1.Prevalence of RsaI Polymorphism in the 5’ Untranslated Region (UTR) of Proopiomelanocortin (POMC) Gene and its Association with Obesity in the Kampar Health Clinic Cohort, Malaysia
Malaysian Journal of Medicine and Health Sciences 2012;8(1):61-68
The pandemic of obesity is of great concern as its associated co-morbidities are devastating; causing
lifelong burden to individual’s health and is economically costly to a country. Factors that lead to obesity
are a combination of environmental and genetic factors. The Pro-opiomelanocortin (POMC) gene resides
in chromosome 2p23.3, and its protein is composed of 241 amino acids which is responsible for the
production of polyhormones that regulate appetite and food intake. The study aimed to investigate the
prevalence of the RsaI single nucleotide polymorphism (SNP) site in the 5’-untranslated region (UTR)
of POMC and its possible association with obesity among 302 multi-ethnic Malaysian subjects (142
obese, 160 non-obese; 120 males, 182 females) from the Kampar Health Clinic. Subjects were recruited
by convenience sampling with informed consent and socio-demographic data as well as anthropometric
measurements were taken. Subjects were genotyped by polymerase chain reaction - restriction fragment
length polymorphism (PCR-RFLP) analysis using DNA extracted from blood. The distribution of the
RsaI genotypes was significantly different among the different ethnicities, but the mutated RsaI (- / -)
genotype was rare as it only occurred in 8.9% of the subjects. With the frequency of the RsaI (-) allele
of 0.31, it was associated with the percentage of skeletal muscles (p<0.05), but not with obesity, gender,
ethnicity and related anthropometric measurements. In conclusion, the 5’-UTR RsaI SNP in POMC
may not be associated with obesity in the Kampar Health Clinic cohort; however, it could lead to the
down-regulation of skeletal muscle build-up of up to 0.71%.
2.Plasma Total Antioxidant Capacity (TAC) in Obese Malaysian Subjects
Malaysian Journal of Nutrition 2012;18(3):345-354
Introduction: There is a pressing need to better understand the complex biochemical pathways that lead to the pathogenesis of obesity. Increased oxidative stress and decreased antioxidant capacity have been identified to be associated with obesity. Therefore, the objectives of this study were to determine the plasma total antioxidant capacity (TAC) levels of Malaysian subjects and to
evaluate its potential association with obesity and related anthropometric measurements. Methods: Plasma TAC of 362 multi-ethnic Malaysian subjects from the Kampar Health Clinic (138 males, 224 females; 124 ethnic Malays, 152 Chinese, 86 Indians; 192 non-obese, 170 obese) was measured using Trolox equivalent antioxidant capacity (TEAC) 96-well plate assay. Results: Plasma TAC was significantly lower in obese subjects (M ± SE = 292 ± 10.4 mol/L) compared to non-obese subjects (397 ± 8.58 mol/L), whereas it was significantly higher in males and those in the 21-30 age group. Those with salty food preference
and practising a strict vegetarian diet also had significantly higher plasma TAC. However, no association was found for other dietary habits (coffee intake) and
lifestyle factors (physical activity, smoking). Plasma TAC was also significantly negatively correlated with diastolic blood pressure, waist and hip circumferences,
weight, body mass index, total body fat, % subcutaneous fat, visceral fat level, resting metabolism and % skeletal muscle. Conclusion: Plasma TAC was found
to be associated with obesity, strict vegetarian practice, salty food preference and all obesity anthropometric indicators, except systolic blood pressure and
pulse rate. Obese people have decreased plasma TAC indicating a compromised systemic antioxidant defence and increased oxidative stress.
3.No Association of Peptide Tyrosine-Tyrosine (PYY) Gene R72T Variant with Obesity in the Kampar Health Clinic Cohort, Malaysia
Malaysian Journal of Nutrition 2011;17(2):201-212
Introduction: Peptide Tyrosine-Tyrosine (PYY) is a 36-amino acid peptide
hormone released post-prandially from the endocrine cells in the intestinal tract
to suppress pancreatic secretions and eventually reduce appetite. The R72T variant
in the PYY gene (rs1058046) has been associated with increased susceptibility to
obesity. Therefore, the objective of this study was to investigate the association
of this variant with obesity and its related anthropometric measurements among
the Kampar Health Clinic cohort, Malaysia. Methodology: A total of 197 (78
males, 119 females; 98 non-obese, 99 obese) subjects were recruited by convenience
sampling and anthropometric measurements were taken. Genotyping was
performed using StuI Polymerase Chain Reaction-Restriction Fragment Length
Polymorphism (PCR-RFLP), revealing 61 RR, 94 RT and 42 TT subjects. Results:
Most of the obese subjects had the RT genotype (50.5%), while only 18.2% were
TT. PYY R72T genotypes and alleles had no association with obesity (p=0.535;
0.074, respectively), gender (p=0.767; p=0.100, respectively) but were associated
with ethnicity (p=0.003; p=0.002, respectively). Among the 13 anthropometric
measurements taken, significant difference was only found in Waist
Circumference (WC) and Visceral Fat Level (VFL) among the alleles, suggesting
that subjects with T allele will have an increment of 1.82 cm in WC and 1.32% in
VFL. Conclusion: The R72T variant in PYY gene was not associated with obesity
and most of its related anthropometric measurements. This suggests that other
genes and/or environmental factors like dietary habits and lifestyle factors may
be the contributors of obesity.
4.Demographic Differences of Preference, Intake Frequency and Craving Hedonic Ratings of Sweet Foods Among Malaysian Subjects in Kuala Lumpur
BT Sia ; SY Low ; WC Foong ; M Pramasivah ; CZ Khor ; YH Say
Malaysian Journal of Medicine and Health Sciences 2013;9(1):55-64
As the sugar intake of Malaysians is one of the highest in the Asia Pacific region, we wanted to
investigate how this high prevalence of ‘sweet tooth’ is influenced by biological determinants like age,
gender, ethnicity and Body Mass Index (BMI). Therefore, this study was to determine the demographic
and BMI differences of preference, intake frequency and craving of a list of sweet beverages and food
among Malaysian subjects. Convenience sampling was performed around Kuala Lumpur, with informed
consents, involving 367 multi-ethnic subjects (163 males, 204 females; 83 Malays, 201 Chinese, 83
Indians; 209 lean, 158 overweight). Demographics and anthropometric measurements were taken and
questionnaire on the preference/frequency/craving of a list of 22 sweet food and beverages with a 7
point hedonic scale (from 1= very unpleasant/never/never crave to 7 = very pleasant/at least once a day/
always crave) was performed. Females significantly preferred more, took less frequently but had equal
craving of sweet foods compared to males. Lean subjects and those <25 years showed significantly
higher preference, intake frequency and craving of sweet foods. The ethnic differences in rating the
preference, intake frequency and cravings seemed to be food-specific and culturally-related, where
overall, ethnic Chinese had significantly higher intake frequency but lesser craving of sweet foods
compared to Malays and Indians. Understanding the demographic and anthropometric factors that may
affect the preference, intake frequency and craving of certain sweet foods can help to plan for strategies
to prevent the detrimental health burden of high sugar intake among Malaysians.