School of Medicine and Sciences

Dr. School of Medicine and Sciences

orcid

Research Focus & Metrics

Academic Career Length

27Years (2000-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 January 2015 in BMC Public Health
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MPMaude E Phipps
Maude E Phipps
KCKevin Kl Chan
Kevin Kl Chan
RNRakesh Naidu
Rakesh Naidu
NMNazaimoon W Mohamad
Nazaimoon W Mohamad
BHBoon-Peng Hoh
Boon-Peng Hoh
SSSchool of Medicine and Sciences
School of Medicine and Sciences
South East Asia (SEA) is home to over 30 tribes of indigenous population groups who are currently facing rapid socio-economic change. Epidemiological transition and increased prevalence of non-communicable diseases (NCD) has occured. In Peninsular Malaysia, the Orang Asli (OA) indigenous people comprise 0 · 6% (150,000) of the population and live in various settlements. OA comprise three distinct large tribes with smaller sub-tribes. The three large tribes include Proto-Malay (sub-tribes: Orang Seletar and Jakun), Senoi (sub-tribes: Mahmeri and Semai), and Negrito (sub-tribes: Jehai, Mendriq and Batek). We studied the health of 636 OA from seven sub-tribes in the Peninsular. Parameters that were assessed included height, weight, BMI and waist circumference whilst blood pressure, cholesterols, fasting blood glucose and HbA1c levels were recorded. We then analysed cardio-metabolic risk factor prevalences and performed multiple pair-wise comparisons among different sub-tribes and socio-economic clusters. Cardio-metabolic risk factors were recorded in the seven sub-tribes.. Prevalence for general and abdominal obesity were highest in the urbanized Orang Seletar (31 · 6 ± 5 · 7%; 66 · 1 ± 5 · 9%). Notably, hunter gatherer Jehai and Batek tribes displayed the highest prevalence for hypertension (43 · 8 ± 9 · 29% and 51 · 2 ± 15 · 3%) despite being the leanest and most remote, while the Mendriq sub-tribe, living in the same jungle area with access to similar resources as the Batek were less hypertensive (16.3 ± 11.0%), but displayed higher prevalence of abdominal obesity (27.30 ± 13.16%). We describe the cardio-metabolic risk factors of seven indigenous communities in Malaysia. We report variable prevalence of obesity, cholesterol, hypertension and diabetes in the OA in contrast to the larger ethnic majorities such as Malays, Chinese and Indians in Malaysia These differences are likely to be due to socio-economic effects and lifestyle changes. In some sub-tribes, other factors including genetic predisposition may also play a role. It is expected that the cardio-metabolic risk factors may worsen with further urbanization, increase the health burden of these communities and strain the government’s resources.

17 September 2018 in Nutrients
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STSuzanne Tan
Suzanne Tan
YCYilynn Chiew
Yilynn Chiew
BABadariah Ahmad
Badariah Ahmad
SSSchool of Medicine and Sciences
School of Medicine and Sciences
Tocotrienol-rich vitamin E from palm oil (Tocovid) has been shown to ameliorate diabetes through its superior antioxidant, antihyperglycemic, and anti-inflammatory properties in diabetic rats. This study aimed to investigate the effects of Tocovid on diabetic nephropathy in patients with type 2 diabetes. Baseline parameters of potential subjects such as HbA1c, blood pressure, Advanced Glycation Endproduct (AGE), soluble receptor for AGE (sRAGE), Nε-Carboxymethyllysine (Nε-CML), and Cystatin C were assessed for possible correlation with diabetic nephropathy. Only subjects with diabetic nephropathy or urine microalbuminuria-positive defined as Urine Albumin to Creatinine Ratio (UACR) >10 mg/mmol were recruited into a prospective, randomized, double-blinded, placebo-controlled trial. The intervention group (n = 22) received Tocovid 200 mg twice a day while the control group (n = 23) received placebo twice a day for 8 weeks. Changes in Hemoglobin A1c (HbA1c), blood pressure, serum biomarkers and renal parameters such as UACR, serum creatinine, and estimated Glomerular Filtration Rate (eGFR) were compared between the two groups. It was found that serum Nε-CML significantly correlated to the severity of microalbuminuria. For every 1 ng/mL increase in serum Nε-CML, the odds of diabetic nephropathy increased by 1.476 times. Tocovid, compared to placebo, significantly reduced serum creatinine but not eGFR, UACR, HbA1c, blood pressure, and serum biomarkers. In conclusion, serum Nε-CML is a potential biomarker for diabetic nephropathy. Treatment with Tocovid significantly reduced serum creatinine; therefore Tocovid may be a useful addition to the current treatment for diabetic nephropathy.

23 May 2020 in Nutrients
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YNYeek Tat Ng
Yeek Tat Ng
SPSonia Chew Wen Phang
Sonia Chew Wen Phang
GTGerald Chen Jie Tan
Gerald Chen Jie Tan
ENEn Yng Ng
En Yng Ng
NBNevein Philip Botross
Nevein Philip Botross
SSSchool of Medicine and Sciences
School of Medicine and Sciences
Chronic hyperglycemia increases oxidative stress, activates inflammatory pathways and reduces nerve growth factor (NGF) among diabetic patients, which contribute to development of diabetic peripheral neuropathy (DPN). Tocotrienol-Rich Vitamin E (Tocovid) possesses potent antioxidant and anti-inflammatory properties which are postulated to target these pathogeneses in order to ameliorate DPN. This study aims to evaluate the effects of Tocovid on nerve conduction parameters and serum biomarkers among diabetic patients. This multicenter, prospective, randomized, double-blind, placebo-controlled clinical trial was conducted on 80 eligible participants. The intervention group (n = 39) was randomly allocated to receive 200 mg of Tocovid twice a day, and the control group (n = 41) received placebo twice a day. At the end of eight weeks, the nerve conduction parameters, as assessed by nerve conduction study, as well as serum biomarkers (NGF, malondialdehyde, vascular cell adhesion molecule 1, tumor necrosis factor receptor 1 and thromboxane B2) were compared between the two groups. Compared to placebo, Tocovid significantly improves the nerve conduction velocities of all nerves (+1.25 m/s, interquartile range [IQR] 3.35, p < 0.001, median nerve; +1.60 m/s, IQR 1.80, p < 0.001, sural nerve; +0.75 m/s, IQR 2.25, p < 0.001, tibial nerve). Meanwhile, the levels of serum NGF were significantly higher in the Tocovid group as compared to placebo at eight weeks post-intervention. Participants receiving Tocovid illustrated highly significant improvement in terms of nerve conduction velocities for all nerves tested after eight weeks of supplementation. In addition, Tocovid supplementation elevated the levels of serum NGF, in which its increase is postulated to reflect enhanced neuronal functions. This novel finding suggests that Tocovid could be a disease-modifying agent targeting serum NGF to improve nerve conduction velocities.

18 January 2021 in Nutrients
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Journal Article
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YKYan Koay
Yan Koay
GTGerald Chen Jie Tan
Gerald Chen Jie Tan
SPSonia Chew Wen Phang
Sonia Chew Wen Phang
JHJ-Ian Ho
J-Ian Ho
PCPei Fen Chuar
Pei Fen Chuar
SSSchool of Medicine and Sciences
School of Medicine and Sciences
Diabetic kidney disease (DKD) is a debilitating complication of diabetes, which develops in 40% of the diabetic population and is responsible for up to 50% of end-stage renal disease (ESRD). Tocotrienols have shown to be a potent antioxidant, anti-inflammatory, and antifibrotic agent in animal and clinical studies. This study evaluated the effects of 400 mg tocotrienol-rich vitamin E supplementation daily on 59 DKD patients over a 12-month period. Patients with stage 3 chronic kidney disease (CKD) or positive urine microalbuminuria (urine to albumin creatinine ratio; UACR > 20–200 mg/mmol) were recruited into a randomized, double-blind, placebo-controlled trial. Patients were randomized into either intervention group (n = 31) which received tocotrienol-rich vitamin E (Tocovid SupraBioTM; Hovid Berhad, Ipoh, Malaysia) 400 mg daily or a placebo group which received placebo capsules (n = 28) for 12 months. HbA1c, renal parameters (i.e., serum creatinine, eGFR, and UACR), and serum biomarkers were collected at intervals of two months. Tocovid supplementation significantly reduced serum creatinine levels (MD: −4.28 ± 14.92 vs. 9.18 ± 24.96), p = 0.029, and significantly improved eGFR (MD: 1.90 ± 5.76 vs. −3.29 ± 9.24), p = 0.011 after eight months. Subgroup analysis of 37 patients with stage 3 CKD demonstrated persistent renoprotective effects over 12 months; Tocovid improved eGFR (MD: 4.83 ± 6.78 vs. −1.45 ± 9.18), p = 0.022 and serum creatinine (MD: −7.85(20.75) vs. 0.84(26.03), p = 0.042) but not UACR. After six months post washout, there was no improvement in serum creatinine and eGFR. There were no significant changes in the serum biomarkers, TGF-β1 and VEGF-A. Our findings verified the results from the pilot phase study where tocotrienol-rich vitamin E supplementation at two and three months improved kidney function as assessed by serum creatinine and eGFR but not UACR.

7 September 2017 in Nutrients
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Journal Article
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HCHong Sheng Cheng
Hong Sheng Cheng
STSo Ha Ton
So Ha Ton
JLJoash Tan Ban Lee
Joash Tan Ban Lee
SSSchool of Medicine and Sciences
School of Medicine and Sciences
The clinical value of tocotrienols is increasingly appreciated because of the unique therapeutic effects that are not shared by tocopherols. However, their effect on metabolic syndrome is not well-established. This study aimed to investigate the effects of a tocotrienol-rich fraction (TRF) from palm oil in high-fat-diet-treated rats. Male, post-weaning Sprague Dawley rats were provided high-fat (60% kcal) diet for eight weeks followed by a TRF (60 mg/kg) treatment for another four weeks. Physical, metabolic, and histological changes were compared to those on control and high-fat diets respectively. High-fat feeding for eight weeks induced all hallmarks of metabolic syndrome. The TRF reversed systolic and diastolic hypertension, hypercholesterolemia, hepatic steatosis, impaired antioxidant defense, and myeloperoxidase hyperactivity triggered by the high-fat diet. It also conferred an inhibitory effect on protein glycation to reduce glycated hemoglobin A1c and advanced glycation end products (AGE). This was accompanied by the suppression of the receptor for advanced glycation end product (RAGE) expression in the liver. The treatment effects on visceral adiposity, glycemic control, triglyceride level, as well as peroxisome proliferator-activated receptor α and γ expression were negligible. To conclude, treatment with a TRF exhibited protective effects on the cardiovascular and liver health in addition to the amelioration of plasma redox imbalance and AGE-RAGE activation. Further investigation as a therapy for metabolic syndrome is therefore worthwhile.

1 June 2015 in Diabetes Research and Clinical Practice
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Journal Article
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SGS.G.K. Goh
S.G.K. Goh
BRB.N. Rusli
B.N. Rusli
SSSchool of Medicine and Sciences
School of Medicine and Sciences
To construct a type-2 diabetes specific quality of life (QOL) tool for Asian populations that is valid and reliable across different ethnicities, languages, and socio-economic backgrounds.A focus group determined the domains affecting QOL in consultation with an expert group. A pilot study was conducted to validate the Asian Diabetes QOL (AsianDQOL) in English, Malay and Chinese-Mandarin. The World Health Organization Brief Quality of Life Questionnaire (WHOQOL-BREF) was used for comparison. Exploratory factor analysis (EFA), reliability analysis (RA) using Cronbach's alpha, test-retest reliability, and confirmatory factor analysis (CFA) using structural equation modeling (SEM) was undertaken using the statistical software IBM SPSS Statistics version 20.EFA with eigenvalues (>1) and factor loadings ≥0.3 for English and Malay language demonstrated 21 items (5 components). CFA (English version) confirmed the model (CMIN 201.08, p-value 0.071, GFI 0.88, RMSEA 0.036, CFI 0.978). CFA (Malay version) confirmed the 5-factor model (CMIN 189.39, p-value 0.085, GFI 0.937, RMSEA 0.025, CFI 0.987). The Cronbach's alpha scores (English version) were 0.917, 0.818, 0.816, 0.749 and 0.719, respectively. The Malay version scored 0.833, 0.819, 0.816, 0.775, 0.673, respectively, whilst the Chinese/Mandarin version scored 0.890, 0.719, 0.826, 0.862 and 0.759, respectively. Test-retest reliability showed Pearson correlation of 0.600 (English version), 0.700 (Malay version) and 0.500 (Chinese-Mandarin version). A scoring system was generated based on the 25th, 50th and 75th centiles for all the three languages.The AsianDQOL is a valid, reliable and stable tool for assessing QOL in multi-ethnic and multi-lingual T2DM Asian populations.