Michael H.M. Chan

Hepatic steatosis in obese Chinese children

OBJECTIVES: The aims of our study were: (1) to determine the prevalence of asymptomatic hepatic steatosis and presumed nonalcoholic steatohepatitis, in our local population of obese Chinese children referred for medical assessment; and (2) to assess the correlation between severity of ultrasonographic hepatic steatosis and degree of obesity, insulin resistance and serum biochemical abnormalities.DESIGN: Cross-sectional study.METHODS: In total, 84 obese children, 25 girls and 59 boys with median age and body mass index (BMI) of 12.0 years (interquartile range (IR): 9.5–14.0) and 30.3 kg/m2 (IR: 27.1–33.4), respectively, referred for medical assessment were studied. All subjects underwent physical examination, anthropometric and dual energy X-ray absorptiometry (DEXA) scan measurements and real-time ultrasonographic (US) examination of the liver. Fasting blood samples were collected for the measurement of liver function, hepatitis status, levels of serum glucose and insulin and lipid profile. Degree of fatty infiltration of the liver was graded according to ultrasonic appearance of liver echotexture, liver–diaphragm differentiation in echo amplitude, hepatic echo penetration and clarity of hepatic blood vessels.RESULTS: All recruited subjects had no history of alcohol abuse and tests for Hepatitis B or C virus were negative. Thorough examination showed all of them to be in general good health without signs of chronic liver disease. Hepatic steatosis identified by defined ultrasonic appearances was diagnosed in 65 subjects (77%); 17 girls and 48 boys. The severity of fatty liver was positively related to anthropometric measurements including BMI, waist and hip circumference, subscapular skinfold thickness; insulin resistance markers [QUICKI and homeostasis model assessment (HOMA)], and hypertriglyceridaemia. Multvariate ordinal regression analysis showed that BMI and raised alanine aminotransferase (ALT) were positively associated with fatty liver. Combination of hepatic steatosis with raised ALT (presumptive NASH) was found in 19 subjects (24%). This group of patients had significantly higher waist hip ratio and conicity index compared to those with isolated hepatic steatosis. Boys with presumed NASH were also found to have significantly higher insulin resistance.CONCLUSION: Nonalcoholic fatty liver disease (NAFLD) was common among our cohort of obese children referred for medical assessment. The prevalence of simple steatosis and presumed NASH was 77 and 24%, respectively. The severity of US steatosis was positively correlated with BMI, raised ALT, insulin resistance and hypertryglyceridaemia. Ultrasonography being noninvasive and readily available could be used for the monitoring of the progression of hepatic steatosis. Further longitudinal studies are required to determine the natural disease progression and the role of insulin resistance and other factors in the pathophysiology of NAFLD.

IFCC educational materials on selected analytical and clinical applications of high sensitivity cardiac troponin assays.

In 2011, the IFCC Task Force on Clinical Applications of Cardiac Bio-Markers (TF-CB) was formed, with the purpose of providing evidence based educational materials to assist all biomarker users, i.e. laboratorians, clinicians, researchers, in-vitro diagnostics and regulatory agencies, in better understanding important analytical and clinical aspects of established and novel cardiac biomarkers for use in clinical practice and research. The goal of the task force was to promulgate the same information conjointly through the in vitro diagnostic industry to the laboratory, emergency department and cardiologists. The initial undertaking of the TF-CB, which is comprised of laboratory medicine scientists, emergency medicine physicians and cardiologists, was to address two key issues pertaining to implementing high-sensitivity cardiac troponin (hs-cTn) assays in clinical practice: the 99th percentile upper reference limit (URL) and calculating serial change values in accord with the Universal Definition of AMI. The highlights of both concepts from IFCC statements are described.

BMI and Waist Circumference in Predicting Cardiovascular Risk Factor Clustering in Chinese Adolescents

Objective: To derive the optimal BMI and waist circumference (WC) cut‐off values to predict clustering of cardiovascular risk factors in Hong Kong Chinese adolescents.

Vertebral Deformity in Chinese Men: Prevalence, Risk Factors, Bone Mineral Density, and Body Composition Measurements

Abstract. The prevalence and risk factors for vertebral deformity were studied in 396 community-dwelling Chinese men aged 70–79 years. Anterior to posterior (Ha/Hp), middle to posterior (Hm/Hp) and posterior to posterior (Hp/Hp − 1 or Hp/Hp + 1) ratios from T5 to L5 were derived from lateral spine X-ray films, using standardized digitization methods. Using values of 3 standard deviations (SD) or more below the mean and 4 SD or more below the mean as the cutoff, 16% and 7% of these men, respectively, were deemed to have one or more deformed vertebra. Heavy cigarette smoking, heavy alcohol consumption, and working as a heavy manual worker were risk factors for vertebral deformity. Men with severe vertebral deformity (VHR < mean − 4 SD below mean) had much lower body weight, fat mass, and bone mineral density (BMD) than controls. The odds ratios for severe vertebral deformity was 9.9 (95% CI 2.1–45.7) in the lowest quartile of femoral neck BMD.

Overweight, family history of diabetes and attending schools of lower academic grading are independent predictors for metabolic syndrome in Hong Kong Chinese adolescents

Background: Overweight and metabolic syndrome (MES) are emerging in both adult and paediatric populations. Aims: To study the prevalence of and associated risk factors for the MES, using the National Cholesterol Education Program definition, among Hong Kong Chinese adolescents studying in secondary schools. Methods: This was a cross-sectional, population-based study. A sample of 2115 Chinese adolescents was randomly selected from 14 secondary schools throughout Hong Kong. Data on anthropometric parameters, fasting blood and urine samples were collected in the school setting. Information regarding the adolescent’s family history of diabetes, perinatal history, socioeconomic status and school grading was evaluated. Results: The prevalence of MES was 2.4% (95% confidence interval (CI) 1.8 to 3.1), with no significant difference between boys (2.9%) and girls (2%). The prevalence of various components of MES was 32.2% (30.2 to 34.2) for hypertension, 10.9% (9.6 to 12.2) for increased triglyceride, 9.0% (7.8 to 10.2) for central adiposity, 2.4% (1.7 to 3) for low high-density lipoprotein cholesterol and 0.3% (0.1 to 0.6) for impaired fasting glucose. On multivariate analysis, overweight (odds ratio 32.2; 95% CI 13.2 to 78.4), positive family history of diabetes (4.3; 1.3 to 14.1) and studying at schools of lower academic grading (5.5; 2.2 to 13.7) were found to be independent risk factors for MES. Conclusion: A comparable prevalence of MES (2%) is observed in our study group Chinese adolescent girls and in US girls (2.1%), but a lower prevalence in Chinese boys (2.9%) than in US boys (6.1%). In our study, 41.8% harbour at least one component of the syndrome. Both families and schools should be alerted to this growing epidemic.

Association between obesity and atopy in Chinese schoolchildren.

Background: Despite parallel increases in asthma and obesity prevalence, there is little data on obesity as a risk factor for atopy. The latter is an important phenotype in asthmatic patients. This study investigates the association between asthma traits, atopy and obesity-related markers in Chinese adolescents. Methods: 486 schoolchildren were recruited among participants of our population-based study on the epidemiology of obesity, and their allergy status was ascertained using a standardized questionnaire. Subjects’ anthropometry was recorded on-site, and fasting blood was collected for allergen-specific immunoglobulin E (IgE), lipids and systemic inflammatory biomarkers. Results: 98 (20.2%) subjects were classified as overweight or obese. Obesity status was not associated with asthma, allergic rhinitis or eczema (p > 0.25). Atopy was not associated with age-adjusted body mass index (BMI) or waist circumference. Atopy and presence of allergen-specific IgE did not differ between overweight or obese children and those with normal BMI (p > 0.25), although subgroup analysis suggested that cockroach sensitization was more common among males who were obese or overweight (p = 0.045). White cell count (WCC) was higher among atopic than nonatopic children (mean values 6.5 × 109/l vs. 6.2 × 109/l, p = 0.006). Logistic regression revealed WCC to be the only risk factor for atopy (OR 18.97, p = 0.004). Conclusions: Obesity is not associated with asthma or atopy in Chinese children. High WCC is an important risk factor for atopy in both males and females. Gender does not exert any consistent effect on the association between obesity and allergen sensitization in children.

Mercury intoxication presenting with tics

A 5 year old Chinese boy presented with recurrent oral ulceration followed by motor and vocal tics. The Chinese herbal spray he used for his mouth ulcers was found to have a high mercury content. His blood mercury concentration was raised. Isolated tics as the sole presentation of mercury intoxication has not previously been reported.

Steroid‐induced osteonecrosis in severe acute respiratory syndrome: a retrospective analysis of biochemical markers of bone metabolism and corticosteroid therapy

Aim: We investigated the effect of massive doses of corticosteroid therapy on bone metabolism using specific biochemical markers of bone metabolism, and the prevalence of osteonecrosis in severe acute respiratory syndrome (SARS) patients at a university teaching hospital in Hong Kong. Methods: Seventy‐one patients with a clinical diagnosis of SARS were studied according to the modified World Health Organization case definition of SARS who were involved in the SARS epidemic between 10 March and 20 June 2003. The clinical diagnosis was confirmed by serological test and/or molecular analysis. Biochemical markers of bone metabolism were analysed retrospectively using serial clotted blood samples collected from each patient during the course of hospital admission to discharge and subsequent follow‐up at out‐patient clinic using the arbitrary time periods: (i) Day <10; (ii) Day 28–44; (iii) Day 51–84; and (iv) Day >90 after the onset of fever. Magnetic resonance imaging of the knee and hip joints were performed post‐admission to evaluate the prevalence of osteonecrosis amongst these SARS patients. Various risk factors for the development of osteonecrosis were assessed using receiver operating characteristics curve comparison with appropriate test statistics and Spearmans coefficients of rank correlation with biochemical bone markers. Results: Biochemical markers of bone metabolism showed significant bone resorption as evidenced by a marked increase in serum C‐terminal telopeptide concentration (CTx) from Day 28–44 after the onset of fever. With tapering down of corticosteroid dosage, CTx started to return to previous baseline level from Day 51 onwards, while other bone formation markers, serum osteocalcin and bone‐specific alkaline phosphatase concentrations (OC and BALP, respectively), started to increase. The latter effect was even more marked after Day >90. Seven patients developed radiological evidence of osteonecrosis. The prevalence of osteonecrosis in this cohort was 9.9%. A total corticosteroid dosage of >1900 mg hydrocortisone, >2000 mg methylprednisolone, >13 340 mg hydrocortisone‐equivalent corticosteroid therapy, and >18 days on corticosteroid therapy were found to be significant risk factors for the subsequent development of osteonecrosis. There were also significant positive correlations amongst various biochemical bone markers in this patient cohort. Conclusions: Both bone resorption and formation markers were unable to predict the subsequent development of osteonecrosis. The use of high dose of hydrocortisone or methylprednisolone for an extended duration was shown to be a significant risk factor for osteonecrosis. Its prevalence in this cohort is comparable to those reported in the literature for SARS patients with high‐dose corticosteroid therapy. The Day 28–44 increase in the serum CTx coincided with the timing of corticosteroid use. The Day >51 increase in serum OC and BALP coincided with the timing of corticosteroid withdrawal.

Severe Hypoglycemia Identifies Vulnerable Patients With Type 2 Diabetes at Risk for Premature Death and All-Site Cancer: The Hong Kong Diabetes Registry

OBJECTIVE We examined the associations of clinical profiles in type 2 diabetic patients who developed severe hypoglycemia and their clinical outcomes, including death and all-site cancer. RESEARCH DESIGN AND METHODS A consecutive cohort of 8,767 type 2 diabetic patients with and without severe hypoglycemia in the 12 months before enrollment were recruited between 1995 and 2007, with follow-up until 2009. Severe hypoglycemia was defined by ICD-9 codes as hospitalizations resulting from hypoglycemia. Cox proportional hazards regression was used to calculate the hazard ratio (HR) and 95% CIs of clinical factors collected at enrollment for severe hypoglycemia. RESULTS In this cohort, mean age was 57.4 (SD 13.2) years and median disease duration of diabetes was 5 (interquartile range [IQR] 1–11) years. During a median follow-up of 6.71 (IQR 3.47–10.38) years, 235 patients had severe hypoglycemia (incidence 3.96 [95% CI 3.45–4.46] per 1,000 patient-years). At enrollment, patients with and without severe hypoglycemia had similar cancer rates. During follow-up, patients with severe hypoglycemia had a higher incidence of all-site cancer (13.4 vs. 6.4%, P < 0.0001) and mortality (32.8 vs. 11.2%, P < 0.0001) than those without severe hypoglycemia. After adjusting for confounders, old age, low BMI, high glycated hemoglobin, low triglyceride (TG), low LDL cholesterol (LDL-C), albuminuria, and chronic kidney disease were independent predictors for severe hypoglycemia. CONCLUSIONS In type 2 diabetes, severe hypoglycemia is associated with advanced age, renal dysfunction, poor glycemic control, and cancer subphenotypes (low BMI, low LDL-C, and low TG).

Role of 'atypical pathogens' among adult hospitalized patients with community-acquired pneumonia

Background and objective:  Agents such as Mycoplasma pneumoniae, Chlamydophila pneumoniae and Legionella pneumophila are recognized as important causes of community‐acquired pneumonia (CAP) worldwide. This study examined the role of these ‘atypical pathogens’ (AP) among adult hospitalized patients with CAP.