A simple and sensitive double-antibody radioimmunoassay for human growth hormone (HGH) was developed, optimised and validated. The anti-hGH sera raised in 2 rabbits were highly specific with low cross-reactions of 0.19% and 0.3% with human placental lactogen and 0.21% and 0.13% with human prolactin. The mean sensitivity of the assay determined from 28 assays was found to be 0.4 +/- 0.2 mIU/L. Mean recovery of added exogenous hGH was 98.8 +/- 6.8%. Linearity studies of samples diluted at 1:2, 1:4 and 1:8 gave values of 101.3 +/- 5.3%, 109.6 +/- 13.4% and 97.3 +/- 13% respectively of those expected. The reproducibility of the assay was good; within assay coefficient of variation for serum samples with GH concentrations of 2.7, 13.6 and 28.2 mU/l ranged from 5.1 to 8.3% while the inter-assay precision varied from 4.9 to 10.3%. The in-house assay showed good correlation (r = 0.96, p less than 0.001) with a commercial HGH RIA kit (Dainabot, Japan). A reference normal adult fasting GH level of less than 7 mIU/l was established from 95 samples assayed by this method.
A modified micromethod for measuring urine iodine was successfully established and validated. The micromethod showed good correlation with the method used by several World Health Organization (WHO) collaborative laboratories (y = 0.9342x + 4.6213; r = 0.962; p = 0.01; n = 50). The micromethod also showed good agreement when compared to the reference WHO method. The sensitivity of the assay was 13.809 ug/L (n = 8) and mean recoveries were 114, 103 and 106% at concentrations of 30, 40 and 50 ug/L (n = 3) respectively. At iodine concentrations of 51 +/- 15.5, 108 +/- 32.4 and 149 +/- 38.6 ug/L, intra-assay coefficient of variations (CVs) were 13%, 7% and 5% respectively (n = 20), and inter-assay CVs were 10%, 15% and 7% respectively (n = 10). The assay showed good linearity plot (y = 1.0407x + 60.451; r = 0.993; n = 3).
We successfully developed an in-house, competitive enzyme immunoassay to measure advanced glycosylation end-products (AGE) in serum. The assay involved coating microtitre wells with AGE-BSA at 8 micrograms/ml for 4 hours, followed by overnight incubation of 20 microliters sample (prediluted at 1:6) with 80 microliters antiserum (1:8000). HRP-labelled goat anti-rabbit was used as the second antibody and 3,5',5,5'-tetramethylbenzidine dihydrochloride as the substrate. Incubation was carried out at 4 degrees C. As suggested in an earlier study, we standardised the AGE units against normal human serum (NHS). Thus, one AGE unit was defined as the inhibition that resulted when the 1:6 diluted NHS was assayed. Mean (+/- SD) AGE level in normal subjects (n = 37) was significantly lower than in diabetes subjects with microalbuminuria (n = 57) (6.0 +/- 0.7 versus 10.2 +/- 4.7 units/ml, p = 0.0001). With the availability of in-house assay and by standardising the AGE unit with the other laboratories, more studies could be undertaken and results compared, and possibly, further elucidate the roles of AGE in the pathogenesis of diabetic complications.
This study determined the effects of palm vitamin E (TRF) diet on the levels of blood glucose, glycated hemoglobin (gHb), serum advanced glycosylation end-products (AGE) and malondialdehyde (MDA) of diabetic Sprague-Dawley rats. The rats received either control (normal rat chow), TRF diet (normal chow fortified with TRF at 1 g/kg) or Vitamin C diet (vitamin E-deficient but contained vitamin C at 45 g/kg). The animals were maintained on the respective diet for 4 weeks, made diabetic with streptozotocin (STZ), then followed-up for a further 8 weeks. At week-4, mean serum AGE levels of rats given TRF diet (0.7 +/- 0.3 units/ml) were significantly lower than those of control or Vitamin C diet rats (p pounds 0.03). The levels increased after STZ and became comparable to the other groups. At week 12, blood glucose (20.9 +/- 6.9 mM) and gHb (10.0 +/- 1.6%) of rats on TRF diet remained significantly low compared to that of control or Vitamin C diet rats (p pounds 0.03). MDA however, was not affected and remained comparable between groups throughout the study. This study showed that TRF may be a useful antioxidant; effectively prevented increase in AGE in normal rats, and caused decrease in blood glucose and gHb in diabetic rats. Further studies are needed to elucidate the mechanisms of action of TRF.
Thyroid hormones have been shown to be involved in the regulation of insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3) expression. This is a cross-sectional study to look at the effects of thyroid hormone status on the circulating levels of IGF-I and IGFBP-3 in a group of 127 patients, aged 20-80 years, who were hyperthyroid, hypothyroid, rendered euthyroid and clinically euthyroid with normal free thyroxine (fT4), but suppressed thyroid stimulating hormone (TSH) levels. TSH was measured by the IMx (Abbott) ultrasensitive assay, while radioimmunoassays for total T3 and T4 were performed using kits from ICN, USA; fT4 and fT3 using kits from DPC USA; IGF-I and IGFBP-3 using kits from Nichols Institute Diagnostics B.V., Netherlands. Differences in the levels of IGF-I between the 4 groups of patients were significant only in the patients aged 20-40. Mean (+/-SEM) IGF-I levels of hypothyroid patients (169+/-19ng/ml) was significantly lower than hyperthyroid (315+/-26 ng/ml, p=0.003), euthyroid patients (241+/-19 ng/ml, p=0.002) and patients with suppressed TSH (308+/-29 ng/ml, p=0.02). The IGF-I levels of the hyperthyroid and suppressed TSH patients were, however, comparable to age-matched normal subjects (281+/-86 ng/ml). Although there was no difference in mean IGFBP-3 levels between the 4 groups of patients, the levels in the patients aged 20-40 with hyperthyroidism (3.7+/-0.9 microg/ml) and suppressed TSH (3.9+/-1.2 microg/ml) were significantly higher (p=0.02) than age-matched normal subjects (3.1+/-0.8 microg/ml). The IGF-I levels of the thyroid patients aged 20-40 showed significant negative correlation to TSH and positive correlations to the thyroid hormones. Hence, whilst low IGF-I is associated with hypothyroidism, high IGFBP-3 is associated with hyperthyroidism. Our finding that IGFBP-3 remained significantly elevated in patients with suppressed TSH but normalised fT4 and fT3 is important as it suggests a prolonged tissue effect of thyroid hormones on IFGBP-3. As such patients have been shown to have higher risk for atrial fibrillation, the significance and possible role of IGFBP-3 in these conditions should be further elucidated in future studies.
Malaysian edible bird's nests (EBN) are from the swiflet species, Aerodromus fuciphagus. The objective of this study was to determine and compare the nutrient composition of EBN obtained from different parts of Peninsular Malaysia, collected at three different harvesting seasons, to four commercial brands. A total of 18 raw, unprocessed EBN samples from the North, South and East Coast zones of Peninsular Malaysia and duplicate samples of 4 commercial brands (processed) of EBN samples were analysed. The protein and mineral contents of unprocessed EBN samples between zones and harvesting seasons were comparable. Mean (± SEM) protein content of unprocessed EBN was 61.5 ± 0.6 g/100g and the top four minerals detected were calcium, sodium, magnesium and potassium with mean (± SEM) concentration of 553.1 ± 19.5 mg/100g, 187.9 ± 10.4 mg/100g, 92.9 ± 2.0 mg/100g and 6.3 ± 0.4 mg/100g respectively. Sialic acid content ranged between 0.7 to 1.5%, and remained comparable between samples from different zones and harvesting seasons. The commercial brands were found to contain higher amounts of calcium, sodium, magnesium, potassium and phosphorus compared to unprocessed EBN, warranting further investigation and verification with more samples. Since the nutrient contents of EBN may be affected by seasonal variations and even breeding sites, it is recommended that a more comprehensive study be conducted involving more samples and breeding sites as such data are important to ensure sustainability of the EBN industry in this country.
BACKGROUND: The urinary iodine micromethod (UIMM) is a modification of the conventional method and its performance needs evaluation.
METHODS: UIMM performance was evaluated using the method validation and 2008 Iodine Deficiency Disorders survey data obtained from four urinary iodine (UI) laboratories. Method acceptability tests and Sigma quality metrics were determined using total allowable errors (TEas) set by two external quality assurance (EQA) providers.
RESULTS: UIMM obeyed various method acceptability test criteria with some discrepancies at low concentrations. Method validation data calculated against the UI Quality Program (TUIQP) TEas showed that the Sigma metrics were at 2.75, 1.80, and 3.80 for 51±15.50 µg/L, 108±32.40 µg/L, and 149±38.60 µg/L UI, respectively. External quality control (EQC) data showed that the performance of the laboratories was within Sigma metrics of 0.85-1.12, 1.57-4.36, and 1.46-4.98 at 46.91±7.05 µg/L, 135.14±13.53 µg/L, and 238.58±17.90 µg/L, respectively. No laboratory showed a calculated total error (TEcalc)
The expression and synthesis of IGF-I and IGFBP-3 have been shown to be regulated by hormones and nutrition. We study the effects of malnutrition and iodine deficiency on these growth factors and the height attainment of a group of children.
This is a cross-sectional study conducted from January to September 2004 in a group of school children aged 8 -10 years old. The schools and study subjects were selected using stratified systematic sampling technique. A total of 44 schools and 1100 subjects were selected from schools with iodinator and schools without iodinator. Samples collected were spot urine and drinking water. Dietary and iodised water consumption data were obtained from interviews. A total of 931 subjects (84.6%) responded; 558 (50.7%) from schools with iodinator and 373 (33.9%) from schools without iodinator. Results showed that in more than half (53.8%) of the schools with iodinators, mean water iodine level was below 25 microg/L. The study population in Terengganu was found to be mildly iodine deficient with an overall median urine iodine concentration (uIC) of 74 microg/L. Based on WHO criteria, 4.1% with uIC <20 microg/L (severe), 19.5% with uIC between 20-49 microg/L (moderate), 49.2% with uIC between 50-99 microg/L (mild) and 27.2% was iodine sufficient with uIC >100 microg/L. Majority of the study subjects were found to have high seafood intake (> 90%) and low in goitrogen food intake. This study suggests water iodinator system may not be a suitable method of supplying iodine and an alternative is needed in order to eradicate the iodine deficiency problem seen in some parts of Malaysia.
We evaluated the effects of a standardized Labisia pumila var. alata (LPva) extract on body weight change, hydroxysteroid (11-beta) dehydrogenase 1 (HSD11B1) expressions and corticosterone (CORT) level in ovariectomized (OVX) rats. The decoction of LPva has been used for generations among Malay women in Malaysia to maintain a healthy reproductive system.Thirty-six Sprague-Dawley OVX rats were treated orally with LPva extract (10, 20 or 50 mg/kg/day) or estrogen replacement (ERT) for 30 days. Sham operated rats were used as controls. Compared to untreated OVX rats, LPva-treated rats showed less weight gain and had significantly down-regulated HSD11B1 mRNA in liver tissues. HSD11B1 mRNA in adipose tissues increased by 55% (p < 0.05) in OVX rats but normalized in rats treated with LPva. Similarly, there was significant down-regulation (p < 0.05) of protein levels of HSD11B1 in both liver and adipose tissue of LPva and ERT groups, and CORT levels were significantly reduced in both groups of rats. This is the first study ever conducted to evaluate the beneficial effects of LPva in relation to weight gain caused by estrogen insufficiency. Results implied that the bioactive components in LPva extract affect not only HSD11B1 expressions in both adipose and liver tissues but also decrease circulating CORT. The extract should be explored for its potential use as a natural remedy for weight management.
New options are needed to prevent and treat metabolic disorders associated with polycystic ovary syndrome (PCOS). Labisia pumila var. alata (LPva)-a Malaysian herb thought to have phytoestrogenic effects-has shown promise in reducing body weight gain in ovariectomized rats. In this study, we investigated the effect of LPva on body composition and metabolic features in female rats treated continuously with dihydrotestosterone, starting before puberty, to induce PCOS.
Thyroid function and pubertal development of aborigines (Orang Asli) and Malays at different socioeconomic strata were assessed among 1136 subjects aged 7 years and above. Anthropometric measurements, goitre and pubertal staging were done. Serum thyroxine (T4), triiodothyronine (T3) and growth hormone were measured using radioimmunoassays (RIA) and serum thyroid stimulating hormone (TSH) by immunoradiometric assays (IRMA). It was found that serum T3 in children was significantly higher in Malays from rural areas, girls and children aged less than 13 years. However, in adults, T3 was significantly associated with anthropometric indices. On the contrary, serum T4 levels were higher among children from urban areas. In adults, serum T4 levels were significantly related to nutritional status and they increased according to the levels of social development, being lowest in remote areas and highest in urban areas. However, serum TSH levels were significantly higher in Orang Asli at all ages and among malnourished children. By using multiple regression, apart from age, gender and ethnicity, nutritional status was a significant predictor for T3 levels in children and adults. Presence of goitre was an important factor which determined the T4 levels in children and adults after controlling for other factors. It was also a predictor for TSH levels in children but not in adults. Fasting serum growth hormone (GH) levels were significantly higher among less privileged groups and decreased according to social development. Serum growth hormone was negatively correlated with anthropometric indices and had a significant association with malnutrition.(ABSTRACT TRUNCATED AT 250 WORDS)
The effect of thyroid hormones on the renin-angiotensin-aldosterone system has not been fully resolved. Highly specific immunoassays for measurement of renin, aldosterone, free T4 (fT4), free T3 (fT3) and ultrasensitive TSH enables a direct and more accurate measurement of these hormones. We investigated the relationship between plasma renin, aldosterone and thyroid hormones in the basal state and after intravenous frusemide. This is a cross-sectional study involving 37 patients with thyrotoxicosis, 42 rendered euthyroid with normal fT4, fT3 and TSH levels, 17 with euthyroid levels of fT4 and fT3 but suppressed TSH, and 11 with hypothyroidism. Basal plasma renin was significantly higher in thyrotoxicosis (63.4 +/- 9.8 microU/ml, mean +/- SEM) compared to euthyroid (32.7 +/- 4.4 microU/ml) and hypothyroid (26.7 +/- 9.8 microU/ml). Basal plasma renin for euthyroid with suppressed TSH (41.0 +/- 7.4 microU/ml) was significantly higher than hypothyroid (p = 0.02). Basal plasma aldosterones were not significantly different except for suppressed TSH (157.7 +/- 13 pg/ml), which was higher than normal (109.9 +/- 10.4 pg/ml; p = 0.04). Following frusemide, plasma renin and aldosterone were significantly increased in all groups. Plasma renin was highly correlated to fT3 (r = 0.405, p < 0.001), total T3 (r = 0.359, p < 0.001), fT4 (r = 0.331, p < 0.001) and TSH (r = 0.300, p < 0.001) in the basal state, but less to total T4 (r = 0.248, p < 0.01). Plasma renin correlated poorly to serum aldosterone (r = 0.212, p < 0.03). This study clearly showed that regulation of renin was mainly influenced by fT3, and that aldosterone response to frusemide was blunted in thyrotoxicosis despite normal electrolytes.
BACKGROUND: The role of endothelial injury and circulating adhesion molecule in the development and progression of diabetic peripheral neuropathy in the long-term has been established previously.
AIMS: To study the effects of short-term glycemic control using insulin and oral hypoglycemic agent therapy (OHA) on the peroneal nerve function and vascular cell adhesion molecule-1 (VCAM-1) and advanced glycation endproducts (AGE) levels in type 2 diabetic patients.
SETTINGS AND DESIGN: A randomized controlled study involving poorly controlled (HbA1c, 7.5%-11%) type 2 diabetic patients attending the endocrinology outpatient center in a tertiary hospital in Kuala Lumpur.
MATERIALS AND METHODS: Twenty-nine patients were randomized to receive insulin (n=15) or OHA (n=14) for 8 weeks. The glycemic variables (HbA1c, fasting plasma glucose [FPG], fructosamine), VCAM-1, serum AGE and the peroneal motor conduction velocity (PMCV) were measured at baseline and at 4-week intervals.
STATISTICAL ANALYSIS USED: Paired 't' test or Kruskal Wallis test; and the unpaired 't' test or Mann-Whitney U test were used for within-group and between-group analyses, respectively. Correlation was analyzed using Spearman's correlation coefficient.
RESULTS: Within-group analysis showed significant progressive improvement in HbA1c at weeks 4 and 8 in the insulin group. The PMCV improved significantly in both groups by week 8, and by week 4 (P = 0.01) in the insulin group. PMCV correlated negatively with VCAM-1 (P = 0.031) and AGE (P = 0.009) at week 8.
CONCLUSION: Aggressive glycemic control with insulin improves the peroneal nerve function within 4 weeks. Improvement in the serum VCAM-1 and AGE levels correlated significantly with improvement in peroneal nerve conduction velocity only in the insulin group.
Study site: Tertiary endocrinology outpatient center in Kuala Lumpur, Malaysia
This is a report of a cross sectional study involving 3 groups of children, moderately malnourished (BMI < 15), mildly malnourished (BMI 15-18) and well nourished (BMI > 18) to determine the differences in hormonal and biochemical parameters between the groups. The children were of age range from 7-17 years old. The children were from the same area with exposure to the same food, drinking water and environment. There were significant differences in the nutritional indices between the three groups. No differences were observed in levels of triiodothyronine (T3), thyroxine (T4) and T3:T4 ratio. Significant difference however was found in the TSH levels using highly sensitive IRMA TSH assays. Moderately malnourished children had higher TSH levels (p < 0.05) compared to mildly malnourished and well-nourished children. No difference was found between the mildly malnourished and well-nourished groups. There were no significant differences in serum cortisols done at similar times, fasting growth hormone and calcium. Serum alanine transminase (ALT) however was higher in moderately malnourished than in well-nourished children. Thus using highly sensitive IRMA TSH assays, we were able to detect differences in TSH levels even though T3, T4 and T3:T4 ratio, cortisol, growth hormone and calcium were normal, implying in moderately malnourished children, a higher TSH drive to maintain euthyroid state.
The Malaysian National Health Morbidity Survey III (NHMS III), conducted in 2006, was a cross-sectional household survey of the prevalence of chronic diseases, involving 34,539 respondents of age > or =18 years old, in all states of Malaysia. Data collection was by face-to-face interview. Those who self-professed not to be diabetics underwent finger-prick glucose test following at least 8 hours of fasting. The overall prevalence of diabetes mellitus (known and newly diagnosed) was 11.6%. The Indians had the highest prevalence of 19.9% followed by Malays 11.9% and Chinese 11.4%. The prevalence of people with known diabetes and newly diagnosed diabetes was 7.0% and 4.5% respectively. Impaired Fasting Glycaemia was found to be 4.2%. Majority (73.5%) of the patients used government healthcare facilities for their diabetic care. Usage of insulin alone or in combination was low at 7.2% of patients. Only 45.05% of known diabetics have ever had their eye examined. Amputees formed 4.3% of the patients with known diabetes while 3.4% had suffered a stroke event and 1.6% was on some form of renal replacement therapy.
Study name: National Health and Morbidity Survey (NHMS-2006)
This cross-sectional study looked at the prevalence of microalbuminuria and retinopathy in a cohort of 926 young, Type 1 and Type 2 diabetes mellitus (DM) patients, and determined the factors which were associated with these microvascular complications. The prevalence of microalbuminuria, defined as the albumin:creatinine ratio > or = 2.5 (for males) or > or = 3.5 mg/mmol (for females), was 13.4% in Type 1 DM, 69.5% in insulin-requiring Type 2 DM and 16% in Type 2 DM treated only with oral hypoglycemic agents. Compared to those with normal renal functions, these patients were older (P < or = 0.01), had significantly elevated blood pressures (P < 0.01 or P = 0.0001), and in the case of Type 1 DM, with a higher body mass index (P = 0.0001) and waist-hip ratio (P < 0.01). The prevalence of diabetic retinopathy in Type 1 DM was found to increase with the duration of diabetes, from 1.4% in the newly-onset (< 5 years), to 9.9% in those with 5-10 years disease, to 35% among patients with more than 10 years of diabetes (P < 0.0001). In this study, it was also observed that 10% of the Type 2 DM patients already had retinopathy within 5 years of diagnosis, and the prevalence increased significantly to 42.9% (P < 0.0001) among patients who had been diabetics for more than 10 years. Stepwise multiple regression analysis showed that besides the disease duration, systolic blood pressure was the most common and significant determinant for both microalbuminuria and retinopathy in both types of DM, thus implying that in order to reduce the risk of microvascular complications in diabetes mellitus, systolic and not just the diastolic blood pressure, should be effectively controlled.
This study determined the prevalence of glutamic acid decarboxylase antibodies (GAD Ab) in a group of 926 young Malaysian diabetics of three ethnic groups, Malay, Chinese, and Indian. Patients were clinically diagnosed to be Type 1 or Type 2 before the age of 40 years. The overall GAD Ab positivity was 17.4% (161/926), significantly higher in the Type 1 than the Type 2 diabetics (35.5%, 116/329 vs. 7.5%, 45/597, P=0.0001). Compared to GAD Ab negative patients, seropositive diabetics were diagnosed at younger age (21.2+/-0.9 vs. 27.4+/-0.3 y, P=0.0001), had lower fasting (289+/-27.4 vs. 640+/-17.6 pmol/l, P=0.0001) and post-glucagon C-peptide levels (527+/-51.8 vs. 1030+/-28.9 pmol/l, P=0.0001). There were no racial differences in the prevalence of GAD Ab; of the total Type 1, 30.8, 36.4, and 39.4% were Malay, Chinese, and Indian diabetics, respectively and of the total Type 2, 8.8, 8.2, and 4.4% were Malay, Chinese, and Indian diabetics respectively. There was a curvilinear relationship between GAD Ab and the post-glucagon C-peptide levels, suggesting that GAD Ab do play a role in the beta-cells destruction and could be an important immune marker for the LADA group. This study reconfirmed previous reports that the autoimmune mechanisms in the Type 1 Asian diabetics are indeed different from the Caucasians, and further investigations should be carried out to explain the differences.
The purpose of this study was to investigate the usefulness of triglyceride to hdl-c ratio (TG:HDL-C) as an insulin resistance (IR) marker for overweight and obese children. A total of 271 blood samples of obese and overweight children aged 9-16 years were analysed for fasting glucose, lipids and insulin. Children were divided into IR and non-insulin resistance, using homeostasis model assessment (HOMA). The children were then stratified by tertiles of TG: HDL-C ratio. The strength between TG:HDL-C ratio and other parameters of IR were quantified using Pearson correlation coefficient (r). Odds ratio was estimated using multiple logistic regression adjusted for age, gender, pubertal stages and IR potential risk factors. Children with IR had significantly higher TG:HDL-C ratio (2.48) (p = 0.01). TG:HDL-C ratio was significantly correlated with HOMA-IR (r = 0.104, p