Association Between Changes in Sleep, Nap Duration and Bone Mineral Density in Mexican Adults.

Studies have found associations between sleep, nap duration, and bone mineral density (BMD). However, the longitudinal relationship between sleep, nap duration, and BMD has not been explored. We evaluated the association between the change in sleep and nap duration and BMD in Mexican adults. Data come from 1,337 adult participants of the Health Workers Cohort Study (341 were men and 996 were women, including 450 women < 45 years old and 546 ≥ 45 years old), with two study waves. At each wave, sleep and nap duration was assessed using self-administered questionnaires and BMD in g/cm2 was determined by dual X-ray absorptiometry. We used fixed-effect regression models stratified by sex and adjusted for BMI, diet, physical activity, vitamin supplements, and hormone replacement therapy. Women who changed from < 7 to ≥ 7 h/day of sleep from baseline to follow-up were associated with increases in the total hip (ß = 0.012 g/cm2; 95% CI: 0.002, 0.022) and lumbar spine BMD (ß = 0.024 g/cm2; 95% CI: 0.009, 0.039). Furthermore, most of these associations were observed in women ≥ 45 years. For women, a changing from 0 to > 60 min/day of napping was associated with a significant increase in total hip BMD of 0.012 g/cm2 (95% CI: 0.004, 0.024) and lumbar spine BMD of 0.027 g/cm2 (95% CI: 0.009, 0.045). No significant associations were observed for men. Our results suggest that increased sleep and nap duration are associated with gains in BMD in Mexican women, emphasizing sleep's role in promoting bone health and supporting established recommendations.

Calcium supplementation and body mass index modify associations between prenatal phthalate exposure and perinatal bone ultrasound measures among pregnant women.

Phthalates have endocrine activity that may interfere with bone health, particularly during pregnancy and the early postpartum period, when bone resorption increases. We evaluated associations between prenatal phthalate exposure and perinatal bone health among 289 mothers in the ELEMENT birth cohort in Mexico City who were randomized upon recruitment to receive 1,200 mg daily calcium supplementation or placebo throughout pregnancy. Spot urine samples at up to three timepoints during pregnancy were assayed for 9 phthalate metabolites. Bone integrity was assessed by quantitative ultrasound speed of sound (SOS) measurements of the phalange and distal radius at 3, 6, and 8 months of pregnancy and 1, 3, 7, and 12 months postpartum. Geometric means of specific gravity-corrected phthalate concentrations were used as overall measures of prenatal exposure. Linear mixed effect models estimated associations between phthalate exposure and repeated perinatal bone SOS measures, adjusting for age, pre-pregnancy body mass index (BMI), education, parity, calcium supplementation, and month of pregnancy/postpartum. Effect modification by calcium supplementation and BMI were assessed in sensitivity analyses. An interquartile range increase in MEP and MiBP increased pregnancy phalange z-scores (ß: 0.11; 95%CI: 0.003, 0.31 and ß: 0.15; 95%CI: 0.00,0.42, respectively). Higher concentrations of several phthalate metabolites resulted in lower SOS measures among women who received calcium supplements (compared to placebo group) but higher SOS measures among women with a BMI≥25 (compared to BMI<25). These results suggest that phthalate exposure may interfere with bone remodeling during pregnancy, and that consideration of effect modifiers is paramount to fully understand the effects of environmental exposures on bone health.

Exposure to Phenols, Phthalates, and Parabens and Development of Metabolic Syndrome Among Mexican Women in Midlife.

Background: Evidence suggests exposure to endocrine-disrupting chemicals (EDCs) can influence Metabolic Syndrome (MetS) risk in adults, but it is unclear if EDCs impact women during midlife. We examined if EDCs measured in adult women were predictive of MetS and its components 9 years later. Methods: We measured urinary phthalate metabolites, phenols, and parabens collected in 2008 among 73 females from the ELEMENT study. MetS and its components (Abdominal Obesity, Hypertriglyceridemia, Cholesterolemia, Hypertension, and Hyperglycemia) were assessed in 2017. We regressed log-transformed EDC concentrations on MetS and MetS components using logistic regression, adjusting for age and physical activity. Results: At follow-up, the mean (SD) age was 46.6 (6.3) years; the prevalence of MetS was 34.3%. Sum of dibutyl phthalate metabolites (ΣDBP), monobenzyl phthalate (MBzP), and monoethyl phthalate (MEP) were associated with an increased odds of hypertriglyceridemia. 2,5-dichlorophenol (2,5 DCP) and 2,4-dichlorophenol (2,4 DCP) were associated with increased odds of hypertriglyceridemia. The odds of hypertension were 4.18 (95% CI: 0.98, 17.7, p < 0.10) and 3.77 (95% CI: 0.76, 18.62, p < 0.10) times higher for every IQR increase in MCOP and propyl paraben, respectively. The odds of hyperglycemia were 0.46 (95% CI: 0.18, 1.17 p < 0.10) times lower for every IQR increase in the sum of di-2-ethylhexyl phthalate metabolites (ΣDEHP), and the odds of abdominal obesity were 0.70 (95% CI: 0.40, 1.21, p < 0.10) lower for every IQR increase in the concentration of triclosan. Conclusion: We found EDCs measured in 2008 were marginally predictive of hypertriglyceridemia and hypertension 9 years later. Results suggest that lower exposure to certain toxicants was related to lower markers of metabolic risk among midlife women.

MERS-CoV and SARS-CoV infections in animals: a systematic review and meta-analysis of prevalence studies.

INTRODUCTION: Coronaviruses are zoonotic viruses that include human epidemic pathogens such as the Middle East Respiratory Syndrome virus (MERS-CoV), and the Severe Acute Respiratory Syndrome virus (SARS-CoV), among others (e.g., COVID-19, the recently emerging coronavirus disease). The role of animals as potential reservoirs for such pathogens remains an unanswered question. No systematic reviews have been published on this topic to date. METHODS: We performed a systematic literature review with meta-analysis, using three databases to assess MERS-CoV and SARS-CoV infection in animals and its diagnosis by serological and molecular tests. We performed a random-effects model meta-analysis to calculate the pooled prevalence and 95% confidence interval (95%CI). RESULTS: 6,493articles were retrieved (1960-2019). After screening by abstract/title, 50 articles were selected for full-text assessment. Of them, 42 were finally included for qualitative and quantitative analyses. From a total of 34 studies (n=20,896 animals), the pool prevalence by RT-PCR for MERS-CoV was 7.2% (95%CI 5.6-8.7%), with 97.3% occurring in camels, in which pool prevalence was 10.3% (95%CI 8.3-12.3). Qatar was the country with the highest MERS-CoV RT-PCR pool prevalence: 32.6% (95%CI 4.8-60.4%). From 5 studies and 2,618 animals, for SARS-CoV, the RT-PCR pool prevalence was 2.3% (95%CI 1.3-3.3). Of those, 38.35% were reported on bats, in which the pool prevalence was 14.1% (95%CI0.0-44.6%). DISCUSSION: A considerable proportion of infected animals tested positive, particularly by nucleic acid amplification tests (NAAT). This essential condition highlights the relevance of individual animals as reservoirs of MERS-CoV and SARS-CoV. In this meta-analysis, camels and bats were found to be positive by RT-PCR in over 10% of the cases for both; thus, suggesting their relevance in the maintenance of wild zoonotic transmission.

Bone mineral density and mammographic density in Mexican women.

BACKGROUND: Bone mineral density (BMD) is a putative marker for lifetime exposure to estrogen. Studies that have explored whether BMD is a determinant of mammographic density (MD) have observed inconsistent results. Therefore,we examined this potential association in a sample of women (n = 1,516) from the clinical sub-cohort in the Mexican teachers' cohort (n = 115,315). METHODS: We used multivariable linear regression to assess the association between quartiles of BMD and percent MD, as well as total dense and non-dense area of the breast, stratified by menopausal status. We also examined the associations by body mass index (BMI) (< 30 kg/m(2), ≥ 30 kg/m(2)). RESULTS: Overall, there was no association between BMD and MD among premenopausal women. However, when we stratified by BMI, there was a modest inverse association between BMD and percent MD (difference between extreme quartiles = -2.8, 95 % CI -5.9, 0.27, p trend = 0.04) among women with BMI < 30 kg/m(2), but a positive association among obese women (comparable difference = 5.1, 95 % CI 0.02, 10.1, p trend = 0.03;p interaction < 0.01). Among postmenopausal women, BMD and percent MD were positively associated after adjustment for BMI (p trend < 0.01). Postmenopausal women in the highest two quartiles of BMD had 4­5 % point higher percent MD compared to women in the lowest quartile. The association did not differ by BMI in postmenopausal women (p interaction = 0.76). CONCLUSION: Among obese premenopausal women as well as postmenopausal women, BMD was positively associated with percent MD. Among leaner premenopausal women, BMD and percent MD were modestly inversely associated. These findings support the hypothesis that cumulative exposure to estrogen (as measured by BMD) may influence MD.

Treatment options for osteoporosis and decision making criteria: 2009.

Osteoporosis is recognized worldwide as a major public health problem since many decades ago, mainly due to the cost of treatment for related fragility fractures. Fortunately, WHO has provided new strategies for identifying populations with a high ten-year fracture risk, which together with increasingly sensitive diagnostic methods make it feasible for decision makers in this field to design cost effective fracture prevention strategies. These strategies are aimed at preventing falls and improving bone strength and therefore diminishing the prevalence and incidence of new or recurrent osteoporosis related fractures. Herein we review the content of these new strategies, and the medical treatments available, as well as their efficacy in the Mexican context. Several countries are now reporting a decreasing incidence and prevalence of osteoporosis related fractures, after 30 years of clinical and population-based interventions. Mexico has several effective anti-fracture drug treatments available. Such drugs can be classified according to the mechanism that makes them effective as: 1) antidestructive or anticatabolic, 2) bone forming or anabolic, and 3) those with both actions or mixed drugs. The authors argue that treatment strategies that use drugs to strengthen bone tissue must assure normal mineralization of the already formed, remnant bone tissue and/or the newly formed bone tissue in order to encourage biochemical outcomes like formation of mature hydroxyapatite crystals with complete biomechanical and biochemical properties and therefore long term benefits. The present review includes some perspectives that will surely enhance osteoporosis management in the near future and which will bring about a decrease in the impact of the problems in Mexico.

Treatment options for osteoporosis and decision making criteria: 2009 / Alternativas de tratamiento para osteoporosis y criterios de decisión: 2009

Osteoporosis is recognized worldwide as a major public health problem since many decades ago, mainly due to the cost of treatment for related fragility fractures. Fortunately, WHO has provided new strategies for identifying populations with a high ten-year fracture risk, which together with increasingly sensitive diagnostic methods make it feasible for decision makers in this field to design cost effective fracture prevention strategies. These strategies are aimed at preventing falls and improving bone strength and therefore diminishing the prevalence and incidence of new or recurrent osteoporosis related fractures. Herein we review the content of these new strategies, and the medical treatments available, as well as their efficacy in the Mexican context. Several countries are now reporting a decreasing incidence and prevalence of osteoporosis related fractures, after 30 years of clinical and population-based interventions. Mexico has several effective anti-fracture drug treatments available. Such drugs can be classified according to the mechanism that makes them effective as: 1) antidestuctive or anticatabolic, 2) bone forming or anabolic, and 3) those with both actions or mixed drugs. The authors argue that treatment strategies that use drugs to strengthen bone tissue must assure normal mineralization of the already formed, remnant bone tissue and/or the newly formed bone tissue in order to encourage biochemical outcomes like formation of mature hydroxyapatite crystals with complete biomechanical and biochemical properties and therefore long term benefits. The present review includes some perspectives that will surely enhance osteoporosis management in the near future and which will bring about a decrease in the impact of the problems in Mexico.

La osteoporosis se reconoce mundialmente como un problema de salud pública desde hace muchas décadas, principalmente por el impacto global implícito en la atención de las fracturas que ocasiona. Afortunadamente, cada vez contamos con más y mejores estrategias desarrolladas por la OMS para identificar oportunamente a las personas en riesgo de sufrir una fractura; actualmente es posible definir este riesgo para los siguientes diez años. Lo cual, aunado a métodos cada vez más sensibles para establecer diagnósticos definitivos y opciones de tratamiento costo-eficaces para evitar caídas y disminuir significativamente la presentación de fracturas, permite a quien toma decisiones en este problema diseñar y poner en práctica planes de atención sustentados en la mejor evidencia científica, que son motivo de esta revisión. Varios países empiezan a informar un abatimiento del número de fracturas, después de haber establecido programas dirigidos a este fin desde hace 30 años. Contamos con medicamentos que han demostrado su eficacia para abatir la presentación de la primera fractura o de fracturas recurrentes de manera costo-eficiente, estos se pueden dividir para su estudio de acuerdo al mecanismo de acción que los vuelve eficaces. Así, aquellos que frenan la destrucción del tejido óseo se clasifican como anti-catabólicos, los que estimulan la formación de tejido óseo nuevo son anabólicos, los que tienen ambas acciones se conocen como de acción mixta. En todos los casos, el tejido remanente, previamente formado o en vías de destrucción, que se fortalecerá o el tejido de nueva formación, requieren medidas para garantizar que el proceso de mineralización suceda normalmente y se genere hidroxiapatita o un compuesto con características similares para que la eficiencia biomecánica del tejido realmente mejore a largo plazo. Esta revisión incluye algunas perspectivas que seguramente mejorarán nuestro manejo de la osteoporosis en el futuro inmediato y que...

Relationship of blood and bone lead to menopause and bone mineral density among middle-age women in Mexico City.

To describe the relationship of blood lead levels to menopause and bone lead levels, we conducted a cross-sectional study on 232 pre- or perimenopausal (PreM) and postmenopausal (PosM) women who participated in an osteoporosis-screening program in Mexico City during the first quarter of 1995. Information regarding reproductive characteristics and known risk factors for blood lead was obtained using a standard questionnaire by direct interview. The mean age of the population was 54.7 years (SD = 9.8), with a mean blood lead level of 9.2 microg/dL (SD = 4.7/dL) and a range from 2.1 to 32.1 microg/dL. After adjusting for age and bone lead levels, the mean blood lead level was 1.98 microg/dL higher in PosM women than in PreM women (p = 0.024). The increase in mean blood lead levels peaked during the second year of amenorrhea with a level (10.35 microg/dL) that was 3.51 microg/dL higher than that of PreM women. Other important predictors of blood lead levels were use of lead-glazed ceramics, schooling, trabecular bone lead, body mass index, time of living in Mexico City, and use of hormone replacement therapy. Bone density was not associated with blood lead levels. These results support the hypothesis that release of bone lead stores increases during menopause and constitutes an internal source of exposure possibly associated with health effects in women in menopause transition.

Vitamin D receptor polymorphisms and bone mineral density in Mexican women without osteoporosis.

Polymorphisms corresponding to Apa I, Bsm I, and Taq I restriction endonucleases at the vitamin D receptor (VDR) gene and bone mineral density (BMD) at lumbar spine (L2-L4) and proximal femur (neck, Ward's triangle and trochanteric region) sites were examined in a sample of 98 Mexican women (age 55 +/- 10 years). None of the subjects were pregnant or nursing and none had a previous diagnosis of osteoporosis. Polymorphisms were assessed by the restriction fragment length polymorphism - polymerase chain reaction (RFLP-PCR) technique. Alleles were denoted with capital letters for the absence of the RFLP site (A, B, or T) and with small letters for its presence (a, b, or t). BMD was assessed by dual energy X-ray absorptiometry (DXA). A structured, self-administrated questionnaire was used to obtain data on age, menopause, number of pregnancies, breast-feeding, fractures, exercise, smoking, alcohol, estrogens, calcium supplement, height, weight, and BMI. There were no differences between BMD at the skeletal sites and the genotypes disclosed by Apa I (Allele A = 0.43), Bsm I (Allele B = 0.26) and Taq I (Allele T = 0.76). The present study provides data for comparison with other studies to determine the possible value of genotyping VDR to predict predisposition for osteoporosis in Mexican or Mexican-American women. Am. J. Hum. Biol. 11:793-797, 1999. Copyright 1999 Wiley-Liss, Inc.

Critical appraisal of the estimation of body composition via two-, three-, and four-compartment models.

Withers RT, Laforgia J, Heymsfield SB. 1999. Critical appraisal of the estimation of body composition via two-, three-, and four-compartment models. Am J Hum Biol 11:175-185. Line 4 of Validity of assumptions should read, 1.565 g/cm(3) instead of, 1.555 g/cm(3). The authors regret this error.

Reproducibilidad de un cuestionario para el estudio del climaterio / Reproductibility of a questionnarire for studying menopause

Objetivo. Evaluar la reproductibilidad de un cuestionario sobre aspectos clínicos y epidemiológicos del climaterio. Material y métodos. La población de estudio (n=100) fueron usuarias de servicios de ginecología y obstetricia que asistieron a consulta por motivos relacionados con el climaterio y que aceptaron participar voluntariamente. Cada paciente seleccionada respondió el mismo cuestionario en dos oportunidades con un intervalo de 15 a 30 días entre la primera y segunda entrevista. Se utilizó el estadístico de Kappa para evaluar la concordancia de las variables categóricas. Para variables continuas se estímo la media de las diferencias y se obtuvieron los intervalos de confianza respectivo. Resultados. La concordancia fue alta (Kappa de 0.81-1.0) para variables categóricas, como el tipo de ciclos menstruales, tipo de menopausia, lactancia al seno materno, uso de estrógenos en menopausia y uso de anticonceptivos hormonales; fue moderada (Kappa de 0.7-0.8) para síntomas relacionados con la menopausia, como bochornos, sudoración, dispareunia, resequedad vaginal y disminución de la libido. La media de las diferencias entre la primera y segunda medición fue muy cercana a cero para las variables continuas, como edad de la menarquia, edad de la menopausia, tiempo de uso de estrógenos y tiempo de lactancia al seno materno. De igual forma, los intervalos de confianza al 95 por ciento de las diferencias de las medias de estas variables incluyeron siempre el valor nulo. El cuestionario incluyó otras características de la población, como las socio-demográficas, consumo de tabaco y frecuencia de consumo de alimentos, las cuales mostraron de moderada a alta concordancia (Kappa 0.7-1.0). Conclusiones. Los resultados del estudio permiten afirmar que el instrumento utilizado es altamente reproducible y será de utilidad para los estudios relacionados con el climaterio en la población mexicana

Objective. This study evaluated the reproducibility of a questionnaire concerned with the clinical and epidemiological aspects of menopause. Material and methods. The study population consisted of a hundred perimenopausal Mexican women seeking care at gynecology and obstetric health care services. Their participation was voluntary and they answered the same questionnaire two times with a 15-30 day lag between each application. Results. The Kappa coefficient was high (0.81-1.0) for categorical variables such as: type of menstrual cycles, type of menopause, breast-feeding, use of estrogen during menopause and use of hormonal contraceptives. The Kappa coefficient was moderate (0.7-0.8) for symptoms related to menopause such as hot flashes, sweating, painful coitus, vaginal dryness and a decrease in libido. Mean differences were calculated for continuous variables such as age at menarche, age at menopause, time using estrogen and the duration of breast feeding, the majority had a value of zero and 95% confidence intervals for these mean differences included the null value. The questionnaire also included other characteristics such as tobacco consumption and a short food frequency questionnaire, which showed high concordance (Kappa 0.7-1.0). Conclusions. The results of this study show that this questionnaire has a high level of reproducibility and can be useful as a research tool to explore menopause in Mexican women.

Osteopenia secundaria al uso crónico de glucocorticoides en artritis reumatoide

En la búsqueda retrospectiva realizada en 850 pacientes estudiados en la Clínica de Osteoporosis de Médica Sur (México, D.F.), se encontraron 60 casos (7 por ciento) en quienes la osteoporosis estaba relacionada con el uso crónico de corticoesteroides (ò 6 meses de tratamiento); de ellos, 5 (grupo I) correspondieron a artritis reumatoide (AR) definida (según criterios ARA). Se investigó en ellos: dosis acumulada de prednisona, aparición de fracturas, bioquímica de remodelado óseo y medición de la masa femoral y lumbar, comparando esta última con un grupo control de 5 personas sanas que acudieron a la clínica para evaluación preventiva (Grupo II). El grupo I mostró bioquímica de alto remodelamiento óseo y un 10-15 por ciento de osteopenia fémoro-lumbar, mayor al óptimo esperado, con significancia estadística cuando se hizo la comparación con el grupo control (p< 0.05). La dosis acumulada de prednisona igual a 6.6 gramos, si bien condicionó osteopenia, no predispuso a la aparición de fracturas. Es necesario evaluar bioquímica y densitométricamente a aquellos pacientes reumáticos sometidos a tratamiento crónico con corticoesteroides