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Biomedical subjects

J S Cheah

Publications and source records attributed to J S Cheah.

At least 91 records · Page 5Linked to original sources

HLA and insulin dependent diabetes mellitus in Singaporean Chinese.

Singaporean Chinese IDDM was significantly associated with AW33, BW58, DR3 and DR4. AW33, BW58 and DR3 being in strong linkage disequilibrium among the Chinese, were associated most strongly with IDDM whose onset was less than or equal to 10 years. The strength of this association showed a significant inverse relationship with age of onset. The frequency of DR4 was significantly elevated on in the 11-20 year IDDM group. The importance of DR3 in Chinese IDDM was also reflected in the observations of joint occurrences of DR antigens. In the less than or equal to 10 years subgroup, the significant association were either DR3/DRW9, DR3/DR4 or DR3/BLANK. In the 11-20 years subgroup, DR4 appeared to be more important and DR4/DR3 and DR4/BLANK were strongly associated with IDDM in this subgroup.

Adolescent↗

HLA and Chinese patients with juvenile onset diabetes mellitus.

The HLA profile of 147 Chinese patients with juvenile onset diabetes mellitus was studied. There were HLA associations related to different age of onset of the disease. The patients who presented during the first decade of life had strong linkages with AW 33, B 17 and BW 22 (BW 54/55) but a weak association with DR 4. In contrast, patients whose age of onset ranged from 31 to 39 years had increased frequency of BW 46. Patients with diabetic complications (retinopathy, nephropathy, neuropathy and peripheral vascular disease) which were present singly or in combination were associated with HLA AW 33 and B 17. It would appear that genetic factor may be related to both the age of onset of diabetes as well as to the development of complications.

Adolescent↗

Insulin secretory capacity in Singapore diabetic subjects.

The determination of serum C-peptide has been found to be a sensitive indicator of endogenous insulin secretion, and serves to define diabetic patients who require insulin therapy i.e., insulin-dependent (Type I, IDDM) and those non-insulin dependent (Type II, NIDDM). The aim of our study is to establish the types of diabetes mellitus with C-peptide measurement in a group of diabetic subjects on different modes of therapy. Eighty-eight diabetic patients (60 males, 28 females) were studied. Thirty-four were on insulin (age 40 +/- 2 years; means +/- SEM), 35 on oral agents (54 +/- 1 years), and 19 on diet alone (46 +/- 3 years). Twenty healthy subjects (10 males, 10 females) serve as normal controls (37 +/- 3 years). Blood samples for serum C-peptide and blood glucose estimations were obtained after an overnight fast and one hour after a 75 grams oral glucose load. Fasting C-peptide levels obtained for the various groups were: 0.62 +/- 0.07 (nmol/L, means +/- SEM) (normal), 0.16 +/- 0.02 (insulin), 0.79 +/- 0.06 (oral), 2.15 +/- 0.15 (diet). The C-peptide values after oral glucose were 1.80 +/- 0.20 (normal), 0.23 +/- 0.05 (insulin), 1.72 +/- 0.02 (oral), 2.15 +/- 0.15 (diet). Both the fasting and post-glucose C-peptide concentrations were significantly lower (p less than 0.001) in the insulin group compared to the normals, whereas values for the diet and oral groups were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Infections in diabetes with special reference to diabetics in Singapore.

Most physicians believe that the diabetic patient is predisposed to infections and that infections complicate the control of the diabetes. Despite the lack of scientific proof, certain infections (such as tuberculosis, bacteriuria in females, malignant external otitis, rhinocerebral mucormycosis, emphysematous cholecystitis, emphysematous pyelonephritis, acute papillary necrosis etc) are widely regarded to be associated with the diabetic. Foot infections, infections of the respiratory tract and the urinary tract are very important in the diabetic. The reasons why diabetics are susceptible to infections are unclear: although the production of humoral antibody appear intact, defective function of the polymorphonuclear leucocytes has been demonstrated. Successful treatment of infections in the diabetic requires early and exact diagnosis, the exhibition of the correct antimicrobials, the treatment of the diabetic state and associated disorders and prompt surgical intervention where required. Good control of blood glucose in diabetic patients is a desirable goal in the prevention of certain infections and to ensure maintenance of normal host defense mechanisms that determine resistance and response to infection.

Abscess↗

Reversal of azoospermia in an insulin dependent diabetic.

A 32-year old Chinese man with insulin dependent diabetes developed impotence and infertility with total azoospermia. The azoospermia was reversed following improved diabetic control with soluble insulin three times daily. With the reversal of azoospermia, his wife conceived five months later.

Adult↗

Hypoglycaemia in diabetes mellitus.

Hypoglycaemia in diabetes mellitus, occurring as a complication of treatment with insulin or oral hypoglycaemia drug therapy or spontaneously as a result of other medical conditions, is a frequent clinical problem. This paper will discuss the common causes of hypoglycaemia in diabetes mellitus, principles of treatment and prevention.

Diabetes Complications↗

A comparative study of three methods of glycosylated haemoglobin measurements.

This report summarizes our experience with 3 methods of glycosylated haemoglobin (HbA1) determinations. Glycosylated haemoglobin levels were determined using microcolumn chromatography (Boehringer Mannheim), agar gel electrophoresis (Corning GlytracTM) and colorimetry. The HbA1 values for 40 normal controls using chromatography, electrophoresis and colorimetry were 7.31 +/- 0.67 (+/- 1 S.D.), 7.98 +/- 0.81 and 8.54 +/- 1.09% respectively. The intra-assay coefficients of variation were 3.3, 4.5 and 2.0% respectively. There were also good correlations among the 3 methods of HbA1 measurements: electrophoresis vs chromatography, r = 0.91 (p less than 0.001) and electrophoresis vs colorimetry, r = 0.84 (p less than 0.001). Similarly, all 3 methods correlated well with the fasting and mean grouped blood glucose values (p less than 0.001). The chromatographic method is precise and well suited for small sample analysis. The colorimetric method, although the least expensive is labour intensive, suitable only for large batch analysis and in situations where results are not required immediately. The electrophoresis method is also precise, the least labour intensive and well suited for small and large volume laboratories. This study showed that since all 3 methods demonstrated similar precision and good correlation with fasting and grouped blood glucose values, the method of choice will depend on the requirements and support facilities of the individual laboratories.

Blood Glucose↗

Epidemiology of diabetes mellitus in Singapore: comparison with other ASEAN countries.

Singapore is a tropical island city-state with a population of 2.4178 million consisting of Chinese (76.7%), Malays (14.7%), Indians (6.4%) and other races (2.2%). A diabetic survey of the adult population, aged 15 years and above, carried out in 1975, shows that the prevalence of diabetes is 1.99%; it is higher in males (2.36%) than in females (1.64%). It occurs mainly in the age group 40 years and above (5.08%) and is uncommon in the age group 15-39 years (0.40%). In males, the highest prevalence of diabetes (7.0%) is in the age group 45-49 years while in females the highest prevalence (7.2%) is in the age group 55-59 years. 43.3% of the diabetics are of normal weight while 44.3% are overweight and 12.4% are underweight. 59.6% of the diabetics are newly diagnosed while 40.4% are known diabetics; 64.3% of the newly diagnosed diabetics have no symptoms. The prevalence of diabetes among the Indians (6.07%) is significantly higher than that in Malays (2.43%) and Chinese (1.55%). Indian diabetics have a slightly higher positive family history of diabetes (12.7%) than Malays (10.9%) and Chinese (6.5%). Obesity is commoner in Malay diabetics (64.7%) than in Chinese (41.6%) and Indians (35.7%). The possible factors leading to the significantly higher prevalence of diabetes among the Indians compared to the other ethnic groups in Singapore are discussed. It is suggested that the Indian gene is susceptible to diabetes (diabetic genotype) and increased food consumption, altered lifestyle and greater obesity leads to the expression of diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Home blood glucose monitoring, glycaemic control and diabetic complications.

The aim of this study was to evaluate the effect of home blood glucose monitoring on diabetic complications and metabolic control. Forty Chinese and Indian patients participated in the Diabetic Society of Singapore National Home Blood Glucose Monitoring (HBGM) Programme. The clinical progress, the blood glucose and glycosylated haemoglobin concentrations, and the platelet aggregation of the aforementioned patients were studied over a 6-month period; the results were compared with those from a matched, albeit smaller, control group of 18 diabetic patients who were on treatment but not in the HBGM programme. At the end of the six month period, three patients in the control group showed clinical deterioration of peripheral neuropathy in contrast to one patient on HBGM. Due to the small number of patients, the difference in the findings was not statistically significant. Patients on HBGM demonstrated significant improvement in mean grouped blood glucose profile values, 135 +/- 8 to 118 +/- 5 mg/dl, p less than 0.01, and glycosylated haemoglobin levels, 10.3 +/- 0.4 to 9.3 +/- 0.3%, p less than 0.01. The platelet aggregability was unchanged. In contrast, patients in the control group developed a significant increase in platelet aggregation (30 +/- 4% to 37 +/- 5%, p less than 0.05), although the blood glucose and glycosylated haemoglobin concentrations were not significantly altered. This study demonstrated that patients on a six-month HBGM programme were able to achieve improved glycaemic control associated with a trend towards decreased deterioration of diabetic neuropathy and platelet aggregability.

Adult↗

Combined team management of diabetes mellitus in pregnancy.

225 women with diabetes in pregnancy were managed by a team of obstetricians, physicians (endocrinologists) and paediatricians from the National University of Singapore. A protocol of management was formulated and followed. The incidence of 1.1% or 1 in 90 pregnancies was found, with significantly higher incidence in Indians and lower in Malays. There were 37 established diabetics and 188 diagnosed during pregnancy. Of these (188), 74 were gestational diabetics. All the women were treated with Insulin and Diet or Diet alone. 177 (79%) were treated with Insulin and Diet. Blood sugar profiles were done for monitoring diabetic control. 72.8% of the women were between para 0 and 1 and 85.2% between the ages of 20 and 34. 72.5% of the women delivered at 38 weeks gestation or later. 48.9% went into spontaneous labour, 32.4% were induced and 18.7% had elective caesarean section. 62.2% of the women had labour of less than 12 hours. The overall caesarean section rate was 41.7%. There were 3 stillbirths and 2 neonatal deaths. The perinatal mortality rate was 2.2%. Thirteen babies had congenital malformations (5.8%). 77.8% of the babies had Apgar score of 7 or more at 5 minutes after delivery. 79.1% of the babies weighed between 2.5 kgm and 3.9 kgm. Pre-eclamptic toxaemia was the commonest complication in pregnancy followed by Urinary Tract Infection and Polyhydramnios. Postpartum complications in the mother were confined to 14 women (6.2%), and wound infection or breakdown was the commonest cause.

Adult↗

Extremes of foetal birthweight for gestation in infants of diabetic mothers.

100 patients were registered at the Diabetic Clinic in 1981, where they were managed by a team of physician, obstetrician and paediatrician, based on a preset protocol. Only 92 patients were eventually analysed. The study showed a 1.3% incidence of pregnancies complicated by diabetes mellitus. The mean birthweights of infants of both gestational and established diabetics were heavier than that of the general population by race and gestation. 25% of the 92 infants of diabetic mothers have birthweight exceeding the 90th centile of population. Further division of the 92 patients into the "true gestational" diabetics, as shown by an oral glucose tolerance test performed 6 weeks post-natally, also showed a 25% incidence of macrosomia. Late antenatal booking, delayed detection of abnormal glucose tolerance and treatment attributed to the high incidence of macrosomia. Only one infant had birthweight below the tenth centile. There were no perinatal mortality in the 92 patients studied. Macrosomia is a common complication in infants of diabetic mothers despite a physician-obstetrician joint-care system. Also, the risk of having macrosomia amongst gestational diabetics is high.

Birth Weight↗

Insulin dependent diabetes and goitre in a case of hypomelanosis of Ito (Incontinentia Pigmenti Achromians).

Incontinentia Pigmenti Achromians (IPA) or, more aptly, Hypomelanosis of Ito is now largely accepted as a Neurocutaneous Disorder. Studies, so far, have focussed on the ultrastructural abnormalities and to our knowledge, there have been no attempts to ascertain if there is a particular HLA pattern. We describe an interesting case where IPA occurred in association with Insulin Dependent Diabetes as well as a goitre, suggesting that HLA studies may well be worthwhile. The literature is also reviewed.

Adult↗

Current concepts of the pathogenesis and management of diabetic ketoacidosis (DKA).

Diabetic ketoacidosis (DKA) is the commonest endocrine emergency encountered in clinical practice. Although in the last 3 decades the average worldwide immediate mortality has decreased from 10% to 5%, survival has not improved strikingly. The pathogenesis of DKA is currently attributed to a combination of two hormonal abnormalities--a relative insulin insufficiency and stress hormone excess (glucagon, catecholamines, cortisol and growth hormone). Withdrawal of exogenous insulin, pancreatic beta cell failure and insulin resistance are factors leading to relative insulin insufficiency. Factors leading to stress hormone excess include fasting, stress and dehydration. The combination of these two hormonal abnormalities leads to impaired carbohydrate utilization and ketonaemia which in turn results in metabolic acidosis with loss of water through acidotic breaths, rise in plasma lipids, hyperglycaemia and glycosuria leading to osmotic diuresis and further loss of water, excretion of partly neutralised ketoacids via the kidney with loss of cations (Na+ and K+). A net increase in protein catabolism which leads to an increased amino acid flux from muscle and an enhanced load of gluconeogenic precursor to the liver and a rise in blood pyruvate and lactate concentration. The prevention of either of these hormonal abnormalities will prevent the development of DKA. The successful outcome in the treatment of DKA is clearly related to the prompt recognition of the diagnosis and the precipitation factors, the severity of the initial metabolic derangements, the judicious use of fluid and electrolyte replacement, the choice, route and dosage of the insulin therapy and above all the close monitoring and meticulous clinical care of the patient throughout the entire course of the treatment. Current acceptable treatment of DKA include the following: adequate fluid replacement: low dose insulin therapy at frequent intervals; adequate potassium replacement from time of first insulin therapy with ECG monitoring; bicarbonate replacement if pH less than 7.1; broad spectrum antibiotics if infections is suspected and other supportive measures. The role of phosphate and magnesium replacement is still controversial. An awareness of the complications during the treatment of DKA including cerebral edema (paradoxical acidosis), altered central nervous system oxygenation, vascular thrombosis, shock, myocardial infarction, pancreatitis, infection, inhalation of vomitus , overhydration, underhydration , hypoglycaemia, hyperkalemia and hypokalemia all certainly help improve the morbidity and mortality of DKA.

Aged↗

The role of sympathomimetic amines in the dyspnoea of thyrotoxicosis.

Nine untreated thyrotoxic patients (5 males and 4 females) aged 23 to 56 years who complained of dyspnoea on moderate exertion were studied. Measurements of forced expiratory volume (FEV1), vital capacity (VC) and total lung capacity (TLC), oxygen consumption, (VO2), carbon dioxide output (VCO2) and the minute ventilation (VE) were determined on three occasions: before treatment; after treatment with propranolol and after carbimazole. Dyspnoea disappeared in 4 patients out of 9 after treatment with propranolol, while none were dyspnoeic when they became euthyroid. There was no significant difference in FEV1, VC, TLC and FRC on the three occasions. The differences between the VO2, VCO2 and VE before treatment and these values after treatment with carbimazole were significant. We conclude that the dyspnoea of thyrotoxicosis is due to both the effect of catecholamines and the metabolic effect of thyroxine.

Adult↗