PubMed · 11987010
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C A Sharp, H Davies, M Davie, M J Haddaway. 2002. Bone density scanning.. https://doi.org/10.1038/sj.sc.3101287
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The purpose of this study was to determine total and regional bone mineral density (BMD) in highly competitive young adult and master male cyclists. Three groups of men were studied: older cyclists (51.2+/-5.3 years, n=27); young adult cyclists (31.7+/-3.5 years, n=16); and 24 non-athletes matched by age (+/-2 years) and body weight (+/-2 kg) to the master cyclists. All of the master cyclists had been training and racing for a minimum of 10 years (mean 20.2+/-8.4 years) and engaging in little to no weight-bearing exercise. The younger cyclists also engaged in little weight-bearing exercise and had been training and racing for 10.9+/-3.2 years. Age-matched controls were normally active. The History of Leisure Activity Questionnaire was used to determine the influence on BMD of self-reported total and weight-bearing exercise during three periods of life: 12-18 years, 19-34 years, and 35-49 years. BMD (measured by DXA) of the spine (L2-L4) and total hip was significantly (P<0.033) lower in the master cyclists compared to both age-matched controls and young adult cyclists. Total body BMD was lower in the master cyclists compared to the young-adults (P<0.033). Furthermore, four (15%) of the master cyclists, but none of the men in the other groups, had T-scores (spine and/or hip) lower than -2.5. Weight-bearing exercise performed during teen and young adult years did not appear to influence BMD, as there were no differences at any site between those within the upper and lower 50th percentiles for weight-bearing exercise during the 12-18, 19-34, or 35-49 year time periods. These data indicate that master cyclists with a long history of training exclusively in cycling have low BMD compared to their age-matched peers. Although highly trained and physically fit, these athletes may be at high risk for developing osteoporosis with advancing age.
Recent studies indicate that decreased bone mineral density (BMD) occurs in the spine, femoral necks and greater trochanters of some adults and children with Marfan syndrome. Because there is uncertainty regarding the BMD status of patients with Marfan syndrome, we undertook an analysis of BMD in both adults and children with Marfan syndrome. Dual energy X-ray absorptiometry analysis was performed on a convenience sample of 51 patients (30 adults and 21 children) with diagnosed Marfan syndrome from 1993 to 2000. T-Scores (i.e. the number of standard deviations above or below the average normal peak bone density) were determined for comparison of adults. Mean+/-SD of individual BMD values were used for comparison of the data of children. Compared to standard values obtained from normal adult patients, adult males with Marfan syndrome demonstrated significantly reduced femoral neck BMD with an average T-score of -1.54 ( P<0.001), diagnostic of osteopenia. Although osteopenia and osteoporosis were observed in several middle aged and pre- and postmenopausal women, the average T-score value for adult females and children were within normal limits. The etiology and full significance of decreased BMD in adult male patients with Marfan syndrome remain uncertain at the present time. Our results lead us to question the value of aggressive BMD evaluations by DXA in these patients, particularly prior to reaching mid-age. Further investigations will be required to shed insights into the natural history of BMD in adults and children with Marfan syndrome. Any application of bone mineral replacement therapy such as bisphosphonate, selective estrogen receptor modulators, hormone replacement therapy and vitamin D in these patients may be premature based on the existing evidence.
OBJECTIVE: The present study investigated bone turnover with exchange of hormone replacement therapy (HRT) by treatment with 1alpha-hydroxycholecalciferol in early postmenopausal women. METHODS: Subjects included a total of 75 postmenopausal women between 49 and 59 years of age who visited the Department of Obstetrics and Gynecology at Osaka Medical College Hospital for regular gynecological checkups and menopausal disorder, postmenopausal osteoporosis or hyperlipidemia, and were diagnosed with menopausal disorder or osteopenia. Changes in bone turnover and vertebral bone mineral density (BMD) in 28 patients who had undergone HRT; conjugated equine estrogen 0.625 mg daily and medroxyprogesterone acetate 2.5 mg daily) for at least 2 years and then switched to 1alpha-hydroxycholecalciferol (0.5 microg orally twice daily) and in 26 patients who were observed without drug administration after discontinuation of HRT were compared with those in 37 patients who continued HRT. BMD of the lumbar spine (L2-4) was determined using Dual Energy X-ray Absorptiometry. RESULTS: While we observed a significant decrease in vertebral bone mass in the HRT-no medication group at 12 months (P=0.049) and 18 months (P=0.013), there was no significant decrease in vertebral bone mass in either the continuous HRT group or the group with change of HRT to 1alpha-hydroxycholecalciferol. In the group with change of HRT to 1alpha-hydroxycholecalciferol, although urinary pyridinoline level increased significantly from the baseline level throughout the study period (P<0.05), serum propeptide of type-1 procollagen (P1CP) level also increased significantly from the baseline level throughout this period (P<0.001). Furthermore, significant increase from the baseline value (P<0.01) was observed in serum osteocalcin level at 6, 12 and 18 months. CONCLUSIONS: These results indicate that switching to 1alpha-hydroxycholecalciferol therapy after short-term HRT increased both bone resorption and bone formation, and permitted maintenance of increase in bone mass due to HRT for at least 18 months, though this switching accelerated bone turnover. This may have occurred because stimulation of bone formation induced by HRT was maintained by 1alpha-hydroxycholecalciferol, though bone turnover was slightly promoted because of withdrawal of HRT. This method was thus found to be very effective in preventing bone loss in patients who have discontinued HRT and are considered relatively contraindicated for use of estrogen.