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C C Chow

Publications and source records attributed to C C Chow.

At least 19 recordsLinked to original sources
PubMed2007

The alpha(1S) subunit of the L-type calcium channel is not a predisposition gene for thyrotoxic periodic paralysis.

OBJECTIVE: Thyrotoxic periodic paralysis (TTP) has been associated with genetic variations in the gene encoding the alpha 1 subunit of the L-type calcium channel (CACNA1S). Mutations in CACNA1S are known to account for the majority of cases of familial hypokalaemic periodic paralysis (HOKPP). In this study we have examined 48 genetic polymorphisms in the CACNA1S gene and genotyped a tagging set of representative polymorphisms to determine the role of this gene in TPP. DESIGN AND PATIENTS: A genetic association study was carried out with 98 TPP patients and 162 male thyrotoxic controls. Among 47 polymorphisms evaluated for linkage disequilibrium (LD) and the spectrum of haplotypes in the Chinese population, 31 were selected as tagging single-nucleotide polymorphisms (SNPs) for genotyping the whole sample. A new genotyping protocol was used to analyse an insertion/deletion (I/D) polymorphism. RESULTS: We studied the LD among 47 polymorphisms in the CACNA1S gene, which comprised a set of high-density markers with an average of one SNP every 2 kb. Subsequently, 31 tagSNPs were genotyped for all the samples. The gene is composed of three LD blocks. With this block structure, we were confident that variations of the gene were comprehensively covered by the tagSNPs. No significant association was found between the polymorphisms and TPP. CONCLUSION: We established the LD structure of this calcium channel subunit gene (CACNA1S) for the first time. However, its genetic variations are not associated with TPP in Chinese patients.

Adult↗
PubMed2006

End-stage renal disease risk equations for Hong Kong Chinese patients with type 2 diabetes: Hong Kong Diabetes Registry.

AIMS/HYPOTHESIS: The objective of the study was to investigate risk factors and develop risk equations for end-stage renal disease (ESRD) in Chinese patients with type 2 diabetes. SUBJECTS AND METHODS: A prospective cohort of 4,438 patients with type 2 diabetes mellitus and without ESRD (median observation period 2.9 years, interquartile range 1.6-4.1 years) was included in the analysis. The end-point (ESRD) was defined by: (1) death due to diabetes with renal manifestations or renal failure; (2) hospitalisation due to renal failure; (3) estimated GFR (eGFR) <15 ml min(-1) 1.73 m(-2). Cox proportional hazards regression was used to develop risk equations. The data were randomly and evenly divided into the training data for development of the risk equations and the test data for validation. The validation was performed using the area under the receiver operating characteristic curve (aROC), which takes into account follow-up time and censoring. RESULTS: During the observation period, 159 patients or 12.45 per 1,000 person-years (95% CI 10.52-14.37 per 1,000 person-years) developed ESRD. Known duration of diabetes, systolic blood pressure, log(10) total cholesterol:HDL cholesterol ratio and retinopathy were significant predictors of ESRD. After further adjusting for eGFR, log(10) spot albumin:creatinine ratio (ACR) and haematocrit, only eGFR, haematocrit and log(10) ACR remained as independent predictors of ESRD. The risk equation derived from these three independent predictors had good discrimination, with an aROC of 0.97. CONCLUSIONS/INTERPRETATION: Estimated GFR, haematocrit and ACR were independent predictors of ESRD and the derived risk equation performed well in Chinese patients with type 2 diabetes.

Asian People↗
PubMed2006

Chronic hepatitis B viral infection independently predicts renal outcome in type 2 diabetic patients.

AIMS/HYPOTHESIS: We examined the association between chronic hepatitis B virus (HBV) infection and clinical outcomes in a consecutive cohort of Chinese patients with type 2 diabetes. SUBJECTS, MATERIALS AND METHODS: Between 1995 and 1999, 2,838 type 2 diabetes patients underwent comprehensive assessments and blood screening for hepatitis B surface antigen (HBsAg). The risk of occurrence of cardiovascular events and end-stage renal disease (defined as need for dialysis, doubling of serum creatinine or serum creatinine > or =500 micromol/l) was compared between HBsAg-positive and HBsAg-negative groups. RESULTS: At baseline, HBV-infected patients (n=286, 10.1%) were younger (51.0+/-11.5 vs 53.7+/-12.7 years, p=0.004), had earlier onset of diabetes (51.0+/-11.5 vs 53.7+/-12.7 years, p=0.001) and a higher frequency of retinopathy (28 vs 22%, p=0.03) than non-HBV-infected patients. After a median follow-up of 3.5 years (interquartile range: 1.7-5.9 years) and adjustment of age, glycaemic control and other potential confounding factors, HBV-infected patients were more likely to develop end-stage renal disease than non-HBV infected patients (8.7 vs 6.4%) with a hazard ratio of 4.5 (95% CI 1.1-18.6). The difference in the frequency of cardiovascular endpoints was not statistically significant. CONCLUSIONS: In Chinese type 2 diabetes patients, chronic HBV infection was associated with increased risk of end-stage renal disease, and this was independent of other potential confounding factors. Early identification of HBV status and close surveillance of renal function are important in patients with type 2 diabetes who are living in areas where HBV is endemic or who are at risk of chronic HBV infection.

Age of Onset↗
PubMed2006

Metabolic syndrome by the international diabetes federation definition in Hong Kong Chinese.

In this report, we aimed to examine the impact of the new International Diabetes Federation (IDF) definition on the prevalence and clinical characteristics of subjects with metabolic syndrome (MES). Data were obtained from a prevalence survey for cardiovascular risk factors in a Hong Kong Chinese working population. There were 1513 subjects well representing all occupational groups from managers to general laborers [910 (60.1%) men and 603 (39.9%) women (mean age 37.5+/-9.2, median 37.0, range 18-66 years)]. The crude prevalence of MES defined by the IDF criterion was 7.4% (compared to other criteria: NCEP, 9.6%; WHO, 13.4% and EGIR, 8.9%). The age-standardized prevalence of MES by the IDF criterion was 8.8% in women and 7.3% in men. Subjects with MES defined by IDF criterion had higher body mass index and waist compared to those with MES defined by NCEP or WHO criteria, and lower triglyceride compared to those with MES defined by NCEP criterion after adjustment for age, gender and smoking. Non-MES subjects defined by IDF criterion had higher 2h glucose and insulin resistance compared to non-MES subjects defined by WHO. In conclusion, the new IDF criterion for MES is easy to implement in clinical practice. It may be potentially more 'specific' in identifying subjects with MES although compared to the NCEP criterion, it may have missed a proportion of subjects, especially men, who have metabolic derangement. Prospective and interventional studies are needed to validate the prognostic values of this new definition in comparison with other existing definitions.

Adolescent↗
PubMed2006

Assessment of glomerular filtration rate in addition to albuminuria is important in managing type II diabetes.

Although much emphasis has been placed on screening for albuminuria in type II diabetic patients, less attention has been focused on the role of glomerular filtration rate (GFR) in the assessment of risk. Herein, we examined the association between GFR and vascular complications in a consecutive cohort of 5174 type II diabetic patients between 1995 and 2000. Renal function was assessed by GFR (estimated by Modification of Diet in Renal Disease equation). The frequency of chronic kidney disease (CKD) as defined by GFR <60 ml/min/1.73 m(2), micro- and macrovascular complications, and their associations were analyzed. In this study cohort, 6% had serum creatinine > or =150 micromol/l and 15.8% had CKD. After adjustment for potential confounders, including urinary albumin excretion, odds ratios [95% confidence interval (CI)] across different stages of estimated GFR (> or =90, 60-89, 30-59, 15-29, <15 ml/min/1.73 m(2)) for macrovascular disease were 1.00, 1.42 [1.12-1.80], 1.80 [1.32-2.45], 2.74 [1.64-4.56], and 4.05 [1.77-9.26], respectively (P for trend <0.001); for retinopathy were 1.00, 1.23 [1.04-1.46], 1.80 [1.40-2.30], 2.05 [1.25-3.37], and 4.12 [1.56-10.90], respectively (P for trend <0.001); for sensory neuropathy were 1.00, 1.53[1.27-1.85], 2.09 [1.58-2.76], 4.32 [2.41-7.77], and 3.16 [1.25-8.02], respectively (P for trend <0.001); and for microalbumuria (with GFR <15 ml/min/1.73 m(2) excluded from the analysis) were 1.00, 1.51 [1.30-1.75], 5.80 [4.52-7.44], and 52.5 [16.4-168.2] respectively (P for trend <0.001). Measurement of serum creatinine alone without GFR may underestimate renal impairment in type II diabetic patients. Decreasing GFR was significantly associated with increasing frequency of micro- and macrovascular complications.

Adult↗
PubMed2006

Angiotensin-converting enzyme (ACE) inhibition in type 2, diabetic patients-- interaction with ACE insertion/deletion polymorphism.

Angiotensin-converting enzyme (ACE) insertion(I)/deletion (D) polymorphism may modify the effect of inhibition of the renin-angiotensin-aldosterone system (RAAS) on survival and cardiorenal outcomes in type 2, diabetes. A consecutive cohort of 2089 Chinese type 2 diabetic patients with mean (+/- standard deviation) age of 59.7 +/- 13.1 years were genotyped for this polymorphism by polymerase chain reaction method and were followed prospectively for a median period of 44.6 (interquartile range: 23.7, 57.5) months. Clinical outcomes, including all-cause mortality, cardiovascular and renal end points, were examined. The frequency for I allele was 67.1 and 32.9% for D allele, with observed genotype frequencies of 45.8, 42.6, and 11.6% for 3, DI and DD, respectively. ACE DD polymorphism was an independent predictor for renal end point with hazard ratio (HR) (95% confidence interval) of 1.72 (1.16, 2.56), but not for cardiovascular end point or mortality. After controlling for confounding factors, including ACE I/D genotype, the usage of RAAS inhibitors was associated with reduced risk of mortality (HR 0.34 (0.23, 0.50)) and renal end point (HR 0.55 (0.40, 0.75)). On subgroup analysis, the beneficial effects on survival (II vs DI vs DD: HR 0.29 (0.16, 0.51) vs 0.25 (0.14, 0.46) vs 1.33 (0.41, 4.31)) and renoprotection (II vs DI vs DD: 0.52 (0.30, 0.90) vs 0.43 (0.25, 0.72) vs 0.95 (0.43, 2.12)) were most evident in II and DI carriers. In conclusion, inhibition of RAAS was associated with reduced risk of mortality and occurrence of renal end point in Chinese type 2 diabetic patients. These benefits were most evident among II and DI carriers.

Aged↗
PubMed2006

Vascular defect beyond the endothelium in type II diabetic patients with overt nephropathy and moderate renal insufficiency.

There is a paucity of data on the effects of overt nephropathy and moderate renal impairment on endothelial function in diabetic patients. A total of 26 type II diabetic (DM) patients with nephropathy (DMN+) (mean +/- s.d. age: 63.7 +/- 6.3 years), 32 diabetic patients without nephropathy (DMN-) (59.4 +/- 10.1 years), and 52 non-diabetic subjects (54.9 +/- 8.2 years) were recruited. High-resolution ultrasound scan was used to measure carotid intima media thickness (IMT) and flow-mediated dilation (FMD) of the brachial artery. Endothelium-independent dilation was determined by maximal vascular dilation after sublingual nitroglycerine (glyceryl trinitrate (GTN)-induced dilation). The mean carotid IMT increased progressively from non-DM to DMN- to DMN+ groups (0.74 +/- 0.23 vs 0.80 +/- 0.25 vs 1.03 +/- 0.38 mm; P=0.001 for trend) whereas FMD- (4.3 +/- 2.5 vs 3.9 +/- 1.7 vs 1.9 +/- 2.0%, P<0.001 for trend) and GTN-induced dilation (14.7 +/- 4.0 vs 14.5 +/- 3.9 vs 10.3 +/- 3.2%; P<0.001 for trend) declined in an opposite manner. On multivariate analysis, age (beta=0.257, P=0.009), glomerular filtration rate (beta=-0.364, P<0.001), and smoking (beta=0.25, P=0.013) were independently associated with carotid IMT (F=15.76, R(2)=0.340, P<0.001). After adjustment for baseline brachial arterial diameter, history of smoking (beta=-0.039, P<0.001), fasting plasma glucose (beta=-0.033, P=0.002), and total cholesterol (beta=-0.023, P=0.024) were independently associated with vessel diameter after FMD (F=2446.5, R(2)=0.992, P<0.001); whereas age (beta=-0.069, P=0.001) and urinary albumin excretion (beta=-0.048, P=0.018) were independently associated with vessel diameter after GTN (F=851.6, R(2)=0.967, P<0.001). Type II diabetic patients with overt nephropathy and moderate renal impairment had both structural and functional vascular abnormalities beyond the endothelium.

Aged↗
PubMed2005

Polycystic ovarian syndrome in Hong Kong Chinese women: patient characteristics and diagnostic criteria.

OBJECTIVES: To identify the characteristics of Hong Kong Chinese women with polycystic ovarian syndrome and to compare different diagnostic criteria. DESIGN: Retrospective study. SETTING: Gynae-endocrinology Clinics in the Prince of Wales Hospital, Hong Kong. PATIENTS: Ninety Hong Kong Chinese women with polycystic ovarian syndrome who were diagnosed according to the hospital's criteria. MAIN OUTCOME MEASURES: Prevalence of typical features of polycystic ovarian syndrome, including anovulation and hyperandrogenism (with other endocrine causes excluded), polycystic ovarian features on ultrasonography, luteinising hormone predominance, obesity, and insulin resistance. RESULTS: Almost all (98.9%) patients with polycystic ovarian syndrome presented with anovulation, only 48.9% of them had clinical or biochemical evidence of hyperandrogenism. Typical ultrasound appearances of polycystic ovaries were observed in 86.7% of patients. Luteinising hormone predominance and insulin resistance were demonstrated in 67.8% and 40.7% of the cohort, respectively. Eight-six (95.6%) patients should have also been diagnosed with polycystic ovarian syndrome based on the 2003 Rotterdam new criteria. About 60% of patients who screened positive for insulin resistance had normal fasting serum glucose levels. The same proportion who had full screening for insulin resistance by oral glucose tolerance tests and fasting serum glucose to insulin ratios had discordant results of these two tests. CONCLUSIONS: The 2003 Rotterdam new diagnostic criteria for polycystic ovarian syndrome are generally applicable to the Hong Kong Chinese population. Early detection of insulin resistance in patients with polycystic ovarian syndrome can be ensured by performing an oral glucose tolerance test combined with measurement of fasting serum glucose to insulin ratio.

Adult↗
PubMed2004

No mutation in the KCNE3 potassium channel gene in Chinese thyrotoxic hypokalaemic periodic paralysis patients.

OBJECTIVES: Mutation in KCNE3 gene (Isk-related family potassium voltage-gated channel member 3 gene) was recently associated with the aetiology of thyrotoxic periodic paralysis (TPP). We studied 79 Chinese TPP patients by DNA sequencing of the entire coding sequence of KCNE3 to determine if this gene is the cause of TPP in Chinese patients. DESIGN AND MEASUREMENTS: A case-control genetic association study was carried out to determine the role of mutation/polymorphism in KCNE3 gene in the pathogenesis of TPP. Genomic DNA was extracted from peripheral blood samples. DNA sequencing was performed to cover the coding region of the KCNE3 gene for the TPP subjects. Restriction fragment length polymorphism was used to genotype specific sequence variants. subjects Seventy-nine TPP patients (cases) and 111 male thyrotoxic patients without history of paralysis (controls) were identified from thyroid clinic and during acute admission in a teaching hospital. RESULTS: No pathogenic mutation in KCNE3 was found in the TPP patients. The reported R83H mutation was also not found in the Chinese TPP patients. In addition, another silent polymorphism, 290T/C, was also not associated with TPP. CONCLUSION: The results indicate that mutation in KCNE3 is not a cause of TPP in Chinese patients.

Adult↗
PubMed2004

The associations of body mass index, C-peptide and metabolic status in Chinese Type 2 diabetic patients.

BACKGROUND: Chinese Type 2 diabetic subjects are generally less obese than their Caucasian counterparts. We hypothesized that lean and obese Chinese Type 2 diabetic subjects have different metabolic and insulin secretory profiles. We compared the clinical features, C peptide and metabolic status between lean/normal weight and obese diabetic subjects. STUDY DESIGN: We conducted a cross-sectional study on 521 consecutive diabetic subjects newly referred to a Diabetes Clinic in 1996. The subjects were categorized into underweight (< 18.5 kg/m(2)), normal weight (18.5-23 kg/m(2)) and overweight (>/= 23 kg/m(2)) according to the re-defined WHO criterion for obesity in Asia Pacific Region. Metabolic and anthropometric parameters were compared between groups with different levels of obesity. RESULTS: In this cohort, 5.8, 30.6 and 63.7% of subjects were underweight, normal weight and overweight, respectively, using the 'Asian' criteria. Of these 521 subjects, 20% had fasting C-peptide less than 0.2 nmol/l, suggesting insulin deficiency. Fasting C-peptide showed linear increasing trend (P < 0.001) while HbA(1c) showed decreasing trend (P = 0.001) with BMI after adjustment for duration of disease. There were more subjects in the underweight group who were treated with insulin (41.3% vs. 13.9 and 8.2%, P < 0.001). Although homeostasis model assessment was similar amongst the three groups, systolic (P = 0.006) and diastolic blood pressure (P < 0.001) and triglyceride (P < 0.001) showed increasing, while HDL-C (P < 0.001) showed decreasing, trends across different BMI groups. The underweight patients had the lowest C-peptide and highest HbA(1c) while overweight patients had the highest C-peptide, blood pressure, triglyceride but lowest HbA(1c) levels. CONCLUSION: In Chinese Type 2 diabetic patients, lean subjects had predominant insulin deficiency and obese subjects had features of metabolic syndrome. Clinicians should have low threshold to initiate insulin therapy in lean Type 2 diabetic patients with suboptimal glycaemic control. In obese diabetic patients, aggressive control of multiple cardiovascular risks is of particular importance.

Adolescent↗
PubMed2004

A patient with low free T4 and low thyroid-stimulating hormone without hypopituitarism.

A 39-year-old entertainer was referred in November 2000 for suspected secondary hypothroidism found during a routine insurance check. Thyroid stimulating hormone (TSH) was 0.30 mIU/L (NR 0.47-4.68 mIU/L) and total T4 was 21.6 nmol/l (NR 57.9-154.4 nmol/l). She had enjoyed good past health and gave birth to a baby girl at 32 weeks gestation in July 2000. She was clinically euthyroid and there was no goiter. Menses was regular with oral contraception. Thyroid function was rechecked with free T4 7.9 pmol/1 (NR 10.2-19.6 pmol/1) and TSH 5.44 mIU/l (NR 0.3-4 mIU/l). Further inquiry revealed that she had been taking a weight reducing drug since December 1999 for fear of potential weight gain during pregnancy. This was identified to be Tri-iodothyroacetic acid (Triac). Serial thyroid function tests showed gradual recovery of thyroid function after Triac was stopped.

Adult↗
PubMed2004

Use of an electronic barcode system for patient identification during blood transfusion: 3-year experience in a regional hospital.

OBJECTIVE: To evaluate the use of an electronic barcode system for patient identification during blood transfusion. DESIGN: Retrospective study. SETTING: Regional hospital, Hong Kong. PATIENTS: For all patients requiring blood transfusion between May 1999 and April 2002, with the exception of patients in the psychiatric wards and the accident and emergency department, a portable, hand-held scan-and-print electronic device was used to verify and document patients' identity at two critical points of transfusion: blood sampling for the compatibility test and blood administration. MAIN OUTCOME MEASURES: Scope of use of the electronic device, cost, effectiveness, staff compliance, problems and solution for improvement. RESULTS: In the first 3 years of hospital-wide use of the new device, no incidents of blood transfusion to wrong patients, or wrong labelling of blood samples, occurred with 41,00 blood sampling procedures and administration of 27 000 units of blood. Blood sampling took 6 minutes to complete with the use of the electronic device-similar to that taken by the conventional second-checker system. Among hospital staff, the compliance rate of using the new device approached 90%. Battery problems occurred in 12% of episodes of use of the device. CONCLUSIONS: The electronic barcode system was effective in reducing human error related to bedside transfusion procedures. The future goal is to tailor-make a more efficient device with additional functions.

Attitude of Health Personnel↗
PubMed2004

Infective thyroiditis in two cases of systemic lupus erythematosus.

We report on two patients with systemic lupus erythematosus, both of whom developed suppurative thyroiditis. One suffered from Staphylococcus aureus-induced thyroiditis and the other had tuberculous thyroiditis. The occurrence of tuberculous thyroiditis in systemic lupus erythematosus has not previously been reported. The diagnoses were made by fine-needle aspiration biopsy and subsequent bacteriological confirmation. Transient alteration of thyroid function was observed in both patients. In patients with systemic lupus erythematosus who present with fever and anterior neck pain, infection of the thyroid gland should be considered, and appropriate investigations undertaken.

Adult↗
PubMed2003

Triglyceride, albuminuria and blood pressure are the major associations of non-fatal cardiovascular disease in Chinese type 2 diabetes.

Diabetes is associated with an increased risk of cardiovascular disease (CVD). We studied risk factors for CVD in a cohort of Chinese type 2 diabetic patients recruited between July 1994 and August 1998. Ischemic heart disease (IHD) was defined as a history of: (i) confirmed coronary artery disease (with typical electrocardiographic changes or a positive exercise tolerance test) in patients under care of a cardiologist; (ii) documented myocardial infarction; or (iii) coronary interventions such as angioplasty or coronary artery bypass graft. Cerebrovascular accident (CVA) was defined as any definite cerebral vascular event with or without residual neurological deficit. CVD was defined as a history of IHD or CVA. The study enrolled 3333 patients, including 1370 men (41.1%) and 1963 women (58.9%) of mean age 55.9+/-13.3 years (range, 16-91 years; median, 57 years). A total of 279 patients (8.4%) had CVD (including 4.1% with CVA, 4.9% with IHD, and 0.6% with both CVA and IHD). Men had an overall higher rate of CVD than women (10.1% vs. 7.1%, p=0.002). All cardiovascular diseases showed a progressive increase in prevalence with increasing age with the peak among those aged </=60 years. Logistic regression analysis was used to examine the predictive value of age, body mass index, waist-to-hip ratio, blood pressure, fasting plasma glucose, glycated hemoglobin, lipid profiles, albuminuria, smoking and family history of diabetes on the risk of CVD. In women, age, systolic blood pressure and triglyceride level and in men, age and albuminuria, were predictive for CVD. In conclusion, 8.4% of Hong Kong Chinese type 2 diabetic patients being followed in a hospital out-patient setting have a history of established and confirmed cardiovascular disease. Age, systolic blood pressure, triglyceride and albuminuria were the major independent risk factors for non-fatal cardiovascular diseases.

Adolescent↗
PubMed2003

Oral alendronate increases bone mineral density in postmenopausal women with primary hyperparathyroidism.

The effect of biphosphonate therapy on bone mineral density (BMD) in patients with primary hyperparathyroidism (PHP) is unknown. Forty postmenopausal women (mean age, 70 yr) with PHP were randomized to receive alendronate 10 mg/d or placebo for 48 wk, followed by treatment withdrawal for 24 wk. The mean (+/-SD) changes in BMD at femoral neck (+4.17 +/- 6.01% vs. -0.25 +/- 3.3%; P = 0.011) and lumbar spine (+3.79 +/- 4.04% vs. 0.19 +/- 2.80%; P = 0.016) were significantly higher with alendronate at 48 wk. Serum calcium was reduced with alendronate but not placebo (-0.09 vs. +0.01 mmol/liter; P = 0.018). Serum bone-specific alkaline phosphatase activity was lower with alendronate from 12 wk onward and increased 24 wk after treatment withdrawal (21.1 +/- 12.8 to 7.3 +/- 4.9 IU/liter at 48 wk, and 15.0 +/- 14.8 IU/liter 24 wk after withdrawal; P = 0.002 for trend). Osteocalcin concentration decreased at 48 wk and increased 24 wk after alendronate withdrawal (P = 0.019 for trend of change over time) but not with placebo. Urinary N-telopeptide/creatinine ratio decreased with alendronate at 48 wk and increased 24 wk after treatment withdrawal (P = 0.008 for trend). N-telopeptide/creatinine ratio did not change with placebo. Alendronate improves BMD and reduces bone turnover markers in postmenopausal women with PHP.

Administration, Oral↗