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Biomedical subjects

C Cooper

Publications and source records attributed to C Cooper.

At least 145 records · Page 8Linked to original sources
PubMed1999

Determinants of bone loss in elderly men and women: a prospective population-based study.

While several studies have described the rate and pattern of involutional bone loss in women, far less information is available for men. Furthermore, the roles of lifestyle and body build in determining bone loss rate in both sexes have been largely extrapolated from cross-sectional studies. We addressed this issue in a population-based longitudinal study which sought to ascertain rates of bone loss at the femoral neck and lumbar spine in a cohort of men and women aged 60-75 years at baseline, and to relate this loss to anthropometric and lifestyle variables. We additionally investigated the capacity of biochemical markers of bone turnover to predict bone loss rates in these subjects. Women lost bone at all sites; this ranged from 0.20%/year at the lumbar spine to 1.43%/year at the femoral trochanteric region. By contrast, men lost only 0. 20%/year at the trochanteric region, and gained at the lumbar spine (0.33%/year) and at Ward's triangle (0.27%/year) over the 4-year period. Anthropometric measurements were associated with bone loss in both sexes; lower baseline body mass index (BMI) and a greater rate of loss of adiposity over the follow-up period were both associated with greater bone loss at all proximal femoral sites. These attained statistical significance after Bonferroni correction at the total proximal femur among both men (r = 0.29), p<0.01) and women (r = 0.31, p<0.05). Lifestyle factors associated with lower rates of bone loss (after adjustment for BMI) included alcohol consumption at the femoral neck among women (p = 0.007) and physical activity at the lumbar spine among men (p = 0.05). Serum parathyroid hormone, 25-hydroxyvitamin D and biochemical markers of bone turnover did not predict bone loss after adjustment for adiposity.

Aged↗
PubMed1999

Biochemical markers of bone turnover and bone loss at the lumbar spine and femoral neck: the Taiji study.

The purpose of this study was to ascertain whether biochemical markers of bone turnover predict bone loss. The survey was carried out in Taiji, Wakayama Prefecture, Japan. From a list of inhabitants aged 40-79 years, 400 participants (50 men and 50 women in each of four age groups) were selected randomly. Bone mineral density (BMD) was measured, and blood and urine samples of all participants were examined to obtain values for eight biochemical markers: alkaline phosphatase (ALP), bone Gla protein (BGP), type I procollagen (carboxyterminal peptide of type I procollagen; PICP), cross-linked carboxyterminal telopeptide region of type I collagen (ICTP), and urinary excretion of calcium (Ca), phosphate (P), pyridinoline (Pyr), and deoxypyridinoline (D-Pyr). Each marker was evaluated as a predictor of the rate of bone change in lumbar spine and femoral neck BMD over a 3-year period. The value of Pyr was significantly related to the change of lumbar spine BMD in men (P = 0.009), and that of BGP was found to be significant in women (P = 0.045). By contrast, none of the bone markers significantly correlated with bone loss at the femoral neck. The coefficient of determination at the lumbar spine was 5% and 7% at the femoral neck only. We conclude that biochemical markers of bone turnover cannot predict bone loss rates in middle-aged or elderly Japanese men and women over a 3-year period with sufficient accuracy for use in clinical decision making.

Adult↗
PubMed1999

Size at birth and plasma leptin concentrations in adult life.

OBJECTIVE: To determine whether low birthweight is associated with higher plasma leptin concentrations in adult life and whether leptin contributes to the metabolic alterations in adults that are associated with reduced foetal growth. DESIGN: Measurement of plasma leptin concentrations in a group of 502 men and women, aged 61-73, who were born in Hertfordshire and for whom records of birth and infant weight are available. Glucose tolerance was measured with a standard 75 g oral glucose tolerance test. MEASUREMENTS: Leptin concentrations were assayed in fasting plasma samples using a radioimmunoassay. RESULTS: Leptin concentrations ranged from 1.4 to 128.9 (mean 13.4) ng/ml and were higher in the 193 women than the 309 men (23.4 vs. 7.1 ng/ml). In both sexes leptin concentrations correlated positively with body mass index (r=0.65 in both men and women). Leptin concentration also correlated with fasting insulin (r=0.41) and with glucose and insulin concentrations 2 h after a glucose load (r=0.19 and 0.49). Adults with lower birth or infant weight had higher leptin concentrations than those of higher birthweight with similar degrees of obesity (P=0.02 and 0.06, respectively). Although both 2 h glucose and insulin concentrations negatively correlated with birthweight (r=-0.17, P<0.001 and r=-0.18, P<0.001, respectively), regression analysis suggested that the higher levels of leptin in adults who had low birthweight did not explain the association between low birthweight and glucose or insulin concentrations. CONCLUSION: These results suggest that adults who had had low birthweight had higher plasma concentrations of leptin than would be expected from their degree of obesity. The higher leptin concentrations, however, do not account for the association between birthsize and glucose tolerance. They may be a consequence of the altered body composition, hyperinsulinaemia, and other long-term endocrine changes associated with reduced foetal growth.

Aged↗
PubMed1999

ZNF198-FGFR1 transforms Ba/F3 cells to growth factor independence and results in high level tyrosine phosphorylation of STATS 1 and 5.

The ZNF198- FGFR1 fusion gene arises as a result of the t(8;13)(p11;q12) in the 8p11 myeloproliferative syndrome. To determine the transforming properties of this chimeric protein we transfected ZNF198-FGFR1 into the interleukin (IL)-3 dependent cell line Ba/F3. Growth factor independent subclones were obtained in which ZNF198-FGFR1, STAT1, and STAT5 were constitutively tyrosine phosphorylated, as determined by immunoprecipitation and Western blot analysis. To test the hypothesis that constitutive activation of ZNF198-FGFR1 tyrosine kinase activity is a result of self-association of the fusion protein, we in vitro transcribed and translated ZNF198-FGFR1 and a derivative construct, ZNF198- FGFR1deltaC-myc, in which the C-terminal FGFR1 epitope was replaced by a c-myc tag. As expected, an anti-FGFR1 antibody immunoprecipitated ZNF198-FGFR1 but not ZNF198-FGFRdeltaC-myc. However when both products were translated together, both were coimmunoprecipitated by anti-FGFR1 antisera. Similar results were obtained by using an anti-myc antibody and demonstrated a physical interaction between the two proteins. Analysis of COS-7 cells transfected with ZNF198-FGFR1 demonstrated that the fusion gene, in contrast to normal FGFR1, is located in the cytoplasm. We conclude that ZNF198-FGFR1 is a cytoplasmic protein that self-associates and has constitutive transformation activity. These data suggest that ZNF198-FGFR1 plays a primary role in the pathogenesis of the t(8;13) myeloproliferative syndrome and is the first report to implicate STAT proteins in FGFR1-mediated signaling.

Animals↗
PubMed1999

Frequency and impact of regional musculoskeletal disorders.

Regional musculoskeletal disorders are a major cause of morbidity both in the community and in the workplace. They comprise a heterogeneous group of conditions that are, for the most part, poorly characterized. Consequently, agreed diagnostic criteria have not existed for many of these disorders, and epidemiological investigations have used varied or ill-defined approaches to case definition. This chapter describes our current understanding of the epidemiology of regional pain disorders and details the strengths and weaknesses of the available data. Pain syndromes can be divided anatomically into those which cause generalized pain, such as fibromyalgia syndrome and myofascial pain syndromes, and those which are confined to one regional anatomical area. The latter group comprise those of the neck, shoulder, elbow, wrist/hand, hip, knee and ankle/foot. Current information is considered on the known risk factors for disorders at these sites, in addition to their impact upon both the individual and society.

Carpal Tunnel Syndrome↗
PubMed1999

The prevention of corticosteroid-induced bone loss with intermittent cyclical etidronate.

A prospective, randomised, double-blind, placebo controlled primary prevention trial was undertaken in 28 patients commencing low to moderate doses of corticosteroids for the first time. Patients were randomised to intermittent cyclical etidronate (400 mg daily for 2 weeks) and calcium (500 mg daily for 11 weeks) or intermittent cyclical placebo with calcium. After 52 weeks of treatment, lumbar spine BMD increased by 1.8% in the etidronate group, while it decreased by 3.7% in the placebo group. The differences in bone loss rate were statistically significant (p<0.01) at both 6 and 12 months. Similar trends were observed at the proximal femur, but differences were not statistically significant. These results suggest that intermittent cyclical etidronate therapy is effective in the primary prevention of corticosteroid-induced bone loss at the lumbar spine.

Absorptiometry, Photon↗
PubMed1999

Repeatability and validity of an upper limb and neck discomfort questionnaire: the utility of the standardized Nordic questionnaire.

The repeatability and validity of a questionnaire for upper limb and neck complaints were assessed in a population of 105 hospital outpatients with a range of upper limb and neck disorders (including cervical spondylosis, adhesive capsulitis, lateral epicondylitis, carpal tunnel syndrome and Raynaud's phenomenon). Subjects were asked to complete a modified Nordic-style upper limb and neck discomfort questionnaire on two occasions closely spaced in time. The repeatability of their responses was assessed by calculating a kappa coefficient (kappa), and the sensitivity and specificity of component items in the questionnaire were determined for specific diagnostic categories of upper limb and neck disorder. Symptom reports for pain in the upper limb and neck, pain interfering with physical activities, neurological symptoms and blanching were all found to be highly repeatable (kappa = 0.63-0.90). A number of regional pain reports proved to be very sensitive in relation to specific upper limb disorders, but, with the exception of reported finger blanching in patients with Raynaud's phenomenon, none proved to have a good specificity (range = 0.33-0.38). We conclude that a modified Nordic-style questionnaire is repeatable and sensitive, and is likely to have a high utility in screening and surveillance. However a complementary examination schedule of adequate specificity and repeatability is essential to establish a clinical diagnosis.

Adult↗
PubMed1999

Hip fracture in Hong Kong over the last decade--a comparison with the UK.

BACKGROUND: Hip fracture is a major public health problem in Asia and the UK. The objectives of this study were to describe the trends of hip fracture in Hong Kong over the last decade, and to compare the incidence in Hong Kong with that from the Wessex Health Region of the UK in 1995. METHODS: The number of hip fractures was calculated using hospital discharge records for all public hospitals in Hong Kong in 1991 and 1995. Age-specific incidence rates were then calculated using the mid-year census population for the two years. These rates were presented with previously reported age-specific rates for Hong Kong in 1966 and 1985. These age-specific rates for Hong Kong in 1995 were compared with rates for the Wessex Health Region of the UK. The total number of hip fracture expected in 2010 was calculated by applying the age-specific rates of 1995 to the projected population for 2010. RESULTS: In 1995, a total of 1138 men and 2782 women in Hong Kong fractured their hip. The age-specific rates had remained static from 1985 to 1995, after substantial rise from 1966 to 1985. In 1995, the rates of hip fracture rates were 11/1000 in women and 5/1000 in men who were 70 years and older. These rates were almost identical to those observed in the Wessex Health Region of the UK. CONCLUSION: The age-specific incidence rates of hip fracture had not risen in Hong Kong in the last decade. The incidence of hip fracture in Hong Kong was similar to that in the UK in 1995. The total number of patients with hip fracture in Hong Kong will increase substantially in the future, as a result of the ageing of the population.

Age Distribution↗
PubMed1999

Do all systems age together?

BACKGROUND: Aging changes in different body system are well described, but few studies have considered the relationship between them. OBJECTIVE: The purpose of this study was, therefore, to investigate the interrelationships between markers of aging in different parts of the body. METHODS: A cross-sectional study design was used. Structural and functional markers of aging were measured in a number of different body systems. RESULTS: Conditional independence analysis demonstrated that the aging markers selected clustered into two groups, either related to chronological age or adult height. Visual acuity, lens opacity, hearing threshold, cognitive decline, and the number of teeth were associated with age, while systolic blood pressure and skin thickness were related to height. Grip strength was associated with both. CONCLUSIONS: The differential associations of the aging markers with chronological age and adult height suggest that different systems do not age together. This may have relevance for understanding what underlies aging, and these preliminary findings now require replication in other aging cohorts.

Aged↗
PubMed1999

A sexually dimorphic pattern of growth hormone secretion in the elderly.

In rodents, the sexually dimorphic pattern of pulsatile GH secretion is an important determinant of growth, liver enzyme function and insulin-like growth factor I (IGF-I) expression. Whether this difference is present in humans at different ages is unclear. We studied GH secretory patterns in the elderly by constructing 24-h serum GH profiles in 45 male and 38 female (age, 59.4-73.0 yr) volunteers and related patterns to IGF-I, IGF-binding protein-3 (IGFBP-3), and GH-binding protein levels; body mass index; and waist/hip ratio. Serum GH concentrations were measured in samples drawn at 20-min intervals and analyzed using a sensitive chemiluminescent assay (Nichols Institute Diagnostics: sensitivity, 0.036 mU/L). The 24-h serum GH profiles were analyzed using a concentration distribution method to determine GH peak and trough levels, spectral analysis, and assessment of serial irregularity by approximate entropy (ApEn). There was a highly significant difference in mean 24-h serum GH concentrations in females compared to males (males, 0.88 mU/L; females, 1.31 mU/L; P = 0.009) as a result of significantly higher trough GH levels (males, 0.04 mU/L; females, 0.16 mU/L; P < 0.001). Peak values were not significantly different. Serum IGF-I levels were significantly higher in males (males, 162.4 ng/mL; females, 87.8 ng/ mL; P < 0.001). Peak GH values were related to serum IGF-I levels (males: r = 0.39; P = 0.009; females: r = 0.5; P = 0.002), whereas trough GH levels were not. IGFBP-3 levels were similar and related to GH peaks only in males (r = 0.32; P = 0.03). GH was secreted with a dominant periodicity of 200 min in males and 280 min in females (P < 0.025). The proportion of time taken up by regular oscillatory activity was less in females (females, 11.1%; males, 14.7%; P = 0.01). GH secretion assessed by ApEn was more disordered in females (males, 0.60; females, 0.81; P < 0.001), and increasing disorder was associated with lower IGF-I levels. Body mass index was negatively related to GH in both sexes. In males, trough values were the major determinant (r = -0.31; P = 0.04), whereas in females, the peak value was the major determinant (r = 0.35; P = 0.04). Trough GH levels were inversely related in both sexes to waist/hip ratio (males: r = -0.40; P = 0.006; females: r = -0.44; P = 0.006) and to increasing secretory disorder (ApEn; r = -0.46; P < 0.001). These data demonstrate a sexually dimorphic pattern of GH secretion in the elderly.

Aged↗
PubMed1999

Profiles of endogenous circulating cortisol and bone mineral density in healthy elderly men.

Exogenous glucocorticoids are known to increase the risk of osteoporosis. However, the contribution made by endogenous circulating cortisol concentrations to adult skeletal status remains unknown. We examined this issue in a sample of 34 healthy men, aged 61-72 yr. Venous blood samples were obtained under standard conditions every 20 min over a 24-h period. Measurements were made of serum cortisol and cortisol-binding globulin. Bone mineral density was measured at the lumbar spine and proximal femur using dual energy x-ray absorptiometry. Measurements were made at baseline and 4 yr later. There was a weak negative association between integrated cortisol concentration and lumbar spine bone density (r = -0.37; P < 0.05); similar relationships (P < 0.05) existed at three of five proximal femoral sites. There were also statistically significant positive associations between the trough cortisol concentration and bone loss rate at the lumbar spine (r = 0.38; P < 0.05), femoral neck (r = 0.47; P < 0.001), and the trochanteric region (r = 0.41; P = 0.02) over the 4-yr follow-up period. The cross-sectional relationships between cortisol concentration and bone density were removed by adjustment for body mass index, but the influence on bone loss rate remained significant after adjusting for adiposity, cigarette smoking, alcohol consumption, dietary calcium intake, physical activity, and serum testosterone and estradiol levels. These observations suggest that the endogenous cortisol profile of healthy elderly men is a determinant of their bone mineral density and their rate of involutional bone loss.

Aged↗
PubMed1999

The epidemiology of Paget's disease in Britain: is the prevalence decreasing?

To estimate changes in the age- and gender-specific prevalence of Paget's disease in Britain, we performed a radiographic survey of the disorder in 10 British centers, using sampling and radiographic methods identical to a study performed in 1974. In each center, a sample of abdominal radiographs of people aged 55 years and over was taken from stored films within the radiology department of the principal general hospital. The radiographs were identified by screening radiographic records over the period 1993-1995. Any abdominal radiograph in a subject aged 55 years and over which included the entire pelvis, sacrum, femoral heads, and all lumbar vertebrae was studied. The radiographs were evaluated by a trained observer and the consultant radiologist who participated in the original 1974 survey. Nine thousand eight hundred and twenty-eight radiographs (4625 men, 5203 women) were assessed in the 10 towns. The overall age/gender standardized prevalence rate was 2%, with a male/female ratio of 1.6. Prevalence increased steeply with age among men and women, rising to 6.9% of men and 5.8% of women aged 85 years and over. The prevalence of Paget's disease in the 10 towns in 1994 was only 40% of that observed during the 1974 study. The decline in prevalence was apparent in all 10 centers, but was most marked in those with high rates in the original study. This survey of Paget's disease in 10 British towns suggests a prevalence of 2.5% among men and 1.6% among women aged 55 years and over. Age-adjusted prevalence rates declined steeply between 1974 and 1994. These declines suggest an environmental contribution to the etiology of this disorder that requires further investigation.

Age Factors↗
PubMed1999

Personality and performance on a frustrating cognitive task.

Eysenck's biological model of personality suggests that extravertive persons will not persevere when solving boring, frustrating problems. This hypothesis was tested using a difficult jigsaw task. Quitting behaviour was strongly associated with scores on Extraversion.

Cognition↗
PubMed1999

Frequency and impact of regional musculoskeletal disorders

Regional musculoskeletal disorders are a major cause of morbidity both in the community and in the workplace. They comprise a heterogeneous group of conditions that are, for the most part, poorly characterized. Consequently, agreed diagnostic criteria have not existed for many of these disorders, and epidemiological investigations have used varied or ill-defined approaches to case definition. This chapter describes our current understanding of the epidemiology of regional pain disorders and details the strengths and weaknesses of the available data. Pain syndromes can be divided anatomically into those which cause generalized pain, such as fibromyalgia syndrome and myofascial pain syndromes, and those which are confined to one regional anatomical area. The latter group comprise those of the neck, shoulder, elbow, wrist/hand, hip, knee and ankle/foot. Current information is considered on the known risk factors for disorders at these sites, in addition to their impact upon both the individual and society.

Journal Article↗