Wipa Ratanachaiwong

Serum Uric Acid Levels in Relation to Bone-Related Phenotypes in Men and Women

Serum uric acid levels have recently been found to be associated with bone mineral density (BMD) in elderly males. The purpose of the present study was to investigate the relationship between bone-related phenotypes and serum uric acid levels in young and middle-aged males and females. Subjects consisted of 1320 males and 485 females aged 25-54 yr. Bone densitometry and quantitative ultrasonometry (QUS) were performed on each subject. Serum uric acid and biochemical markers of bone turnover were measured in fasting serum samples. When adjusted for covariates including age, body weight, and serum creatinine in multiple linear regression models, it was found that there was a positive association between uric acid levels and BMD in males at the lumbar spine (p < 0.05). The association between uric acid levels and BMD was found in females after controlling for age, body weight, and serum creatinine at the femoral neck, but in the opposite direction (p < 0.05). Uric acid levels were related to the stiffness index (SI) as assessed by QUS in males, independent of age, body weight, and serum creatinine (p < 0.05). No association between uric acid and SI in females was found. The present study demonstrated a positive association in males between serum uric acid levels and BMD, and SI from QUS, suggesting a beneficial influence of uric acid on both the quantity and quality of bone in males.

Association between Inflammatory Marker, Environmental Lead Exposure, and Glutathione S-Transferase Gene

A number of studies suggested that lead is related to the induction of oxidative stress, and alteration of immune response. In addition, modifying these toxic effects varied partly by GST polymorphism. The objectives of this study were to assess the association between the lead-induced alteration in serum hs-CRP, with GSTM1, GSTT1, and GSTP1 Val105Ile genetic variations and the health consequence from environmental lead exposure. The 924 blood samples were analyzed for blood lead, CRP, and genotyping of three genes with real-time PCR. Means of blood lead and serum hs-CRP were 5.45 μg/dL and 2.07 mg/L. Both CRP and systolic blood pressure levels were significantly higher for individuals with blood lead in quartile 4 (6.48–24.63 μg/dL) compared with those in quartile 1 (1.23–3.47 μg/dL, P < 0.01). In particular, in men with blood lead >6.47 μg/dL the adjusted odds ratio (OR) of CRP levels for individuals with GSTP1 variants allele, GSTM1 null, GSTT1 null, double-null GSTM1, and GSTT1 compared with wild-type allele was 1.46 (95% CI; 1.05–2.20), 1.32 (95% CI; 1.03–1.69), 1.65 (95% CI; 1.17–2.35), and 1.98 (95% CI; 1.47–2.55), respectively. Our findings suggested that lead exposure is associated with adverse changes in inflammatory marker and SBP. GST polymorphisms are among the genetic determinants related to lead-induced inflammatory response.

Cohort Profile: The electricity generating authority of Thailand study

During the past 30–40 years, there has been a tremendous increase in the prevalence of cardiovascular disease (CVD), especially in developing countries. The change from an agricultural to an industrial society, and the introduction of new technology, make people less likely to engage in physical activity and more likely to adopt a sedentary lifestyle. Modern medicine has markedly reduced the mortality from infectious disease and has improved human longevity, consequently leading to more deaths from chronic diseases, particularly cancer and CVD. Thailand, a mediumsized middle-income country, is one of those nations that is encountering this epidemiological transition and is anticipated to experience much greater increases in CVD compared with Western countries over the next 20 years. Observational studies in Western populations suggest that the well-established risk factors for CVD (obesity, diabetes mellitus, elevated blood pressure, dyslipidemia and cigarette smoking) account for most of the attributable risk for CVD. But the manifestations of CVD and prevalence of its risk factors are often different among Western and Asian populations. For instance, stroke is much more common among many Asian populations compared with the USA or European Union. Most CVD events are potentially preventable through modification of risk factors. To prioritize the preventive measures for maximum benefit, and influence change, a clear understanding of the attribution of risk factors in the local environment is needed. Consequently, following the model of the Framingham study, the first cohort study of chronic disease in Thailand was set up by a group of cardiologists at Ramathibodi Hospital, Bangkok, in 1985. Their basic aim was to examine the effects of cardiovascular risk factors, as identified by Framingham and other studies, on health in the Thai population, specifically to see if the same risk factors worked in the same way as elsewhere. Due to issues with contacting participants in a general population setting within Thailand, it was decided to site this study within an occupational workforce. Initial funding was provided by Mahidol University, the Thai Heart Association and the Electricity Generating Authority of Thailand (EGAT) corporation. Later, the National Research Council, Thailand Research Fund and Praman Chansue Foundation became major funders.

Causal relationship between body mass index and fetuin-A level in the asian population: a bidirectional mendelian randomization study

Fetuin‐A is associated with body mass index (BMI) as well as components of the metabolic syndrome. However, it is unclear if fetuin‐A affects BMI or the other way around. We therefore assessed the causal association between fetuin‐A and BMI or vice versa, utilizing a bidirectional Mendelian randomization approach.

Associations Between Serum Lipids and Causes of Mortality in a Cohort of 3499 Urban Thais: The Electricity Generating Authority of Thailand (EGAT) Study

The association between serum lipids and mortality has not previously been established in Thailand. Baseline data from the Electricity Generating Authority of Thailand (EGAT) cohort study, plus a resurvey of the cohort 15 years later were analyzed. Participants were employees of EGAT: 2702 men and 797 women. Total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), and triglycerides (TG) were taken as predictive variables; age, sex, hypertension, diabetes, cigarette smoking, alcohol drinking, and body mass index were taken as confounders. Dependent variables were all-causes and specific causes of mortality over 17 years of follow-up. The major cause of death among men was cardiovascular disease (CVD); among women, it was cancer. Relative risks (RR) for specific causes of death, for a mmol/L increase in each lipid, were estimated after adjustment for confounding factors using Cox proportional hazards regression. TC and LDL-C were negatively associated with liver cirrhosis mortality, although it was likely that the low cholesterol concentration was a consequence of the disease. HDL-C was negatively associated with CVD mortality (RR = 0.59; 95% confidence interval [CI], 0.39-0.93), coronary heart disease (CHD) mortality (RR = 0.36; 95% CI, 0.17-0.75) and all cause-mortality (RR = 0.68; 95% CI, 0.54-0.87). TG was not associated with mortality. HDL-C is an important risk factor for CVD in middle-class urban Thais. Health promotion programs to improve lipid profiles, such as effective exercise campaigns and dietary advice, are required to increase HDL-C and to help prevent CVD and premature death in Thailand.

Association between cigarette smoking and the intraoral distribution of periodontal disease in Thai men over 50 years of age

AIM This study aimed to investigate the effects of cigarette smoking on periodontal conditions in specific tooth regions of older Thai men. METHODS There were 272 current smokers, 714 former smokers, and 477 non-smokers enrolled in the present study. Differences between groups in the mean probing depth or attachment loss were compared using ancova. The relationship between smoking exposure or cessation duration and periodontal conditions was examined using linear trend analysis. RESULTS Smokers had deeper pockets and attachment loss than non-smokers. The greatest differences between smokers and non-smokers were observed in the maxillary posterior palatal region, where current smokers had 0.88 mm greater attachment loss than non-smokers, compared to 0.36-0.60 mm observed in other tooth regions. Among the current smokers, there was a trend towards an increase in attachment loss with increasing smoking exposure in the maxillary posterior regions. However, it was not statistically significant. Among the former smokers, a better periodontal condition was observed, depending on the length of time since smoking cessation; this was most pronounced in the maxillary posterior palatal region. CONCLUSIONS The palatal site of maxillary posterior teeth was the area most affected by cigarette smoke. The results suggest a possible local effect of smoking in addition to its systemic effects.

Causal inference of the effect of adiposity on bone mineral density in adults

The causal effect of adipose tissue on bone mass and the direction of its net influence have not been directly assessed in adult humans. Using the Mendelian randomization analysis, we assessed the causality of adiposity in measurements of bone mass in adult males and females.

Relationship of vitamin D status and bone mass according to vitamin D-binding protein genotypes

BackgroundVitamin D-binding protein (DBP) may alter the biological activity of total 25-hydroxyvitamin D [25(OH)D]; this could influence on the effects of vitamin D in relation to bone mineral density (BMD) and fractures. Emerging data suggest that fetuin-A may be involved in bone metabolism. We aimed to investigate the influence of DBP gene polymorphism on the relationship of vitamin D status and fetuin-A levels to BMD and bone markers.MethodsThis cross-sectional study was part of a health survey of employees of the Electricity Generating Authority of Thailand (1,734 healthy subjects, 72% male). Fasting blood samples were assayed for 25(OH)D, fetuin-A, N-terminal propeptides of type 1 procollagen (P1NP), C-terminal cross-linking telopeptides of type I collagen (CTx-I), and DBP rs2282679 genotypes. L1–L4 lumbar spine and femoral BMD were measured using dual-energy X-ray absorptiometry.ResultsThe DBP rs2282679 genotype distribution conformed to the Hardy–Weinberg equilibrium. There were no correlations between 25(OH)D levels and BMD and bone markers. But a trend of positive correlation was observed for the DBP genotypes with total hip BMD, and for the interaction between 25(OH)D and DBP genotypes with BMD at all femoral sites. We further analyzed data according to DBP genotypes. Only in subjects with the AA (common) genotype, 25(OH)D levels were positively related to BMD and bone markers, while fetuin-A was negatively related to total hip BMD, independently of age, gender and BMI.ConclusionsThe interaction between vitamin D status, as measured by circulating 25(OH)D and DBP rs2282679 genotypes, modified the association between 25(OH)D and BMD and bone markers. Differences in DBP genotypes additionally influenced the correlation of fetuin-A levels with femoral BMD.

Potential causal associations between vitamin D and uric acid: Bidirectional mediation analysis.

Vitamin D deficiency, a major public-health worldwide, is associated with hyperuricemia but casual association is questioned. The study was conducted to determine potential causal associations between 25-hydroxy vitamin D (25(OH)D) and uric acid (UA). A cross-sectional study of the Electricity Generating Authority of Thailand (EGAT3) cohort was conducted. Subjects (n = 2,288) were used to genotype the group-specific component (GC) at rs2282679 and ATP-binding cassette subfamily G member 2 (ABCG2) at rs2231142. Mediation analysis with 1000-replication bootstrap was applied to construct causal pathways i.e., rs2282679 → 25(OH)D → UA and rs2231142 → UA → 25(OH)D: The mediator (i.e., 25(OH)D and UA) was firstly regressed on the studied gene (i.e., rs2282679 and rs2231142). A potential causal effect of C allele on UA through 25(OH)D was −0.0236 (95% CI: −0.0411, −0.0058), indicating every minor C allele resulted in decreasing the 25(OH)D and then significantly decreased the UA by 0.0236 unit. For the second pathway, the mediation effect was 0.0806 (95% CI: 0.0107, 0.1628); every T allele copy for rs2231142 increased UA and thus increased 25(OH)D by 0.0806 unit. Our study suggested potential causal associations between the GC gene and UA through the 25(OH)D mediator, and the ABCG2 and the 25(OH)D through the UA mediator but the absolute effects are very clinically small.

Blood pressure, cholesterol and cardiovascular disease in Thailand

Background Although associations between risk factors such as hypertension and hypercholesterolaemia, and cardiovascular disease (CVD) are well-established it is not known to what extent these associations are similar in people from different ethnicities or regions. This study aims to measure the contributions of systolic blood pressure (SBP) and total cholesterol (TC) to ischaemic heart disease (IHD) and stroke in the Thai population. Methods and results Data from a Thai cohort study were used for analyses. Participants were 2702 males and 797 females aged between 35 and 54 years at the start of study in 1985. Cox Proportional Hazards Models were used to assess RRs of IHD or stroke associated with SBP or TC stratified by age at the time of an event of 30–44, 45–59, and 60–69 years. During the 17 years of follow-up, 96 IHD (40 non-fatal, 56 fatal), 69 strokes (32 non-fatal and 37 fatal) occurred. Each 1 mmol/l increase in TC was associated with a fivefold increase in IHD risk in people aged 30–44 years, but not with significant increase in stroke risk in any age group. The RRs (95% CIs) of IHD per 10 mm Hg increase in SBP were 1.31 (1.04 to 1.64) and 1.46 (1.15 to 1.87), and of stroke, 1.40 (1.10 to 1.79) and 1.85 (1.40 to 2.45) in people aged 45–59 and 60–69 years, respectively. Conclusions Increases in IHD and stroke risks associated with these two risk factors observed in Thailand are comparable with those in the Asia Pacific and western populations.