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1.
Lower extremity strength and fat-free mass were examined in 58 postmenopausal women aged 60-72 yr. Subjects were studied before and after an 11-mo control period (n = 16) or before and after an 11-mo weight-bearing exercise training program designed to generate relatively high ground reaction forces (n = 42). Twenty-two of the exercisers initiated hormone replacement therapy (HRT) at the outset of exercise and continued HRT for 11 mo. Hip extension and abduction strength were assessed using a hand-held dynamometer. Force production during knee extension and flexion was evaluated on an isokinetic dynamometer at 60, 90, and 180 degrees/s. Simultaneous knee and hip extension strength was also assessed on a leg press machine. Total body and lower extremity fat-free mass were determined using dual-energy x-ray absorptiometry. There were no significant changes in muscle strength or body composition in control subjects. Both exercise groups had significant increases in fat-free mass and in all strength measures. Fat-free mass increased from 38.8 +/- 4.3 to 39.7 +/- 4.3 kg in the exercise group and from 37.7 +/- 3.9 to 38.9 +/- 4.6 kg in the exercise-plus-HRT group. The average relative increase in strength was 16.2 +/- 11.0% in the exercise group and 17.0 +/- 13.0% in the exercise-plus-HRT group. Women receiving HRT did not have a gain in fat-free mass or in strength over and above that demonstrated by the women not on HRT. Our results provide evidence that HRT does not augment the increases in muscle mass or strength that occur in response to weight-bearing exercise in older women.  相似文献   

2.
The purpose of this study was to determine the effects of a 12-month resistance training program, of two different intensities, on bone mineral density (BMD) in healthy, older women. Twenty-six Caucasian women (aged 65-79 years) completed the study. Subjects were randomly assigned to one of three groups: high-intensity (HI; n = 8), low-intensity (LI; n = 7), and control (CON; n = 11). The active groups performed 10 exercises, 3 days/week under supervision. Exercise intensity was maintained at 80% of one-repetition maximum (1-RM) for the HI groups, and at 40% 1-RM for the LI group. The volume of work was maintained constant between the two groups by assigning the LI group twice as many repetitions for each exercise. Maximal muscular strength and BMD of the lumbar spine and total hip were measured at baseline and at 12 months. Strength was evaluated using the 1-RM method, and BMD was determined by dual-energy X-ray absorptiometry. Exercise session attendance was similar for the two groups (81.0% HI; 76.8% LI). Muscular strength improved in the exercisers compared with the CON group (p < or = 0.05). Percentage change in lumbar spine BMD was 0.7 +/- 1.9%, 0.5 +/- 2.4%, and -0.1 +/- 2.3% for the HI, LI, and CON groups, respectively. Percentage change in total hip BMD was 0.8 +/- 2.3% (HI), 1.0 +/- 1.7% (LI), and 0.9 +/- 1.3% (CON). Group differences in BMD change were not significant (p > 0.05). These findings suggest that high-intensity and low-intensity resistance training regimens effectively increase muscular strength, but not lumbar spine or total hip BMD, in healthy, older women.  相似文献   

3.
In this cross-sectional study we investigated the effect of compressive and tensile forces applied on the proximal femur during weight-bearing activities. Ninety-seven men (29.9 +/- 1.7 years) were divided into two groups: 69 exercisers who had practiced regular high-impact weight-bearing activities for at least 5 years and 28 controls who had been sedentary for at least 5 years. The maximum isometric hip abduction strength was measured. The bone mineral density (BMD) of the femoral neck and the greater trochanter was assessed using dual-energy X-ray absorptiometry (DXA). Controls were considered as the reference population to calculate the Z score. Mean BMD values of the femoral neck were 0.97 g/cm2 on both sides in the exercisers and 0.83 g/cm2 on the right side and 0.84 g/cm2 on the left side in the controls. Mean BMD values of the greater trochanter were 0.86 g/cm2 on the right side and 0.87 g/cm2 on the left side in the exercisers, 0.73 g/cm2 on the right side and 0.72 g/cm2 on the left side in the controls. The BMD was significantly higher in exercisers at both trochanteric and cervical sites (P = 0. 0001). Both left and right hip abduction strength was significantly greater in the exercisers than in the controls (P < 0.05) and was positively correlated to cervical and trochanteric BMD (P < 0.01). In the exerciser group, the trochanteric Z score was higher than the cervical Z score at both right (P = 0.06) and left (P = 0.002) sides. Therefore, the proximal femoral BMD was significantly greater in exercised subjects as compared with sedentary controls. The difference was observed at the level of both the femoral neck (where it is known anatomically that only compressive gravitational forces are exerted) and the greater trochanter (where it is known that tensile forces are exerted). This result suggests the participation of both compressive and tensile forces in the mechanisms by which exercise influences bone trophicity.  相似文献   

4.
Osteoporotic fractures, and in particular, hip fractures result in significant morbidity and mortality. Low bone mass is the main risk factor of enhanced bone fragility, resulting in an increased risk for hip fracture. Bone density of osteoporotic women with and without hip fractures show a considerable overlap. Therefore, other bone-independent factors also play an important role for the development of hip- and other osteoporotic fractures. One other important factor is falling. In 90% of hip fractures falling was involved [10-15], but only 5% or less of these falls resulted in a subsequent fracture. The view that adequate exercise is beneficial for skeletal health of children and for prevention and treatment of osteoporosis in adults is supported primarily by two lines of evidence: longitudinal and cross-sectional trials in children and young adult athletes showing a significant increase of muscle- and bone mass after strenuous (children) or chronic exercise (athletes) as compared to normally active (children) or sedentary control subjects. What are the potential benefits and limits of specific exercise programs with respect to bone mass, prevention of falls and fractures? In this review these questions are discussed and a specific exercise program in osteoporotic patients with fractures is delineated.  相似文献   

5.
OBJECTIVE: To assess the effectiveness of a home exercise programme of strength and balance retraining exercises in reducing falls and injuries in elderly women. DESIGN: Randomised controlled trial of an individually tailored programme of physical therapy in the home (exercise group, n = 116) compared with the usual care and an equal number of social visits (control group, n = 117). SETTING: 17 general practices in Dunedin, New Zealand. SUBJECTS: Women aged 80 years and older living in the community and registered with a general practice in Dunedin. MAIN OUTCOME MEASURES: Number of falls and injuries related to falls and time between falls during one year of follow up; changes in muscle strength and balance measures after six months. RESULTS: After one year there were 152 falls in the control group and 88 falls in the exercise group. The mean (SD) rate of falls was lower in the exercise than the control group (0.87 (1.29) v 1.34 (1.93) falls per year respectively; difference 0.47; 95% confidence interval 0.04 to 0.90). The relative hazard for the first four falls in the exercise group compared with the control group was 0.68 (0.52 to 0.90). The relative hazard for a first fall with injury in the exercise group compared with the control group was 0.61 (0.39 to 0.97). After six months, balance had improved in the exercise group (difference between groups in change in balance score 0.43 (0.21 to 0.65). CONCLUSIONS: An individual programme of strength and balance retraining exercises improved physical function and was effective in reducing falls and injuries in women 80 years and older.  相似文献   

6.
BACKGROUND: Primary hyperparathyroidism (PHPT) is associated with an increased bone turnover. The simultaneous use of biochemical and bone mass measurements before and after parathyroidectomy is sparsely reported. This study was carried out to evaluate changes in bone mass and markers of bone metabolism in postmenopausal women with PHPT after parathyroidectomy. METHODS: Twelve women, mean age of 63 years, were investigated. Measurements of bone mineral density (total body, spine, hip, and forearm bone mineral density) with dual-energy x-ray absorptiometry were performed before operation and at follow-up at a median of 23 months. Concomitantly, changes in serum intact parathyroid hormone, bone-specific alkaline phosphatase (B-ALP), osteocalcin, carboxyterminal propeptide of type I procollagen, and the immunoactive carboxyterminal telopeptide of type I collagen were recorded. RESULTS: At follow-up a significant increase in bone mineral density of the spine (p < 0.05), femoral neck (p < 0.05), Ward's triangle (p < 0.05), and trochanter (p < 0.01) was observed. No significant changes in the forearm were registered. Levels of parathyroid hormone, B-ALP, and osteocalcin were elevated and intercorrelated before operation. The serum levels of these parameters decreased significantly after operation. Serum levels of carboxyterminal propeptide of type I procollagen and the immunoactive carboxyterminal telopeptide of type I collagen did not significantly differ from a reference population, and no major changes were observed at follow-up. CONCLUSIONS: Bone mineral density in the spine and hip is improved after parathyroidectomy in postmenopausal women with primary hyperparathyrodism. Serum levels of B-ALP and osteocalcin are elevated in PHPT and decrease after operation. The clinical usefulness of serum markers of collagen metabolism in investigating bone metabolism in PHPT seems limited.  相似文献   

7.
BACKGROUND: Significant morbidity and mortality are associated with falls in older adults. We tested the hypothesis that older women with a history of falls demonstrate decreased muscle endurance and longer recovery times following fatiguing exercise. METHODS: We evaluated dynamic endurance and recoverability of the quadriceps femoris of 29 young women (YW) (M age = 21.7), 26 older women with a history of falls (FA) (M age = 73.3), and 27 older women with no history of falls (NF) (M age = 71.2) using an isokinetic dynamometer. Subjects performed repeated maximal concentric knee extensions until the force output of two consecutive repetitions fell below 50% of their maximal voluntary contraction (MVC). Recovery was defined as the time required for the return of force output > or = 80% MVC for 2 consecutive repetitions, within a set consisting of 3 maximal contractions. One minute rest was allowed between sets. We collected electromyographic (EMG) data from the quadriceps during all testing to evaluate spectral shifts. RESULTS: ANOVA with a post-hoc Bonferroni-Dunn test revealed time to fatigue was significantly faster in FA than YW (p < .02) and in FA than NF (p < .05), but not different between YW and NF. Time to recovery was significantly slower in FA than YW (p = .01), but not different between YW and NF, or between FA and NF, EMG median frequency power shift (from the beginning to the end of the test) was significantly less in FA (p < .001) than either YW (p < .002) or NF (p < .05). CONCLUSIONS: Older women with a history of falls demonstrate decreased muscular endurance compared to YW and NF, and increased time to recover from fatiguing exercise when compared to young women.  相似文献   

8.
The objectives of this study were to determine the pattern of fall and the bone mineral density distribution in hip fracture patients. The study was carried out on 260 patients (204 females and 56 males) with hip fractures over a period of three years (i.e. 1991 to 1993). The patients were all above 50 years old and the average age was 77.7 years for women and 76.8 years for men. Information relating to their falls and subsequent hip fractures were collected. Bone mineral density of the contralateral intact femoral neck was measured using dual energy X-ray absorptiometry (Model XR26, Norland Corporation, USA). Bone mineral density in the patients with hip fracture (mean value 0.55 g/cm2) was significantly lower than the fracture threshold value of 0.64 g/cm2. Falls which would result in direct impact on the hip such as sideways, backwards and straight down formed 95.6% of the cohort. Forty-six (17.7%) of the patients fell from a seated or lying position and their bone mineral density were significantly lower (i.e. 0.45 g/cm2). Two hundred and twenty-three (85.7%) of the patients fell on hard surfaces such as ceramic, marble and concrete. Two hundred and twelve (81.5%) of the falls occurred indoors and 153 (58.8%) while walking. Low bone mineral density and falls are important risk factors in hip fracture in the elderly population. Patients with low bone mineral density can sustain a hip fracture from mild trauma such as falling from a seated or lying position. It is therefore necessary to monitor bone mineral density values as well as to prevent or minimise the risk of falling.  相似文献   

9.
Although bone loss occurs universally with age, the incidence of age-related osteoporotic fractures varies widely among ethnic groups. In the U.S., age-adjusted hip fracture incidence is 50% lower in African-American than in white women. Adult African-American women also have higher bone mass, but it is not known whether this difference is entirely due to higher peak bone mass or also results from slower rates of bone loss. Rates of bone loss were measured prospectively in 122 white and 121 African-American healthy, nonobese, pre- and postmenopausal women. Bone density was measured at 6-month intervals over a mean of 3-4 yr using single and dual photon absorptiometry of the forearm (cortical bone) and spine (trabecular bone). Similar rates of premenopausal bone loss were documented in both white and African-American women. However, in early menopause, bone loss was faster in the white women in the forearm (-2.4%/yr in whites vs. -1.2%/yr in African-Americans; P = 0.045), with a similar trend in the spine (-2.2%/yr in whites vs. -1.3/yr in African-Americans; P = 0.27). In women more than 5 yr postmenopause, the rates of bone loss did not differ by ethnic group. Our results indicate that the higher bone mass in African-American women is largely due to the attainment of a greater peak bone mass by early adulthood. However, slower rates of bone loss in the early postmenopausal period may also contribute to the higher bone density of older African-American women. Although bone loss occurs in both groups, there are ethnic differences in bone loss rates which indicate that data derived from white women cannot be simply extrapolated to nonwhite populations. Ethnic group-specific data on the determinants of bone homeostasis are needed.  相似文献   

10.
BACKGROUND: Although changes in body weight with aging are common, little is known about the effects of weight change on health in old age. OBJECTIVES: To study the effects of weight loss and weight gain from age 50 years to old age on the risk of hip fracture among postmenopausal white women aged 67 years and older and to determine if the level of weight at age 50 years modifies this risk. METHODS: The association between weight change and the risk of hip fracture was studied in 3683 community-dwelling white women aged 67 years and older from three sites of the Established Populations for Epidemiologic Studies of the Elderly. RESULTS: Extreme weight loss (10% or more) beginning at age 50 years was associated in a proportional hazards model with increased risk of hip fracture (relative risk [RR], 2.9; 95% confidence interval [CI], 2.0-4.1). This risk was greatest among women in the lowest (RR, 2.3; CI, 1.1-4.8) and middle (RR, 2.8; CI, 1.5-5.3) tertiles of body mass index at age 50 years. Among the thinnest women, even more modest weight loss (5% to < 10%) was associated with increased risk of hip fracture (RR, 2.3; CI, 1.0-5.2). Weight gain of 10% or more beginning at age 50 years provided borderline protection against the risk of hip fracture (RR, 0.7; CI, 0.4-1.0). The RRs for weight gain of 10% or more were protective only among women in the middle and high tertiles of body mass index at age 50 years and were not significant (middle tertile RR, 0.8; CI, 0.3-1.8; high tertile RR, 0.6; CI, 0.2-1.9). CONCLUSIONS: Weight history is an important determinant of the risk of hip fracture. Weight loss beginning at age 50 years increases the risk of hip fracture in older white women, especially among those who are thin at age 50 years; weight gain of 10% or more decreases the risk of hip fracture. Physicians should include weight history in their assessment of postmenopausal older women for risk of hip fracture.  相似文献   

11.
BACKGROUND: It is important to determine if permanent lifestyle changes may result from physical activity interventions and whether health may be affected by these changes. OBJECTIVE: To conduct a 10-year follow-up of physical activity and self-reported health status in participants of a randomized clinical trial of walking intervention. METHODS: Of the original 229 volunteer postmenopausal women who participated in the original clinical trial, 196 (N = 96 intervention and 100 controls) completed the 10-year follow-up telephone interview. The interview protocol included questions on self-reported walking for exercise and purposes other than exercise, the Paffenbarger sport and exercise index, functional status, and various chronic diseases and conditions. RESULTS: The median values for both usual walking for exercise and total walking were significantly higher for walkers compared with controls (for both, P = .01), with median differences of 706 and 420 kcal/wk, respectively. After excluding women who reported heart disease during the original trial, 2 women in the walking group (2%) and 11 women in the control group (12%) reported physician-diagnosed heart disease over the last 10 years (P = .07). There were also fewer hospitalizations, surgeries, and falls among women in the walking group, although these differences were not statistically significant (P>.05). CONCLUSIONS: Although limited by self-report, this study may be the first to demonstrate long-term exercise compliance to a randomized control trial in older women and to suggest that health benefits may have ensued as a result of these increased activity levels.  相似文献   

12.
Vasomotor, somatic, and psychological symptoms associated with menopause are often treated with hormone replacement therapy (HRT), but the role of nonpharmacological interventions has received little attention. Two studies used the Profile of Mood States (POMS) and Women's Health Questionnaire (WHQ) to examine the effects of exercise among 4 groups of Australian women: premenopausal, perimenopausal, postmenopausal without HRT, and postmenopausal with HRT. Study 1, a comparison of exercisers and nonexercisers, showed that exercisers' moods were significantly more positive than sedentary women's moods, regardless of menopausal state. Exercising women also scored lower on somatic symptoms and memory-concentration difficulties. Study 2 examined the acute effects of aerobic exercise (premenopausal, postmenopausal without HRT, and postmenopausal with HRT) and found significant enhancements in mood and reductions in reported somatic and vasomotor symptoms immediately following an aerobic class. Exercise may assist in the alleviation of some menopausal symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
One of the latest developments in quantitative ultrasound (QUS) is the measurement of the speed of sound (SOS) of cortical bone of the midtibia. To determine the diagnostic validity of this method we measured 150 healthy women aged 22-94 years. Additionally, we report on first results of patients with hip fracture. Precision in vivo of the tibial QUS expressed as the percentage coefficient of variation (CV) was 0.39% for the first day and 0.45% after repositioning the second day (mean CV = 0.42%). No significant dependency of tibial SOS was found with weight, height, and body mass index in pre- and postmenopausal women. There was a significant decline of SOS with age in postmenopausal women (SOS = 4225 - 5.3 age, r = -0.46, P < 0. 001), whereas premenopausal women showed no decline (SOS = 3906 + 1. 3 age, r = 0.13, ns) Mean SOS values of premenopausal women were significantly higher than those of postmenopausal women (3960 +/- 78.7 m/second and 3898 +/- 120 m/second, respectively, P < 0.001). Postmenopausal women on estrogen substitution had significantly higher mean tibial SOS values than age-comparable postmenopausal women without estrogen substitution (3980 +/- 99 m/second and 3869 +/- 100 m/second, respectively, P < 0.001). Significant difference between age-matched healthy women, n = 11, and hip fracture patients, n = 13, expressed as z-score of -1.4 SD was found. In conclusion, tibial QUS declines with age and detects higher values in premenopausal women and postmenopausal women on estrogen substitution and lower values in hip fracture patients. Further prospective studies are needed to clarify its role in fracture risk assessment.  相似文献   

14.
The mechanism(s) governing the gain of upper-body fat and its relationship to the decrease in bone mass with age is still unclear. Therefore, four groups of subjects matched for weight, height, and body mass index (n = 119; 60 women, 59 men), but differing in age (above and below 50 y) and sex were investigated using dual energy x-ray absorptiometry (DXA) to assess body composition (bone, lean, and fat mass as well as its distribution) and indirect calorimetry to determine resting fuel metabolism. Fat mass of trunk and arms (P < 0.01), but not legs, increased with advancing age in males, resulting in a continuous increase in the ratio of upper- to lower-body fat (r = 0.45, P < 0.001). In contrast, total fat mass remained stable in women, irrespective of menopause, but a redistribution of fat occurred with advancing age (r = 0.43, P < 0.001), resulting in a higher upper- to lower-body fat ratio (P < 0.05) in older than in younger women. Total lean soft-tissue mass of all segments of the body was greater in men than in women irrespective of age (P < 0.001), and lower in the older groups than in the younger ones irrespective of sex. In males, but not females, lean soft-tissue mass in arms and legs decreased (r = 0.57, P < 0.001), whereas the ratio of total fat to lean soft-tissue mass increased (r = 0.53, P < 0.001) with age. Bone mineral content correlated with total body fat in both groups of women and in young males (r > 0.5, P < 0.001), but not in older males. With advancing age, the proportion of lean soft-tissue mass occupied by total skeleton declined in women (n = 59, P < 0.001), but remained stable in males. Resting energy expenditure decreased with age in both sexes. Protein and carbohydrate oxidation were similar in all four groups of subjects. Total fat oxidation and fat oxidation per kilogram of lean soft-tissue mass decreased with age (r > 0.36, P < 0.01) in males, but not in females, whereas it increased with increasing fat mass in females (r > 0.32, P < 0.03), but not in males. In contrast, fat oxidation per kilogram of fat mass decreased with fat mass in males (r = 0.61, P < 0.001), but not in females. Our results suggest that aging affects body composition and fuel metabolism differently in each gender, leading to reduced fat oxidation and accumulation of upper-body fat with loss of striated muscle in men, and to an increased ratio of upper- to lower-body fat and bone loss in women, the latter depending on fat mass.  相似文献   

15.
Reduction in the biomechanical competence of the axial skeleton can result in challenging complications. Osteoporosis consists of a heterogeneous group of syndromes in which bone mass per unit volume is reduced in otherwise normal bone, which results in more fragile bone. The geriatric population has an increased risk for debilitating postural changes because of several factors. The two most apparent factors are involutional loss of functional muscle motor units and the greater prevalence of osteoporosis in this population. Obviously, the main objective of rehabilitation is to prevent fractures rather than to treat the complications. These complications can vary from "silent" compression fractures of vertebral bodies, to sacral insufficiency fractures, to "breath-taking" fractures of the spine or femoral neck. The exponential loss of bone at the postmenopausal stage is not accompanied by an incremental loss of muscle strength. The loss of muscle strength follows a more gradual course and is not affected significantly by a sudden hormonal decline, as is the case with bone loss. This muscle loss may contribute to osteoporosis-related skeletal disfigurations. In men and women, the combination of aging and reduction of physical activity can affect musculoskeletal health, and contribute to the development of bone fragility. The parallel decline in muscle mass and bone mass with age is more than a coincidence, and inactivity may explain some of the bone loss previously associated with aging per se. Kyphotic postural change is the most physically disfiguring and psychologically damaging effect of osteoporosis and can contribute to an increment in vertebral fractures and the risk of falling. Axial skeletal fractures, such as fracture of the sacral alae (sacral insufficiency fracture) and pubic rami, may not be found until radiographic changes are detected. Management of chronic pain should include not only improvement of muscle strength and posture but also, at times, reduction of weight bearing on the painful pelvis with insufficiency fractures. Axial skeletal health can be assisted with improvement of muscular supportive strength. Disproportionate weakness in the back extensor musculature relative to body weight or flexor strength considerably increases the risk of compressing porous vertebrae. A proper exercise program, especially osteogenic exercises, can improve musculoskeletal health in osteoporotic patients. Exercise not only improves musculoskeletal health but also can reduce the chronic pain syndrome and decrease depression. Application of a proper back support can decrease kyphotic posturing and can expedite the patient's return to ambulatory activities. Measures that can increase safety during ambulatory activities can reduce risk of falls and fractures. Managing the musculoskeletal challenges of osteoporosis goes hand in hand with managing the psychological aspects of the disease.  相似文献   

16.
OBJECTIVE: Because parathyroid hormone (PTH) stimulates bone resorption, resistance to its actions might help maintain bone mass. We tested the hypothesis that the effects of estrogen on bone are accomplished in part by decreasing the sensitivity of the skeleton to the resorbing effects of PTH. STUDY DESIGN: Comparison of response to PTH infusion in untreated and estrogen-treated postmenopausal women with osteoporosis. INTERVENTION: (1-34) human PTH, 0.55 U/(kg.h), was infused intravenously over 20 hours. SETTING: The inpatient clinical research unit of a referral hospital. PATIENTS: Women with primary postmenopausal osteoporosis who were untreated (n = 15) or treated with estrogen (n = 17). MAIN OUTCOME MEASURES: Skeletal turnover indices including hydroxyproline, deoxypyridinoline, pyridinoline, tartrate-resistant acid phosphatase, alkaline phosphatase, bone Gla protein, and insulin-like growth factor-1. RESULTS: All basal indices were higher in untreated than in estrogen-treated women, but statistical differences were seen only for deoxypyridinoline and pyridinoline. During the 20-hour infusion, hydroxyproline/creatinine increased 0.023 mumol/mumol in untreated women but only 0.010 mumol/mumol in estrogen-treated women (P < 0.05). Corresponding changes for deoxypyridinoline/creatinine were 14.6 mumol/mumol and 3.5 mumol/mumol (P = 0.06). Tartrate-resistant acid phosphatase and pyridinoline increased only in untreated group. A circadian rhythm in circulating bone Gla protein was seen in both groups without clear PTH-induced effects or differences between groups. Alkaline phosphatase levels decreased and insulin-like growth factor-1 levels increased in both groups with no distinction between untreated and estrogen-treated women [corrected]. CONCLUSION: The estrogenized postmenopausal osteoporotic skeleton is less sensitive to the bone resorbing effects of acutely administered PTH. There are no differential effects on bone formation.  相似文献   

17.
BACKGROUND: Physical activity in old age probably protects against hip fracture. However, very little is known about the impact of occupation during working life, in terms of its physical activity level and the socio-economic status (SES) it indicates, on the risk of hip fracture in later life. METHOD: A population-based case-control study was conducted on 416 subjects to investigate relationships between risk of hip fracture and occupational physical activity and occupation-related SES. Occupational physical activity was coded according to the proportion of the working day at ages 20 and 50 years that the subjects were likely to have spent sitting. The Australian Classification of Standard Occupations (ASCO) was used as the basis for the coding of SES, indicated by job titles. RESULTS: Compared with those in the intermediate category, women with a sedentary job at age 50 years (odds ratio (OR) 7.2, 95 per cent confidence interval (CI) 1.2-41.9) or a mainly weight-bearing job (OR 5.1, 95 per cent CI 1.1-23.2) had an increased risk of hip fracture. A decreasing hip fracture risk with increasing SES of the longest held job was also observed. CONCLUSION: The finding of a J-shaped relationship in women between occupational physical activity and risk of hip fracture supports the need for research into the most effective types of exercise for maintenance of bone strength. Furthermore, the protective effect of SES demonstrated in this study still need to be corroborated in other studies before establishing evidence of a causal relationship.  相似文献   

18.
Twelve women who had received oestradiol implantation on demand for at least 15 years following hysterectomy with bilateral oophorectomy, underwent bone densitometry of hip and spine. Bone mass of hip and spine was significantly elevated above that of both the age matched mean to a degree hitherto undocumented. This suggests that oestrogen in high doses or over a long period may produce a true anabolic effect on bone mass.  相似文献   

19.
OBJECTIVE: In the postmenopausal years, women develop a central pattern of fat distribution and an increased risk of developing cardiovascular disease (CVD). The possibility that these events are related has not been extensively investigated. The object of the present study was to test the hypotheses that, 1) menopause-related differences in lipids are associated with greater estimated intra-abdominal adiposity, and 2) the relationship between individual adipose depots and plasma lipids differs with menopausal status. DESIGN: Cross-sectional. SUBJECTS: 141 healthy pre- and postmenopausal women aged 35-65 y. MEASUREMENTS: Total body fat by hydrodensitometry was used as an index of whole-body adiposity, the sum of five central skinfold measurements as an index of subcutaneous upper-body adiposity, and estimated intra-abdominal adipose tissue (IAF) as an index of visceral adiposity. Fasting plasma concentrations of total cholesterol (total-C), high- and low-density-lipoprotein cholesterol (HDL-C, LDL-C), and triglycerides were used as indices of CVD risk. RESULTS: Postmenopausal women had greater total body fat (P < 0.001), summed central skinfolds (P < 0.01), estimated IAF (P < 0.001), higher plasma concentrations of total-C (P < 0.001), LDL-C (P < 0.001) and triglycerides (P < 0.001), than premenopausal women. The relationship between central skinfolds and LDL-C differed with menopausal status, being significant in pre- but not postmenopausal women. Adjustment for estimated IAF with analysis of covariance decreased menopause-related differences in levels of total-C, LDL-C and triglycerides by approx 40-70%. CONCLUSION: These observations suggest that, 1) menopause-related changes in IAF may adversely affect the plasma lipid profile, and 2) menopausal status affects the relationship between central subcutaneous fat and LDL-C. Studies with measured IAF are needed to confirm present results.  相似文献   

20.
OBJECTIVE: To determine whether female college athletes had increased muscle strength and bone mass in comparison with age-matched nonathletic female subjects and, if so, whether participation in weight-bearing versus non-weight-bearing exercise made a difference. MATERIAL AND METHODS: We performed a comparative statistical analysis of the bone mineral density (BMD) of the total body, lumbar spine, and femoral neck, maximal oxygen uptake (VO2max), muscle strength, and level of physical activity in 21 runners, 22 swimmers, and 20 control subjects. The study participants were female college students, 18 to 24 years old, who had had more than 8 normal menstrual cycles during the past year. RESULTS: Statistical analyses showed significantly higher VO2max in the two athletic study groups than in the control subjects (P < 0.0001). No significant difference in BMD was noted among the three groups. Total body BMD (r = 0.30; P = 0.02) and femoral neck BMD (r = 0.39; P = 0.002) were positively correlated with weight-bearing activity but not with non-weight-bearing activity. VO2Max (an index of physical fitness) was positively correlated with femoral neck BMD (r = 0.33; P = 0.009) and trochanteric BMD (r = 0.29; P = 0.021). Shoulder muscle strength (determined by isokinetic dynamometry) was positively correlated with total body BMD (r = 0.34; P = 0.007) and lumbar spine BMD (r = 0.28; P = 0.028). Swimmers had higher muscle strength in the back and upper extremities than did runners and control subjects. Hip girdle muscle strength was not significantly different among the three groups. Total body BMD had a positive correlation with percentage of body fat and height. Lumbar spine BMD was higher in subjects who had previously used oral contraceptives. The athletes had a lower percentage of body fat, were less likely to have used oral contraceptives, and had fewer years of normal menses than did the control subjects. CONCLUSION: Our study shows that (1) total body BMD and femoral neck BMD were significantly higher in the study group that performed weight-bearing exercises than in control subjects, (2) swimming exercise had no effect on BMD, and (3) although swimming is not a bone-building exercise, it can significantly improve shoulder, back, and grip muscle strength.  相似文献   

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