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Biomedical subjects

P Lips

Publications and source records attributed to P Lips.

At least 19 recordsLinked to original sources
PubMed2006

Additional weight bearing during exercise and estrogen in the rat: the effect on bone mass, turnover, and structure.

Mechanical loading and estrogen play important roles in bone homeostasis. The aim of this study was to evaluate the effects of mechanical loading on trabecular bone in the proximal femur of ovariectomized rats. We hypothesized that mechanical loading suppresses bone resorption and increases bone formation, which differs from the suppressive effects of estrogen on both resorption and formation. Furthermore, we expected to find changes in trabecular architecture elicited by the effects of mechanical loading and estrogen deficiency. Sixty female Wistar rats, 12 weeks old, were assigned to either the sedentary groups sham surgery (SED), ovariectomy (SED+OVX), and ovariectomy with estrogen replacement (SED+OVX+E2) or to the exercise groups EX, EX+OVX, EX+OVX+E2. Following ovariectomy, 5 microg 17beta-estradiol was given once weekly to the estrogen replacement groups. Exercise consisted of running with a backpack (load +/-20% of body weight) for 15 minutes/day, 5 days/week, for 19 weeks. Dual-energy X-ray absorptiometry (DXA) scans were performed before (T0), during (T6), and after (T19) the exercise period to obtain bone mineral content (BMC) and bone mineral density (BMD) data. After the exercise program, all rats were killed and right and left femora were dissected and prepared for micro-CT scanning and histomorphometric analysis of the proximal femoral metaphysis. After 19 weeks, increases in BMC (P = 0.010) and BMD (P = 0.031) were significant. At T19, mechanical loading had a significant effect on BMC (P = 0.025) and BMD (P = 0.010), and an interaction between mechanical loading and estrogen (P = 0.023) was observed. Bone volume and trabecular number decreased significantly after ovariectomy, while trabecular separation, mineralizing surface, bone formation rate, osteoclast surface, degree of anisotropy, and structure model index increased significantly after ovariectomy (P < 0.05). Trabecular bone turnover and structural parameters in the proximal femur were not affected by exercise. Estrogen deficiency resulted in a less dense and more oriented trabecular bone structure with increased marrow cavity and a decreased number of trabeculae. In conclusion, mechanical loading has beneficial effects on BMC and BMD of the ovariectomized rat. This indicates that the load in the backpack was high enough to elicit an osteogenic response sufficient to compensate for the ovariectomy-induced bone loss. The results confirm that estrogen suppresses both bone resorption and bone formation in the proximal metaphysis in the femoral head of our rat-with-backpack model. The effects of mechanical loading on the trabecular bone of the femoral head were not significant. This study suggests that the effect of mechanical loading in the rat-with-backpack model mainly occurs at cortical bone sites.

Absorptiometry, Photon↗
PubMed2006

What does quality of life mean to older frail and non-frail community-dwelling adults in the Netherlands?

Quality of life is a commonly used but seldom defined concept and there is no consensus on how to define it. The aim of this study was to explore the meaning of quality of life to older frail and non-frail persons living in the community. Qualitative interviews were conducted with 25 older men and women. The audio-taped interviews were transcribed and coded for content and analyzed using the grounded-theory approach. Five themes emerged: (physical) health, psychological well-being, social contacts, activities, and home and neighborhood. Factors that influenced quality of life were having good medical care, finances and a car. Respondents compared themselves mostly to others whose situation was worse than their own, which resulted in a satisfactory perceived quality of life. However, the priorities of the domains of quality of life were observed to change. Moreover, the health of the frail limited the amount and scope of activities that they performed. This led to a lower quality of life perceived by the frail compared to the non-frail.

Adult↗
PubMed2006

[Fortification of food with vitamin D is a reasonable approach to fracture prophylaxis].

Vitamin-D deficiency is common in immobile elderly and non-Western immigrants and has been related to muscle weakness in these populations. When serum calcidiol concentrations are below 50 nmol/l, parathyroid hormone concentrations increase, causing bone resorption. Bone mineral density and proximal muscle strength increase as the serum concentration ofcalcidiol increases. Vitamin-D supplementation is reported to reduce the incidence of fractures in nursing home residents. Dutch guidelines recommend vitamin-D supplementation for nursing home residents and for those who are house-bound. Fortification of milk and other foods with vitamin D in the United States and Sweden has led to a better nutritional state with respect to vitamin D than in the Netherlands. Therefore the dairy industry should be allowed to add vitamin D to dairy products to prevent fractures.

Aging↗
PubMed2006

Addressing the musculoskeletal components of fracture risk with calcium and vitamin D: a review of the evidence.

Osteoporotic fractures are an extremely common and serious health problem in the elderly. This article presents the rationale for calcium and vitamin D supplementation in the prevention and treatment of osteoporotic fractures and reviews the literature evidence on the efficacy of this strategy. Two musculoskeletal risk factors are implicated in osteoporotic fractures in the elderly: the loss of bone mass due to secondary hyperparathyroidism and the increased propensity to falls. Calcium and vitamin D reverse secondary hyperparathyroidism with resultant beneficial effects on bone mineral density (BMD). Additionally, calcium and vitamin D supplementation significantly improves body sway and lower extremity strength, reducing the risk of falls. The effects of combined calcium and vitamin D on parathyroid function and BMD provide a strong rationale for the use of this therapy in the prevention and treatment of osteoporosis and osteoporotic fractures. There is general agreement that, in patients with documented osteoporosis, calcium and vitamin D supplementation should be an integral component of the management strategy, along with antiresorptive or anabolic treatment. Frail elderly individuals constitute another major target population for calcium and vitamin D because evidence from randomized studies in institutionalized elderly subjects demonstrates that these supplements reduce osteoporotic fracture risk, particularly in the presence of dietary deficiencies. However, the results of trials in community-dwelling subjects have been equivocal. Within the primary-care setting, further research is required to establish appropriate target subgroups for calcium and vitamin D supplementation; overall, the data are consistent with a benefit individuals with insufficient calcium and/or vitamin D, although patients with documented osteoporosis will derive further benefit in terms of fracture prevention from the addition of an antiresorptive agent.

Accidental Falls↗
PubMed2006

Different responsiveness to mechanical stress of bone cells from osteoporotic versus osteoarthritic donors.

INTRODUCTION: Osteoporosis (OP) and osteoarthritis (OA) are both common diseases in the elderly, but remarkably seldom coexist. The bone defects that are related to both diseases develop with increasing age, which suggests that they are related to some form of imperfect bone remodeling. Current opinion holds that the bone remodeling process is supervised by bone cells that respond to mechanical stimuli. An imperfect response of bone cells to mechanical stimuli might thus relate to imperfect bone remodeling, which could eventually lead to a lack bone mass and strength, such as in OP patients. MATERIALS: To investigate whether the cellular response to mechanical stress differs between OP and OA patients, we compared the response of bone cells from both groups to fluid shear stress of increasing magnitude. Bone cells from 9 female OP donors (age 60-90 year) and 9 female age-matched OA donors were subjected to pulsating fluid flow (PFF) of low (0.4+/-0.1 Pa at 3 Hz), medium (0.6+/-0.3 Pa at 5 Hz), or high shear stress (1.2+/-0.4 at 9Hz), or were kept under static culture conditions. RESULTS: We found subtle differences in the shear-stress response of the two groups, measured as nitric oxide (NO) and prostaglandin E2 (PGE2) production. The NO-response to shear stress was higher in the OP than the OA cells, while the PGE2-response was higher in the OA cells. CONCLUSIONS: Assuming that NO and PGE2 play a role in cell-cell communication during remodeling, these results suggest that slight differences in mechanotransduction might relate to the opposite bone defects in osteoporosis and osteoarthritis.

Aged↗
PubMed2006

Biomechanical comparison of hard and soft hip protectors, and the influence of soft tissue.

INTRODUCTION: Hip protectors appear to be promising in preventing hip fractures. Currently, many different hip protectors exist, and it is not clear which hip protector has the best biomechanical properties. Therefore, the objective of this study was to compare the force attenuation capacity of 10 different hip protectors. Both hard hip protectors, which primarily shunt away energy, and soft hip protectors, which primarily absorb energy, were included. METHODS: Using a drop weight impact testing system and a surrogate femur, a weight of 25 kg was dropped from a height of 8 cm causing a force of almost 7,806 N on the bare femur, which simulates a severe fall. After this calibration test, soft tissue and the different hip protectors in combination with the soft tissue were tested. Each test was repeated six times. To simulate normal-weight elderly people, a 1/2-inch-thick layer of foam was chosen, reducing the force by 18%. To examine the influence of soft tissue thickness, soft tissue was also simulated by a 1-inch-thick layer of foam, reducing the force by 49%. RESULTS: In the 1-inch soft tissue test, all hip protectors were capable in reducing the impact to below the average fracture threshold of elderly people (3,100 N), although the hard types performed significantly better than the soft ones (P < 0.001). In the 1/2-inch soft tissue test, only the hard hip protectors were capable of attenuating the peak force to below the average fracture threshold of 3,100 N (hard vs. soft hip protectors: P < 0.001). CONCLUSIONS: This study showed that the hard, energy-shunting hip protectors were superior to the soft, energy-absorbing ones, especially in a simulation of normal-weight elderly people. With increased soft tissue thickness, soft hip protectors were also capable in reducing the impact to below the average fracture threshold of 3,100 N.

Aged↗
PubMed2006

Vitamin D physiology.

Vitamin D3 is synthesized in the skin during summer under the influence of ultraviolet light of the sun, or it is obtained from food, especially fatty fish. After hydroxylation in the liver into 25-hydroxyvitamin D (25(OH)D) and kidney into 1,25-dihydroxyvitamin D (1,25(OH)2D), the active metabolite can enter the cell, bind to the vitamin D-receptor and subsequently to a responsive gene such as that of calcium binding protein. After transcription and translation the protein is formed, e.g. osteocalcin or calcium binding protein. The calcium binding protein mediates calcium absorption from the gut. The production of 1,25(OH)2D is stimulated by parathyroid hormone (PTH) and decreased by calcium. Risk factors for vitamin D deficiency are premature birth, skin pigmentation, low sunshine exposure, obesity, malabsorption and advanced age. Risk groups are immigrants and the elderly. Vitamin D status is dependent upon sunshine exposure but within Europe, serum 25(OH)D levels are higher in Northern than in Southern European countries. Severe vitamin D deficiency causes rickets or osteomalacia, where the new bone, the osteoid, is not mineralized. Less severe vitamin D deficiency causes an increase of serum PTH leading to bone resorption, osteoporosis and fractures. A negative relationship exists between serum 25(OH)D and serum PTH. The threshold of serum 25(OH)D, where serum PTH starts to rise is about 75nmol/l according to most surveys. Vitamin D supplementation to vitamin D-deficient elderly suppresses serum PTH, increases bone mineral density and may decrease fracture incidence especially in nursing home residents. The effects of 1,25(OH)2D and the vitamin D receptor have been investigated in patients with genetic defects of vitamin D metabolism and in knock-out mouse models. These experiments have demonstrated that for active calcium absorption, longitudinal bone growth and the activity of osteoblasts and osteoclasts both 1,25(OH)2D and the vitamin D receptor are essential. On the other side, bone mineralization can occur by high ambient calcium concentration, so by high doses of oral calcium or calcium infusion. The active metabolite 1,25(OH)2D has its effects through the vitamin D receptor leading to gene expression, e.g. the calcium binding protein or osteocalcin or through a plasma membrane receptor and second messengers such as cyclic AMP. The latter responses are very rapid and include the effects on the pancreas, vascular smooth muscle and monocytes. Muscle cells contain vitamin D receptor and several studies have demonstrated that serum 25(OH)D is related to physical performance. The active metabolite 1,25(OH)2D has an antiproliferative effect and downregulates inflammatory markers. Extrarenal synthesis of 1,25(OH)2D occurs under the influence of cytokines and is important for the paracrine regulation of cell differentiation and function. This may explain that vitamin D deficiency can play a role in the pathogenesis of auto-immune diseases such as multiple sclerosis and diabetes type 1, and cancer. In conclusion, the active metabolite 1,25(OH)2D has pleiotropic effects through the vitamin D receptor and vitamin D responsive elements of many genes and on the other side rapid non-genomic effects through a membrane receptor and second messengers. Active calcium absorption from the gut depends on adequate formation of 1,25(OH)2D and an intact vitamin D receptor. Bone mineralization mainly depends on ambient calcium concentration. Vitamin D metabolites may play a role in the prevention of auto-immune disease and cancer.

Animals↗
PubMed2006

Positive effect of alendronate on bone mineral density and markers of bone turnover in patients with rheumatoid arthritis on chronic treatment with low-dose prednisone: a randomized, double-blind, placebo-controlled trial.

INTRODUCTION: Alendronate has been described to have a bone-sparing effect in patients treated with moderate and high dosages of prednisone for heterogeneous diseases, however no data are available on groups of patients with the same underlying diseases who receive chronic low-dose prednisone treatment. The objective of the investigation reported here was, therefore, to study the effect of alendronate on bone mineral density (BMD) of the lumbar spine and hips in patients with rheumatoid arthritis (RA) who are on chronic low-dose prednisone treatment. METHODS: A total of 163 patients with RA, according to the ACR-criteria, were enrolled in a double-blind, placebo-controlled trial. The patients were treated with low-dose prednisone (<or=10 mg/day) for at least 3 months. The patients were randomized to receive daily doses of alendronate or placebo: men and premenopausal women received 5 mg alendronate (or placebo) daily; postmenopausal women received 10 mg alendronate (or placebo) daily. All patients received daily calcium (500 mg, or 1000 mg, depending on baseline dietary calcium intake) and vitamin D3 (400 IU) supplementation. BMD of the lumbar spine (L1-L4) and the (total) hip was measured at baseline and after 6 and 12 months. The primary endpoint was change in BMD of the lumbar spine after 12 months (ITT). At baseline and after 3 and 12 months, serum bone-specific alkaline phosphatase (BAP) and urinary excretion of N-telopeptide (NTX) were measured. Radiographs of the thoracic and lumbar spine were made at baseline and after 12 months and subsequently scored for vertebral deformities. RESULTS: The groups were comparable at baseline in age, gender, daily dosage of prednisone, BMD at the spine and the hip and markers of bone turnover, while the number of patients with prevalent vertebral deformities was slightly higher in the alendronate-treated patients (54% versus 39%, not significant). After 12 months, BMD at the lumbar spine had increased by 3.7% in the alendronate-treated patients and decreased by -1.0% in the placebo-treated patients (p<0.0001); at the hip, the changes were +1.0% and -0.1%, respectively (not significant). After 3 months, serum BAP had decreased by 16.9% in the alendronate group versus 3.3% in the placebo group (p=0.0005), while urinary NTX had decreased by 46.4% in the alendronate group versus 12.1% in the placebo group (p<0.0001). After 12 months, no statistically significant difference was found between the groups with respect to number of patients with incident vertebral or non-vertebral fractures. Adverse effects were relatively common in these patients with severe RA: adverse effects were observed in 68% of the alendronate-treated patients and in 73% of the placebo patients (not significant), while serious adverse events were observed in 13% and 17%, respectively (not significant). CONCLUSION: We observed a favourable effect of alendronate on the BMD of the lumbar spine and on the markers of bone turnover in patients with RA treated with low-dose prednisone. These data support the conclusion that the prescribing of alendronate is not only beneficial in patients treated with high-dose prednisone but also in RA patients chronically treated with low-dose prednisone.

Absorptiometry, Photon↗
PubMed2006

A risk profile for identifying community-dwelling elderly with a high risk of recurrent falling: results of a 3-year prospective study.

INTRODUCTION: The aim of the prospective study reported here was to develop a risk profile that can be used to identify community-dwelling elderly at a high risk of recurrent falling. MATERIALS AND METHODS: The study was designed as a 3-year prospective cohort study. A total of 1365 community-dwelling persons, aged 65 years and older, of the population-based Longitudinal Aging Study Amsterdam participated in the study. During an interview in 1995/1996, physical, cognitive, emotional and social aspects of functioning were assessed. A follow-up on the number of falls and fractures was conducted during a 3-year period using fall calendars that participants filled out weekly. Recurrent fallers were identified as those who fell at least twice within a 6-month period during the 3-year follow-up. RESULTS: The incidence of recurrent falls at the 3-year follow-up point was 24.9% in women and 24.4% in men. Of the respondents, 5.5% reported a total of 87 fractures that resulted from a fall, including 20 hip fractures, 21 wrist fractures and seven humerus fractures. Recurrent fallers were more prone to have a fall-related fracture than those who were not defined as recurrent fallers (11.9% vs. 3.4%; OR: 3.8; 95% CI: 2.3-6.1). Backward logistic regression analysis identified the following predictors in the risk profile for recurrent falling: two or more previous falls, dizziness, functional limitations, weak grip strength, low body weight, fear of falling, the presence of dogs/cats in the household, a high educational level, drinking 18 or more alcoholic consumptions per week and two interaction terms (high education x 18 or more alcohol consumptions per week and two or more previous falls x fear of falling) (AUC=0.71). DISCUSSION: At a cut-off point of 5 on the total risk score (range 0-30), the model predicted recurrent falling with a sensitivity of 59% and a specificity of 71%. At a cut-off point of 10, the sensitivity and specificity were 31% and 92%, respectively. A risk profile including nine predictors that can easily be assessed seems to be a useful tool for the identification of community-dwelling elderly with a high risk of recurrent falling.

Accidental Falls↗
PubMed2006

Calcium and vitamin D in the prevention and treatment of osteoporosis - a clinical update.

Combined calcium and vitamin D supplementation is an essential component of the management of osteoporosis, supported by a strong scientific rationale. The types of individuals who should receive calcium and vitamin D supplements are those: (i) patients with documented osteoporosis receiving antiresorptive or anabolic treatment; (ii) patients receiving glucocorticoids; and (iii) individuals with or at high risk of calcium and/or vitamin D insufficiencies, in particular older women and men. This article describes the evidence base that supports targeting these groups. Benefits are most apparent when 800 IU day(-1) vitamin D is complemented with a dose of 1000-1200 mg day(-1) elemental calcium. Compliance is also key to optimizing clinical efficacy.

Aged↗
PubMed2006

The prevalence of vitamin D inadequacy amongst women with osteoporosis: an international epidemiological investigation.

INTRODUCTION: Vitamin D is essential for calcium metabolism as well as for fracture prevention, and a recent review suggested that the optimal serum 25(OH)D lies in the region of 50-80 nmol L-1 (20-32 ng mL-1). A high prevalence of inadequacy has been reported in many studies but the prevalence of inadequacy amongst women with osteoporosis in different regions of the world has not been well characterized. SETTING AND SUBJECTS: A multinational study of 18 countries at various latitudes (range 64N-38S) was conducted in 2004 and 2005 to determine the average levels of serum 25(OH)D and the prevalence of vitamin D inadequacy. A total of 2606 postmenopausal women with osteoporosis (low bone mineral density, history of fragility fracture) seeking routine medical care were enrolled and serum 25(OH)D levels were measured at a single laboratory visit. RESULTS: Mean serum 25(OH)D level was 26.8 ng mL-1 (SE 0.3) and ranged from 7 to 243 ng mL-1. Regional mean values were highest in Latin America (29.6 ng mL-1, SE 0.6) and lowest in the Middle East (20.4 ng mL-1, SE 0.5). Overall, 64% of women had serum levels<30 ng mL-1. Serum parathyroid hormone reached a nadir at serum 25(OH)D levels>35 ng mL-1. In nonequatorial countries, women recruited during the winter months had somewhat lower serum 25(OH)D levels than those recruited during the summer months in some, but not all, countries. CONCLUSIONS: Low levels of serum 25(OH)D are common amongst women with osteoporosis. The results underscore the value of assuring vitamin D adequacy in these women.

Adult↗
PubMed2005

Development of the Qualeffo-31, an osteoporosis-specific quality-of-life questionnaire.

INTRODUCTION: Vertebral deformities are a common consequence of osteoporosis and are known to decrease quality of life. The Qualeffo-41 is a quality-of-life questionnaire especially developed for measuring quality of life in patients with vertebral deformities. It consists of 41 questions arranged in five domains: pain, physical function, social function, general health perception, and mental function. The objectives of this study were: (1) to develop a shorter version of the Qualeffo-41 by removing redundant questions; and (2) to investigate the scale characteristics, reliability, and validity of this shorter version. METHODS: The study was performed using data from the Qualeffo validation study and the Multiple Outcomes of Raloxifene Evaluation (MORE) study. The analyses were performed in patients with vertebral deformities (n=579). Factor analysis on polychoric correlations and an item response theory (IRT) model, i.e., the generalized partial credit model (GPCM), were used to create a shorter version of Qualeffo-41. Using GPCM, scoring weights were computed for all items. RESULTS: Three items were removed from the data set because of too many missing values. Factor analysis identified three instead of five domains: (1) pain, (2) physical function, and (3) mental function. Five items had factor loadings <0.4 and were not included in the GPCM. After excluding several items, the domains pain (four items), physical function (18 items), and mental function (nine items) showed a good, reasonable, and excellent fit, respectively. This indicates that the mental function domain and the pain domain are more unidimensional than the physical function domain. All three domains showed a very high correlation (r > or =0.95) with the corresponding domains of the Qualeffo-41. CONCLUSIONS: Qualeffo-31 was developed, consisting of three domains with a reasonable to excellent fit to the GPCM. Although the fit to the GPCM supports the construct validity of the Qualeffo-31, validation in a new study should be performed before using it in practice.

Activities of Daily Living↗
PubMed2005

Vitamin D status among patients with hip fracture and elderly control subjects in Yekaterinburg, Russia.

PURPOSE: Vitamin D deficiency leads to secondary hyperparathyroidism and osteomalacia, and both conditions are associated with fractures, the most severe being hip fracture. The serum 25-hydroxyvitamin D level depends on latitude and season. Yekaterinburg is situated at a high latitude and the duration of winter is about 5 months. METHODS: In this study, the serum 25(OH)D and PTH concentrations, and the prevalence of hypovitaminosis D in elderly people, inhabitants of Yekaterinburg, were investigated. The study was performed on 63 people with hip fracture (mean age, 68.8 years) and 97 independently living elderly people (mean age, 70.2 years). RESULTS: Serum 25(OH)D (mean+/-SD) in the hip fracture group was 22.4+/-11.4 nmol/L, significantly lower than in control group, which was 28.1+/-10.1 nmol/L. The percentage of patients with severe hypovitaminosis D (<25 nmol/L) in the hip fracture group was 65%, compared to 47% in the control group (p<0.05). The prevalence of hypovitaminosis D among hip fracture patients, as well as among independently living elderly people in Yekaterinburg, was high. CONCLUSION: Supplementation of vitamin D in elderly people with and without fracture might prevent secondary hyperparathyroidism, osteomalacia and fractures.

Aged↗
PubMed2005

Static and dynamic measures of frailty predicted decline in performance-based and self-reported physical functioning.

OBJECTIVE: To determine the effect of frailty on decline in physical functioning and to examine if chronic diseases modify this effect. METHODS: The study sample was derived from the Longitudinal Aging Study Amsterdam and included respondents with initial ages 65 and over at T(2) (1995/1996), who participated at T(1) (1992/1993) and T(2) and performed physical performance tests (n = 1,152) or reported functional limitations (n = 1,321) at T(2) and T(3) (1998/1999). Nine frailty markers were determined in two ways: low functioning at T(2) (static definition); and decline in functioning between T(1) and T(2) (dynamic definition). Using logistic regression analyses, the effect of frailty was examined on change in physical functioning between T(2) and T(3), adjusting for sex, age, education, and additionally chronic diseases. RESULTS: Static frailty was associated with performance decline only in the middle-old group (OR 2.43; 95%CI 1.23-4.80) and associated with decline in self-reported functioning (OR 2.44; 95%CI 1.77-3.36). Dynamic frailty was associated with decline in performance only in women (OR 1.72; 95%CI 1.11-2.67) and with self-reported functional decline (OR 1.77; 95%CI 1.29-2.43). These associations were independent of chronic diseases. CONCLUSION: Frailty is more strongly associated with self-reported functional decline in older persons than with performance decline.

Activities of Daily Living↗
PubMed2004

Additive effects of estrogen and mechanical stress on nitric oxide and prostaglandin E2 production by bone cells from osteoporotic donors.

Mechanical loading is thought to provoke a cellular response via loading-induced flow of interstitial fluid through the lacuno-canalicular network of osteocytes. This response supposedly leads to an adaptation of local bone mass and architecture. It has been suggested that loss of estrogen during menopause alters the sensitivity of bone tissue to mechanical load, thereby contributing to the rapid loss of bone. The present study aimed to determine whether estrogen modulates the mechanoresponsiveness of bone cells from osteoporotic women. Bone cell cultures from nine osteoporotic women (aged 62-90 years) were pre-cultured for 24 h with 10(-11) mol/l 17beta-estradiol (E2) or vehicle, and subjected to 1 h of pulsating fluid flow (PFF) or static culture. E2 alone enhanced prostaglandin E(2) (PGE(2)) and nitric oxide (NO) production by 2.8-fold and 2.0-fold, respectively, and stimulated endothelial nitric oxide synthase protein expression by 2.5-fold. PFF, in the absence of E2, stimulated PGE(2) production by 3.1-fold and NO production by 3.9-fold. Combined treatment with E2 and PFF increased PGE(2) and NO production in an additive manner. When expressed as PFF-treatment-over-control ratio, the response to fluid shear stress was similar in the absence or presence of E2. These results suggest that E2 does not affect the early response to stress in bone cells. Rather, E2 and shear stress both promote the production of paracrine factors such as NO and PGE(2) in an additive manner.

Aged↗
PubMed2004

Impact of vertebral deformities, osteoarthritis, and other chronic diseases on quality of life: a population-based study.

Vertebral deformities and spinal osteoarthritis are common disorders in elderly persons and are associated with back pain, impaired physical functioning, and loss of quality of life. The objectives of this study were to assess the impact of vertebral deformities and osteoarthritis on quality of life in a population-based sample, and to compare this with the impact of six other important chronic diseases on quality of life. The study was performed as a substudy of the Longitudinal Aging Study Amsterdam. Vertebral deformities and osteoarthritis were assessed by spinal radiographs; chronic diseases were assessed by self-report; quality of life was estimated by the SF-12, EQ-5D (EuroQol) and Qualeffo-41 (n = 336). In univariate analyses, severe osteoporosis of the vertebrae significantly worsened the physical component summary scale of the SF-12 and the total score of Qualeffo-41, while osteoarthritis of the spine did not significantly reduce quality of life. The other chronic diseases reduced quality of life, although not all changes reached statistical significance. In multivariate analyses, severe osteoporosis of the vertebrae, cardiac disease, peripheral arterial disease, and diabetes mellitus significantly reduced quality of life. In conclusion, most persons in an elderly population suffer from one or more chronic diseases, and therefore experience loss of quality of life. After adjustment for age, sex, and other chronic diseases, severe osteoporosis of the vertebrae, cardiac disease, peripheral arterial disease, and diabetes mellitus significantly reduced quality of life in the general population.

Activities of Daily Living↗
PubMed2004

Functional limitations and poor physical performance as independent risk factors for self-reported fractures in older persons.

OBJECTIVE: This study examined whether three aspects of functioning (i.e., functional limitations, physical performance, and physical activity) were associated with fractures in older men and women. DESIGN: A 3-year prospective cohort study. PARTICIPANTS AND SETTING: A total of 715 men and 762 women, aged 65 years and older, of the population-based Longitudinal Aging Study Amsterdam. MEASUREMENTS: During an interview at home, three aspects of functioning were assessed: functional limitations (what people say they can do), physical performance, i.e., three performance tests and handgrip strength (what people are able to do), and physical activity (what people actually do). Afterward, a follow-up on fractures was conducted for 3 years. RESULTS: 77 patients (5.2%) suffered a fracture during 3-year follow-up. Most patients suffered a hip fracture (1.6%) or a wrist fracture (1.4%). The fracture rate per 1,000 person-years was 20.1. During 3-year follow-up, a fracture was reported by 12%, 10%, 12%, and 6% of the respondents with functional limitations, low performance test score, poor handgrip strength, and low physical activity, respectively. Using Cox proportional hazard analysis, functional limitations (RR = 3.5; 95% CI, 2.1 to 6.0), low performance test score (RR = 1.9; 95% CI, 1.1 to 3.3), low handgrip strength (RR = 2.5; 95% CI, 1.5 to 4.1), and low physical activity (RR = 1.9; 95% CI, 1.1 to 3.5) were significantly associated with fractures after adjustment for age and sex. Functional limitations (RR = 3.2; 95% CI, 1.8 to 5.5), low performance test score (RR = 1.8; 95% CI, 1.0 to 3.3) and low handgrip strength (RR = 2.0; 95% CI, 1.1 to 3.6) remained significantly associated with fractures after additional adjustment for body composition, chronic diseases, psychosocial factors, life style factors, and the other levels of functioning. No significant interaction terms were found. CONCLUSIONS: Functional limitations and poor physical performance were independent risk factors for fractures.

Activities of Daily Living↗