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Biomedical subjects

J R Guthrie

Publications and source records attributed to J R Guthrie.

32 records · Page 2Linked to original sources
PubMed1998

A prospective study of bone loss in menopausal Australian-born women.

Two hundred and twenty-four women (74 pre-, 90 peri-, 60 post-menopausal), aged 46-59 years, from a population-based cohort participated in a longitudinal study of bone mineral density (BMD). BMD was measured by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and femoral neck and the time between bone scans was on average 25 (range 14-41) months. The aim of the study was to assess changes in BMD in relation to changes in normal menopausal status. During the study period women who were between 3 and 12 months past their last menstrual period (n = 22, late perimenopausal) at the time of the second bone scan had a mean (SE) annual change in BMD of -0.9% (0.4%) at the lumbar spine and -0.7% (0.6%) at the femoral neck (both p < 0.05 compared with women who remained premenopausal). In the women who became postmenopausal (n = 42) the mean annual changes in BMD were -2.5% (0.2%) at the lumbar spine and -1.7% (0.2%) at the femoral neck (both p < 0.0005), and in the women who remained post-menopausal (n = 60) they were -0.7% (0.2%) per year and -0.5% (0.3%) per year respectively (both p < 0.05), compared with women who remained premenopausal. In the 1-3 years after the final menstrual period (FMP) there was greater bone loss from the lumbar spine than the femoral neck (p < 0.05). In women who were menstruating at the time of the second bone scan and whose FMP could be dated prospectively (n = 35), higher baseline oestradiol levels were associated with less lumbar spine bone loss (p < 0.005). In the women who remained postmenopausal there was an association between baseline body mass index (BMI) and percentage change per year in femoral neck BMD (p < 0.05), such that women with higher BMI had less bone loss. In conclusion, during the time of transition from peri- to post-menopause, women had accelerated BMD loss at both the hip and spine.

Absorptiometry, Photon↗
PubMed1998

Menopausal status: subjectively and objectively defined.

This study aims to assess the relationship between self-rated and menstrually defined menopausal status, assesses criteria women use in perceiving their own menopausal status and compares symptom reporting and hormonal levels for self-rated and menstrually defined menopausal status. Women in the third year of the longitudinal phase of the Melbourne Women's Midlife Health Project (n = 332) were asked to assess their own menopausal status and the basis for this assessment. They were also specifically questioned on current menstrual cycle characteristics and levels of follicle-stimulating hormone (FSH), estradiol and inhibin were measured. For 67% of the women, the two definitions of menopausal status were in agreement. In women menstrually defined as premenopausal, self-rated menopausal status of peri- or postmenopausal appeared to be based on the occurrence of symptoms. In women menstrually defined as postmenopausal, persistence of hot flushes was taken to mean that 'the menopause was still in progress' despite absence of menses for more than 12 months. In women menstrually defined as perimenopausal yet who self-rated as premenopausal, FSH was lower (p < 0.01) and inhibin higher (p = 0.05) than women who self-rated as peri- or postmenopausal. Women's perceptions of the menopause are based on symptoms. Self-rated menopausal status appears to relate more closely to a women's endocrine status than definitions based on purely menstrual cycle characteristics.

Attitude to Health↗
PubMed1998

Using longitudinal data to define the perimenopause by menstrual cycle characteristics.

OBJECTIVES: To determine which aspects of menstrual change best predict time to postmenopause. METHODS: A total of 250 Australian-born women aged 45-55 years were divided into five menstrual status categories: Group I reported no change in menstrual flow or frequency; Group II reported change in flow; Group III reported change in frequency; Group IV reported change in both frequency and flow; and Group V reported between 3 and 11 months of amenorrhea. Menstrual status groups were compared on baseline data for age, hormone levels, hot flushes and self-rated menopausal status. The proportion of women moving to postmenopause in subsequent years was compared using 4 years of follow-up data. RESULTS: Women in Group V were older, had lower estradiol and inhibin levels, higher follicle stimulating hormone levels, and were more likely to report hot flushes, and to self-rate themselves as having started the menopausal transition, compared with the women who had menstruated in the last 3 months (Groups I-IV). Groups I and II were similar in age and hormonal status, as were Groups III and IV. The proportion of women who had moved to postmenopausal status in the 4 years after baseline were 12%, 14%, 58%, 53% and 94% for Groups I-V, respectively. CONCLUSIONS: Amenorrhea is the best predictor of future menopause followed by changes in menstrual frequency. Change in flow only was not predictive of future menopause. A two-stage classification scheme is suggested for defining the perimenopause. 'Early perimenopause' is defined as the self-reporting of changes in menstrual frequency over the last year, and 'late perimenopause' is defined as the self-report of 3-11 months of amenorrhea.

Amenorrhea↗
PubMed1997

Changes in physical activity and health outcomes in a population-based cohort of mid-life Australian-born women.

Cross-sectional studies and intervention programs have suggested that physical activity is a potential contributor to the health and wellbeing of mid-life and older women. This prospective longitudinal study investigates whether natural changes in physical activity are associated with changes in health outcomes in a population-based cohort of Australian-born women aged 45-55 years living in Melbourne. Of the 352 women from the Melbourne Women's Midlife Health Project who filled in a base-line physical activity questionnaire, 292 (83 per cent) were evaluated around three years later with regard to physical activity, psychological wellbeing, self-rated health, symptoms experienced, body mass index (BMI), blood pressure and serum lipids. Mean (SD) physical activity measured at base-line was 5.9 (5.7) hours/week, or 1496 (1449) kcal/week; mean (SD) change in physical activity per week was 0.05 (5.24) hours, or 44 (1347) kcal, indicating that although mean change was small there was substantial variation in change. There were significant increases in BMI (P < 0.001), wellbeing (P < 0.05), the number of reported menopause-related symptoms, and high-density lipoprotein cholesterol (HDL-C) levels (P < 0.001), and a decrease in low-density lipoprotein cholesterol (LDL-C) levels (P < 0.05). Change in level of physical activity was positively associated with change in HDL-C (P < 0.01) and change in wellbeing (P = 0.08) and negatively associated with change in coronary heart disease risk score. By increasing physical activity in mid-life, women may reduce at least one risk factor (HDL-C) associated with coronary heart disease.

Australia↗
PubMed1996

Hot flushes, menstrual status, and hormone levels in a population-based sample of midlife women.

OBJECTIVE: To determine the frequency of hot flushes in a population sample of 453 pre-, peri-, and postmenopausal women (aged 48-59 years), and to investigate the relationship of hot-flush reporting with menstrual status, serum levels of estradiol (E2), inhibin, and FSH, history of premenstrual complaints, and physical and life-style factors. METHODS: We used a population-based sample. Interviews were conducted in the women's homes. RESULTS: Frequency of hot-flush reporting was associated with menstrual status (P < .001). Twenty-nine percent of women who had more than 3 and less than 12 months of amenorrhea, and 37% of postmenopausal women experienced hot flushes several times a day. In total, 13% of premenopausal women, 37% of perimenopausal women, 62% of postmenopausal women, and 15% of women on hormone therapy reported having had at least one hot flush in the previous 2 weeks. Follicle-stimulating hormone levels were higher in women who experienced hot flushes at least once a day or more (P < .001); E2 levels were higher in women experiencing one or no hot flushes per week (P < .001). The women in the perimenopausal group who experienced hot flushes had higher FSH levels (P = .008) and were more likely to have reported premenstrual complaints at the first interview 3 years earlier (P = .03). In the postmenopausal group, there was no significant difference with any of the variables studied between the women who were experiencing hot flushes and those who were not. CONCLUSION: Reporting of hot flushes is greatest 3 months or more after the final menstrual period. The frequency of hot flushes is associated with increasing FSH, decreasing E2, and a history of premenstrual complaints.

Body Mass Index↗
PubMed1996

Bone turnover markers and bone density across the menopausal transition.

We measured lunbar spine and femoral neck bone mineral density (BMD); urine markers of bone resorption; serum markers of bone formation; and serum gonadotrophin, estradiol and inhibin concentrations in a population-based cohort of 281 women aged 45-57 yr. Women were classified into pre-, peri-, and postmenopausal groups, depending on menstrual bleeding patterns. Compared with premenopausal women, BMD was lower only in postmenopausal women but not in women currently using hormone replacement therapy (HRT). BMD decreased with age in the perimenopausal group. Compared with premenopausal women, perimenopausal women had 20% greater urine N-telopeptide excretion (P < 0.05) and a doubling of gonadotrophin levels (P < 0.01), whereas serum estradiol and bone formation marker concentrations were no different. Postmenopausal Women had greater levels of bone turnover markers (P < 0.0001), except free deoxypyridinoline and type I procollagen propeptide. Among postmenopausal women, bone resorption markers were lower in those using HRT. Levels of nearly all bone turnover markers were positively related to serum FSH concentrations (P < 0.0001). Overall, the major independent predictors of BMD were age, urine N-telopeptide, serum bone alkaline phosphatase, and serum, FSH, whereas urine free deoxypyridinoline was positively related to BMD in pre- and perimenopausal women. In conclusion, the perimenopause is associated with elevated bone resorption rates and declining BMD, and factors in addition to estrogen deficiency may also contribute to the pathogenesis of postmenopausal osteoporosis.

Aging↗
PubMed1996

Bone mineral density and hormone levels in menopausal Australian women.

To assess the relationships between bone mineral density (BMD) at the lumbar spine and femoral neck and menopausal status, age, physical variables, and lifestyle and gynecological factors. BMD and follicle-stimulating hormone (FSH), estradiol and inhibin levels were measured in 167 women born in Australia, aged 46-57 years, who had no record of receiving hormone replacement therapy. Using the premenopausal group as a baseline, the FSH level was higher in peri- and postmenopausal subjects (p < 0.0005), and estradiol and inhibin levels in the postmenopausal women were lower (p < 0.0005). Mean (+/- SE) lumbar spine and femoral neck BMD were 15 +/- 3% and 10 +/- 3% lower, respectively, in postmenopausal than in premenopausal women. Lumbar spine BMD decreased with increasing age in perimenopausal women only (p < 0.005), and femoral neck BMD decreased with increasing age in the pre-, peri-(p < 0.05) and postmenopausal women. The difference between femoral neck BMD in the pre- and postmenopausal women was explained by the difference in age between these groups, whereas for lumbar spine BMD the menopausal status was an additional determining factor. There was a negative effect of smoking on femoral neck BMD (p < 0.05) in postmenopausal women. In the perimenopausal decade the femoral neck BMD is primarily dependent on age, whereas lumbar spine BMD is dependent on both age and menopausal status.

Aging↗
PubMed1994

Physical activity and the menopause experience: a cross-sectional study.

A randomly selected community cohort of 2000 Australian born women aged 45 to 55 were interviewed on the telephone and information obtained on their health and well-being. These women were divided into pre-, peri-, natural and surgical menopausal groups on their menstrual history. A physical activity questionnaire was sent to 1181 women in the first three of these groups. These questionnaires were completed and returned by 61.6% of the women. The response rate in all groups was significantly associated with the years of education, employment status, body mass index (BMI) and self-rated health of the participants. The aim of the study was to test the hypothesis that physical activity is a major contributor to health and well-being by establishing the relationships between physical activity and certain health outcomes, such as menopausal symptoms, psychological well-being, self-rated health and BMI in this cohort of mid-life women. The inter-relationship between physical activity and other variables, including menopausal status, interpersonal stress, health related and preventive health behaviours was examined. Levels of physical activity were significantly associated with better self-rated health, lower BMI measurements, moderate alcohol intake and self-breast examination. There was no significant association between levels of physical activity, psychological well-being and women's experience of symptoms during the natural menopause transition.

Attitude to Health↗
PubMed1987

Albumin has no role in the uptake of copper by human fibroblasts.

The mechanism of copper uptake by cells has been the subject of controversy for some time. This paper examines the possibility of a role for albumin in the uptake of copper by fibroblasts. Although the cells could accumulate copper from a copper-albumin complex, there was no evidence for either copper-albumin or albumin receptors on the cell surface. The possibility of a surface exchange mechanism for copper was examined. While copper uptake showed saturation with increasing concentrations of labelled copper-albumin, adding unlabelled copper to the incubation medium did not inhibit uptake. Adding albumin or histidine to the copper-albumin complex resulted in an inhibition of copper uptake. The results can only be explained by the cell taking up free copper from the incubation medium, with the albumin then releasing its copper to maintain the equilibrium between free and bound metal. Since, in vivo there is essentially no free copper in serum, it is concluded that albumin is most unlikely to play a role in the uptake of copper by fibroblasts.

Albumins↗
PubMed1987

The medical trial.

Explore the source record for details and available documents.

Expert Testimony↗
PubMedDate not supplied

Risk factors for osteoporosis: A review.

Skeletal fragility and falls are the 2 most potent factors leading to osteoporotic fractures. The aim of this article is to review factors associated with women's risk of developing skeletal fragility and subsequent osteoporosis. Many factors have been implicated, but the evidence for some is unsubstantial. Low premenopausal bone mineral density (BMD), a decrease in BMD, and an increase in bone fragility -- which occur as a result of both aging and the menopause -- are major determinants of subsequent risk for osteoporotic fracture. In addition, low body mass index (BMI), low calcium intake, low physical activity, and smoking can affect BMD. The relative importance of the effects these physical and lifestyle factors have on BMD in midlife women is not fully established. The impact of gynecologic history (parity, lactation, oral contraceptive use, age of menarche) on BMD is uncertain.

Body Mass Index↗
PubMedDate not supplied

Risk factors for osteoporosis: prevalence, change, and association with bone density.

OBJECTIVES: To describe the prevalence of risk factors for osteoporosis in a population-based cohort of Australian-born midlife women; determine the effect of these risk factors on premenopausal and early perimenopausal bone mineral density (BMD); and describe changes in risk factors and any effect of these on bone loss. DESIGN: 4-year longitudinal community-based study. BMD of the lumbar spine (LS) and femoral neck (FN) was measured using dual x-ray absorptiometry (DXA). SETTING: Melbourne, Australia PARTICIPANTS: 224 Australian-born women aged 46-56 years MAIN OUTCOME MEASURES: Risk factors for osteoporosis, LS-BMD, FN-BMD, and change in risk factors and BMD. RESULTS: At baseline, 52% reported a calcium intake of less than 800 mg/day and 46% reported a caffeine intake of more than 360 mg/day; 29% exercised less than 1.5 hours/week; 5% had a body mass index (BMI) of less than 20; 14% were current smokers; 23% were past smokers; 10% reported abnormal menstrual histories; and 25% reported a family history of osteoporosis. BMD was positively associated with weight; BMI; and waist, hip, and trunk skin-fold measure (P less than .0005). At 4-year follow-up, there were increases in weight (P less than .0005), waist/hip ratio (P less than. 05), trunk skin-fold measurements (P less than.005), and calcium intake (P less than.05). In women who became late perimenopausal or postmenopausal, bone loss was associated with time in relation to the final menstrual period but not with other variables. CONCLUSIONS: There are multiple risk factors for osteoporosis in this Australian-born population of midlife women, but only anthropometric variables were associated with BMD at baseline. Significant changes during the menopausal transition in anthropometric variables and calcium intake were in the direction that could decrease the risk of osteoporosis but were not found to affect menopausal bone loss.

Body Mass Index↗