RESUMEN
Our objective was to evaluate the impact of hydroxyethyl starch (HES) use in organ donors after neurologic determination of death (DNDD) on recipient renal graft outcomes. The following data elements were prospectively collected for every DNDD managed by a single organ procurement organization from June 2011 to July 2013: demographics; critical care endpoints; treatments, including the use of HES; graft cold ischemia time (CIT); and the occurrence of recipient delayed graft function (DGF, dialysis in the first week after transplantation). Logistic regression was performed to identify independent predictors of DGF with a p-value <0.05. The results were then adjusted for each donor's calculated propensity to receive HES. Nine hundred eighty-six kidneys were transplanted from 529 donors. Forty-two percent received HES (1217 ± 528 mL) and 35% developed DGF. Kidneys from DNDDs who received HES had a higher crude rate of DGF (41% vs. 31%, p < 0.001). After accounting for the propensity to receive HES, independent predictors of DGF were age (OR 1.02 [1.01-1.04] per year), CIT (OR 1.04[1.02-1.06] per hour), creatinine (OR 1.5 [1.32-1.72] per mg/dL) and HES use (OR 1.41 [1.02-1.95]). HES use during donor management was independently associated with a 41% increase in the risk of DGF in kidney transplant recipients.
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Derivados de Hidroxietil Almidón/administración & dosificación , Trasplante de Riñón , Donantes de Tejidos , Adulto , Humanos , Pruebas de Función RenalRESUMEN
The aims of this prospective cohort study were to determine rates of premenopausal and early postmenopausal bone loss, age at onset of bone loss, and whether rates of bone loss depend on baseline bone mineral density (BMD). The cohort of 614 women aged 24-44 years at baseline from the longitudinal Michigan Bone Health Study was followed for 6 years beginning in 1992-1993. Up to five BMD measurements of the lumbar spine (L(2-4)) and the femoral neck were obtained through 1998-1999 by using dual x-ray absorptiometry and were standardized (as z scores) relative to a young adult, female BMD distribution. Regression models were used to estimate rates of BMD change and to examine BMD as a function of age. At the lumbar spine, the rate of BMD change for premenopausal women varied with time. At the femoral neck, the rate of change was -1.6% (95% confidence interval: -0.9%, -2.3%) of a z score annually (annual loss of 0.3% of baseline BMD (g/cm(2))). Evidence for age at onset of bone loss at the lumbar spine was inconclusive. Bone loss began by the midtwenties at the femoral neck. Additional annual change of -0.7% (95% confidence interval: -0.2%, -1.2%) of a z score was observed at the femoral neck for each unit increase in BMD z score at baseline.
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Densidad Ósea , Osteoporosis Posmenopáusica/epidemiología , Premenopausia , Absorciometría de Fotón , Adulto , Distribución por Edad , Femenino , Humanos , Estudios Longitudinales , Michigan/epidemiologíaRESUMEN
UNLABELLED: Discrepancies exist between radiographic osteoarthritis of the knee (OAK) and report of knee joint pain. Little is known about how these two definitions of osteoarthritis (OA) and their correlates differ between African American (AA) and Caucasian (CA) women. OBJECTIVE: We compared the prevalence of radiographic OAK and knee joint pain in AA and CA women, and the congruency of these outcomes according to age, body size, and knee injury. DESIGN: A cross-sectional study of African American and Caucasian women aged 40-53 years (N=829) in Southeast Michigan used the Kellgren and Lawrence Atlas of Standard Radiographs of Arthritis to characterize radiographs of both knee joints (weight bearing) and self-report of knee pain. RESULTS: Current pain was a significantly more sensitive predictor of radiographic OAK among AA women (Se=0.51) compared to CA women (Se=0.35). Specificity was similar between AA women (Sp=0.77) and CA women (Sp=0.82). Positive predictive value was significantly greater for AA compared with CA women (PV+=0.40 and PV+=0.15, respectively). The odds of having radiographic OAK increased with BMI >32 kg/m(2) in both groups. Knee pain was related to BMI in CA women, but not AA women. Previous knee injury was associated with knee pain in both AA and CA women (OR=3.0 and OR=2.4). CONCLUSIONS: Joint pain in AA women was more likely to be associated with radiographic OAK as compared with CA women. This suggests differences in these two groups in both how pain is experienced in the OAK process and in the prevalence of non-OAK related pain in knee joints.
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Población Negra , Osteoartritis de la Rodilla/etnología , Dolor/etnología , Población Blanca , Adulto , Factores de Edad , Análisis de Varianza , Constitución Corporal , Índice de Masa Corporal , Distribución de Chi-Cuadrado , Intervalos de Confianza , Estudios Transversales , Femenino , Humanos , Traumatismos de la Rodilla/complicaciones , Análisis de los Mínimos Cuadrados , Modelos Logísticos , Michigan/epidemiología , Persona de Mediana Edad , Oportunidad Relativa , Osteoartritis de la Rodilla/diagnóstico por imagen , Osteoartritis de la Rodilla/etiología , Dolor/diagnóstico por imagen , Dolor/etiología , Valor Predictivo de las Pruebas , Curva ROC , Radiografía , Sensibilidad y EspecificidadRESUMEN
We evaluated five genetic markers for products that contribute to skeletal mineralization including the Sp1 polymorphism for type I collagen Ai (COLIA1), the vitamin D receptor (VDR) translation initiation site polymorphism, the promoter of the osteocalcin gene containing a C/T polymorphism, the estrogen receptor (ER) gene containing a TA repeat, and the polymorphic (AGC)n site in the androgen receptor. These markers were evaluated for their potential relationship with bone mineral density (BMD), measured by dual-energy X-ray densitometry, or its 3-year change. Additionally, potential associations of these genotypes and with baseline osteocalcin concentration or its 3-year change (assessed using radioimmunoassay) were evaluated. The study was conducted in 261 pre- and perimenopausal women of the Michigan Bone Health Study, a population-based longitudinal study of musculoskeletal characteristics and diseases. The polymorphic (AGC)n site in the androgen receptor showed a strong association with BMD of the femoral neck (FN) and lumbar spine and remained highly significant after adjusting for body mass index (BMI), oophorectomy/hysterectomy, oral contraceptive (OC) use and hormone replacement use (p < 0.001). The TA repeat at the 5' end of the ER gene was associated with total body calcium (p < 0.05) after adjusting for BMI, oophorectomy and hysterectomy, and OC use. The frequency of oophorectomy and hysterectomy within selected genotypes explained much of the statistically significant association of the ER genotypes with BMD of the FN and spine. There was no association of measures of BMD or bone turnover with the Sp1 polymorphism for COLIA1, the VDR translation initiation site polymorphism, or the C/T promoter polymorphism of the osteocalcin gene. These findings suggest that sex hormone genes may be important contributors to the variation in BMD among pre- and perimenopausal women.
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Densidad Ósea/fisiología , Marcadores Genéticos , Osteocalcina/sangre , Polimorfismo Genético , Receptores de Estrógenos/genética , Adulto , Colágeno/genética , Femenino , Genotipo , Humanos , Persona de Mediana Edad , Repeticiones de Minisatélite , Iniciación de la Cadena Peptídica Traduccional/genética , Polimorfismo de Longitud del Fragmento de Restricción , Receptores Androgénicos/genética , Receptores de Calcitriol/genética , Secuencias Repetitivas de Ácidos NucleicosRESUMEN
OBJECTIVE: To determine whether Caucasian women ages 28-48 years with newly defined osteoarthritis (OA) would have greater bone mineral density (BMD) and less bone turnover over time than would women without OA. METHODS: Data were derived from the longitudinal Michigan Bone Health Study. Period prevalence and 3-year incidence of OA were based on radiographs of the dominant hand and both knees, scored with the Kellgren/Lawrence (K/L) scale. OA scores were related to BMD, which was measured by dual-energy x-ray absorptiometry, and to serum osteocalcin levels, which were measured by radioimmunoassay. RESULTS: The period prevalence of OA (K/L grade > or =2 in the knees or the dominant hand) was 15.3% (92 of 601), with 8.7% for the knees and 6.7% for the hand. The 3-year incidence of knee OA was 1.9% (9 of 482) and of hand OA was 3.3% (16 of 482). Women with incident knee OA had greater average BMD (z-scores 0.3-0.8 higher for the 3 BMD sites) than women without knee OA (P < 0.04 at the femoral neck). Women with incident knee OA had less change in their average BMD z-scores over the 3-year study period. Average BMD z-scores for women with prevalent knee OA were greater (0.4-0.7 higher) than for women without knee OA (P < 0.002 at all sites). There was no difference in average BMD z-scores or their change in women with and without hand OA. Average serum osteocalcin levels were lower in incident cases of hand OA (>60%; P = 0.02) or knee OA (20%; P not significant). The average change in absolute serum osteocalcin levels was not as great in women with incident hand OA or knee OA as in women without OA (P < 0.02 and P < 0.05, respectively). CONCLUSION: Women with radiographically defined knee OA have greater BMD than do women without knee OA and are less likely to lose that higher level of BMD. There was less bone turnover among women with hand OA and/or knee OA. These findings suggest that bone-forming cells might show a differential response in OA of the hand and knee, and may suggest a different pathogenesis of hand OA and knee OA.
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Densidad Ósea , Remodelación Ósea , Osteoartritis/sangre , Premenopausia/fisiología , Adulto , Biomarcadores , Femenino , Mano , Humanos , Incidencia , Articulación de la Rodilla , Estudios Longitudinales , Persona de Mediana Edad , Osteoartritis/epidemiología , Osteocalcina/sangre , Prevalencia , Factores de RiesgoRESUMEN
There is a need to better understand potential bone mineral density (BMD) loss during the menopausal transition since this period may include the initiation of interventions. The study purpose was to determine if there was BMD loss at the femoral neck, lumbar spine, or total body bone sites in a population-based study of women approaching or transitioning the midlife. The 583 enrollees were 25-45 years of age at the first of four annual measurements from 1992 through 1996. Bone mineral content and bone width were measured using dual-energy X-ray absorptiometry. Considering all enrollees collectively, there was a significant 3-year decline (1%) in BMD at the femoral neck over the 3-year period (p = 0.076). There was no significant annual change in the lumbar spine (p = 0.11), and a significant annual increase in the total body BMD (p = 0.0003). Within subgroups and cross-sectionally, BMD values of the femoral neck were 5% lower in women classified as perimenopausal compared with premenopausal enrollees; BMD was 3% and 1% lower at the lumbar spine and total body site, respectively. Longitudinally, among perimenopausal women, a double oophorectomy was associated with BMD loss in the spine (p = 0.0003), even though 75-85% of these women had a hormone replacement prescription at some time during the study period. In summary, the site with evidence of loss was the femoral neck, specifically among perimenopausal women. There was little evidence of substantial total body or lumbar spine BMD loss in premenopausal women with ovaries who maintained follicle-stimulating hormone levels < 20 mIU/l in the early follicular period. Double oophorectomy, even with hormone replacement, was associated with bone loss.
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Densidad Ósea/fisiología , Premenopausia/fisiología , Población Blanca , Absorciometría de Fotón , Adulto , Estudios de Cohortes , Estudios Transversales , Terapia de Reemplazo de Estrógeno , Femenino , Cuello Femoral/diagnóstico por imagen , Humanos , Vértebras Lumbares/diagnóstico por imagen , Michigan , Persona de Mediana Edad , Ovariectomía , Análisis de Regresión , Encuestas y CuestionariosRESUMEN
We hypothesized that lower ovarian and gonadotropin hormone concentrations would be associated with lower levels of peak bone mineral density (BMD) in apparently normally menstruating women who did not exercise intensively and did not report anorexia or bulimia. This hypothesis was evaluated using a case-with-control study design (n = 65) which was nested within a population-based longitudinal study of peak bone mass (Michigan Bone Health Study) with annual assessment in women aged 25-45 years (n = 582). Cases were 31 premenopausal women with BMD of the lumbar spine, femoral neck, and total body less than the 10th percentile of the distribution, where controls were 34 premenopausal women with BMD between the 50th and 75th percentile. BMD was measured by dual-energy X-ray absorptiometry. In addition to their annual measurement, these 65 participants collected first-voided morning urine specimens daily through two consecutive menstrual cycles. The urine from alternating days of this collection was analyzed for estrone-3-glucuronide (E1G), pregnanediol glucuronide (PdG), testosterone, and follicle-stimulating hormone by radioimmunoassay and these values adjusted for daily creatinine excretion levels. Additionally, analyses of daily urine specimens for luteinizing hormone (uLH) was undertaken to better characterize the possible uLH surge. Cases had significantly lower amounts of E1G (p = 0.009) and PdG (p = 0.002) than did controls, whether amounts were characterized by a mean value, the highest value, or the area under the curve, and after statistically controlling for body size. Further, when B-splines were used to fit lines to the E1G and PdG data across the menstrual cycle, the 95% confidence intervals (CIs) about the line for the controls consistently excluded and excluded and exceeded the 95% confidence bands for the cases in the time frame associated with the luteal phase in ovulatory cycles. Likewise, 95% CIs for the LH surge in controls exceeded the fitted line for cases around the time associates with the LH surge. The cases and controls were not different according to dietary intake (energy, protein, calcium), family history of osteoporosis, reproductive characteristics (parity, age at menarche, age of first pregnancy), follicular phase serum hormone levels, calciotropic hormone levels, or by evidence of perimenopause. We conclude that these healthy, menstruating women with BMD at the lowest 10th percentile from a population-based study had significantly lower urinary sex steroid hormone levels during the luteal phase of menstrual cycles as compared with hormone levels in premenopausal women with BMD between the 50th and 75th percentile of the same population-based study, even after considering the role of body size. These data suggest that subclinical decreases in circulating gonadal steroids may impair the attainment and/or maintenance of bone mass in otherwise reproductively normal women.
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Densidad Ósea , Hormona Folículo Estimulante/orina , Gonadotropinas/orina , Hormona Luteinizante/orina , Premenopausia/orina , Testosterona/orina , Absorciometría de Fotón , Adulto , Estudios de Casos y Controles , Estrógenos Conjugados (USP)/orina , Estrona/análogos & derivados , Estrona/orina , Femenino , Cuello Femoral/diagnóstico por imagen , Humanos , Vértebras Lumbares/diagnóstico por imagen , Michigan , Aptitud Física/fisiología , Pregnanodiol/análogos & derivados , Pregnanodiol/orinaRESUMEN
Low bone mineral density (BMD) is a major risk factor for development of osteoporosis; increasing evidence suggests that attainment and maintenance of peak bone mass as well as bone turnover and bone loss have strong genetic determinants. We examined the association of BMD levels and their change over a 3-year period, and polymorphisms of the estrogen receptor (ER), vitamin D receptor (VDR), type I collagen, osteonectin, osteopontin, and osteocalcin genes in pre- and perimenopausal women who were part of the Michigan Bone Health Study, a population-based longitudinal study of BMD. Body composition measurements, reproductive hormone profiles, bone-related serum protein measurements, and life-style characteristics were also available on each woman. Based on evaluation of women, ER genotypes (identified by PvuII [n = 253] and XbaI [n = 248]) were significantly predictive of both lumbar spine (p < 0.05) and total body BMD level, but not their change over the 3-year period examined. The VDR BsmI restriction fragment length polymorphism was not associated with baseline BMD, change in BMD over time, or any of the bone-related serum and body composition measurements in the 372 women in whom it was evaluated. Likewise, none of the other polymorphic markers was associated with BMD measurements. However, we identified a significant gene x gene interaction effect (p < 0.05) for the VDR locus and PvuII (p < 0.005) and XbaI (p < 0.05) polymorphisms, which impacted BMD levels. Women who had the (-/-) PvuII ER and bb VDR genotype combination had a very high average BMD, while individuals with the (-/-) PvuII ER and BB VDR genotype had significantly lower BMD levels. This contrast was not explained by differences in serum levels of osteocalcin, parathyroid hormone, 1,25-dihydroxyvitamin D, or 25-dihydroxyvitamin D. These data suggest that genetic variation at the ER locus, singly and in relation to the vitamin D receptor gene, influences attainment and maintenance of peak bone mass in younger women, which in turn may render some individuals more susceptible to osteoporosis than others.
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Densidad Ósea/genética , Osteocalcina/sangre , Receptores de Calcitriol/genética , Receptores de Estrógenos/genética , Absorciometría de Fotón , Adulto , Adhesión Celular , Colágeno/sangre , Colágeno/genética , Susceptibilidad a Enfermedades , Femenino , Marcadores Genéticos , Genotipo , Humanos , Estudios Longitudinales , Osteocalcina/genética , Osteonectina/sangre , Osteonectina/genética , Osteopontina , Osteoporosis Posmenopáusica/genética , Polimorfismo de Longitud del Fragmento de Restricción , Posmenopausia/sangre , Posmenopausia/genética , Premenopausia/sangre , Premenopausia/genética , Receptores de Calcitriol/sangre , Receptores de Estrógenos/sangre , Sialoglicoproteínas/sangre , Sialoglicoproteínas/genética , Población BlancaRESUMEN
The postpartum period can be a time when profound changes in calcium metabolism and bone mineral density (BMD) occur, particularly in association with lactation. We investigated the hypothesis that calciotrophic hormones [1,25-dihydroxyvitamin D, 25-hydroxyvitamin D, and parathyroid hormone (PTH)] are different by lactation practice or hormone status [PTH-related peptide (PTHrP), estradiol, and prolactin] and have a potential role in the bone loss and recovery associated with lactation. 1,25-Dihydroxyvitamin D, 25-hydroxyvitamin D, PTH, femoral BMD, PTHrP, prolactin, estradiol, and bone turnover markers were measured at 2 wk and at 2, 4, 6, 12, and 18 mo postparturition in 115 postpartum women aged 20-40 y (parity: 0-1). Lumbar spine BMD was measured at 2 wk and at 6, 12, and 18 mo during the postpartum period. PTH, 1,25-dihydroxyvitamin D, and 25-hydroxyvitamin D concentrations were nonlinear across the 18-mo postpartum period. Between baseline and 18 mo postparturition, PTH and 1,25-dihydroxyvitamin D concentrations did not decline, while there was a substantial decline in 25-hydroxyvitamin D concentrations. PTH, 1,25-dihydroxyvitamin D, and 25-hydroxyvitamin D concentrations did not differ by lactation practice or by PTHrP, estradiol, or prolactin status. These classic calciotrophic hormones were not associated with concentrations of bone turnover markers or changes in BMD in lactating women. In summary, patterns of change in calciotrophic hormones (PTH, 1,25-dihydroxyvitamin D, and 25-hydroxyvitamin D) in the 18-mo postpartum period appeared to be independent of PTHrP, estradiol, prolactin, or lactation status and were not associated with bone turnover markers. These data do not support the hypothesis that these three calciotrophic hormones are a central part of the calcium mobilization associated with the bone loss of lactation.
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Calcifediol/fisiología , Calcitriol/fisiología , Calcio/metabolismo , Lactancia/metabolismo , Hormona Paratiroidea/fisiología , Periodo Posparto/metabolismo , Adulto , Densidad Ósea/fisiología , Lactancia Materna , Calcifediol/sangre , Calcitriol/sangre , Estradiol/sangre , Femenino , Humanos , Hormona Paratiroidea/sangre , Radioinmunoensayo , Valores de ReferenciaRESUMEN
OBJECTIVE: To investigate the hypothesis that parathyroid hormone-related peptide (PRHrP) may be involved with bone loss and recovery as a means of providing adequate calcium and phosphate to infants. DESIGN: An 18-month prospective cohort study. SETTING: General community setting with recruitment occurring at birthing education classes. PARTICIPANTS: Volunteer sample of 115 postpartum healthy women aged 20 to 40 years, and 0 or 1 parity prior to parturition with no intent to breast-feed or intent to breast-feed at least 6 months. MAIN OUTCOME MEASURES: Parathyroid hormone-related peptide, prolactin, estradiol, 1,25-dihydroxyvitamin D, 24-hydroxyvitamin D, femoral bone mineral density, and bone turnover markers were measured in 115 postpartum women at 2 weeks, 2 months, 4 months, 6 months, 12 months, and 18 months postpartum. Lumbar bone mineral density was measured at 2 weeks, 6 months, 12 months, and 18 months postpartum. RESULTS: Elevated PTHrP values were significantly associated (P<.001) with breast-feeding status, elevated prolactin levels, and lower serum estradiol levels, conditions occurring during lactation. Furthermore, elevated PTHrP levels were negatively and significantly associated (P<.01) over time with bone mineral density change at both the spine and the femoral neck, even after accounting for prolactin levels, breast-feeding status, return of menstruation, estradiol levels, PTH levels, 1,25-dihydroxyvitamin D levels, dietary calcium intake, physical activity, and body size. CONCLUSION: These data clearly support the hypothesis that PTHrP is an alternative mechanism associated with bone loss and recovery during and subsequent to lactation.
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Densidad Ósea/fisiología , Remodelación Ósea/fisiología , Lactancia/fisiología , Hormona Paratiroidea/fisiología , Proteínas/fisiología , Absorciometría de Fotón , Lactancia Materna , Estudios de Cohortes , Estradiol/sangre , Femenino , Humanos , Ensayo Inmunorradiométrico , Lactancia/sangre , Hormona Paratiroidea/sangre , Proteína Relacionada con la Hormona Paratiroidea , Periodo Posparto/fisiología , Prolactina/sangre , Estudios Prospectivos , Proteínas/análisis , Análisis de Regresión , Sensibilidad y EspecificidadRESUMEN
This population-based longitudinal study describes the 4.5-year changes in body composition and body mass distribution in women aged 20-45 years, and characterizes predictors of these changes. Body weight, waist-to-hip ratio, Quetelet index, fat and lean body mass were measured in 404 white menstruating women aged 20-40 at baseline and 4.5 years later (follow-up). Variables considered for predicting body composition differences were hormonal status, menstrual status, parity, diet and physical activity. Average body weight increased 4.3 kg in 4.5 years (6.4 kg increase in fat and 2.1 kg decrease in lean)--a net increase of 7.1% total body fat. Measured predictors were not significantly associated with weight or Quetelet index; however, they were associated with measured amounts of lean and fat. Longitudinally, women who preserved the most lean body mass tended to be nulliparous, to be still menstruating, to have higher testosterone levels, and to smoke. Physical activity was associated with preserving lean body mass. Increasing age and higher follicle-stimulating hormone levels were associated with increasing waist-to-hip ratio. Average body weight showed a steady increase--characterized by an expanding fat compartment and a shrinking lean compartment--with the older women increasing more in waist girth relative to hip girth than younger women. Predictor variables of these changes included hormonal environment, physical activity, smoking behaviour, parity, and oophorectomy.
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Composición Corporal , Constitución Corporal , Tejido Adiposo/anatomía & histología , Adulto , Envejecimiento/sangre , Envejecimiento/patología , Índice de Masa Corporal , Peso Corporal , Femenino , Hormonas Esteroides Gonadales/sangre , Humanos , Histerectomía , Estilo de Vida , Estudios Longitudinales , Persona de Mediana Edad , Ovariectomía , ParidadRESUMEN
Mechanical stress on the cartilage and metabolic and/or hormonal influences have been suggested as possible etiologic factors for osteoarthritis. This paper reports findings from data collected in 1992 that were used to examine associations between osteoarthritis and risk factors in 573 Caucasian women aged 24-45 years from the Michigan Bone Health Study. Radiographs of the dominant hand and both knees were evaluated using the Kellgren and Lawrence grading scale. The prevalence of osteoarthritis (grade 2 or higher) in this population was 2.8% for hands and 3.6% for knees. Using polytomous multiple logistic regression, the authors found older age, increasing bone mineral density, and decreasing testosterone levels to be significantly associated with increasing hand scores. Older age and hand injury were significantly associated with grades of 2 or higher. Increasing osteoarthritis knee scores were associated with older age, increasing bone density, increasing body mass index, and current use of hormone replacement therapy. A knee grade of 2 or higher was associated with increasing estradiol levels, knee injury, and higher blood pressure. This study indicates that age, bone density, and injury are risk factors common to the development of hand and knee osteoarthritis in this non-elderly female population.
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Densidad Ósea , Estradiol/sangre , Osteoartritis/epidemiología , Premenopausia , Testosterona/sangre , Adulto , Estudios Transversales , Femenino , Mano/diagnóstico por imagen , Humanos , Articulación de la Rodilla/diagnóstico por imagen , Estudios Longitudinales , Michigan/epidemiología , Persona de Mediana Edad , Osteoartritis/sangre , Osteoartritis/diagnóstico por imagen , Premenopausia/sangre , Premenopausia/fisiología , Prevalencia , Radiografía , Análisis de Regresión , Factores de RiesgoRESUMEN
We measured two bone-formation markers, osteocalcin and bone-specific alkaline phosphatase, and one bone-resorption marker, N-telopeptide, in a longitudinal study in order to describe levels of these markers in lactating and nonlactating women after parturition. This 18-month postpartum period included an initial 6 months in which a 5% short-term bone loss occurred at both spine and femoral neck among breast-feeding women. The second part of the 18-month period was characterized by bone recovery among women who had lost bone. These bone-change characteristics provided an opportunity to evaluate the performance of biochemical markers during both bone loss and recovery and to identify environmental exposures during lactation associated with bone turnover. The eligible population comprised 115 women whose bone-turnover markers were measured at 2 weeks (baseline) and at 2, 4, 6, 12, and 18 months after parturition. Participants reported reproductive characteristics, diet, physical activity, use of medications, and infant-feeding practices at each contact. Women were grouped according to lactation duration: 0-1 months, 2-5 months, and 6 months or more. Women who breast-fed for at least 6 months had significantly different levels of all three bone-turnover markers compared with the levels in bottle-feeding controls, which were indicative of substantially increased bone turnover. Factors that predicted the difference in biochemical markers from baseline to 6-month values by regression analysis were lactation of 2-6 months duration and lactation for 6 months or more. Dietary calcium intake, physical activity level, and body size did not explain the differences in the change from the baseline level to the 6-month level, a period of time that corresponded with bone loss in the lactating women. Factors that predicted the differences in bone-turnover markers between 6 and 18 months (the time of bone-mass recovery) were lactation status and number of months to resumption of menses. By the 18-month observation, there was no difference in the mean values for the measured bone-turnover markers among the three lactation groups. This suggests that menstrual activity, rather than diet or physical activity, is the primary factor in bone-mass recovery after the bone loss of lactation.
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Fosfatasa Alcalina/sangre , Biomarcadores/sangre , Densidad Ósea , Desarrollo Óseo , Resorción Ósea , Lactancia Materna , Colágeno/sangre , Lactancia/fisiología , Osteocalcina/sangre , Péptidos/sangre , Periodo Posparto/fisiología , Adulto , Factores de Edad , Calcio de la Dieta , Colágeno Tipo I , Femenino , Humanos , Estudios Longitudinales , Estadísticas no Paramétricas , Factores de TiempoRESUMEN
OBJECTIVE: To test the a priori hypotheses that significant bone loss occurs in lactation of greater than 5 months' duration and that bone mass returns to baseline levels when breast-feeding ceases. DESIGN: Prospective cohort study design of 12 months' duration. SETTING: General community setting with recruitment occurring at birthing education classes. PARTICIPANTS: Volunteer sample of 98 healthy women of white (n = 95) and Asian (n = 3) origin, aged 20 to 40 years, and 0 to 1 parity prior to parturition, grouped according to lactation duration: 0 through 1, 2 through 5, and 6 or more months. MAIN OUTCOME MEASURES: Bone mineral density (BMD) of the proximal femur was measured by dual-energy x-ray densitometry at 2 weeks (baseline), 2 months, 4 months, 6 months, and 12 months following parturition, and BMD of the lumbar spine was measured at baseline, 6 months, and 12 months after parturition. RESULTS: Women with lactation duration of 6 months or longer had mean BMD losses of 5.1% and 4.8% at the lumbar spine and femoral neck, respectively, comparing baseline values with those at 6 months post partum. Women who breast-fed 0 through 1 month lost no BMD at either bone site. Bone loss in women who breast-fed 6 months or longer was not explained by differences in age, diet, body size, or physical activity. Among women who breast-fed 6 months or longer, there was evidence of return to baseline levels of the lumbar spine at 12 months after parturition. The BMD of the lumbar spine of those women who continued to breast-feed more than 9 months had increased but was still significantly lower than baseline. CONCLUSION: Extended lactation (> or = 70% of energy intake is provided for > or = 6 months) is associated with bone loss; however, there is evidence of return to baseline BMD measurement at 12 months after parturition.
Asunto(s)
Densidad Ósea/fisiología , Lactancia/fisiología , Absorciometría de Fotón , Adulto , Análisis de Varianza , Femenino , Fémur/diagnóstico por imagen , Fémur/fisiología , Humanos , Lactancia/sangre , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/fisiología , Estado Nutricional , Estudios Prospectivos , Factores de Tiempo , DesteteRESUMEN
Body composition (fat and lean compartments) and bone mineral density were measured in 246 healthy premenopausal women, aged 20-40 years, residing in Tecumseh, Michigan. Body composition was measured using four-point bioelectrical impedance and values for fat and lean compartments categorized into tertiles. Additionally, each woman was classified into one of nine different cells based on her location within a 3 x 3 table which reflects the joint distribution of both fat and lean compartments. Bone mineral density of the proximal femur, including the femoral neck and trochanter, was measured using dual photon densitometry. The mean femoral neck bone mineral density values increased significantly and linearly for each tertile of muscle mass (0.90, 0.95, and 1.02 g/cm2, p less than 0.0002). Femoral bone mineral density increased significantly but not linearly as the fat compartment progressed from the lowest to the highest tertile (0.95, 0.93, and 0.99 g/cm2). Bone mineral density of the proximal femur was similar and significantly greater in the high muscle/low fat and high muscle/high fat body composition subgroups compared with bone mineral density in the seven other groups. However, women in the high muscle/low fat subgroup had substantially lower mean weight (67 vs. 91 kg, p less than 0.0001) and mean Quetelet index (22.1 vs. 33.7 kg/m2, p less than 0.0001) than women in the high muscle/high fat subgroup. Bone mineral density values were similar and significantly lower in the following body composition cells: low muscle/low fat, low muscle/medium fat, and low muscle/high fat. Similar findings were observed at the trochanteric site. Low muscle is a risk factor for low bone mineral density in young adult women while higher fat is protective only when associated with substantial muscle.
Asunto(s)
Tejido Adiposo/química , Composición Corporal , Densidad Ósea , Músculos/química , Absorciometría de Fotón , Adulto , Índice de Masa Corporal , Estudios Transversales , Impedancia Eléctrica , Femenino , Fémur/diagnóstico por imagen , Humanos , Menopausia , Michigan/epidemiología , Obesidad/complicaciones , Obesidad/diagnóstico , Osteoporosis Posmenopáusica/epidemiología , Osteoporosis Posmenopáusica/etiología , Cintigrafía , Factores de Riesgo , Grosor de los Pliegues CutáneosRESUMEN
The contributions of polygenic loci and environmental factors to femoral bone mineral density (BMD) in g/cm2) variability were estimated in modified family sets consisting of women of child-bearing age. Femoral BMDs were measured in 535 women who were members of 137 family sets consisting minimally of an index, her sister, and unrelated female control. The family set could also include multiple sisters and first cousins. Women included in these family sets were all between 20 and 40 years of age to minimize the cohort effects of maturation and menopause on measures of BMD. BMDs were measured at three femoral sites using dual photon densitometry. Values were regressed on age and Quetelet Index which explained 13-15% of the variability in BMD (dependent on site). Subsequent variance components analysis on the residuals indicated that unmeasured polygenic loci accounted for substantial additional variability: 67% for femoral neck, 58% for Wards triangle, and 45% for trochanter. These results suggest that polygenic loci account for approximately half of the variability in maximal femoral BMD.
Asunto(s)
Densidad Ósea/genética , Métodos Epidemiológicos , Fémur/metabolismo , Osteoporosis/genética , Adulto , Análisis de Varianza , Densidad Ósea/fisiología , Femenino , Variación Genética , Humanos , Osteoporosis/epidemiologíaRESUMEN
During pregnancy, mineralization of the fetal skeleton creates a demand for approximately 30 g of calcium from maternal sources. We examined whether this fetal demand results in maternal femoral bone mineral loss. Femoral bone mineral density was measured twice by dual photon densitometry, once before conception and again within 15 days of parturition, in 32 white women aged 20-40 years. Femoral bone mineral density was also measured twice in 32 non-pregnant controls matched to the cases for weight, height, age, and parity. There was no significant mean bone mineral density loss in cases compared with controls (P greater than .63). Pregnant women with smaller body size, expressed as Quetelet index, were more likely to have femoral neck bone mass increase than their matched controls (P less than .03). This study provides evidence that fetal demand for calcium has a minimal effect on bone mineral density at parturition. Smaller women may experience a slight increase in femoral bone mineral density compared with controls.
Asunto(s)
Densidad Ósea , Embarazo/metabolismo , Adulto , Femenino , Estudios de Seguimiento , Humanos , Estudios ProspectivosRESUMEN
Maximum bone mineral density of the femur was measured by dual-photon densitometry in 282 healthy white women, aged 20 to 40 years. Femoral sites included the neck, Wards triangle, and the trochanter. Quetelet Index was used as a measure of weight adjusted for height, and body composition was measured using four-point bioelectrical impedance and anthropometry. Maximum bone mass is believed to be an important measure if the level established which remain characteristic or predict bone mineral density during the aging process. Body weight was correlated with each measure of femoral bone density, including the femoral neck (r = .42), Wards triangle (r = .34), and the trochanter (r = .44). Weight was more highly correlated with bone mass than with other measures of body composition, including fat-free mass, percent body fat, humeral muscle area, and humeral fat area. We observed that age was negatively associated with bone mass at all three femoral sites, even in subjects within the age range of 20 to 40 years, and the relationship was significant after controlling for Quetelet Index. There was no evidence of a nonlinear relationship that would indicate when maximal femoral bone mass reaches its peak within this age range.
Asunto(s)
Composición Corporal , Densidad Ósea , Adulto , Envejecimiento/fisiología , Estatura , Peso Corporal , Densitometría , Femenino , HumanosRESUMEN
OBJECTIVE: To determine some personality and psychoneurotic characteristics of adults who have the sleepwalking-night terrors syndrome. DESIGN: Prospective assessment of two groups of consecutive patients with a firm diagnosis of either of two specific sleep disorders as established clinically and by polysomnography. SETTING: Outpatient sleep disorders clinic and sleep laboratory in a tertiary referral centre. PATIENTS: 12 Patients referred consecutively to the clinic in whom a diagnosis of sleepwalking (six) or night terrors (six) was confirmed. MAIN OUTCOME MEASURES: Psychological characteristics as measured at the time of clinical assessment by means of the Eysenck personality questionnaire, the hostility and direction of hostility questionnaire, and the Crown-Crisp experiential index. RESULTS: Both groups scored exceptionally highly on the hysteria scale of the Crown-Crisp experiential index and the night terrors group also scored highly on the anxiety scale. The patients with sleepwalking also scored highly on a measure of externally directed hostility. CONCLUSIONS: The physiological and psychological features identified in these patients, possibly reflecting different expressions of a constitutional cerebral characteristic, may be explored in terms of hysterical dissociation. The findings contribute to the debate concerning the nature of sleepwalking, in particular with and without the forensic aspects.
Asunto(s)
Estado de Conciencia , Trastornos del Sueño-Vigilia/psicología , Sonambulismo/psicología , Adulto , Nivel de Alerta , Femenino , Hostilidad , Humanos , Histeria , Masculino , Personalidad , Pruebas de Personalidad , Estudios ProspectivosRESUMEN
A case of chronic painful nocturnal penile erection is described. Repeated awakenings led to a degree of REM sleep deprivation. Treatment with propanolol was initially successful in alleviating the symptoms, but tolerance to the drug developed rapidly.