Relation of Bone Mineral Density to Vitamin D Receptor Gene Polymorphism and Lifestyle Factors in Japanese Female Workers Aged 22-44 Years: A Cross-Sectional Study

Bone mineral density (BMD) reflects both genetic and lifestyle factors. The aim of this cross-sectional study was to investigate the influence of vitamin D receptor (VDR) gene polymorphism and lifestyle factors on BMD in premenopausal female workers. The subjects were 162 premenopausal female employees aged 22-44 y who worked at a large-scale integrated manufacturing facility in Japan. BMD was measured at the nondominant radius by dual energy X-ray absorptiometry. Lifestyle information was obtained by a questionnaire at the same time and genomic DNA was isolated from peripheral leukocytes. BMD was positively correlated with age, weight, and body mass index (BMI). The genotype frequencies of VDR gene polymorphism detected by TaqI analysis were 77.2, 22.8, and 0.0% for TT, Tt, and tt, respectively. Analysis of covariance with adjustment for age and BMI showed that the mean BMD was significantly lower in subjects with the Tt genotype than in those with the TT genotype. Subjects who drank alcohol also showed a significantly lower BMD if they had the Tt genotype than if they had the TT genotype. According to multiple linear regression analysis, the independent determinants of BMD were age, BMI, and VDR gene polymorphism. Our data show that BMD is negatively correlated with the Tt genotype of the VDR gene, but positively correlated with age and BMI. These findings suggest that analysis of VDR gene polymorphism may be useful for identifying individuals who are susceptible to osteoporosis so that early preventive measures can be provided

Effects of air pollution and seasons on health-related quality of life of Mongolian adults living in Ulaanbaatar: cross-sectional studies

Abstract Background Ulaanbaatar, Mongolia, is known as severely air-polluted city in the world due to increased coal consumption in the cold season. The health effects of air pollution in Mongolia such as mortality, morbidity and symptoms have been previously reported. However, the concept of health-related quality of life (HR-QoL), which refers to the individual’s perception of well-being, should also be included as an adverse health outcome of air pollution. Methods Surveys on the Mongolian people living in Ulaanbaatar were performed in the warm and cold seasons. Self-completed questionnaires on the subjects’ HR-QoL, data from health checkups and pulmonary function tests by respiratory specialists were collected for Mongolian adults aged 40–79 years (n = 666). Ambient PM2.5 and PM10 were concurrently sampled and the components were analyzed to estimate the source of air pollution. Results In logistic regression analyses, respiratory symptoms and smoke-rich fuels were associated with reduced HR-QoL (> 50th percentile vs. ≤ 50th percentile). PM 2.5 levels were much higher in the cold season (median 86.4 μg/m3 (IQR: 58.7–121.0)) than in the warm season (12.2 μg/m3 (8.9–21.2). The receptor model revealed that the high PM2.5 concentration in the cold season could be attributed to solid fuel combustion. The difference in HR-QoL between subjects with and without ventilatory impairment was assessed after the stratification of the subjects by season and household fuel type. There were no significant differences in HR-QoL between subjects with and without ventilatory impairment regardless of household fuel type in the warm season. In contrast, subjects with ventilatory impairment who used smoke-rich fuel in the cold season had a significantly lower HR-QoL. Conclusions Our study showed that air pollution in Ulaanbaatar worsened in the cold season and was estimated to be contributed by solid fuel combustion. Various aspects of HR-QoL in subjects with ventilatory impairment using smoke-rich fuels deteriorated only in the cold season while those with normal lung function did not. These results suggest that countermeasures or interventions by the policymakers to reduce coal usage would improve HR-QoL of the residents of Ulaanbaatar, especially for those with ventilatory impairment in the winter months

Prevalence and risk factors of airflow limitation in a Mongolian population in Ulaanbaatar: Cross-sectional studies

<div><p>The burden of chronic obstructive pulmonary disease (COPD) is expected to increase in the coming decades. In Ulaanbaatar, Mongolia, air pollution, which has been suggested to correlate with COPD, is a growing concern. However, the COPD prevalence in Ulaanbaatar is currently unknown. This study aims to estimate the prevalence of airflow limitation and investigate the association between airflow limitation and putative risk factors in the Mongolian population. Five cross-sectional studies were carried out in Ulaanbaatar. Administration of a self-completed questionnaire, body measurements, and medical examination including spirometry were performed in 746 subjects aged 40 to 79 years living in Ulaanbaatar. The age- and sex-standardized prevalence of airflow limitation in Ulaanbaatar varied widely from 4.0 to 10.9% depending on the criteria for asthma. Age, body mass index (BMI), and smoking habit were independent predictors for airflow limitation while residential area and household fuel type were not significant. In conclusion, prevalence of putative COPD was 10.0% when subjects with physician-diagnosed asthma were excluded from COPD. Older age, lower BMI, and current smoking status were putative risk factors for airflow limitation. This prevalence was consistent with reports from Asian countries.</p></div

Characteristics of the study subjects with valid spirometry.

<p>Characteristics of the study subjects with valid spirometry.</p

Additional file 1: Table S1. of Effects of air pollution and seasons on health-related quality of life of Mongolian adults living in Ulaanbaatar: cross-sectional studies

Factors associated with HR-QoL of Mongolian subjects. (DOCX 44 KB

A large cohort study concerning age-dependent impacts of anthropometric variables on spirometric parameters in nonsmoking healthy adults.

BACKGROUNDS: Although height (H) has been considered the principal anthropometric variable governing lung function, the age-dependent differences in its influences on determining spirometric parameters (SPs) have not been conclusively investigated. Moreover, there has been no study centered on age-dependent effects of other anthropometric variables, including body weight (BW) and body fat mass (BFM) on SPs. In addition, the age-dependent influences of these anthropometric variables are anticipated to differ quantitatively between male and female participants. METHODS: A total of 16,919 nonsmoking healthy Japanese adults (men: 6,116, women: 10,803) were partitioned into six groups stratified by gender and age at intervals of 20-years: young-, middle-, and advanced-age groups of either gender. Using a model in which a SP was described by a logarithmic additive function of age, H, BW, and BFM, we determined the partial regression coefficients of the respective anthropometric variables to predict the reference means of SPs, including FVC, FEV1, FEV1/FVC, PEF, FEF50, and FEF75, in the six groups. RESULTS/DISCUSSION: Although the impact of H on FVC and FEV1 was relatively homogeneous irrespective of gender and age, its homogeneity faded for flow parameters, particularly in the female middle- and advanced-age groups, indicating that the age-dependent contribution of H to SPs was enhanced more in women. The impact of BW on SPs differed depending on age, and this effect was also more conspicuous for female participants. H and BW generally exerted positive effects on SPs, whereas BFM had negative effects. Opposite effects of BW and BFM were observed in the female middle-age group in particular. CONCLUSIONS: The effects of anthropometric variables on spirometric parameters are highly age-dependent, particularly in women, leading to the conclusion that the assumption of age-independent, constant partial regression coefficients of anthropometric variables while predicting the reference mean of a certain spirometric parameter may result in substantial errors

Factors affecting the prevalence of airflow limitation.

<p>Factors affecting the prevalence of airflow limitation.</p