PubMed Health⌕ Search

Biomedical subjects

S L Bonnick

Publications and source records attributed to S L Bonnick.

14 recordsLinked to original sources
PubMed2000

Bone health and osteoporosis.

Good bone health is important to everyone, regardless of age. Osteoporosis is a preventable disease, and steps for increasing bone mass should begin at an early age. To increase bone mass, much of the recent evidence suggests that the best time for intervention with calcium or exercise may be during the prepubertal years. In the older female athlete, BMD is typically well above normal, but even young amenorrheic athletes can have bone density values equal to that of an elderly osteoporotic woman. Myriad treatment options are available for the person with low bone mass, but prevention is a much more preferable alternative.

Bone Density↗
PubMed1998

Lumbar bone mineral density in adolescent female runners.

BACKGROUND: The purpose of this study was to determine if there were significant differences in lumbar bone mineral density (L2-L4, g/cm2) or several hormones among 3 groups of adolescent females: 10 amenorrheic runners, 10 eumenorrheic runners, and 10 eumenorrheic controls. METHODS EXPERIMENTAL DESIGN: comparative. SETTING: Cooper Clinic, Aerobics Center, Dallas, Texas. PATIENTS OR PARTICIPANTS: The subjects were white, non-smokers, aged 15.1-18.8 years, who were not taking birth control pills. All amenorrheic runners had less than 5 menstrual period in the past year, averaging 2,4 periods. The runners averaged approximately 36 miles/week (58.1 km) during the last 9 months of their training season and had been running for 1-5 years. INTERVENTIONS: None. MEASURES: Lumbar bone mineral density (BMD), 10 hormones, percentage of body fat, and dietary intake were measured. RESULTS: Mean lumbar BMD (g/cm2) did not differ significantly among groups (amenorrheic runners = 1.134, eumenorrheic runners = 1.165, controls = 1.148). However, expected trends were observed. Compared to the controls, the amenorrheic runners tended to have lower lumbar BMD and the eumenorrheic runners, higher. Although there were significant differences in concentrations of five serum hormones measured, all mean hormonal values were within normal ranges. Calcium intakes were low for all groups. CONCLUSIONS: In this study, with its small number of subjects and great variability within each group, it was concluded that there is no significant difference among amenorrheic runners, eumenorrheic runners, and controls in lumbar BMD. However, a longer period of amenorrhea might result in significantly lower BMD for the amenorrheic runners.

Adipose Tissue↗
PubMed1997

Dissimilar spine and femoral Z-scores in premenopausal women.

The purpose of this study was to determine if differences exist in premenopausal women between z-scores for lumbar spine and proximal femoral bone mineral densities (BMD). Participants were 237 women ranging in age from 20 to 45 years. BMDs of the lumbar spine and proximal femur (femoral neck, Ward's area, and trochanter) were assessed using dual-energy X-ray absorptiometry (Lunar DPX). Mean (+/-SD) age, height, and weight of the participants were 29.4 +/- 6.9 years, 164.4 +/- 6.1 cm, and 64.9 +/- 12.1 kg, respectively. Lumbar spine BMD and BMD at the femoral neck, Ward's area, and trochanter were significantly correlated with large SEEs (r = 0.59-0. 65; SEE = 0.09-0.11). No positive correlation with age and BMD at any site was seen in this population but a significant negative correlation with age was seen in the proximal femur beginning at age 30. Twenty to 24% of the 20-29-year-olds exhibited a difference in z-scores of greater than 1 between the spine and sites in the proximal femur. This percentage increased to 32-46% in the 30-45-year-olds but the nature of the observed differences changed. The differences in spine and proximal femoral z-scores that are seen in the older age group appear to be the result of the earlier onset of bone loss in the proximal femur rather than an initial difference in peak bone mass which has been maintained.

Absorptiometry, Photon↗
PubMed1996

Consensus of an international panel on the clinical utility of bone mass measurements in the detection of low bone mass in the adult population.

Low bone mass, in the asymptomatic patient, predicts future fracture risk as well as high cholesterol or high blood pressure predicts the risk of heart disease or stroke. In patients without fractures, osteoporosis can be diagnosed based on the extent of reduction in bone mass below mean peak bone mass of healthy young individuals. As bone mass decreases, fracture risk increases exponentially. Prevention of the first fracture is a clinical goal. Clinical situations in which an assessment of bone mass and fracture risk affects therapeutic decisions include estrogen deficiency, vertebral abnormalities, radiographic osteopenia, asymptomatic primary hyperparathyroidism, and longterm corticosteroid therapy. Serial measurements can also be used to monitor the effects of osteoporosis treatment in certain situations. The appropriate technique and skeletal site for bone mass measurements should be chosen based on the patient's circumstances. A clinical interpretation can enhance the value of computer-generated bone mass measurement reports and enhance decision making.

Adult↗
PubMed1996

Right and left proximal femur analyses: is there a need to do both?

The purpose of this study was to determine if differences existed between right and left proximal femur bone mineral density (BMD) in a group of women. Participants for the study were 198 women ranging in age from 16 to 73 years. Bone mineral densities of both proximal femurs (femoral neck, Ward's area, and trochanter) were assessed using dual energy X-ray absorptiometry (Lunar DPX). Mean (+/-SD) age, height, and weight of the participants were 32.9 +/- 18 years, 164 +/- 7.4 cm, and 64.9 +/- 12.1 kg, respectively. Significant differences between right and left femoral BMDs were found only in the trochanter. Overall, mean differences in BMD were low (neck = 0. 7%, Ward's = 0.2%, and trochanter = 1.9%) but individual variations were as high as 22%. Based on BMD z-scores of <-1.0, 84 women were classified as "at risk" for osteoporosis. When right and left z-scores were compared, misclassifications of at risk women were 4, 15, and 11 for neck, Ward's area, and trochanter, respectively. In conclusion, analyses of both right and left proximal femurs may not be necessary for either the researcher or the clinician.

Adolescent↗
PubMed1996

Clinical utility of bone mass measurements in adults: consensus of an international panel. The Society for Clinical Densitometry.

Low bone mass predicts future fracture risk as well as high cholesterol or high blood pressure can predict the risk of heart disease or stroke. Prevention of the first fracture should be a clinical goal. In patients without fractures, osteopenia and osteoporosis can be diagnosed based on the extent of reduction in bone mass below mean peak bone mass of young healthy individuals. As bone mass decreases, fracture risk increases exponentially. Clinical situations in which an assessment of bone mass and fracture risk affects therapeutic decisions include estrogen deficiency, vertebral abnormalities, radiographic osteopenia, asymptomatic primary hyperparathyroidism, and long-term corticosteroid therapy. Serial measurements can also be used to monitor the effects of osteoporosis treatments. The appropriate technique and skeletal site for bone mass measurements should be chosen based on the patient's circumstances and the precision of measurement. A clinical interpretation can enhance the value of computer-generated bone mass measurement reports and improve decision making.

Absorptiometry, Photon↗
PubMed1995

Associations of body fat distribution, circulating sex hormones, and bone density in postmenopausal women.

The associations of body fat distribution, sex hormone levels, and bone mineral density (BMD) were examined in 52 postmenopausal Caucasian women. Body fat distribution was assessed by waist to hip ratio (WHR) and abdominal fat weight (between the iliac crest and L1), as determined by dual energy x-ray absorptiometry. Bone mineral densities were determined by dual energy x-ray absorptiometry, and total estradiol, total testosterone, and sex hormone-binding globulin (SHBG) levels were determined by RIA. Subjects taking hormone replacement had significantly greater total estradiol and SHBG concentrations and a lower free androgen index. BMDs tended to be higher in subjects taking estrogen replacement after adjustment for body weight. There was no difference between subjects taking hormone replacement or not taking hormone replacement in WHR or abdominal fat weight. Subjects with a gynoid (lower body) distribution of body fat had higher SHBG concentrations than subjects with a more android (upper body) distribution of body fat. Subjects with an android distribution of body fat had greater BMDs than subjects with a gynoid distribution of body fat. Abdominal fat weight and WHR were significant predictors in regression models for all BMD parameters. The results of this study suggest that there is an association between body fat distribution and BMD, with the android distribution having higher BMDs.

Adipose Tissue↗
PubMed1995

Relationship of regional body composition to bone mineral density in college females.

The purpose of this study was to examine relationships between regional body composition and bone mineral density (BMD) in college females. Subjects were 12 nonathletic females (< 3 h.wk-1 of exercise) and 46 female varsity athletes: basketball (N = 14), volleyball (N = 13), gymnastics (N = 13), and tennis (N = 6). Dual energy x-ray absorptiometry was used to determine BMD and body composition. The mean (+/- SD) age, height, weight, and menarche for the subjects were 19.9 +/- 2.1 yr, 167.9 +/- 9.4 cm, 62.1 +/- 9.0 kg, and 13.6 +/- 1.7 yr, respectively. Mean lumbar (1.327 g.cm-2), femoral neck (1.172 g.cm-2), and total body (1.200 g.cm-2) BMD of the athletes were significantly greater than nonathletes (P < 0.05) but did not differ among the teams. Significant correlations were found between regional leg BMD and leg lean tissue mass (LTM) (r = 0.59, P < 0.001) and between arm LTM and arm and lumbar BMD (r = 0.47 and 0.56, respectively). Significant correlations were also found between leg fat mass and leg BMD (r = 0.40). However, only regional LTM was a significant predictor of BMD using stepwise multiple regression. In summary, regional LTM appears to be a better predictor of BMD than regional fat mass.

Absorptiometry, Photon↗
PubMed1994

The effects of gymnastics training on bone mineral density.

The purpose of this study was to examine the effect of 27 wk of gymnastics training on bone mineral density (BMD), body composition, insulin-like growth factor I (IGF-I), and osteocalcin. Subjects were 11 female intercollegiate gymnasts and 11 controls. Dual energy x-ray absorptiometry (Lunar DPX) was used to determine BMD (L2-L4 and femur) and to assess body composition. The gymnasts were significantly lower in weight (53.9 and 60.8 kg) and % body fat (22.6 and 30.6) compared with controls. After training, body weights of gymnasts remained the same but there was a significant increase in lean tissue mass of 2.9 kg (6.7%, P < 0.05). No changes in body composition were observed in the controls. The gymnasts had significantly higher mean lumbar (1.321 vs 1.225), and femoral neck (1.163 vs 1.079) BMD (g.cm-2) than the controls. Lumbar BMD increased significantly (1.3%) in gymnasts following training but femoral neck BMD did not increase. No BMD changes occurred in the control group. Regarding serum IGF-I, no differences were seen between the groups or across time. Serum osteocalcin values were significantly higher in the gymnasts than the controls, but no differences were found across time. In conclusion, gymnasts had significantly higher BMDs than controls, and a significant increase in lumbar BMD was seen in the gymnasts following 27 wk of training.

Absorptiometry, Photon↗