Suwannee Chanprasertyotin

Diagnostic criteria for diabetes mellitus and other categories of glucose intolerance: 1997 criteria by the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus (ADA), 1998 WHO Consultation criteria, and 1985 WHO criteria

To compare 1997 ADA diagnostic criteria for diabetes mellitus and other categories of glucose intolerance/1998 WHO Consultation criteria versus 1985 WHO criteria, we analyzed data from a 75-g oral glucose tolerance test (OGTT) performed on 1051 high-risk subjects without medical history of diabetes at Diabetes Screening Clinic, Ramathibodi Hospital, Thailand. There were 372 males and 679 females, aged (mean +/- S.D.) = 50.3 +/- 12.55 years, BMI = 25.62 +/- 4.39 kg/m2. If fasting plasma glucose (FPG) was used as recently recommended then 54.1, 20.4, and 25.5% of cases were classified as normal, impaired fasting glucose (IFG), and diabetic, respectively. In diagnosing diabetes using a full OGTT based on the 1985 WHO criteria as the reference test, FPG > or = 7 mmol/l had a sensitivity of 57.7%, specificity of 97.4%, positive predictive value of 94.0%, and negative predictive value of 76.4%; 53.7% of subjects with IFG had 2-h plasma glucose > or = 11.1 mmol/l. The 1997 ADA/1998 WHO Consultation criteria and 1985 WHO criteria for a full OGTT yield similar overall results. FPG ( > or = 7 mmol/l) was not sensitive for diagnosing diabetes. Moreover, about half of the subjects with IFG were actually diabetic. Therefore, OGTT remains a valuable test in diagnosing diabetes and classifying various categories of glucose intolerance.

Changes in circulating 25-hydroxyvitamin D according to vitamin D binding protein genotypes after vitamin D3 or D2supplementation

BackgroundIt is not known whether genetic variation in the vitamin D binding protein (DBP) influences 25-hydroxyvitamin D levels [25(OH)D] after vitamin D supplementation. We aimed to investigate the changes of total 25(OH)D, 25(OH)D3 and 25(OH)D2 in a Thai cohort, according to type of vitamin D supplement (vitamin D3 or D2) and DBP genotype, after receiving vitamin D3 or D2 for 3 months.MethodsThirty-nine healthy subjects completed the study. All subjects received 400 IU of either vitamin D3 or D2, plus a calcium supplement, every day for 3 months. Total serum 25(OH)D, 25(OH)D3 and 25(OH)D2 were measured by LC-MS/MS. Individual genotyping of rs4588 in the DBP gene was performed using real-time PCR.ResultsVitamin D3 supplementation of 400 IU/d increased 25(OH)D3 significantly (+16.2 ± 4.2 nmol/L, p <0.001). Vitamin D2 (400 IU/d) caused increased 25(OH)D2 levels (+22.0 ± 2.11 nmol/L, p <0.001), together with a decrease of 25(OH)D3 (−14.2 ± 2.0 nmol/L, p <0.001). At 3 month, subjects in vitamin D3 group tended to have higher total 25(OH)D levels than those in vitamin D2 (67.8 ± 3.9 vs. 61.0 ± 3.0 nmol/L; p = 0.08). Subjects were then classified into two subgroups: homozygous for the DBP rs4588 C allele (CC), and the rest (CA or AA). With D3 supplementation, subjects with CA or AA alleles had significantly less increase in 25(OH)D3 and total 25(OH)D when compared with those with the CC allele. However, no difference was found when the supplement was vitamin D2.ConclusionGenetic variation in DBP (rs4588 SNP) influences responsiveness to vitamin D3 but not vitamin D2.

A genome-wide association study identifies novel susceptibility genetic variation for thyrotoxic hypokalemic periodic paralysis

Several lines of evidence have pointed out that genetic components have roles in thyrotoxic hypokalemic periodic paralysis (TTPP). In this study, for the first time we performed genome-wide association study (GWAS) in male hyperthyroid subjects in order to identify genetic loci conferring susceptibility to TTPP. We genotyped 78 Thai male TTPP cases and 74 Thai male hyperthyroid patients without hypokalemia as controls with Illumina Human-Hap610 Genotyping BeadChip. Among the SNPs analyzed in the GWAS, rs312729 at chromosome 17q revealed the lowest P-value for association (P=2.09 × 10−7). After fine mapping for linkage disequilibrium blocks surrounding the landmark SNP, we found a significant association of rs623011; located at 75 kb downstream of KCNJ2 on chromosome 17q, reached the GWAS significance after Bonferronis adjustment (P=3.23 × 10−8, odds ratio (OR)=6.72; 95% confidence interval (CI)=3.11–14.5). The result was confirmed in an independent cohort of samples consisting of 28 TTPP patients and 48 controls using the same clinical criteria diagnosis (replication analysis P=3.44 × 10−5, OR=5.13; 95% CI=1.87–14.1; combined-analysis P=3.71 × 10−12, OR=5.47; 95% CI=3.04–9.83).

Vitamin D status is a determinant of skeletal muscle mass in obesity according to body fat percentage

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. METHODS We enrolled 163 obese Thai individuals (59.5% women) from the obesity clinic at the Ramathibodi Hospital, Mahidol University, in Bangkok, Thailand. RESULTS 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. CONCLUSIONS 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.

Random capillary plasma glucose measurement in the screening of diabetes mellitus in high-risk subjects in Thailand

To assess the usefulness of random capillary plasma glucose (RCPG) measurement in screening for diabetes mellitus in high-risk subjects, a RCPG measurement and a 75-g oral glucose tolerance test (OGTT) were performed in 684 women and 164 men, aged 16-76 years (mean+/-SD: 41.9+/-11.3 years). Risk factors included family history of diabetes in first degree relatives (53.8%), obesity (BMI > or =27 kg/m(2)) in 37.9%, dyslipidemia (78.4%), hypertension, i.e. BP > or =140/90 mmHg (28.5%), and history of gestational diabetes mellitus (16.6%). According to the 1997 ADA/1998 WHO Consultation criteria for a full OGTT, 118 cases (13.9%) were found to have diabetes. Each of 19 cases with RCPG > or =13.3 mmol/l had diabetes according to OGTT, 4.7% of 427 cases with RCPG<6.1 mmol/l had diabetes. Among 402 subjects with RCPG between 6.1 and <13.3 mmol/l, 19.7% were found to have diabetes. Thus, 446 (52.6%) of 848 subjects would have been saved from OGTT if RCPG was used as a screening test, in comparison to 33.1% if the cutpoints for RCPG (12.2 and 5.5 mmol/l) recommended by WHO Study Group (1985)/WHO Consultation (1998) were applied. Therefore, RCPG measurement is a useful screening test for the screening of diabetes mellitus in high-risk subjects.

Association of genetic variants in GABRA3 gene and thyrotoxic hypokalaemic periodic paralysis in Thai population

Background  Genetic predisposition has been suggested to play role in the pathogenesis of thyrotoxic hypokalaemic periodic paralysis (THPP).

Is bisphenol A exposure associated with the development of glucose intolerance and increased insulin resistance in Thais

Bisphenol A (BPA), the monomeric component of polycarbonate plastics, reportedly possesses endocrine-disrupting effects. Exposure to low levels of BPA during more vulnerable periods leads to abnormalities related to sexual development in experimental animals. Moreover, recently a few epidemiological studies in Caucasians have demonstrated the association of BPA exposure with type 2 diabetes. Therefore, in the present study we examined the association of BPA exposure and abnormal glucose tolerance in Thais. This is a cross-sectional study of 240 participants aged at least 50 years, randomly selected by computer-generated random numbers within each glucose tolerance status from an oral glucose tolerance study of 661 participants. There were 80 participants in each group of type 2 diabetes, impaired glucose tolerance (IGT) and normal glucose tolerance (NGT). Serum BPA was measured by competitive ELISA. The detection rate of BPA was significantly higher in participants with IGT compared to those with NGT (p < 0.05), while no difference was found between participants with type 2 diabetes and NGT. When participants with type 2 diabetes were stratified into those with fasting plasma glucose (FPG) under the diabetic threshold (<126 mg/dL) and those over (≥126 mg/dL), it was found that those with FPG under the diabetic threshold had measurable rates of BPA comparable to those with IGT, and rates significantly higher than the NGT group (p < 0.05), while those with FPG over the diabetic threshold did not have higher rates of measurable BPA compared with the NGT group. In conclusion, BPA exposure is not uncommon in Thais. There is an association between BPA exposure and IGT, but not type 2 diabetes.