.001) between TBBMC and CA and to a higher range (r = -0.697, p < 0.001) with YSM. Menopausal females over 60 (n = 87) presented less bone mass than younger females (n = 81) (p < 0.01). These data suggest that regarding TBBMC, menopausal onset is a more important factor in bone mass loss, which persists rather markedly even during periods of time far from menopause and that TBBMC depends more on BW than on LBM and FM in women.

Adipose Tissue↗
PubMed1993

Body composition in postpubertal boy cyclists.

Twenty-two young male cyclists aged 15 to 19 years (mean 16.2 +/- 0.4 years) were studied in order to assess the effect of physical training on the body composition of adolescents. The subjects had been training on the road 10 hours per week for over 2 years, and were compared to 22 sedentary normal subjects of similar age range (mean 16.9 +/- 0.3 years). Food and calcium intake was similar in both groups. The total body bone mineral content and total body bone mineral density were lower in the group of cyclist adolescents (p < 0.05 respectively). There were no differences in height, weight, corporal index, percent body fat, fat-free mass and soft tissue mass between groups. Our results suggest that cycling in male adolescents may be associated with a lower bone mass gain. In our opinion, the recommendable nature, quantity and quality of exercise at these ages must be better defined, through additional experimentally-designed studies, in order to prevent negative effects over bone mass gain.

Absorptiometry, Photon↗
PubMed1992

[The 4-component model of body composition].

BACKGROUND: Given the importance of knowing the corporal composition according to the model of the four components (fat, mineral, fat free and aqueous) the same was calculated in 220 women and 130 men, considered as normal, between the ages of 15 and 49. METHODS: The corporal components were determined with double energy x-ray densitometry with the component corresponding to water being obtained from the fat free component, thereby evaluating the four principal parts of corporal composition. RESULTS: In the men all of the values except those of fat were greater than in the women (p less than 0.001), with the fat in the latter being (p less than 0.001). The values of mineral content demonstrated sexual differences in reaching of the peak of osseous mass and were maintained stable in women up to the age of 49. CONCLUSIONS: With regards to the mineral component, there is a sexual difference in achieving the maximum value. While the fat values in men are super-impossible to those referred in the literature for ther media and with other techniques they are not so in women, in whom superior values are observed leading to reanalysis of how the physical constitution, habits and way of life of women in this country may have repercussions in this sense.

Absorptiometry, Photon↗
PubMed1992

Sex differences in the acquisition of total bone mineral mass peak assessed through dual-energy X-ray absorptiometry.

Dual energy X-ray absorptiometry evaluation of total body bone mineral content (TBBM), total bone mineral density (TBMD), and regional bone mineral content (BMC) (head, trunk, arms, and legs) was carried out in order to assess sex differences of bone in 120 women and 121 men aged 15-29 years. Subjects from both sexes were divided into 5-year groups (15 through 19, 20 through 24, and 25 through 29 years old, respectively). Significantly higher values for TBBM, TBMD, and regional BMC were observed in males compared with females in the 20 to 24 and 25 to 29-year-old groups (P less than 0.001), but not in the group aged 15-19. After adjusting TBBM for lean body mass (LBM), we observed significantly lower values of TBBM/LBM in the males compared with females in all the age groups. A positive and significant correlation was observed between TBBM and age in the males of all the groups (r = 0.624, P less than 0.001), but not in the females. These data suggest that total bone mass peak acquisition takes place earlier in women than in men, leading to more reduced bone mass value, which in turn may be an osteoporosis predisposing factor.

Absorptiometry, Photon↗
PubMed1992

Is pelvic bone mineral content assessed through dual energy X-ray absorptiometry an appropriate anatomical area for bone mass estimation in women?

Bibliographic references seem very controversial regarding the most appropriate anatomical area for bone mass estimation. Since some overlapping in the different bone mass measurements among normal and osteoporotic females has been observed, we have studied the bone mineral content of the pelvic bone through DEXA, and have correlated it with the total body bone mineral content, a highly discriminating measure, in order to observe whether pelvic bone mineral may be a useful measure in bone mass assessment. Pelvic and total body bone mineral values did not decrease until menopause in 104 normal premenopausal females aged 20 to 49 years. On the other hand, these values decreased in normal postmenopausal women (n = 44) aged 50 to 65 years (p < 0.001), with a 16% pelvic bone mineral content and an 11% total body bone mineral content decrease. Osteoporotic females (n = 30), showed lower values for both levels than normal postmenopausal ones (p < 0.001), with a 54% pelvic and a 24% total decrease. A 15% overlap was observed when pelvic values between normal postmenopausal and osteoporotic females were compared. The greater percentage decrease in pelvic BMC compared to total body bone mineral content and the lower overlap observed suggest that the pelvis may be an ideal anatomical area for bone mass evaluations.

Absorptiometry, Photon↗
PubMed1992

Total and regional bone mineral content in relation to menopause.

Total body bone mineral content (TBBM) and anatomical region bone mineral content (head, trunk and extremities) were measured using dual-energy X-ray absorptiometry in 188 women aged 60 +/- 6 years, of whom 154 were normal and 34 were osteoporotic. Of the 154 normal subjects, 90 were premenopausal (40 aged 44 +/- 3 years and 50 aged 34 +/- 8 years), the remaining 64 being postmenopausal and aged 58 +/- 7 years. There were no TBBM or regional changes in the premenopausal women, whereas there was a significant reduction in bone mineral content in the postmenopausal as compared with the premenopausal women in all regions. The osteoporotic subjects showed a general decrease (P < 0.001) in all measurements which was more marked in the trunk. The rate of TBBM reduction was 16% in the normal postmenopausal women and 29% in the osteoporotic subjects. All the postmenopausal women (both normal and osteoporotic) showed lower TBBM values than those in the Wisconsin trial, similar results being obtained in the case of the premenopausal group. Such differences can only be explained by hardship experienced by these now postmenopausal women during their childhood and adolescence.

Absorptiometry, Photon↗
PubMed1991

Age- and weight-related changes in total body bone mineral in men.

Since the incidence of osteoporotic fractures in men increase with age, bone mass, as total body bone mineral content (TBBM) measured by dual energy X-ray absorptiometry (DEXA), and other variables were determined in men in order to observe whether changes in these parameters justify the increased incidence of bone fractures in men with age. Measurements were conducted in 190 men aged 20-85 years. By correlation tests, no changes were observed in body weight and age. There was a significant correlation (r = 0.67981, r2 = 0.46214, p less than 0.001) between TBBM and body weight, and an inverse significant correlation between TBBM with age (r = 0.34729, r2 = 0.12061, p less than 0.001); this decrease is linear with age and represents a 0.3% annual bone loss. These results suggest that lower weight and/or worse psychomotor response and its effects minimizing trauma, may be responsible for the high fracture rate observed in older males.

Adult↗
PubMed1991

[Bone mass peak, evaluation using bone densitometry of the whole body in a normal female population in our environment].

Considerable debate exists about when the maximal bone mass, or "bone mass peak" is physiological acquired. In the present study, 140 normal females aged 15 through 19 years (n = 18), 20 through 29 years (n = 58) and 30 through 39 years (n = 64), were assessed in order to determine their total body bone mineral (TBBM) content, as bone mass parameter, by bone densitometry with dual energy X rays. We did not observe significant differences in TBBM values between the different groups. A positive and significant correlation existed between age and TBBM (r = 0.486, p less than 0.05) in female aged 15 to 19 years but not in the rest of the groups. These data suggest that female acquired their maximal bone mass, or bone mass peak, up to the age of 20 years and that it remains stable until, at lest, the age of 39 years. We point up the importance of achieving an adequate skeletal development in females during their first 20 years of life that could perhaps protect them from suffering subsequently from osteoporosis.

Absorptiometry, Photon↗