INTRODUCTION: Rheumatoid arthritis (RA) patients who have active disease with longer disease duration have been reported to have increased risk of cardiovascular events compared to the normal population.
OBJECTIVE: The primary aim of our study is to ascertain the prevalence of significant asymptomatic coronary artery disease (CAD) in Asian RA patients who are in remission using multi-detector computed tomography (MDCT). The secondary aims of our study are the usage of pulse wave velocity and the biomarkers N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-senstivity C-reactive protein (hs-CRP) to detect subclinical atherosclerosis in RA patients.
METHODS: We performed a comparative cross-sectional study of 47 RA patients who were in remission with a control group of non-RA patients with a history of atypical chest pain in Sarawak General Hospital from November 2008 to February 2009. All patients underwent 64-slice MDCT, assessment of arterial stiffness using the SphygmoCor test and blood analysis for NT-proBNP and hsCRP.
RESULTS: There were 94 patients in our study with a mean age of 50 +/- 8.8 years. The RA and control patients in each group were matched in terms of traditional CV risk factors. Our RA patients had a median disease duration of 3 years (IQR 5.5). MDCT showed evidence of CAD in nine (19.1%) RA patients and three (6.4%) control patients (P = 0.06). There was no significant association between pulse wave velocity (PWV) and presence of CAD in our RA group. There was no significant correlation between PWV with levels of proBNP or hsCRP in our RA patients.
CONCLUSIONS: In our current pilot study with the limitation of small sample size, RA was not associated with an increased risk of CAD in our RA patients who were in remission. Larger studies of CAD in Asian RA patients are needed to confirm our current finding.
Study site: Sarawak General Hospital, Kuching, Sarawak, Malaysia
Matched MeSH terms: Asian Continental Ancestry Group/statistics & numerical data*
Gastroesophageal reflux disease is thought to be the commonest cause of 'non-cardiac chest pain'. The use of proton-pump inhibitors resulting in improvement in the chest pain symptom would support this causal association.
Matched MeSH terms: Asian Continental Ancestry Group/statistics & numerical data*
OBJECTIVE:
Assess the effectiveness of sildenafil in Asian males with erectile dysfunction (ED) and one or more of the co-morbidities, mild-to-moderate hypertension, dyslipidemia, and diabetes.
MATERIAL AND METHOD:
A six-week, double-blind, randomized, placebo-controlled, multicenter study was carried out in Thailand, Malaysia and Singapore. One hundred and fifty five male subjects were randomized (2:1) to sildenafil (n = 104) or placebo (n = 51). Sildenafil was started at 50 mg and increased (100 mg) or decreased (25 mg) at week 2 if necessary.
RESULTS:
On the primary efficacy endpoint, sildenafil-treated subjects had significantly better scores on the International Index of Erectile Function (IIEF) questions 3 and 4 than placebo (p < 0.001, both questions). When accumulated into IIEF domains, all five domains were significant in favor of sildenafil. In addition, sildenafil-treated subjects were more satisfied with treatment and had a higher intercourse success rate. The majority of adverse events were mild in severity; the most commonly reported treatment-related events were dizziness (7.7%) and tinnitus (2.9%).
CONCLUSION:
Sildenafil (25, 50, and 100 mg) was found to be an effective, safe, and well-tolerated treatment for ED in the present study population of Thai, Malaysian, and Singaporean males who also had increased cardiovascular risk.
Matched MeSH terms: Asian Continental Ancestry Group*
To examine clinical outcomes in Asian patients with schizophrenia receiving monotherapy with olanzapine, risperidone or typical antipsychotics in naturalistic settings.
Matched MeSH terms: Asian Continental Ancestry Group/statistics & numerical data*
OBJECTIVE: The number of hip fractures is expected to double in the next 20 years, with current estimates that Asia will account for 37% of these cases. As bone mineral density (BMD) may be used as a measure of fracture risk, we sought to compare the effects of teriparatide with salmon calcitonin treatment on changes in BMD, biochemical bone markers, and safety in postmenopausal Asian women with osteoporosis.
METHODOLOGY: A total of 104 patients (n = 47 teriparatide [20 g/day subcutaneously] and n = 57 calcitonin [100 IU/day subcutaneously]) were enrolled in Hong Kong, Singapore, Philippines, Malaysia, and Thailand. Calcium (> or = 500 mg/day) and vitamin D (200-400 IU/day) supplements were taken throughout the 6-month controlled, randomized study.
RESULTS: Teriparatide was associated with a 5.03 +/- 4.77% increase in lumbar spine BMD (p < 0.0001, mean +/- SD change from baseline), whereas changes in lumbar spine BMD for patients on calcitonin were not statistically significant (mean change of 0.36 +/- 4.12%, p = 0.16). Comparison of the two groups indicated that teriparatide treatment improved lumbar spine BMD statistically significantly more than calcitonin (p < 0.0001). No statistically significant changes were observed for total hip or femoral neck BMD. Serum bone-specific alkaline phosphatase (BSAP) increased by 55.9% (median change from baseline, p < 0.0001) in the teriparatide group, and remained stable with calcitonin (5.0% change, p = 0.24); osteocalcin increased by 156.15% (median change from baseline, p < 0.0001) with teriparatide, and decreased with calcitonin (-15.25%, p = 0.03). Similar rates of adverse events were observed, with nausea and dizziness the most commonly reported for both groups (teriparatide versus calcitonin, 13.0% versus 23.2% p = 0.21, 10.9% versus 21.4% p = 0.19, respectively). There were no clinically relevant changes observed in laboratory parameters.
CONCLUSIONS: Both treatments were similarly tolerated, however teriparatide was associated with greater increases in lumbar spine BMD and bone formation markers, demonstrating the unique mechanism of action and safety of this treatment for osteoporosis in these Asian women.
Matched MeSH terms: Asian Continental Ancestry Group*
The aim of this study was to measure craniofacial morphology and nasal respiratory resistance (NRR) in Malay, Indian and Chinese subjects with obstructive sleep apnoea (OSA). The sample consisted of 34 male subjects, 27-52 years of age (Malay n = 11, which included five mild and six moderate-severe OSA; Indian n = 11, which included six mild and five moderate-severe OSA; and Chinese n = 12, which included six mild and six moderate-severe OSA) diagnosed using overnight polysomnography. After use of a decongestant, NRR was recorded using anterior and posterior rhinomanometry. Standardized lateral cephalometric radiographs were used to record linear and angular dimensions. Malay subjects with moderate-severe OSA had a shorter maxillary (sp-pm) and mandibular (gn-go) length when compared with a mild OSA reference sample (P < 0.05). The hyoid bone was located more caudally in the Chinese moderate-severe subjects (hy-NL, hy-ML)(P < 0.05), and may be a useful diagnostic indicator for severity in this racial group. No pattern of differences for NRR was seen between the moderate-severe and mild OSA subjects. The consistently lower values for nasopharyngeal resistance in all the moderate-severe subjects when compared with the mild group may indicate that some compensation at this level of the airway had taken place. Strong positive correlations between craniocervical angulation (NL/OPT) and total airway resistance and the turbulent component of flow (k(2)) suggest that head posture is sensitive to fluctuations in airway resistance (P < 0.01).
Matched MeSH terms: Asian Continental Ancestry Group/ethnology*
Marked epidemiological changes in upper gastrointestinal diseases and Helicobacter pylori infection have taken place in the Asian Pacific region. In particular, differences with respect to race in the multiracial Asian population in Malaysia have been important and interesting.
Matched MeSH terms: Asian Continental Ancestry Group/ethnology*
The frequency of the HLA class II antigens/alleles (HLA-DR, DQ and DP) were studied in 70 Malaysian Chinese patients with systemic lupus erythematosus (SLE) to examine the contribution of these genes to disease susceptibility, their clinical expression and Immunological responses. This was done using modified PCR-RFLP technique. These samples were then compared with 66 ethnically matched controls. We found a strong association of the DQA1*0102 (p corr = 0.032, rr = 3.39), DQB1*0501 (p corr = 0.003, rr = 4.55), *0601 (p corr = 0.006, rr = 4.22) and DPB1* 0901(p corr = 0.02, rr = 4.58) with SLE. Clinically, we found a strong association of DR2 and DQA1*0301 with renal involvement and DQA1*0102 with alopecia. Immunologically, statistical analysis (Chi-square test ) showed a strong association of DQA1*0102 with anti-Ro/La antibodies while DQA1*0301 was observed to be strongly associated with antibodies to ds DNA. DQA1*0102 was found more frequently in those with a later disease onset (30 years of age or above). From these data we suggest that the HLA class II genes play a role in conferring disease susceptibility and clinical and immunological expression.
Study site: SLE clinics, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
Matched MeSH terms: Asian Continental Ancestry Group/genetics*
Dietary studies often report low calcium intake amongst post-menopausal Malaysian women and calcium deficiency has been implicated as part of the etiology of age-related bone loss leading to osteoporosis. Therefore, the objective of this study was to examine the effectiveness of high calcium skimmed milk (Anlene Gold, New Zealand Milk, Wellington, New Zealand) to reduce bone loss in Chinese postmenopausal women. Two hundred subjects aged 55-65 years and who were more than 5 years postmenopausal were randomized to a milk group and control group. The milk group consumed 50 g of high calcium skimmed milk powder daily, which contained 1200 mg calcium (taken as two glasses of milk a day). The control group continued with their usual diet. Using repeated measures ANCOVA, the milk supplement was found to significantly reduce the percentage of bone loss at the total body compared to the control group at 24 months (control -1.04%, milk -0.13%; P<0.001). At the lumbar spine, the percentage of bone loss in the control group was significantly higher (-0.90%) when compared to the milk (-0.13%) supplemented group at 24 months (P<0.05). Similarly, milk supplementation reduced the percentage of bone loss at the femoral neck (control -1.21%, milk 0.51%) (P<0.01) and total hip (control -2.17%, milk -0.50%) (P<0.01). The supplemented group did not experience any significant weight gain over the 24 months. The serum 25-hydroxy vitamin D level improved significantly (P<0.01) from 69.1 +/- 16.1 nmol/l at baseline to 86.4 +/- 22.0 nmol/l at 24 months in the milk group. In conclusion, ingestion of high calcium skimmed milk was effective in reducing the rate of bone loss at clinically important lumbar spine and hip sites in postmenopausal Chinese women in Malaysia. Supplementing with milk had additional benefits of improving the serum 25-hydroxy vitamin D status of the subjects.
Matched MeSH terms: Asian Continental Ancestry Group*
Alteration of the tumor suppressor gene p53 is considered to be a critical step in the development of human cancer. Changes in this gene have been detected in a wide range of human tumours, including gliomas. In glioma, the presence of p53 gene alterations has been associated with worse prognosis.
Matched MeSH terms: Asian Continental Ancestry Group/genetics*
We have established 3 cell lines ORL-48, -115 and -136 from surgically resected specimens obtained from untreated primary human oral squamous cell carcinomas of the oral cavity. The in vitro growth characteristics, epithelial origin, in vitro anchorage independency, human papilloma-virus (HPV) infection, microsatellite instability status, karyotype and the status of various cell cycle regulators and gatekeepers of these cell lines were investigated. All 3 cell lines grew as monolayers with doubling times ranging between 26.4 and 40.8 h and were immortal. Karyotyping confirmed that these cell lines were of human origin with multiple random losses and gains of entire chromosomes and regions of chromosomes. Immunohistochemistry staining of cytokeratins confirmed the epithelial origin of these cell lines, and the low degree of anchorage independency expressed by these cell lines suggests non-transformed phenotypes. Genetic analysis identified mutations in the p53 gene in all cell lines and hypermethylation of p16INK4a in ORL-48 and -136. Analysis of MDM2 and EGFR expression indicated MDM2 overexpression in ORL-48 and EGFR overexpression in ORL-136 in comparison to the protein levels in normal oral keratinocytes. Analysis of the BAT-26 polyadenine repeat sequence and MLH-1 and MSH-2 repair enzymes demonstrated that all 3 cell lines were microsatellite stable. The role of HPV in driving carcinogenesis in these tumours was negated by the absence of HPV. Finally, analysis of the tissues from which these cell lines were derived indicated that the cell lines were genetically representative of the tumours, and, therefore, are useful tools in the understanding of the molecular changes associated with oral cancers.
Matched MeSH terms: Asian Continental Ancestry Group*
BACKGROUND: We investigated the implications of HER2 amplification in Asian women with small, node-negative breast cancer in low- and middle-income countries (LMCs).
METHODS: We reviewed the charts patients treated between 1989 and 2009 with breast conservation therapy for node-negative breast cancers measuring ≤ 2 cm. Disease-free survival (DFS), ipsilateral breast tumor recurrence (IBTR), distant disease-free survival (DDFS), and overall survival (OS) rates were estimated using the Kaplan-Meier method and were compared by the log-rank test. Potential covariates-age, tumor grade, hormone receptor status--were analyzed by multivariate analysis.
RESULTS: A total of 519 patients were studied including 204 (39%) and 315 (61%) patients diagnosed with pT1ab and pT1c tumors, respectively. Median follow-up was 57 months. HER2 amplification was found in 17.1% of all patients and in 16.7% patients with pT1ab tumors. Among patients with T1ab tumors, 73.0 and 9.3% underwent adjuvant hormonal and chemotherapy, respectively; 3 of 34 T1ab patients with HER2-amplified tumors received trastuzumab. HER2 amplification was associated with poorer 5-year DFS (83.7% vs. 95.5%, P < 0.0001), DDFS (87.5% vs. 97.9%, P < 0.0001), and IBTR (8.6% vs. 2.1%, P < 0.0001) rates in patients with pT1 tumors. Multivariate analysis showed that HER2 amplification remained a significant negative prognostic factor for DFS [hazard ratio (HR) 4.1, 95% confidence interval (CI) 2.1-7.8, P < 0.0001], DDFS (HR 6.3, 95% CI 2.4-17.0, P < 0.0001), and IBTR (HR 4.5, 95% CI 2.0-10.0, P < 0.0001) rates. In the pT1ab subgroup, univariate analysis showed that HER2 amplification prognosticated for DFS (85.1% vs. 95.7%, P = 0.022) and IBTR (14.9% vs. 3.5%, P = 0.004) rates but not for the OS (100% vs. 99.2%, P = 0.487) rate. Similar results were obtained after excluding patients given trastuzumab.
CONCLUSIONS: The decision to use trastuzumab in HER2-amplified pT1ab tumors must balance their poor outcome against intrinsic financial limitations in LMCs. Patient selection criteria needs fine-tuning, and resource-sensitive regimens must be explored.
Matched MeSH terms: Asian Continental Ancestry Group*
Mutations in the ATP-binding cassette transporter ABCA1 underlie Tangier disease and familial hypoalphaliproteinemia (FHA), disorders that are characterised by reduced high-density lipoprotein-cholesterol (HDL-C) concentration and cholesterol efflux, and increased coronary artery disease (CAD). We explored if polymorphisms in the ABCA1 gene are associated with CAD and variations in plasma lipid levels, especially HDL-C, and whether the associations may depend on ethnicity. Male cases and controls from the Singapore Chinese, Malay and Indian populations were genotyped for five ABCA1 single nucleotide polymorphisms. Various single-locus frequency distribution differences between cases and controls were detected in different ethnic groups: the promoter -14C>T in Indians, exon 18 M883I in Malays, and 3'-untranslated (UTR) region 8994A>G in Chinese. For the Malay population, certain haplotypes carrying the I825- A (exon 17) and M883- G alleles were more frequent among cases than controls, whereas the converse was true for the alternative configuration of V825- G and I883- A, and this association was reinforced in multi-locus disequilibrium analysis that utilized genotypic data. In the healthy controls, associations were found for -14C>T genotypes with HDL-C in Chinese; 237indelG (5'UTR) with apolipoprotein A1 (apoA1) in Malays and total cholesterol (TC) in Indians; M883I with lipoprotein(a) [Lp(a)] in Malays and apolipoprotein B (apoB) in Chinese; and 8994A>G with Lp(a) in Malays, and TC, low-density lipoprotein-cholesterol (LDL-C) as well as apoB in Indians. While genotype-phenotype associations were not reproduced across populations and loci, V825I and M883I were clearly associated with CAD status in Malays with no effects on HDL-C or apoA1.
Matched MeSH terms: Asian Continental Ancestry Group/genetics*
Deep understanding of the genomic and immunological differences between Chinese and Western lung cancer patients is of great importance for target therapy selection and development for Chinese patients. Here we report an extensive molecular and immune profiling study of 245 Chinese patients with non-small cell lung cancer. Tumor-infiltrating lymphocyte estimated using immune cell signatures is found to be significantly higher in adenocarcinoma (ADC, 72.5%) compared with squamous cell carcinoma (SQCC, 54.4%). The correlation of genomic alterations with immune signatures reveals that low immune infiltration was associated with EGFR mutations in ADC samples, PI3K and/or WNT pathway activation in SQCC. While KRAS mutations are found to be significantly associated with T cell infiltration in ADC samples. The SQCC patients with high antigen presentation machinery and cytotoxic T cell signature scores are found to have a prolonged overall survival time.
Matched MeSH terms: Asian Continental Ancestry Group/genetics*
OBJECTIVES: Recently, several genome-wide association studies have demonstrated a cumulative association of 5 polymorphic variants in chromosomes 8q24 and 17q with prostate cancer (CaP) risk in Caucasians, particularly those harboring aggressive clinicopathologic characteristics. The purpose of this study was to evaluate the influence of these variants on CaP susceptibility in Singaporean Asian men.
MATERIALS AND METHODS: We performed a case-control study in 289 Chinese CaP patients and 412 healthy subjects (144 Chinese, 134 Malays, and 134 Indians), and examined the association of the 5 single nucleotide polymorphisms (SNPs) with CaP.
RESULTS: In the healthy subjects, rs16901979 A-allele frequency was highest amongst Chinese (0.32) compared with Malays (0.13; P < 0.0001) or Indians (0.09; P < 0.0001); rs6983267 G-allele was highest in Indians (0.51) compared with Chinese (0.42; P = 0.041) or Malays (0.43; P = 0.077); whereas rs1859962 G-allele frequency was highest amongst Indians (0.56) compared with Chinese (0.40; P = 0.0002) or Malays (0.38; P < 0.0001). Individuals with the rs4430796 TT genotype were at increased CaP risk in the Chinese via a recessive model (odds ratios (OR) = 1.56, 95% CI = 1.04-2.33). Significant associations were observed for rs4430796 TT with Gleason scores of ≥ 7 (OR = 1.76, 95% CI = 1.14-2.73) and prostate-specific antigen (PSA) levels of ≥ 10 ng/ml at diagnosis (OR = 1.63, 95% CI = 1.01-2.63), as well as for rs6983267 GG with stage 3-4 CaPs (OR = 1.91, 95% CI = 1.01-3.61). A cumulative gene interaction influence on disease risk, which approximately doubled for individuals with at least 2 susceptibility genotypes, was also identified (OR = 2.18, 95% CI = 1.10-4.32).
CONCLUSIONS: This exploratory analysis suggests that the 5 genetic variants previously described may contribute to prostate cancer risk in Singaporean men.
KEYWORDS: Cancer; Ethnicity; Gleason; Pharmacogenetics; Polymorphism; Prostate
Matched MeSH terms: Asian Continental Ancestry Group/genetics
We conducted a cross-sectional study of Malay participants aged 40-80 years (n = 2,932) to examine the associations between polymorphisms at newly identified, lipid-associated loci with blood lipid levels and prevalent cardiovascular disease (CVD) in a Malay population in Asia. A polymorphism adjacent to the TRIB1 locus (rs17321515) was associated with elevated total cholesterol and LDL-cholesterol (LDL-C) after adjustment for age and sex (both P values <0.007) and with increased risk of coronary heart disease and CVD [odds ratio (OR) 1.23, 95% confidence interval (95% CI) 1.03-1.46; and OR 1.2, 95% CI 1.02-1.42, respectively] under an additive model of inheritance. In addition, using recessive models of inheritance, polymorphisms on chromosome 19 adjacent to the CILP2 and PBX4 loci (rs16996148) and on chromosome 1 at the GALNT2 locus (rs4846914) were associated with elevated HDL-C (P = 0.005) and lower LDL-C (P = 0.048), respectively. Although novel, the former is consistent with the association between this polymorphism and lower blood triglycerides observed in the initial studies conducted in populations of European ancestry. Neither showed statistically significant association with CVD. These observations should form the basis of further investigation to identify the causative polymorphisms at this locus, and also to understand the mechanistic roles that this protein may play in lipoprotein metabolism in Asians and other populations.
Matched MeSH terms: Asian Continental Ancestry Group/genetics*
Clopidogrel is a widely-used antiplatelet drug. It is important for the treatment and prevention of coronary heart disease. Clopidogrel can effectively reduce platelet activity and therefore reduce stent thrombosis. However, some patients still have ischemic events despite taking the clopidogrel due to the alteration in clopidogrel metabolism attributable to various genetic and non-genetic factors. This review aims to summarise the mechanisms and causes of clopidogrel resistance (CR) and potential strategies to overcome it. This review summarised the possible effects of genetic polymorphism on CR among the Asian population, especially CYP2C19 *2 / *3 / *17, where the prevalence rate among Asians was 23.00%, 4.61%, 15.18%, respectively. The review also studied the effects of other factors and appropriate strategies used to overcome CR. Generally, CR among the Asian population was estimated at 17.2-81.6%. Therefore, our overview provides valuable insight into the causes of RC. In conclusion, understanding the prevalence of drug metabolism-related genetic polymorphism, especially CYP2C19 alleles, will enhance clinical understanding of racial differences in drug reactions, contributing to the development of personalised medicine in Asia.
Matched MeSH terms: Asian Continental Ancestry Group/genetics