| 1. |
|
|
| 2. |
- Ahlborg, Henrik
(författare)
-
Changes in bone mass and skeletal structure in the postmenopausal period.
- 2003
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this thesis was to evaluate long-term changes in bone mass and skeletal structure in the forearm in the peri- and postmenopausal period. 156 premenopausal women, at baseline aged 48 years, not taking medications and without disease processes known to interfere with bone metabolism, were followed through menopause by measurements of bone mass and skeletal structure at the cortical site of the distal radius by single photon absorptiometry, on average every second year until age 72. General health and life-style factors were reported, and the postmenopausal serum estradiol level and fragility fractures were noted. Menopause was determined according to the definition established by the World Health Organisation. The age-dependent reduction in bone mineral density accelerated after menopause, with the highest bone loss found during the first 5 years following menopause. Independent of age at menopause, premenopausal women with low, age-specific bone mineral density at age 48 years were likely to have low bone mineral density also at age 64 years. Furthermore, menopause was followed by structural geometrical changes such as endosteal resorption, increasing the medullary cavity, and periosteal apposition, increasing the bone size. Increased periosteal apposition was associated with both increased bone loss and low postmenopausal serum levels of estradiol. The periosteal apposition seemed to partly compensate for the decreased bone strength, caused by the decrease in tissue mineral content. A Strength Index, taking both bone density and skeletal geometry into account, predicted a future fracture of the distal radius. If the structural skeletal changes of the distal radius, with enlargement of the medullary cavity, are a general phenomenon of the diaphyseal bones, this theoretically could have implications for the long-term fixation of a hip prosthesis. Bone loss following menopause was less in physically active than in physically inactive women, so that physically active women had a higher bone mineral density at age 72 than physically inactive women. This suggests that moderate physical activity in the postmenopausal period could possibly be recommended as a strategy to prevent bone loss. Furthermore, the effect of hormone replacement therapy on bone loss after menopause was evaluated in an observational study with 28 women with and 196 women without hormone replacement therapy. Hormone replacement therapy seemed to reduce the rate of bone loss over a period of 23 years, and the longer the duration of the therapy, the less the bone loss.
|
|
| 3. |
- Ahlborg, Henrik, et al.
(författare)
-
Contribution of hip strength indices to hip fracture risk in elderly men and women
- 2005
-
Ingår i: Journal of Bone and Mineral Research. - 1523-4681. ; 20:10, s. 1820-1827
-
Tidskriftsartikel (refereegranskat)abstract
- In this prospective, case-control study, femoral neck diameter, cross-sectional moment of inertia, or section modulus was an independent predictor of hip fracture risk after adjustment for BMD. However, the contribution of each of these indices to hip fracture prediction was modest in the presence of BMD. Introduction: The relative contribution of measures of hip strength to hip fracture prediction is unclear. This study was designed to characterize the association between hip strength indices and hip fracture risk in relation to BMD in elderly men and women. Materials and Methods: Seventy-one women and 25 men >= 60 years of age, who sustained a hip fracture during the study period of 1989-2003, were selected from the prospective, population-based Dubbo Osteoporosis Epidemiology Study. These fracture cases were randomly matched for age and sex in a 1:2 ratio with non-fracture individuals. BMD at the femoral neck was measured before the fracture event by DXA (Lunar DPX-L). Hip strength indices, including femoral neck diameter (FND), cross-sectional moment of inertia (CSMI), and section modulus (Z), were estimated by reanalysis of the image files using hip strength analysis software. Results: In women, after adjustment for BMD, increased risk of hip fracture was associated with smaller FND (OR, 1.6; 95% CI, 1.0, 2.7), lower CSMI (OR, 1.8; 95% Cl, 1.0, 3.2), or Z (OR, 1.6; 95% Cl, 1.1, 5.1). In men, none of these hip strength indices were significant predictors of fracture risk. However, using the results in women as a prior distribution, it was estimated that the BMD-adjusted OR for FND (OR, 1.5; 95% CI, 1.0, 2.3), CSMI (OR, 1.6; 95% CI, 1.0, 2.5), or Z (OR, 2.3; 95% Cl, 1.4,3.9) was each significantly associated with hip fracture risk in men. In the logistic regression model, BMD alone accounted for 32% and 16% of the variance of fracture liability in women and men, respectively. The addition of FND, CSMI, or Z to the model increased the respective variance proportion to 34% and 19%. Conclusions: These data suggest that smaller FND and lower CSMI or Z is an independent risk factor for hip fracture in both women and men. However, the contribution of these measures to hip fracture prediction over and above BMD is likely modest.
|
|
| 4. |
|
|
| 5. |
- Ahlborg, Henrik, et al.
(författare)
-
Incidence and risk factors for low trauma fractures in men with prostate cancer.
- 2008
-
Ingår i: Bone. - : Elsevier BV. - 1873-2763 .- 8756-3282. ; 43, s. 556-560
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Men with prostate cancer on androgen deprivation therapy (ADT) are at increased risk of bone loss. The present study sought to determine the incidence of low trauma fracture in men with prostate cancer (PC), and to characterize the association between potential risk factors and fracture risk in these men. METHODS: In the prospective, population-based Dubbo Osteoporosis Epidemiology Study, 43 men aged 60+ years reported a history of prostate cancer; among whom, 22 men received ADT, and 21 men did not. Low-trauma fractures were ascertained between 1989 and 2004. Bone mineral density at the femoral neck (FNBMD), postural instability and lifestyle factors were obtained at baseline. RESULTS: Men with prostate cancer had significantly higher lumbar spine BMD than those without cancer (p=0.013). During the follow-up period, 15 men with prostate cancer had sustained a fracture, yielding the age-adjusted incidence of fracture among this group was 31.6 per 1000 person-years, which was greater than those without cancer (22.1 per 1000 person-years). The age-adjusted incidence of fracture was more pronounced among those with prostate cancer on ADT (40.2 per 1000 person-years). After adjusting for age, the increase in fracture risk among prostate cancer patients was associated with lower femoral neck BMD (hazard ratio [HR] per SD=1.8, 95% CI: 1.0-3.4) and increased rate of bone loss (HR 2.3, 1.2-4.6). CONCLUSIONS: Men with prostate cancer, particularly those treated with ADT, had an increased fracture risk. Although the average BMD in men with prostate cancer was higher than men without cancer, a low BMD prior to treatment or increased rate of bone loss after initiating ADT treatment was each a significant predictor of fracture in these.
|
|
| 6. |
- Ahlborg, Henrik, et al.
(författare)
-
Prevalence of osteoporosis and incidence of hip fracture in women--secular trends over 30 years.
- 2010
-
Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The number of hip fractures during recent decades has been reported to be increasing, partly because of an increasing proportion of elderly women in the society. However, whether changes in hip fracture annual incidence in women are attributable to secular changes in the prevalence of osteoporosis is unclear. METHODS: Bone mineral density was evaluated by single-photon absorptiometry at the distal radius in 456 women aged 50 years or above and living in the same city. The measurements were obtained by the same densitometer during three separate time periods: 1970-74 (n = 106), 1987-93 (n = 175) and 1998-1999 (n = 178), and the age-adjusted prevalence of osteoporosis in these three cohorts was calculated. Additionally, all hip fractures sustained in the target population of women aged 50 years or above between 1967 and 2001 were registered, whereupon the crude and the age-adjusted annual incidence of hip fractures were calculated. RESULTS: There was no significant difference in the age-adjusted prevalence of osteoporosis when the three cohorts were compared (P = 1.00). The crude annual incidence (per 10,000 women) of hip fracture in the target population increased by 110% from 40 in 1967 to 84 in 2001. The overall trend in the crude incidence between 1967 and 2001 was increasing (1.58 per 10,000 women per year; 95 percent confidence interval, 1.17 to 1.99), whereas the age-adjusted incidence was stable over the same period (0.22 per 10,000 women per year; 95 percent confidence interval, -0.16 to 0.60). CONCLUSIONS: The increased number of hip fracture in elderly women is more likely to be attributable to demographic changes in the population than to secular increase in the prevalence of osteoporosis.
|
|
| 7. |
- Alwis, Gayani, et al.
(författare)
-
A 2-year school-based exercise programme in pre-pubertal boys induces skeletal benefits in lumbar spine.
- 2008
-
Ingår i: Acta Pædiatrica. - : Wiley. - 1651-2227 .- 0803-5253. ; 97, s. 1564-1571
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: The aim of this study was to evaluate if a general school-based exercise intervention programme in pre-pubertal boys would render site-specific benefits in bone mineral accrual and gain in femoral neck structure. Methods: Eighty boys aged 7-9 years were included in a curriculum-based exercise intervention programme comprising 40 min of general physical activity per school day (200 min/week) for 2 years. Fifty-seven age-matched boys, assigned to the general Swedish school curriculum of 60 min/week, served as controls. Bone mineral content was measured with dual X-ray absorptiometry of the total body, the third lumbar vertebra and hip. Specific software, the hip structural analyses, evaluated the structural properties of the femoral neck. Annual changes were compared. The level of physical activity was estimated through questionnaires and accelerometers. Results: The mean annual bone mineral content gain in third lumbar vertebra was 3.0 percentage points (p < 0.01) and in width 1.3 percentage points (p < 0.01) greater in the intervention than in the control group. The weekly duration of exercise estimated through the questionnaire correlated with gain in bone mineral content in third lumbar vertebra (r = 0.25, p = 0.005) and vertebra width (r = 0.20, p = 0.02). Conclusion: A school-based exercise intervention programme in pre-pubertal boys enhances the skeletal benefits at lumbar spine.
|
|
| 8. |
- Alwis, Gayani, et al.
(författare)
-
A one-year exercise intervention program in pre-pubertal girls does not influence hip structure
- 2008
-
Ingår i: BMC Musculoskeletal Disorders. - : Springer Science and Business Media LLC. - 1471-2474. ; 9:9
-
Tidskriftsartikel (refereegranskat)abstract
- Background: We have previously reported that a one-year school-based exercise intervention program influences the accrual of bone mineral in pre-pubertal girls. This report aims to evaluate if also hip structure is affected, as geometry independent of bone mineral influences fracture risk. Methods: Fifty-three girls aged 7-9 years were included in a curriculum-based exercise intervention program comprising 40 minutes of general physical activity per school day (200 minutes/week). Fifty healthy age-matched girls who participated in the general Swedish physical education curriculum (60 minutes/week) served as controls. The hip was scanned by dual X-ray absorptiometry (DXA) and the hip structural analysis (HSA) software was applied to evaluate bone mineral content (BMC), areal bone mineral density (aBMD), periosteal and endosteal diameter, cortical thickness, cross-sectional moment of inertia (CSMI), section modulus (Z) and cross-sectional area (CSA) of the femoral neck (FN). Annual changes were compared. Group comparisons were done by independent student's t-test between means and analyses of covariance (ANCOVA). Pearson's correlation test was used to evaluate associations between activity level and annual changes in FN. All children remained at Tanner stage 1 throughout the study. Results: No between-group differences were found during the 12 months study period for changes in the FN variables. The total duration of exercise during the year was not correlated with the changes in the FN traits. Conclusion: Evaluated by the DXA technique and the HSA software, a general one-year school-based exercise program for 7-9-year-old pre-pubertal girls seems not to influence the structure of the hip.
|
|
| 9. |
- Alwis, Gayani, et al.
(författare)
-
A school-curriculum-based exercise intervention program for two years in pre-pubertal girls does not influence hip structure.
- 2008
-
Ingår i: Dynamic Medicine. - : Springer Science and Business Media LLC. - 1476-5918. ; 7, s. 8-8
-
Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: BACKGROUND: It is known that physical activity during growth has a positive influence on bone mineral accrual, and is thus possibly one strategy to prevent osteoporosis. However, as bone geometry, independent of areal bone mineral density (aBMD), influences fracture risk, this study aimed to evaluate whether hip structure in pre-pubertal girls is also affected by a two-year exercise intervention program. METHODS: Forty-two girls aged 7-9 years in a school-curriculum-based exercise intervention program comprising 40 minutes of general physical activity per school day (200 minutes per week) were compared with 43 age-matched girls who participated in the general Swedish physical education curriculum comprising a mean of 60 minutes per week. The hip was scanned by dual energy X-ray absorptiometry (DXA) and the hip structural analysis (HSA) software was applied to evaluate bone mineral content (BMC, g), areal bone mineral density (aBMD, g/cm2), periosteal diameter, cross-sectional area (CSA, cm2), section modulus (Z, cm3) and cross-sectional moment of inertia (CSMI, cm4) of the femoral neck (FN). Annual changes were compared. Subjective duration of physical activity was estimated by questionnaire and objective level of everyday physical activity at follow-up by means of accelerometers worn for four consecutive days. All children remained at Tanner stage 1 throughout the study. Group comparisons were made by independent student's t-test between means and analyses of covariance (ANCOVA). RESULTS: At baseline, the two groups did not differ with regard to age, anthropometrics or bone parameters. No between-group differences were observed for annual changes in the FN variables measured. CONCLUSION: A two-year school-based moderately intense general exercise program for 7-9-year-old pre-pubertal girls does not influence structural changes in the FN.
|
|
| 10. |
- Atroshi, Isam, et al.
(författare)
-
Low calcaneal bone mineral density and the risk of distal forearm fracture in women and men: a population-based case-control study.
- 2009
-
Ingår i: Bone. - : Elsevier BV. - 1873-2763 .- 8756-3282. ; 45:4, s. 789-93
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We used dual X-ray absorptiometry (DXA) to measure calcaneal bone mineral density (BMD) and estimate the prevalence of osteoporosis in a population with distal forearm fracture and a normative cohort. METHODS: Patients 20 to 80 years of age with distal forearm fracture treated at one emergency hospital during two consecutive years were invited to calcaneal BMD measurement; 270 women (81%) and 64 men (73%) participated. A DXA heel scanner estimated BMD (g/cm(2)) and T-scores. Osteoporosis was defined as T-score< or =-2.5 SD. Of the fracture cohort, 254 women aged 40-80 years and 27 men aged 60-80 years were compared with population-based control cohorts comprising 171 women in the age groups 50, 60, 70 and 80 years and 75 men in the age groups 60, 70, and 80 years. RESULTS: In the fracture population no woman below 40 years or man below 60 years of age had osteoporosis. In women aged 40-80 years the prevalence of osteoporosis in the distal forearm fracture cohort was 34% and in the population-based controls was 25%; the age-adjusted prevalence ratio (PR) was 1.32 (95% CI 1.00-1.76). In the subgroup of women aged 60-80 years the age-adjusted prevalence ratio of osteoporosis was 1.28 (95% CI 0.95-1.71). In men aged 60-80 years the prevalence of osteoporosis in the fracture cohort was 44% and in the population-based controls was 8% (PR 6.31, 95% CI 2.78-14.4). The age-adjusted odds ratio for fracture associated with a 1-SD reduction in calcaneal BMD was in women aged 40-80 years 1.4 (95% CI 1.1-1.8), in the subgroup of women aged 60-80 years 1.2 (95% CI 0.95-1.6), and in men aged 60-80 years 2.6 (95% CI 1.7-4.1). Among those aged 60-80 years the area under the ROC curve was in women 0.56 (95% CI 0.49-0.63) and in men 0.80 (95% CI 0.70-0.80). CONCLUSIONS: The age-adjusted prevalence of osteoporosis based on calcaneal BMD is higher in individuals with distal forearm fracture than in population-based controls. BMD impairment is associated with increased odds ratio for forearm fracture in both women and men but the differences between cases and controls are more pronounced in men than in women, which may have implications in fracture prevention.
|
|
