Epidemiology of venous thromboembolism in a Chinese population

BACKGROUND: Deep vein thrombosis (DVT) is uncommon in Asians and routine thromboprophylaxis for surgery is controversial. Despite recent reports of higher incidences in some Asian countries, population-based data are lacking. METHODS: Information from 2000 to 2001 was retrieved from a centralized computer public healthcare database serving an ethnic Chinese population of 6.7 million. The incidence, demographics and hospital mortality rates of DVT and pulmonary embolism (PE) were obtained, and analysed for different surgical categories. RESULTS: The overall annual incidences of DVT and PE were 17.1 and 3.9 per 100000 population respectively. Venous thromboembolic disease was more common with increasing age in both sexes. The annual age-specific incidences of DVT and PE were 81.1 and 18.6 per 100000 for those aged 65 years and over. Hospital mortality rates associated with DVT and PE were 7.3 and 23.8 per cent respectively. Among 120940 surgical operations a year, the mean incidence of postoperative DVT and PE was only 0.13 and 0.04 per cent respectively. No high-risk surgical group was identified. CONCLUSION: Venous thromboembolism is not as common in Chinese as in Caucasians, but it is certainly not rare. The majority of DVTs and PEs, however, were not associated with surgery, so routine thromboprophylaxis may not be required.     

Continuous measurement of oxygen consumption during cardiopulmonary bypass: description of the method and in vivo observations

BACKGROUND: Systemic oxygen consumption is not routinely measured during cardiopulmonary bypass, despite its potential benefits. We aimed to develop a noninvasive method to continuously measure oxygen consumption using respiratory mass spectrometry during hypothermic cardiopulmonary bypass in pigs. METHODS: Nine pigs weighing 18.5 (1.6) kg underwent hypothermic (32 degrees C) cardiopulmonary bypass for 180 minutes with 120 minutes of aortic cross clamping. An AMIS 2000 mass spectrometer (Innovision A/S, Odense, Denmark) was adapted for the on-line measurement of oxygen consumption by sampling the inlet and outlet gases of the membrane oxygenator together with measurement of the "expired" gas volume. RESULTS: Active cooling for 60 minutes reduced the venous blood temperature by 2.9 (0.8) degrees C and VO(2) by 0.70 (0.33) mL/kg/min. The 40-minute active rewarming restored the venous blood temperature by 4.4 (0.4) degrees C and oxygen consumption increased by 1.36 (0.33) mL/kg/min. There was wide interanimal variability, however, particularly at higher venous blood temperatures. Immediately after the release of aortic cross clamp, there was a noticeably acute increase in oxygen consumption in all the pigs (0.64 [0.21] mL/kg/min). CONCLUSIONS: A simple and safe adaptation of mass spectrometry allows continuous measurement of oxygen consumption during hypothermic cardiopulmonary bypass. The wide interindividual variations observed in this pilot study underscore the need to more accurately describe changes in oxygen consumption and how they are affected by temperature, oxygen delivery, and other interventions during cardiopulmonary bypass. As such, the technique may have an important role in clinical research and management of oxygen transport in patients undergoing cardiac surgery.     

Early Data from the First Population-Wide Breast Cancer-Specific Registry in Hong Kong

Background

Current measures for breast cancer prevention and options for treatment adopted in Hong Kong are mainly based on research data and clinical evidence from overseas. It is essential to establish a cancer-specific registry to monitor the status of breast cancer in Hong Kong.

Objectives

We summarized the current status of breast cancer in Hong Kong based on the data collected from Hong Kong Breast Cancer Registry (HKBCR).

Methods

Prevalent and newly diagnosed breast cancers (including in situ and invasive breast cancers) were registered in the HKBCR. Information on patient demographics, risk factors, medical information, and survival were analyzed and reported in this study.

Results

Data of 2,330 breast cancer patients were analyzed. We observed an earlier median age at diagnosis in Hong Kong than those reported in other countries. Distribution of cancer stage was: stage 0 (11.4%), stage I (31.4%), stage II (41%), stage III (12.5%), stage IV (0.8%), and unclassified (2.9%). The percentages of patients who received surgery, chemotherapy, radiation therapy, and endocrine therapy were 98.7, 67.9, 64.8, and 64.1%, respectively. At a median follow-up of 1.2?years, locoregional recurrence was recorded at 2%, distant recurrence at 2.8%, and breast-cancer–related mortality at 0.3%.

Conclusions

The HKBCR serves as a surveillance program to monitor disease and treatment patterns. It is pivotal to support research for more effective breast cancer prevention and treatment strategies in Hong Kong.     

Ethnic difference of clinical vertebral fracture risk

Summary

Vertebral fractures are the most common osteoporotic fractures. Data on the vertebral fracture risk in Asia remain sparse. This study observed that Hong Kong Chinese and Japanese populations have a less dramatic increase in hip fracture rates associated with age than Caucasians, but the vertebral fracture rates were higher, resulting in a high vertebral-to-hip fracture ratio. As a result, estimation of the absolute fracture risk for Asians may need to be readjusted for the higher clinical vertebral fracture rate.

Introduction

Vertebral fractures are the most common osteoporotic fractures. Data on the vertebral fracture risk in Asia remain sparse. The aim of this study was to report the incidence of clinical vertebral fractures among the Chinese and to compare the vertebral-to-hip fracture risk to other ethnic groups.

Methods

Four thousand, three hundred eighty-six community-dwelling Southern Chinese subjects (2,302 women and 1,810 men) aged 50 or above were recruited in the Hong Kong Osteoporosis Study since 1995. Baseline demographic characteristics and medical history were obtained. Subjects were followed annually for fracture outcomes with a structured questionnaire and verified by the computerized patient information system of the Hospital Authority of the Hong Kong Government. Only non-traumatic incident hip fractures and clinical vertebral fractures that received medical attention were included in the analysis. The incidence rates of clinical vertebral fractures and hip fractures were determined and compared to the published data of Swedish Caucasian and Japanese populations.

Results

The mean age at baseline was 62?±?8.2?years for women and 68?±?10.3?years for men. The average duration of follow-up was 4.0?±?2.8 (range, 1 to 14) years for a total of 14,733 person-years for the whole cohort. The incidence rate for vertebral fracture was 194/100,000 person-years in men and 508/100,000 person-years in women, respectively. For subjects above the age of 65, the clinical vertebral fracture and hip fracture rates were 299/100,000 and 332/100,000 person-years, respectively, in men, and 594/100,000 and 379/100,000 person-years, respectively, in women. Hong Kong Chinese and Japanese populations have a less dramatic increase in hip fracture rates associated with age than Caucasians. At the age of 65 or above, the hip fracture rates for Asian (Hong Kong Chinese and Japanese) men and women were less than half of that in Caucasians, but the vertebral fracture rate was higher in Asians, resulting in a high vertebral-to-hip fracture ratio.

Conclusions

The incidences of vertebral and hip fractures, as well as the vertebral-to-hip fracture ratios vary in Asians and Caucasians. Estimation of the absolute fracture risk for Asians may need to be readjusted for the higher clinical vertebral fracture rate.     

Interleukin-13 genetic polymorphisms in Singapore Chinese children correlate with long-term outcome of minimal-change disease.

BACKGROUND: Minimal-change nephrotic syndrome (MCNS) has been associated with atopy. As interleukin-13 (IL-13) has been implicated in the pathogenesis of MCNS, we postulated that IL-13 genetic polymorphisms could influence either susceptibility or clinical course of the disease. METHODS: Seventy-two Singapore Chinese children with MCNS and 78 normal controls were screened for single nucleotide polymorphisms (SNPs) in the IL-13 gene by direct sequencing. Allele and genotype frequencies of these SNPs were determined and their relationship with different clinical courses was analysed. RESULTS: Six SNPs were identified in the 5' promoter, exon 4 and 3' untranslated region (3'UTR). The three SNPs in the 3'UTR--4738 (G/A), 4793 (C/A) and 4926 (C/T)--were in tight linkage disequilibrium (Delta > or = 0.99). There was no difference in allele or genotype frequencies between MCNS children and normal controls. However, there was a significantly lower frequency of allele 4738G in those MCNS children who were still relapsing after 5 years of follow-up (G = 0.52), compared with those in complete remission (G = 0.72; P<0.05) and normal controls (G = 0.69; P<0.05). Haplotype analysis showed a significantly higher frequency of the GCC haplotype in controls and MCNS patients in complete remission (chi2 = 6.35; P<0.02), while the frequency of AAT haplotype was higher in those MCNS children still relapsing after 5 years of follow-up (chi2 = 5.38; P<0.02). Moreover, peripheral blood mononuclear cell IL-13 mRNA expression in patients with haplotype AAT was significantly higher than in those with haplotype GCC. CONCLUSIONS: These results suggest that genetic polymorphisms in the 3'UTR of the IL-13 gene correlate with long-term outcome of MCNS, rather than disease susceptibility, in Singapore Chinese children.     

Enhanced Fluid Removal Guided by Blood Volume Monitoring During Chronic Hemodialysis

Fluid overload predisposes chronic hemodialysis patients to cardiovascular disease, a significant cause of morbidity and mortality in these patients. We evaluated the efficacy of monitoring changes in blood volume during routine hemodialysis to detect fluid overload. Intradialytic changes in blood volume were monitored by continuously measuring hematocrit in all 56 patients in a single dialysis unit over 7 weeks. After Week 1, patients were categorized into 2 separate groups depending on their maximum intradialytic decreases in blood volume. In Group 1, 46 of 56 or 82% had greater than a 5% decrease in blood volume while in Group 2, 10 of 56 or 18% had less than a 5% decrease in blood volume. During Weeks 2–7, dialytic fluid removal was intentionally increased in Group 2 patients by 0.80 ± 0.62 L (mean ± SD) or 47 ± 43%. This intervention resulted in a larger (p < 0.02) intradialytic decrease in body weight (2.7 ± 0.9 kg versus 2.0 ± 0.8 kg) and a larger (p < 0.02) intradialytic decrease in blood volume (15 ± 5% versus 4 ± 1%) than experienced during Week 1 with a low incidence of symptoms. We conclude that there is a significant percentage of chronic hemodialysis patients who can tolerate additional fluid removal without hypovolemic symptoms even though they are considered to be at dry weight by routine physical examination and that the identification of these patients can be facilitated by intradialytic blood volume monitoring.