A. C. Thai

STUDY OBJECTIVE: The aim of the study was to examine cardiovascular risk factors to see how these might explain differences in cardiovascular disease mortality among Chinese, Malays, and Indians in the Republic of Singapore. DESIGN: The study was a population based cross sectional survey. Stratified systematic sampling of census districts, reticulated units, and houses was used. The proportions of Malay and Indian households were increased to improve statistical efficiency, since about 75% of the population is Chinese. SETTING: Subjects were recruited from all parts of the Republic of Singapore. SUBJECTS: 2143 subjects aged 18 to 69 years were recruited (representing 60.3% of persons approached). There were no differences in response rate between the sexes and ethnic groups. MEASUREMENTS AND MAIN RESULTS: Data on cardiovascular risk factors were collected by questionnaire. Measurements were made of blood pressure, serum cholesterol, low and high density lipoprotein cholesterol, fasting triglycerides and plasma glucose. In males the age adjusted cigarette smoking rate was higher in Malays (53.3%) than in Chinese (37.4%) or Indians (44.5%). In both sexes, Malays had higher age adjusted mean systolic blood pressure: males 124.6 mm Hg v 121.2 mm Hg (Chinese) and 121.2 mm Hg (Indians); females 122.8 mm Hg v 117.3 mm Hg (Chinese) and 118.4 mm Hg (Indians). Serum cholesterol, low density lipoprotein cholesterol and triglyceride showed no ethnic differences. Mean high density lipoprotein cholesterol in males (age adjusted) was lower in Indians (0.69 mmol/litre) than in Chinese (0.87 mmol/litre) and Malays (0.82 mmol/litre); in females the mean value of 0.95 mmol/litre in Indians was lower than in Chinese (1.05 mmol/litre) and Malays (1.03 mmol/litre). Rank prevalence of diabetes for males was Indians (highest), Malays and then Chinese; for females it was Malays, Indians, Chinese. CONCLUSIONS: The higher mortality from ischaemic heart disease found in Indians in Singapore cannot be explained by the major risk factors of cigarette smoking, blood pressure and serum cholesterol; lower high density lipoprotein cholesterol and higher rates of diabetes may be part of the explanation. The higher systolic blood pressures in Malays may explain their higher hypertensive disease mortality.

AIM: The aim of this study was to investigate the relationship between markers of metabolic control and inflammation and periodontal disease parameters in patients with diabetes. MATERIAL & METHODS: One hundred and eighty one adult patients with diabetes attending treatment at two diabetes centres were invited to participate in the study. Periodontal examination included full-mouth assessment for probing depths and bleeding on probing (BOP). Blood analyses were carried out for glycated haemoglobin, (HbA1c), high-sensitivity C reactive protein, (hsCRP) and lipid profile comprising total cholesterol, low-density lipoprotein cholesterol (LDL chol), high-density lipoprotein cholesterol (HDL chol) and triglycerides. RESULTS: Upon multivariate analysis, periodontal disease severity in terms of increased percentage of BOP and mean percentage of sites with probing depths > or = 5 mm were found to be associated with inadequate glycaemic control as measured by HbA1c (p<0.01). HsCRP was also found to be a significant predictor for mean percentage of sites with probing depths > or = 5 mm (p<0.05). After controlling for age, gender, smoking habits and number of teeth, positive correlations were found between HbA1c and percentage sites with probing depths > or = 5 mm, percentage sites BOP, total cholesterol, LDL chol and triglycerides (p<0.05). Using the adjusted differences, subjects with acceptable glycaemic control (HbA1c < 8%) showed a lower percentage of sites with BOP and probing depths > or = 5 mm (p<0.05) when compared with those having inadequate glycaemic control. There was also a trend towards lower blood cholesterol in the well-controlled group. CONCLUSION: The level of glycaemic control as measured by HbA1c emerged as the most consistent risk factor associated with the extent and severity of periodontal disease in this study cohort.

One hundred and twenty-nine patients with systemic lupus erythematosus were screened for thyroid function tests. Of these, 8.9% had hyperthyroidism and 3.9% Hashimoto's thyroiditis. Euthyroid sick syndrome was present in 47.8% of patients. There was a high prevalence of antimicrosomal and antithyroglobulin antibodies (32.2%). Aberrations in thyroid function tests are common in SLE but the incidence of thyroid failure is low.

Muscle weakness in patients with thyrotoxicosis during hypokalemic episodes (thyrotoxic periodic paralysis [TPP]) occurs sporadically and mostly in males. It is treated by infusion or oral supplementation with potassium and with resolution of the thyrotoxicosis state. The clinical features of TPP resemble familial hypokalemic periodic paralysis (hypoKPP), which has been linked to two mutations in the gene encoding the skeletal muscle calcium channel alpha-1 subunit (CACN1AS; Arg528His and Arg1239His) and to the sodium channel alpha-subunit (SCN4A; Arg672His). We screened for the mutations (CACN1AS by polymerase chain reaction-restriction fragment length polymorphism [PCR-RFLP]; SCN4A by single-strand conformation polymorphism analysis) described in hypoKPP in 20 unrelated patients with documented episodes of TPP (mean age, 40.0 +/- 12.3 years 19 males). Forty-eight patients with hyperthyroidism resulting from Graves' disease (48.5 +/- 12.3 years; 13 males), 1 patient with idiopathic hypoKPP (a 32-year-old male) and 32 healthy subjects (41.0 +/- 19.1 years; 16 males) were included. We found none of the TPP patients carry CACN1AS and SCN4A mutations. The hyperthyroid patients and control subjects were also negative for the mutations. The patient with idiopathic hypoKPP was genotyped to have the Arg528His mutation. These results suggest that despite close similarities between TPP and hypoKPP, a likely genetic basis for TPP does not involve the same gene mutations associated with hypoKPP.