Carotid intima-media thickness (IMT) is an established surrogate marker for atherosclerosis. We have previously reported that abdominal fat, notably mesenteric fat, was a major explanatory variable ...for multiple cardiovascular risk factors. Given the intimate relationships between visceral fat, cardiovascular risk factors and atherosclerosis, we hypothesize that there are independent relationships between mesenteric fat and carotid IMT.
Two hundred and eighty-two Chinese subjects (M: 129, F: 153; mean body mass index (BMI): 23.8
kg/m
2; age range: 20–68 years) were recruited. Maximum carotid IMT as well as maximum mesenteric, preperitoneal and subcutaneous fat thickness were measured by carotid and abdominal ultrasound examinations, respectively. Obesity index and conventional cardiovascular risk factors were assessed by physical examination and blood taking.
On univariate analysis, mesenteric but not preperitoneal fat thickness was the major correlate with carotid IMT in both men and women. There was also a weak correlation between carotid IMT and subcutaneous fat thickness in women. On multivariate analysis, mesenteric fat thickness was an independent determinant of carotid IMT after adjustment for subcutaneous and preperitoneal fat thickness, age, gender, blood pressure, insulin resistance, lipid and glycaemic parameters. The association of mesenteric fat thickness with carotid IMT appeared stronger in women than in men, which however was not confirmed on multivariate analysis.
In conclusion, mesenteric fat thickness measured on ultrasound showed significant association with carotid IMT, lending further support to the linking role of portal adipose tissue in obesity-related atherosclerosis. Effect of gender on the relationships of mesenteric fat with atherosclerosis risk require further elucidation. Measurement of mesenteric fat thickness may be a useful indicator of regional fat distribution in the assessment of cardiovascular risks.
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.
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/m2), normal weight (18.5–23 kg/m2) and overweight (≥ 23 kg/m2) 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 HbA1c 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 HbA1c while overweight patients had the highest C‐peptide, blood pressure, triglyceride but lowest HbA1c 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.
The spectrophotometric determination of molar absorptivities of the surface plasmon (SP) resonance for gold and gold–silver nanoparticles is reported. The importance of the optical parameter for ...assessing concentrations of nanoparticles in solution reactions and for estimating thickness of thin film assembly of nanoparticles is highlighted. The high monodispersity (5.6±0.4
nm) of decanethiolate-capped gold nanoparticles produced by thermally activated processing protocol served as a model system, which yielded an
ε value of 1.1×10
7
M
−1
cm
−1. This value was also compared with values determined similarly for nanoparticles of different core sizes and compositions, including decanethiolate-capped gold (1.9
nm), gold–silver alloy (2.7 and 5.6
nm), and citrate-capped gold nanoparticles (13.4
nm). The determined
ε values are used for the thickness estimation of thin film assembly of gold nanoparticles linked by 1,9-nonanedithiol (NDT) and the concentration calculation of nanoparticles in a solution reaction. The results have important implications for quantitative assessment of nanoparticle-related reactivities and structures.
Summary
Aims To examine and compare gastrointestinal (GI) symptoms in Hong Kong Chinese Type 2 diabetic outpatients and non‐diabetic control subjects.
Methods A total of 149 Chinese Type 2 diabetic ...patients (66 men and 83 women, age (mean ± sd) 46.8 ± 11.1 years) newly referred to the diabetes clinic of the Prince of Wales Hospital, Hong Kong were examined. Sixty‐five age and sex‐matched non‐diabetic subjects were recruited from the community as controls (22 men and 43 women, age (mean ± sd) 46.5 ± 6.6 years, P = 0.820). All patients were interviewed regarding GI symptoms over the past year, using a questionnaire that covered 14 items. A scoring system from 0 to 4 was used to grade severity.
Results Diabetic patients had higher blood pressure, fasting plasma glucose and glycated haemoglobin and were more often smokers than control subjects. Of the 149 diabetic subjects, 105 (70.5 ± 45.8%) had GI symptoms while only 20 (30.8%) of the 65 control subjects had GI symptoms (P < 0.001). The respective percentages of upper and lower GI symptoms in diabetic and normal subjects were 44.3% vs. 24.6% (P = 0.006) and 54.4% vs. 13.9% (P < 0.001). The three commonest GI symptoms in diabetic patients were diarrhoea (34.9%), constipation (27.5%) and epigastric fullness (16.8%). After adjustment for age, sex, duration of diagnosed diabetes and smoking, patients with or without metformin had similar percentages or scores for GI symptoms. On multivariate analysis using age, body mass index, fasting plasma glucose, glycated haemoglobin, duration of diagnosed diabetes and presence of peripheral neuropathy as independent variables, duration of diabetes was the only independent parameter associated with total score for GI symptoms (β = 0.116, P = 0.003), for upper GI symptoms (β = 0.073, P = 0.005) and for lower GI symptom (β = 0.043, P = 0.020).
Conclusions Up to 70% of the Chinese Type 2 diabetic outpatients have GI symptoms, which is a much higher rate than in non‐diabetic control subjects. Duration of diabetes is the most important factor associated with the presence of such GI symptoms.
We assessed the effects of angiotensin-converting enzyme (ACE) inhibition on survival and cardiorenal outcomes in a consecutive cohort of Chinese type 2 diabetic patients with varying degree of ...albuminuria, ranging from normoalbuminuria to macroalbuminuria. A total of 3773 consecutive Chinese type 2 diabetic patients were followed prospectively for a mean period of 35.8 months. Clinical end points included all-cause mortality, with cardiovascular end point defined as first hospitalization because of ischemic heart disease, congestive heart failure, revascularization procedures, or cerebrovascular accident as well as renal end point defined as dialysis, doubling of baseline plasma creatinine, or plasma creatinine ≥500 μmol/L. The use of ACE inhibitor was 26.3% in normoalbuminuric (NA), 70.1% in microalbuminuric (MI), and 82.6% in macroalbuminuric (MA) groups. Albuminuria was a major predictor for all-cause mortality with 4-fold difference between NA and MA patients. The 7-year cumulative mortality rate was 7.1%, 10.8%, and 21.7% in the NA, MI, and MA groups, respectively. The use of ACE inhibition was associated with significant reduction of mortality (hazard ratio 0.41 and 95% confidence interval, 0.29, 0.58) in the entire group and was most evident in high-risk patients who had cardiorenal complications or retinopathy at baseline for all albuminuric groups (NA 0.76 0.31,1.87; MI 0.32 0.16, 0.65; and MA 0.20 0.13, 0.33). The prognostic value of albuminuria for death in type 2 diabetes and the beneficial effects of ACE inhibitors in Chinese type 2 diabetic patients with micro- or macroalbuminuria has been confirmed. The effects of ACE inhibitors in type 2 diabetic patients with normoalbuminuria require further evaluation.
Aim: The aim of this study is to investigate the prevalence of metabolic syndrome (MES) in type 2 diabetic patients and the predictive values of the World Health Organization (WHO) and National ...Cholesterol Education Programme (NCEP) definitions and the individual components of the MES on total and cardiovascular mortality.
Methods: A prospective analysis of a consecutive cohort of 5202 Chinese type 2 diabetic patients recruited between July 1994 and April 2001.
Results: The prevalence of the MES was 49.2–58.1% depending on the use of various criteria. There were 189 deaths (men: 100 and women: 89) in these 5205 patients during a median (interquartile range) follow‐up period of 2.1 (0.3–3.6 years). Of these, 164 (87%) were classified as cardiovascular deaths. Using the NCEP criterion, patients with MES had a death rate similar to those without (3.51 vs. 3.85%). By contrast, based on the WHO criteria, patients with MES had a higher mortality rate than those without (4.3 vs. 2.4%, p = 0.002). Compared to patients with neither NCEP‐ nor WHO‐defined MES, only the group with MES defined by the WHO, but not NCEP, criterion had significantly higher mortality rate (2.6 vs. 6.8%, p < 0.001). Using Cox regression analysis, only age, duration of diabetes and smoking were identified as independent factors for cardiovascular or total death. Among the various components of MES, hypertension, low BMI and albuminuria were the key predictors for these adverse events.
Conclusions: In Chinese type 2 diabetic patients, the WHO criterion has a better discriminative power over the NCEP criterion for predicting death. Among the various components of the MES defined either by WHO or NCEP, hypertension, albuminuria and low BMI were the main predictors of cardiovascular and total mortality.
The relationship between Helicobacter pylori infection and gastroesophageal reflux (H. pylori) disease (GERD) is controversial. In Asian populations, the prevalence of H. pylori infection is high and ...GERD is relatively uncommon. The aim of this study was 1) to test the hypothesis that H. pylori protects the esophagus against GERD, and 2) to study the pattern of H. pylori colonization and gastritis in GERD.
We conducted a prospective case-control study in which patients with GERD and asymptomatic controls were compared for the prevalence of H. pylori infection. Diagnosis of GERD was based on symptoms of heartburn that improved with acid-suppressive therapy and/or endoscopic evidence of erosive esophagitis. H. pylori status was determined by serology and, when endoscopy was indicated, was confirmed by rapid urease test and histology. Gastric biopsies were examined under hematoxylin and eosin and Giemsa stains. Density of H. pylori colonization and activity of gastritis at different parts of stomach were graded and compared according to Updated Sydney system.
A total of 106 patients with GERD and 120 age- and sex-matched, asymptomatic controls were enrolled. The prevalence of H. pylori infection was significantly lower in GERD patients (31%) compared with controls (61%, p < 0.001, odds ratio 0.229, 95% confidence interval 0.13-0.41). H. pylori-infected GERD patients showed significantly more severe gastritis in the antrum than in other parts of stomach (mean inflammatory scores: antrum; 3.3 +/- 1.63*, body; 1.85 +/- 1.31; fundus; 1.65 +/- 0.58; cardia, 1.65 +/- 1.39; *p < 0.005). H. pylori colonization was found less commonly and at lower density at the cardia compared with other parts of the stomach.
H. pylori infection protects against the development of GERD, and carditis is unlikely to play an important role.
Background: Magnetic Resonance Imaging (MRI) is a well‐accepted non‐invasive method in the quantification of visceral adipose tissue. However, a standard method of measurement has not yet been ...universally agreed.
Objectives: The objectives of the present study were 2‐fold, firstly, to identify the imaging plane in the Chinese population which gives the best correlation with total visceral adipose tissue volume and cardiovascular risk factors; and secondly to compare the correlations between single‐slice and multiple‐slice approach with cardiovascular risk factors.
Methods: Thirty‐seven Chinese subjects with no known medical history underwent MRI examination for quantifying total visceral adipose tissue volume. The visceral adipose tissue area at five axial imaging levels within abdomen and pelvis were determined. All subjects had blood pressure measured and fasting blood taken for analysis of cardiovascular risk factors. Framingham risk score for each subject was calculated.
Results: The imaging plane at the level of ‘lower costal margin’ (LCM) in both men and women had the highest correlation with total visceral adipose tissue volume (r = 0.97 and 0.99 respectively). The visceral adipose tissue area at specific imaging levels showed higher correlations with various cardiovascular risk factors and Framingham risk score than total visceral adipose tissue volume. The visceral adipose tissue area at ‘umbilicus’ (UMB) level in men (r = 0.88) and LCM level in women (r = 0.70) showed the best correlation with Framingham risk score.
Conclusions: The imaging plane at the level of LCM is preferred for reflecting total visceral adipose tissue volume in Chinese subjects. For investigating the association of cardiovascular risk with visceral adipose tissue in MRI‐obesity research, the single‐slice approach is superior to the multiple‐slice approach, with the level of UMB in men and LCM in women as the preferred imaging planes.
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