[Apa1 VDR polymorphism and osteoporosis risk in postmenopausal Mexican women]. / Papel del polimorfismo Apa1 del gen VDR en el riesgo de osteoporosis en mujeres mexicanas posmenopáusicas.

AIM: To analyze the association between Apa1 VDR polymorphism and osteoporosis in Mexican mestizo postmenopausal women. METHODS: A cross-sectional study was conducted in 534 postmenopausal mestizo women from Mexico City to determine the association of the Apa1 Vitamin D Receptor gene polymorphism (rs7975232) with osteoporosis and osteoporosis plus fracture. Bone mineral density (BMD) was assessed using dual-energy X-ray absorptiometry. Genotyping was performed using real-time PCR with an allelic discrimination assay. RESULTS: The Apa1 allele frequencies were no different between groups. No association was found between Apa1 genotypes and osteoporosis (AA, OR: 1.08; 95% CI: 0.62-1.87; AC, OR: 0.70; 95% CI: 0.45-1.07). Similar results were obtained for osteoporosis plus fracture (AA, OR: 0.93; 95% CI: 0.50-1.71; AC, OR: 0.70; 95% CI 0.45-1.07). After adjusting for age, the result remained. CONCLUSION: These findings are in agreement with previous studies reporting no association of Apa1 VDR polymorphism with osteoporosis.

High prevalence of hypovitaminosis D in Mexicans aged 14 years and older and its correlation with parathyroid hormone.

UNLABELLED: A sample of 585 healthy subjects 14 years and older was studied to estimate the status of 25-hydroxyvitamin D (25(OH)D) and its correlation with parathyroid hormone in healthy Mexicans. In 43.6 % of the sample, levels of vitamin D were below 20 ng/mL and showed an inverse relationship with parathyroid hormone (PTH; p < 0.01). PURPOSE: The purpose of the present study was to estimate the status of 25-hydroxyvitamin D (25(OH)D) and its correlation with parathyroid hormone in healthy Mexicans. METHODS: A cross-sectional study of 585 healthy subjects 14 years and older was carried out. A questionnaire including all relevant demographics, medical history, and lifestyle factors was applied by trained interviewers. Morning fasting blood was collected in all subjects for estimation of 25(OH)D using liquid chromatography-tandem mass spectrometry and PTH hormone-intact molecule by RIA. RESULTS: Of the group of 585 subjects, 54.1 % were women; the sample was divided in three age groups (14-29, 30-50, and >51). Only 9.6 % of the total sample had levels of 25(OH)D above 30 ng/mL; 46.8 % were between 20 and 29 ng/mL, and 43.6 % were below 20 ng/mL. Regarding PTH, a three-phase model was identified using regression smoothing scatterplot (LOESS), with two thresholds of 25(OH)D of 19 and 29 ng/mL. Phase 1 (25(OH)D <19 ng/mL) showed an inverse relationship with PTH (p < 0.01); phases 2 and 3 showed no significant relationship. CONCLUSION: Our results show that 43.6 % of the Mexicans in this study have deficient concentration levels of vitamin D. The cutoff point of 20 ng/mL of 25(OH)D established by the Institute of Medicine has a biological and statistically significant relationship with PTH levels in the Mexican population, independently of principal confounding factors. Like many other countries, Mexico could be included in the global epidemic of hypovitaminosis D.

Physical activity and dark skin tone: protective factors against low bone mass in Mexican men.

A cross-sectional study was conducted on 268 Mexican men between the ages of 13 and 80 yr to evaluate the association of clinical factors related with bone mass. Men from high schools, universities, and retirement homes were invited to participate. Body mass index (BMI) was measured, and bone mineral density (BMD) was assessed using dual-energy X-ray absorptiometry for L1-L4 and total hip. Factors related to bone mass were assessed by questionnaire and analyzed using a logistic regression model. Demographic factors (age, education, and occupation), clinical data (BMI, skin tone, previous fracture, history of osteoporosis [OP], and history of fractures), and lifestyle variables (diet, physical activity, sun exposure, and smoking) were evaluated. Physical activity (≥ 60 min/5 times a week) reduced the risk for low BMD for age, osteopenia, and OP at the spine and total hip (odds ratio [OR]: 0.276; 95% confidence interval [CI]: 0.099-0.769; p=0.014; and OR: 0.184; 95% CI: 0.04-0.849; p=0.03, respectively). Dark skin tone was a protective factor, decreasing the risk by up to 70%. In this population of healthy Mexican men (aged 13-80 yr), dark skin and physical activity were protective factors against low bone mass.

Physical activity is a prognostic factor for bone mineral density in Mexican children

Background. Bone mass is similar in pre-pubertal girls and boys and double in both genders between the onset of puberty and early adult life. Exogenous factors such as nutrition and exercise contribute to the acquisition of bone mass. The objective of this project was to correlate calcium intake and level of physical activity with bone mineral density (BMD) in a sample of Mexican school-age children. Methods. Avalidated questionnaire was applied. The questionnaire included the following dimensions: (a) sociodemographic information, (b) type of sports and games that involved physical activity and hours per week dedicated to them, (c) inactivity measured by hours expended watching TV or playing videogames per day and (d) dietary calcium. After completing the questionnaire, the children were invited to have a BMD and total body composition assessment using a dual-energy x-ray absorptiometry (DXA) (Prodigy LUNAR). Results. In this cross-sectional study, 212 children were included, 48.6% were girls. The average total BMD in boys and girls was 0.8805 ± 0.056 g/cm² and 0.8788 ± 0.056g/cm², respectively, with significant differences in the groups of 10- and 12-year-old girls. An average of 10.9 ± 6.48 h of weekly physical activity was reported in boys and 10.6 ± 7.31 h in girls. Number of glasses of milk consumed was reported (1.7 ± 0.95 and 1.33 ± 0.91) per day in boys and girls, respectively. Differences in BMD in 10- and 12-year-old girls adjusted according to menarche were found. In the linear regression analysis, lean body mass was significantly associated with total, L2-L4, pelvis, and forearm BMD. Physical activity was significantly associated with leg BMD and age was associated with pelvis and forearm BMD. Conclusions. High lean body mass, menarche and regular intense physical activity are predictors for a higher BMD in school-age children in Mexico City.

Efficacy of a chlorhexidine-gluconate impregnated patch for prevention of catheter-related infections in pediatric patients: systematic review and meta-analysis

Background. Nosocomial infections are risk factors related to intrahospital mortality. Among other factors, these infections are strongly associated with invasive devices. In pediatric patients, the central venous catheter (CVC) is one of the most frequently related device-associated bloodstream infections. The aim of this study was to evaluate the efficacy and safety of a chlorhexidine-gluconate impregnated patch (CHGp) in reducing infections related to CVC in pediatric patients. Methods. We conducted a systematic review and meta-analysis. An electronic search of the literature (Medline, EMBASE, Lilacs and the Cochrane Library Plus) from 1966 to December 2010 was carried out for clinical trials comparing the CHGp vs. standard case management for prevention of catheter tip colonization (CTC); bloodstream infections (BSI) were retrieved. Results. Only two clinical trials were found with a total of 850 participants. Patients randomized to the CHGp group showed a lower incidence of CTC than the control group (14% vs. 25%), relative risk [RR]: 0.61, 95% confidence interval [CI 95% (0.45, 0.81)], p = 0.001), with a number needed to treat of 11. BSI showed a RR: 1.14, ([CI 95% (0.57, 2.28)], p = 0.71). Adverse events were found mainly in the CHGp group and were described as local skin reactions in 5.6% (RR 8.17 [95% CI: 1.19-56.14], p = 0.04). Local necrosis was present in only two infants of very low birth weight (0.48%). Conclusions. This meta-analysis demonstrated that the chlorhexidine-gluconate impregnated patch is effective in reducing CVC-related infections in the pediatric population. Serious adverse events are rare.

Impact of nutritional support on length of hospitalization and mortality in children after open heart surgery

Background. Malnutrition is a common cause of morbidity in children with congenital heart disease (CHD). The aim of this study was to assess the impact of malnutrition and nutritional support on the length of hospitalization and mortality at the Pediatric Intensive Care Unit (PICU) in children with CHD after undergoing surgery. Methods. Clinical records (2000-2008) of patients £3 years old with CHD who were admitted for surgery were evaluated for nutritional status, nutritional support, and risk factors. Mortality was evaluated from the beginning of surgery and during the patient's stay at the PICU. Long-term hospitalization was considered according to the length of hospital stay on percentile >50. A multiple logistic regression model was used. Results. Two hundred eighty nine patients were included. Factors related to mortality were malnutrition before surgery (OR 3.447; 95% CI 1.006-11.812, p = 0.049), early or delayed enteral nutrition (OR 0.007; 95% CI 0.000-0.097, p = 0.000, and OR 0.011; 95% CI 0.001-0.126, p = 0.000, respectively), and early parenteral nutrition (OR 0.032; 95% CI 0.002-0.452, p = 0.000) vs. no nutritional support. Factors related to long-term stay were malnutrition at birth (OR 2.772; 95% CI 1.282-5.995, p = 0.010) and delayed parenteral nutrition (OR 12.049; 95% CI 1.626-94.724, p = 0.015). Conclusion. Malnutrition at birth and before surgery increases length of stay and mortality of children after open heart surgery. Early nutritional support reduces length of stay and mortality.