Eric K.H. Liu

Symptoms of asthma and atopic disorders in preschool children: prevalence and risk factors

Background Published epidemiological data suggested that asthma and allergies may be increasing in preschool children. Identification of the risk factors is important for planning possible early intervention to prevent asthma. This study was designed to measure the prevalence of, and risk factors for, asthma and atopic disorders in preschool children from Hong Kong.

Asthma and atopy are associated with DEFB1 polymorphisms in Chinese children

Human β-defensin (HBD)-1 is constitutively expressed in the airway, and hBD-1 plays crucial roles in innate immunity against respiratory pathogens. Asthma was associated with DEFB1 polymorphisms in Caucasians. This study investigates whether three single nucleotide polymorphisms (SNPs) in 5′-untranslated region of DEFB1 are associated with asthma phenotypes in Chinese children. Subjects aged 5–18 years were recruited from general pediatric clinics. Plasma IgE concentrations were measured by immunoassays. DEFB1 SNPs were characterized by restriction fragment length polymorphism. In all, 305 asthmatics and 156 controls were recruited. For asthma diagnosis, atopy and plasma total IgE, higher percentages of subjects with these outcomes had the minor alleles −20A and −52G (P=0.041–0.0002). For log-transformed total IgE, the covariate was positive and significant for G-20A under recessive model (P=0.001) and for G-52A under both recessive and codominant models (P=0.008 and 0.035). The recessive model covariate was also positive and significant (P=0.020) for C-44G on peripheral blood eosinophil count. The GCA haplotype of DEFB1 was significantly associated with asthma (odds ratio (95% confidence interval): 1.64 (1.05–2.57); P=0.029). These results suggest that DEFB1 is a candidate gene for asthma and atopy in children.

Nitric oxide synthase polymorphisms and asthma phenotypes in Chinese children.

Background Nitric oxide (NO) is a key factor for balancing T‐helper type 1/T‐helper type 2 immunity. Single nucleotide polymorphisms (SNPs) in nitric oxide synthase (NOS) genes have been associated with atopy and exhaled NO concentrations in Caucasians. We investigated the association between asthma traits and genetic polymorphisms in neuronal NO synthase (NOS1) and endothelial NO synthase (NOS3) in Chinese children.

Hong Kong Chinese school children with elevated urine melamine levels: A prospective follow up study

BackgroundIn 2008, the outbreak of kidney stones in children fed by melamine-tainted milk products in Mainland China has caused major public concern of food safety. We identified Hong Kong school children with elevated urine melamine level from a community-based school survey in 2007-08 and reviewed their clinical status in 2009.MethodsIn 2007-08, 2119 school children participated in a primary and secondary school survey in Hong Kong using a cluster sampling method. Urine aliquots from 502 subjects were assayed for melamine level. High urine melamine level was defined as urine melamine/creatinine ratio >7.1 μg/mmol. Subjects with high urine melamine level were invited for clinical evaluation in 2009 including urinalysis and ultrasound imaging of the urinary system.ResultsThe age range of this subcohort was 6 - 20 years with 67% girls (335 female and 167 male subjects). The spot urine melamine/creatinine ratio of the 502 urine aliquots ranged from undetectable to 1467 μg/mmol (median 0.8 μg/mmol). Of these, 213 subjects had undetectable level (42%). We invited 47 (9%) subjects with high urine melamine level for re-evaluation and one subject declined. The median duration of follow-up was 23.5 months (interquartile range: 19.8 - 30.6 months). None of the 46 subjects (28% boys, mean age 13.9 ± 2.9 years) had any abnormality detected on ultrasound study of the urinary system. All subjects had stable renal function with a median urine albumin-creatinine ratio of 0.70 mg/mmol (interquartile range: 0.00 - 2.55 mg/mmol).ConclusionsHong Kong Chinese school children with high urine melamine levels appeared to have benign clinical course in the short term although a long term follow-up study is advisable in those with persistently high urine melamine level.

Effects of CPAP therapy on visceral fat thickness, carotid intima-media thickness and adipokines in patients with obstructive sleep apnoea.

Obstructive sleep apnoea (OSA) is associated with an increased prevalence of metabolic syndrome. This study explores the effects of continuous positive airway pressure (CPAP) for patients with OSA on visceral and mesenteric fat thickness, carotid intima‐media thickness (IMT) and adipokines.

Liver physiological T1rho dynamics associated with age and gender

Purpose Using a single breathhold black blood sequence, the current study aims to understand the physiological ranges of liver T1rho relaxation for women and men. Materials and Methods This volunteer study was conducted with institutional ethics committee approval, and included 62 females (age mean: 38.9 years; range: 18-75 years) and 34 males (age mean: 44.7 years, range: 24-80 years). MRI was conducted with a 3.0 T scanner, with six spin-lock times of 0, 10, 20, 25, 35, 50msec and a single breathhold of 12 seconds. Six slices were acquired for each examination. Results Female liver T1rho value ranged between 35.07 to 51.97ms, showed an age-dependent decrease with younger women had a higher measurement. Male Liver T1rho values ranged between 34.94 to 43.39 ms, and there was no evidential age-dependence. For females, there was a trend that liver T1rho value could be 4%-5% lower during menstrual phase than nonmenstrual phase. For both females and males, no evidential association was seen between body mass index and liver T1rho. Conclusion Liver T1rho physiological value for males have relatively narrow distribution, while physiological value for females have wider distribution, and decreases with age. Key points 1. Liver T1rho shows an age-dependency in women, with young women showing higher measurement. This age-dependency of liver T1rho measurement is not evidential in men. Post-menopausal women have similar liver T1rho value as men. 2. Women at menstrual phase may have slight lower liver T1rho measurement. 3. No association was noted between body mass index and liver T1rho 4. When blood signal suppression sequence is used, in a population of 62 healthy women and 34 healthy men, the highest measured liver T1rho was 52 msec for young women, 44.7 msec for post-menopausal women, and 43.4 msec for men.

Association between sonographically measured mesenteric fat thickness and brachial artery flow-mediated dilation in Chinese young male adults

Objective To investigate the potential correlation between sonographically measured mesenteric fat thickness (MFT) and brachial artery flow-mediated dilation (FMD) in a sample of healthy Chinese male young adults. Methods Healthy male participants were recruited from Hong Kong Polytechnic University for this prospective observational study. The physical activity readiness questionnaire and ultrasound measurements of carotid intima media thickness were used to screen for clinically healthy subjects. MFT and brachial artery FMD were measured by ultrasound, and body mass index (BMI) was recorded. Results A total of 34 healthy male subjects, aged 19–26 years (mean ± SD BMI, 21.7 ± 3.2 kg/m2) were included. Pearsons correlation coefficient test showed that brachial artery FMD had a statistically significant inverse relationship with BMI and with Log (MFT). Further stepwise multiple linear regression analysis showed that Log (MFT), and not BMI, was an independent predictor of impaired brachial artery FMD. Conclusions Sonographic measurements of MFT were an independent predictor of brachial artery FMD in Chinese male young adults.