[Show abstract][Hide abstract] ABSTRACT: Background:
Vitamin 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.
This 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.
The 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.
The 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.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study is to explore the impact of sleep duration on glycemic control in type 2 diabetes patients with untreated sleep-disordered breathing (SDB).
Ninety type 2 diabetes patients participated in the study. SDB was diagnosed using an overnight in-home monitoring device (WatchPAT200). Sleep duration was recorded by wrist actigraphy for 7 days. Medical records were reviewed for hemoglobin A1c (HbA1c) values.
Seventy-one patients (78.8 %) were diagnosed with SDB [apnea-hypopnea index (AHI) ≥ 5]. In patients with SDB, there was no significant relationship between AHI and glycemic control. In addition, oxygen desaturation index, minimum oxygen saturation, and time spent below oxygen saturation of 90 % were not significantly correlated with glycemic control. Sleep duration, however, was inversely correlated with HbA1c (r = -0.264, p 0.026). Multiple regression analysis adjusting for age, sex, body mass index, insulin use, diabetes duration, and AHI revealed that sleep duration was significantly associated with HbA1c (p = 0.005). Each hour reduction in sleep duration was associated with a 4.8 % increase in HbA1c of its original value (95 % CI 1.5-8.0).
In type 2 diabetes patients with untreated SDB, shorter sleep duration was independently associated with poorer glycemic control. Sleep duration optimization may lead to improved glycemic control in this population.
Sleep And Breathing 08/2015; DOI:10.1007/s11325-015-1243-6 · 2.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study is to investigate the insulin-like growth factor type 2 (IGF2R) gene and circulating soluble IGF2R in relation to type 2 diabetes (T2DM). Six hundred fifty-four subjects without history of diabetes were screened for diabetes by oral glucose tolerance test. In addition, 145 subjects with known diabetes were recruited from a local diabetes clinic. Circulating IGF2R levels were measured by ELISA method; plasma glucose was measured by colorimetric method; insulin levels were determined by chemiluminescent method; IGF2R gene rs416572 was genotyped using real-time PCR. The distributions of IGF2R genotypes were 69.2% CC, 27.8% CT, and 3.0% TT. The C allele was more commonly found in diabetes subjects, with a significant difference . In the presence of the T allele, circulating IGF2R levels were significantly lower . There was no significant difference in other potential confounders including age, sex, and BMI. Only circulating IGF2R, age, and BMI were independently associated with the degree of insulin resistance, as assessed by the HOMA model. It was found that age, sex, and BMI were associated with beta cell function. In conclusion, IGF2R gene polymorphism and circulating IGF2R are associated with T2DM.
Journal of Diabetes Research 04/2015; 2015:1-5. DOI:10.1155/2015/216383 · 2.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A high percentage have detectable C3 epimer of 25-hydroxyvitamin D3 (3-epi-25(OH)D3) in the population of Thai National Health Examination Survey IV.
C3 epimers of vitamin D have recently been shown to contribute significantly to 25-hydroxyvitamin D (25(OH)D) levels in an infant population. However, the findings in the general adult population are unclear. Therefore, the purpose of the present study is to determine the percentage of the C3 epimer of 25(OH)D (3-epi-25(OH)D) and its determinants in an adult population.
A subsample of 1148 sera randomly selected from the Thai National Health Examination Survey IV (2009) samples were measured for serum 25(OH)D2, 25(OH)D3, 3-epi-25(OH)D2, and 3-epi-25(OH)D3 by LC-MS/MS method. The relative 3-epimer contribution (%) was used to express the amount of 3-epimer-25(OH)D3 as a percentage of total 25(OH)D3 (the sum of 25(OH)D3, and 3-epi-25(OH)D3).
A high proportion of subjects had detectable 3-epi-25(OH)D3 that was <10 % of the total 25(OH)D levels. Since the level of total 25(OH)D2 is low, only a minority of subjects had detectable 3-epi-25(OH)D2. Multivariate analysis suggested that age, male gender, and rural residence were independently related to the 3-epi-25(OH)D3/total 25(OH)D3 ratio.
A high percentage of Thai adults had detectable 3-epi-25(OH)D3 that was <10 % of the total 25(OH)D levels. Age, gender, and living in a rural area were associated with the relative amount of 3-epi-25(OH)D3 to total 25(OH)D3.
Osteoporosis International 04/2015; 26(9). DOI:10.1007/s00198-015-3125-y · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective. The present study aimed to examine the association between serum BPA and hypertension and evaluated whether it was influenced by estradiol level. Methods. A subsample of 2588 sera randomly selected from the Thai National Health Examination Survey IV, 2009, was measured for serum BPA and estradiol. Logistic regression was used to examine the association controlling for age, sex, diabetes, body mass index, and estradiol level. Results. Compared with the lowest quartile, the adjusted odds ratio (AOR) of hypertension for the fourth quartile of serum BPA was 2.16 (95% CI 1.31, 3.56) in women and 1.44 (0.99, 2.09) in men. There was no interaction between serum BPA and estradiol level. For analysis using log(BPA) as a continuous variable, the AOR per unit change in log(BPA) was 1.09 (95% CI 1.02, 1.16). Among postmenopausal women, the AOR for the fourth quartile of BPA was 2.33 (95% CI 1.31, 4.15) and, for premenopausal women, it was 2.12 (95% CI 0.87, 5.19). Conclusion. Serum BPA was independently associated with hypertension in women and was not likely to be affected by estrogen; however, its mechanism related to blood pressure needs further investigation.
International Journal of Hypertension 02/2015; 2015:1-8. DOI:10.1155/2015/594189
[Show abstract][Hide abstract] ABSTRACT: Objectives:
Vitamin D deficiency is now being recognized as an emerging problem worldwide. Obesity has been found to be associated with lower serum 25-hydroxyvitamin D [25(OH)D] concentrations due to various mechanisms. There is increasing evidence showing the extraskeletal health benefit of vitamin D. Previous studies demonstrated the relationship between vitamin D and adiposity. However, the association between vitamin D status and skeletal muscle mass has not been established in healthy obese individuals in tropical countries. The aim of this cross-sectional study was to assess vitamin D status and its relationship to serum 25(OH)D concentrations and body composition, including skeletal muscle mass (SMM) and adiposity in healthy obese individuals without diabetes who live in Thailand, which is located near the equator.
We enrolled 163 obese Thai individuals (59.5% women) from the obesity clinic at the Ramathibodi Hospital, Mahidol University, in Bangkok, Thailand.
The prevalence of vitamin D deficiency (<20 ng/mL) and vitamin D inadequacy (<30 ng/mL) were 49 (30.1%) and 148 (90.8%), respectively. In all, 98% of the individuals with body mass index >35 kg/m(2) had vitamin D inadequacy. Serum 25(OH)D concentrations were negatively associated with percent body fat (%BF) (r = -0.23; P = 0.003). Moreover, vitamin D status was positively associated with SMM (r = 0.18; P = 0.03) and the association remained after controlling for body fat mass and age (P = 0.003). Interestingly, in the individuals with lowest tertile of %BF, multiple linear regression analysis revealed that the significant positive predictors of %SMM were vitamin D status and male sex; the negative predictor was the body mass index after adjusting for age and exercise duration.
Our study demonstrated the high prevalence of vitamin D deficiency in obese, Thai populations without diabetes. Vitamin D status was an independent predictor of %SMM of patients with lowest tertile of %BF. We speculated that adiposity might play a role in the relationship of vitamin D and SMM.
[Show abstract][Hide abstract] ABSTRACT: Objective: Vitamin D deficiency is related to increased risks of a number of diseases. To date, at least three candidate genes, i.e. vitamin D binding protein gene (GC), CYP2R1 and DHCR7/NADSYN1, have been associated with serum 25-hydroxyvitamin D (25(OH)D), but their influence on the prevalence of vitamin D deficiency in relation to other known risk factors has not been clearly defined.Methods: Subjects consisted of 4,476 individuals aged 14-93 years from the Thailand 4th National Health Examination Survey (2008-2009) and the Electricity Generating Authority of Thailand (EGAT) (2008) cohorts. The GC rs2282679 polymorphism on chromosome 4q12-q13 was genotyped by real-time PCR. Serum 25(OH)D was measured by liquid chromatography/tandem mass spectrometry. Vitamin D deficiency was defined as a 25(OH)D concentration lower than 20 ng/mL.Results: Data were expressed as mean ± SD. There were 2,747 (61.4%) males and 1,729 (38.6%) females in the study, with an average BMI of 23.7 ± 4.2 kg/m2 and a mean total 25(OH)D of 28.9 ± 9.0 ng/mL. Serum 25(OH)D levels decreased progressively with the presence of the C allele. Using multiple logistic regression analysis, vitamin D deficiency was significantly associated with the GC rs2282679 genotype (OR per C allele 1.80, 95% CI 1.57-2.01) independent of established risk factors for vitamin D deficiency including age, gender and body mass index.Conclusion: Vitamin D binding protein gene polymorphism is associated with lower 25(OH)D levels independent of age, gender and adiposity in Thais.
Endocrine Practice 11/2014; 1(-1):1-18. DOI:10.4158/EP14266.OR · 2.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Dear Editor,We read with interest the comments by Agilli et al.  on our study of causal relationship between the AHSG gene and BMD through fetuin-A and BMI: multiple mediation analysis . We had applied mediation analysis to assess causal effects of fetuin-A on BMD through BMI. A causal association diagram was constructed [3, 4] with mediator ln[fetuin-A] and BMI, and the outcome of interest of bone mineral density (BMD), and confounding factors including age, gender, smoking, recreation, and work/travel physical activities, see Fig. 1. Three equations were constructed adjusting for confounders in each pathway.Fig. 1Causal association diagram with AHSG (rs2248690) exposure, mediator 1n[fetuin-A] and body mass index (BMI), outcome bone mineral density (BMD), and confounding variable ZAgilli et al.  commented that our analyses were not adjusted for other factors that are also associated with fetuin-A level, e.g., inflammation and infection, rheumatoid arthritis, obesity, diabetes ...
Osteoporosis International 10/2014; 26(2). DOI:10.1007/s00198-014-2913-0 · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives. Sclerostin, an osteocyte-specific protein, has been found to be related to adiposity and glucose metabolism. Irisin, a myokine, can affect browning of white fat and influence glucose and energy homeostasis. Taken together, this suggests a probable network among fat, bone, and muscle that may influence health outcomes. The aims of this study were to investigate the relationship of circulating sclerostin and irisin and their association with adiposity (assessed by body mass index (BMI)). Materials/Methods. A cross-sectional study included 98 adults with impaired fasting glucose and/or impaired glucose tolerance. 75 gm OGTT was performed in all subjects. Fasting plasma samples were obtained for glycated hemoglobin, calcium, creatinine, serum sclerostin and irisin. Results. Circulating irisin and sclerostin were highly correlated (r = -0.4; P < 0.001). After controlling for age, gender, and BMI, irisin was significantly related to sclerostin (P < 0.001). Multivariate linear regression analysis demonstrated that circulating sclerostin (β = -0.45; P < 0.05) and irisin (β = -0.46; P < 0.05) were negatively associated with BMI, independent of age in males. In females, no relationship of sclerostin or irisin to BMI was found. Conclusions. Circulating irisin and sclerostin are highly related. Interventions targeting irisin could affect sclerostin and vice versa.
International Journal of Endocrinology 09/2014; 2014:261545. DOI:10.1155/2014/261545 · 1.95 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A number of healthy workers rarely exercise because of a lack of time or resources. Physical activity related to work and everyday travel may be more feasible, but evidence of its beneficial effect on bone health is scarce. We assessed if this form of physical activity was associated with higher bone mineral density (BMD) and stiffness index (SI) when adjusted for recreational physical activity, age, body mass index, smoking, alcohol consumption, education, and serum level of 25-hydroxyvitamin D. Healthy workers, aged 25-54 yr, of the Electricity Generating Authority of Thailand were surveyed. The outcomes were BMD (lumbar spine, femoral neck, and total hip) and calcaneal SI. Physical activity was estimated using the global physical activity questionnaire and considered active when >600 metabolic equivalent tasks (min). Of 2268 subjects, 74% were men. Active male subjects had significantly higher BMD at the femoral neck and total hip (p < 0.005). However, the association was not significant with male lumbar spine BMD, male SI, or any bone parameters in women (p > 0.05). In men, work and travel physical activity seems beneficial to male bone health; hence, it should be encouraged. Furthermore, smoking appeared harmful while moderate alcohol consumption was beneficial.
[Show abstract][Hide abstract] ABSTRACT: Context Thyroid hormone is critical for fetal neurodevelopment. Perchlorate and thiocyanate decrease thyroidal iodine uptake by competitively inhibiting the sodium/iodide symporter. It is clear that perchlorate and thiocyanate anions can influence thyroid function. However, as pollutants in the environment their impact is conflicting. Objective The objective was to determine the effects of environmental perchlorate and/or thiocyanate exposure on thyroid function in first trimester pregnant women. Design and Patients A cross-sectional study was conducted in 200 pregnant Thai women with a gestational age ≤14 weeks. Measures Urinary iodide, perchlorate, thiocyanate and serum thyroid function tests were measured. Results The women were aged 28.6±6.1 years and the mean gestational age was 9.6±2.7 weeks. Median urinary iodide, perchlorate, and thiocyanate concentrations were 153.5 μ g/l, 1.9 μ g/l, and 510.5 μ g/l, respectively. Using Spearman's rank correlation analyses, there were positive correlations between serum TSH and urine perchlorate/creatinine (r 0.20, p=0.005); and TSH and thiocyanate/creatinine (r 0.22, p=0.001). There were negative correlations between FT4 and perchlorate/creatinine (r-0.18, p=0.01); and FT4 and thiocyanate/creatinine (r-0.19, p=0.008). In multivariate analyses adjusting for log thiocyanate/creatinine, log iodide/creatinine, and gestational age, log perchlorate/creatinine was positively associated with log TSH (p=0.002), and inversely associated with log FT4 (p= 0.002). Log thiocyanate/creatinine was a significant positive predictor of log TSH (p=0.02) in women with urine iodide <100 μ g/l. Conclusions Low-level environmental exposure to perchlorate and thiocyanate is common in Thailand. Low-level exposure to perchlorate is positively associated with TSH and negatively associated with FT4 in first trimester pregnant women using multivariate analyses. In multivariate analyses, thiocyanate exposure is also positively associated with TSH in a subgroup of pregnant women with low iodine excretion.
The Journal of Clinical Endocrinology and Metabolism 04/2014; 99(7):jc20133986. DOI:10.1210/jc.2013-3986 · 6.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
Epidemiological studies of the association between exposure to bisphenol A (BPA) and diabetes have been inconsistent. The present study determined the levels of serum BPA in the Thai population and its association with hyperglycemia and diabetes.MethodsA total of 2,581 serum samples from the Thai National Health Examination Survey in 2009 were used to determine the levels of BPA. Impaired fasting glucose (IFG) was defined as fasting plasma glucose ≥100 and <126 mg/dL. Diabetes was defined by history of physician's diagnosis or fasting plasma glucose ≥126 mg/dL. Multinomial logistic regression was used to examine the association of serum BPA with IFG and diabetes.ResultsOf 2,581 samples tested, BPA was detected in a total of 2,135 (78.1%); among these, the overall geometric mean BPA was 0.34 ng/mL. Serum BPA level was significantly higher among those having diabetes or IFG compared with normoglycemia (0.52, 0.38 and 0.33 ng/mL, respectively, P <0.001). After adjusting for potential confounders, compared with the first quartile, the overall adjusted odds ratios of serum BPA concentration in the third and fourth quartiles for IFG were 1.72 (95% CI 1.19, 2.49) and 1.23 (95% CI 0.80, 1.90), respectively, and for diabetes 1.88 (95% CI 1.18, 2.99) and 1.83 (95% CI 1.12, 2.96), respectively, with a slightly stronger association among men than in women.Conclusions
Serum BPA was not associated with IFG, but was positively associated with diabetes in the Thai population. Further prospective studies to confirm the relationship are needed.
Journal of Diabetes 04/2014; 7(2). DOI:10.1111/1753-0407.12159 · 1.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Using mediation analysis, a causal relationship between the AHSG gene and bone mineral density (BMD) through fetuin-A and body mass index (BMI) mediators was suggested.
Fetuin-A, a multifunctional protein of hepatic origin, is associated with bone mineral density. It is unclear if this association is causal. This study aimed at clarification of this issue.
A cross-sectional study was conducted among 1,741 healthy workers from the Electricity Generating Authority of Thailand (EGAT) cohort. The alpha-2-Heremans-Schmid glycoprotein (AHSG) rs2248690 gene was genotyped. Three mediation models were constructed using seemingly unrelated regression analysis. First, the ln[fetuin-A] group was regressed on the AHSG gene. Second, the BMI group was regressed on the AHSG gene and the ln[fetuin-A] group. Finally, the BMD model was constructed by fitting BMD on two mediators (ln[fetuin-A] and BMI) and the independent AHSG variable. All three analyses were adjusted for confounders.
The prevalence of the minor T allele for the AHSG locus was 15.2 %. The AHSG locus was highly related to serum fetuin-A levels (P < 0.001). Multiple mediation analyses showed that AHSG was significantly associated with BMD through the ln[fetuin-A] and BMI pathway, with beta coefficients of 0.0060 (95 % CI 0.0038, 0.0083) and 0.0030 (95 % CI 0.0020, 0.0045) at the total hip and lumbar spine, respectively. About 27.3 and 26.0 % of total genetic effects on hip and spine BMD, respectively, were explained by the mediation effects of fetuin-A and BMI.
Our study suggested evidence of a causal relationship between the AHSG gene and BMD through fetuin-A and BMI mediators.
Osteoporosis International 02/2014; 25(5). DOI:10.1007/s00198-014-2634-4 · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A number of healthy workers rarely exercise because of a lack of time or resources. Physical activity related to work and everyday travel may be more feasible, but evidence of its beneficial effect on bone health is scarce. We assessed if this form of physical activity was associated with higher bone mineral density (BMD) and stiffness index (SI) when adjusted for recreational physical activity, age, body mass index, smoking, alcohol consumption, education, and serum level of 25-hydroxyvitamin D. Healthy workers, aged 25–54 yr, of the Electricity Generating Authority of Thailand were surveyed. The outcomes were BMD (lumbar spine, femoral neck, and total hip) and calcaneal SI. Physical activity was estimated using the global physical activity questionnaire and considered active when >600 metabolic equivalent tasks (min). Of 2268 subjects, 74% were men. Active male subjects had significantly higher BMD at the femoral neck and total hip (p < 0.005). However, the association was not significant with male lumbar spine BMD, male SI, or any bone parameters in women (p > 0.05). In men, work and travel physical activity seems beneficial to male bone health; hence, it should be encouraged. Furthermore, smoking appeared harmful while moderate alcohol consumption was beneficial.
Journal of Clinical Densitometry 01/2014; · 2.03 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Existing inconclusive data on the relationship between vitamin D status and human glucose homeostasis suggests that other factors, such as adiposity, might influence this relationship. The present study aimed to investigate the association between 25-hydroxyvitamin D [25(OH)D] and fasting plasma glucose (FPG) in the context of different amounts of total body fat in a healthy community-based population in Bangkok, Thailand.
This cross-sectional study was a part of health survey of employees of the Electricity Generating Authority of Thailand. There were 1,990 healthy subjects (72.8% male) in this study. Total body fat was measured by bioelectrical impedance analysis. Total serum 25(OH)D, 25(OH)D3 and 25(OH)D2 were measured by LC-MS/MS.
Age (r = 0.134, p < 0.001) and FPG (r = 0.089, p < 0.001) were positively correlated with 25(OH)D levels, while total body fat mass (r = -0.049,p = 0.03) were negatively correlated with 25(OH)D levels. 25(OH)D levels were higher in males than in females (65.0 +/- 0.5 vs. 53.5 +/- 0.5 nmol/L, p < 0.001). After controlling for age, gender and total fat mass, FPG was no longer correlated with 25(OH)D. However, when subjects were stratified according to fat-free mass tertiles and controlled for age and gender, there was a positive, although weak association between 25(OH)D levels and FPG (p = 0.01) in the lowest tertile.
We therefore speculate that adiposity might influence the relationship of vitamin D status and FPG.