Vitamin D deficiency in northern Vietnam: Prevalence, risk factors and associations with bone mineral density

Purpose: Vitamin D deficiency has been linked to osteoporosis and also to the risk of cancer, autoimmune disorders and cardiovascular diseases. This study sought to determine the prevalence of, and risk factors for, vitamin D deficiency and its relationship with bone mineral density (BMD) in a Vietnamese population. Methods: This cross-sectional study involved 269 women and 222 men aged 13-83. years, who were randomly selected from urban and rural areas in northern Vietnam. Serum concentrations of 25-hydroxy-vitamin D [25(OH)D] and parathyroid hormone (PTH) were measured by electrochemiluminescence immunoassay. Vitamin D deficiency was defined as serum 25(OH)D levels below 20. ng/mL. BMD was measured by dual X-ray absorptiometry. Results: The prevalence of vitamin D deficiency in women was 30%, almost two-fold higher than in men (16%). Significant predictors of vitamin D deficiency in women were urban residency (p < 0.01) and age less than 30. years (p < 0.01), whereas use of contraceptive pills was protective (p < 0.01). In men, winter season was the only significant predictor of vitamin D deficiency (p < 0.01). In multiple linear regression analysis, serum levels of 25(OH)D were positively associated with BMD in both women (p < 0.001) and men (p < 0.001). Conclusions: These data suggest that the prevalence of vitamin D deficiency is high in the Vietnamese population, and that part of this prevalence could be explained by low exposure to sunlight (urban residency and winter season). The high prevalence of vitamin D deficiency should raise the awareness of potentially important health issues such as osteoporosis within the Vietnamese society. © 2012 Elsevier Inc

Sex hormone levels as determinants of bone mineral density and osteoporosis in Vietnamese women and men

© 2014, The Japanese Society for Bone and Mineral Research and Springer Japan. This study sought to investigate the prevalence of osteoporosis and the role of sex hormone levels in the determination of bone mineral density (BMD) and osteoporosis in a Vietnamese population of women and men. The cross-sectional study involved 269 women and 222 men aged 13–83 years, who were randomly selected from urban and rural areas in northern Vietnam. Serum concentrations of estradiol and testosterone were analyzed, and BMD was measured by dual X-ray absorptiometry. We found that the prevalence of osteoporosis in postmenopausal women was 18, 17, and 37 % for the femoral neck, total hip, and lumbar spine, respectively. For men aged 50 years or older, the corresponding values were 8, 7, and 12 %. In men, the most important predictors of BMD for the femoral neck and total hip were age, body mass index, and serum levels of estradiol. For the BMD of the lumbar spine, testosterone also had a significant influence. Determinants of osteoporosis in men for the total hip and lumbar spine were age, weight, and serum concentrations of estradiol and testosterone. In postmenopausal women, age, weight, and residence (urban vs rural) were the most important predictors of BMD and osteoporosis. For all women (including those of reproductive age), serum levels of estradiol were also significant. These data suggest that the prevalence of osteoporosis in the Vietnamese population is high also in men, and that estradiol levels are essential for bone mass in both men and women. The results should have clinical implications and increase awareness of an important health issue within Vietnamese society

Development of a Good Clinical Practice inspection checklist to assess clinical trial sites in Vietnam

Background Assessing the capacity of a healthcare institution to conduct and manage clinical research studies is challenging, especially in developing countries where resources are limited. The objective of this study was to develop a practical and transparent tool for the Vietnam Ministry of Health (MOH) to assess institutions’ capacity to lead clinical trials in line with local and international regulations. Methods We reviewed the literature, relevant official international and national guidelines, regulations and checklists for clinical sites’ assessment to identify key indicators of clinical research capacity. We developed a Good Clinical Practice (GCP) inspection checklist consisting of a questionnaire with 30 key criteria, including 16 core criteria and 14 recommended criteria, related to four central aspects of clinical research management (ie, governance, operations, infrastructures and human resources). Following a detailed review and assessment by a panel of experts, sponsors and academic investigators, we assessed the checklist’s applicability in a pilot study involving 10 sites with various clinical research experiences. Results Independently of their clinical research experience, all participating institutions fulfilled most of the core criteria. In contrast, a significant variability was observed in the compliance to recommended capacity criteria, especially those related to governance (certifications and reporting) as well as operations (existence of a clinical research coordination unit or electronic trial management system). Conclusions A GCP inspection checklist was successfully developed to support the MOH in the assessment of institutions’ capacity to conduct clinical research. Additional efforts from all stakeholders are now warranted to provide local sites with sustainable capacity development resources that will further build up and harmonise Vietnamese clinical research settings

Low aglycone content in commercial soy drink products

The effectiveness of soy isoflavones to prevent bone loss in postmenopausal women is controversial. While consumption of soy in Vietnam is very high, we recently reported a prevalence of osteoporosis comparable to that of many Western populations. In the present study, we analyzed the isoflavone content of soy drink products commercially available in Vietnam and Sweden, and we also compared these products to "home-made" soy drink from beans of different origin. The amounts of the bioactive aglycones (daidzein, glycitein and genistein) and their glycoside isomers were quantified by high-pressure liquid chromatography. We found that the total isoflavone content was low in all preparations, around 70-100 mg/L and of this only 10% were bioactive aglycones. Of these, the Vietnamese products contained significantly lower levels of glycitein than the products from Sweden and "home-made" soy drink preparations. The results show that consumption of several liters of soy drink per day would be needed to achieve threshold levels for a protective effect on bone. There was no significant association between total protein and isoflavone content in different products. Accurate labeling of soy drink and other products eg of aglycone and glycoside content would allow health professionals and researchers to better explore the possible benefits of soy in dietary intervention studies

Tribological properties of liquid milks and dairy fat structured products

Milk lipids exist naturally in bovine and other animal milk, and they play an important role in the chemical & physical properties, sensory characteristics, including nutritional profile of dairy products. In order to understand food texture and sensory behaviour of dairy products especially those in liquid and semi-solid form, the tribometer has attracted a lot of interest since it provides better discrimination for sensory attribute related to fat globule and fat content. The aim of this chapter is to introduce the basic thribology methods for dairy products, summarize the tribological properties of dairy products (milk, yoghurt and cream cheese) and the studies related to the effect of milk fat globule (its size, distribution and population) on the lubrication properties and sensory of the final product

GCMC simulation of argon adsorption in wedge shaped mesopores of finite length

We have used Grand Canonical Monte Carlo simulation to study argon adsorption at 87 K in wedge shaped mesopores. The structural parameters, including mean pore size, wall length and wedge angle, were varied to investigate their effects on the size, shape and the position of the hysteresis loop. Although the effects of pore size have been studied previously, the wall length and wedge angle have received little attention. We find that the wedge angle can have a significant effect on the existence, position, size and shape of the hysteresis loop, while the wall length affects the adsorptive capacity associated with the loop and the behaviour of the isotherm beyond the loop. The results of this work have far-reaching consequences for the characterization of pore size distribution where it is commonly assumed, when constructing a kernel of local isotherms, that pore size is uniform, since even a small deviation from a constant pore width can shift the condensation and evaporation pressures significantly and thus lead to an incorrect estimation of pore size