E. Lau

Simple anthropometric indexes and cardiovascular risk factors in Chinese

OBJECTIVE: Obesity is a major public health problem due to its associations with multiple cardiovascular risk factors. Although there are sophisticated methods, such as imaging, to document total body fat and its distributions, anthropometric measurements remain important in clinical practice. We examined the relationships between cardiovascular risk factors and the three commonest anthropometric measurements for obesity, body mass index (BMI), waist–hip ratio (WHR) and waist circumference (WC), in Hong Kong Chinese subjects. DESIGN AND SETTING: The data are obtained from a prevalence survey for glucose intolerance and lipid abnormality in a representative Hong Kong Chinese working population. All employees from a public utility company and a regional hospital were invited to participate. SUBJECTS: There were 1513 subjects (910 men and 603 women, mean age ± s.e.m.: 37.5±0.2 y). All of them had no significant past medical history. MEASUREMENTS: BMI, WHR and WC of the 1513 subjects were assessed for their relationships with various cardiovascular risk factors. These include blood pressure, fasting and 2 h plasma glucose and insulin, glycated haemoglobin, total cholesterol, triglyceride, high density and low density lipoprotein cholesterol, and urine albumin concentration. RESULTS: After age adjustment, all three anthropometric indexes were significantly correlated with the major cardiovascular risk factors in both men and women. When BMI, WHR and WC were analysed according to quartiles, there was a significant trend for blood pressure, plasma triglyceride, fasting and 2 h plasma glucose and insulin to increase, and high density lipoprotein cholesterol to decrease, with increasing obesity after adjustment for age and smoking. Using stepwise regression analysis with the three indexes as independent variables, most of the variance in blood pressure, plasma lipid, insulin, glucose and urinary albumin concentration were explained either by WC or WHR. In women, BMI was the main explanatory variable for reduced high density lipoprotein cholesterol. CONCLUSIONS: In Hong Kong Chinese, BMI, WHR and WC provide important information in assessing cardiovascular risks. In men, central adiposity as reflected by WC and to some extent, WHR, explained most of the variance in blood pressure, plasma glucose, lipid, insulin and albuminuria. In women, all three indexes reflecting general and central obesity contribute to the variance in these risk factors.

Hypertension, lipoprotein(a), and apolipoprotein A-I as risk factors for stroke in the Chinese.

We analyzed the serum concentrations of lipids and lipoproteins and the prevalence of other risk factors in a case-control study of 304 consecutive Chinese patients with acute stroke (classified as cerebral infarction, lacunar infarction, or intracerebral hemorrhage) and 304 age- and sex-matched controls. For all strokes we identified the following risk factors: a history of ischemic heart disease, diabetes mellitus, or hypertension; the presence of atrial fibrillation or left ventricular hypertrophy; a glycosylated hemoglobin A1 concentration of greater than 9.1%; a fasting plasma glucose concentration 3 months after stroke of greater than 6.0 mmol/l; a serum triglyceride concentration 3 months after stroke of greater than 2.1 mmol/l; and a serum lipoprotein(a) concentration of greater than 29.2 mg/dl. We found the following protective factors: a serum high density lipoprotein-cholesterol concentration of greater than 1.59 mmol/l and a serum apolipoprotein A-I concentration of greater than or equal to 106 mg/dl. The patterns of risk factors differed among the three stroke subtypes. When significant risk factors were entered into a multiple logistic regression model, we found a history of hypertension, a high serum lipoprotein(a) concentration, and a low apolipoprotein A-I concentration to be independent risk factors for all strokes. The attributable risk for hypertension was estimated to be 24% in patients aged greater than or equal to 60 years. In this population, in which cerebrovascular diseases are the third commonest cause of mortality, identification of risk factors will allow further studies in risk factor modification for the prevention of stroke.

The prevalence of diabetes mellitus and impaired glucose tolerance among Hong Kong Chinese adults of working age

We studied 1513 employees (910 men and 603 women) from a public utility company and a regional hospital to document the prevalence of diabetes mellitus (DM) and impaired glucose tolerance (IGT) in the Chinese working population of Hong Kong using a 75-g oral glucose tolerance test and World Health Organisation (1985) criteria. The overall prevalence of DM was 4.5 (95% confidence interval: 3.5-5.7%) and that of IGT 7.3 (6.0-8.6%). The prevalence of DM was 5.1 (3.7-6.5%) in men and 3.6 (2.1-5.1%) in women, while that of IGT was 7.4 (5.7-6.5%) in men and 7.1 (5.1-9.1%) in women. The truncated age-adjusted rate of DM for age 30-64 is 7.7% which is comparable to the age-adjusted prevalence rates among Chinese living in Singapore and Mauritius but in marked contrast to the low prevalence rate in Chinese living in Mainland China. Among the diabetic subjects, 38.2% had been previously diagnosed and 32% gave a family history affecting at least one first degree relative. Using polychotomous logistic regression analysis, the independent predictive factors for the development of DM include age (t = 7.31, P < 0.001), family history (t = 5.1, P < 0.001), waist hip ratio (t = 4.05, P < 0.001) and body mass index (t = 4.62, P < 0.001). Our data further confirm that Hong Kong Chinese have a moderate to high susceptibility to non-insulin-dependent diabetes (NIDDM) when exposed to sufficient environmental and lifestyle factors. The high prevalence of IGT indicates a potential for the prevalence of DM to continue to rise unless effective preventive measures are implemented.

Glycogen synthase kinase-3β and tau genes interact in Alzheimer's disease

We examined the epistatic effect between haplotypes of glycogen synthase kinase‐3β (GSK3B) gene and microtubule‐associated protein Tau (MAPT) gene in Alzheimers disease (AD).

Prevalence and correlates of musculoskeletal pain in Chinese elderly and the impact on 4-year physical function and quality of life

OBJECTIVE To examine the prevalence, correlates and prospective impact of musculoskeletal pain on physical and psychological function in a population health survey of elderly Chinese men and women. STUDY DESIGN Cohort study. METHODS Four thousand men and women, aged 65 years and over, living in the community in Hong Kong took part in this study. A questionnaire to determine demographics, socio-economic status, medical history, smoking, alcohol intake and level of physical activity was administered by an interviewer. Participants were asked about the presence of pain in the back, neck, hip and knee in the past 12 months. They were re-interviewed after 4 years of follow-up to document physical performance measures, psychological function and occurrence of falls, fractures and mortality. RESULTS Overall, back pain was most prevalent (48%), followed by knee (31%), neck (22.5%) and hip (8.9%) pain; the values was nearly twice as high in women compared with men for all sites. The presence of pain was not correlated with age, but was associated with various measures of socio-economic status as well as comorbidities. Baseline prevalence of pain was related to physical performance and quality-of-life measures, and fracture incidence after 4 years of follow-up. CONCLUSION Musculoskeletal pain is prevalent among elderly men and women, being much higher in the latter, giving rise to considerable functional and psychological impairments. Osteoporosis and osteoarthritis are likely to be the main underlying causes. The condition may be considered part of the frailty syndrome, and in this context, prevention and management represent major public health challenges.

Microalbuminuria and other cardiovascular risk factors in nondiabetic subjects

The association between urinary albumin:creatinine ratio and other cardiovascular risk factors such as age, blood pressure, obesity, glycemic indices, insulin and lipid profile was examined in a population in a Chinese community consisting of 795 men (mean age 35.8 +/- 8.8 yr) and 538 women (mean age 37.9 +/- 8.9 yr) with a normal glucose tolerance defined by WHO criteria. Men with a urinary albumin:creatinine ratio above the 90th percentile had higher systolic and diastolic blood pressures, fasting plasma glucose, 2-h glucose after a 75 g oral glucose load, and fasting serum insulin. Women with high urinary albumin:creatinine values had higher systolic and diastolic blood pressures, body mass index, waist-hip ratio, fasting insulin and triglycerides. Multivariate analysis showed that only systolic blood pressure and fasting glucose in men, and diastolic blood pressure and fasting insulin in women, independently contributed to urinary albumin:creatinine. When the effect of blood pressure was eliminated by excluding subjects with systolic blood pressure > 140 and diastolic > 90 mm Hg, only fasting insulin was associated with urinary albumin:creatinine in women. No associations were found for men. We conclude that microalbuminuria may be a marker for cardiovascular disease only because of its association with blood pressure in men, while in women, there is an additional independent association with fasting serum insulin.

Population Bone Mineral Density Measurements for Chinese Women and Men in Hong Kong

Abstract: The aim of the study was to establish population ranges of bone mineral density (BMD) for Hong Kong Chinese men and women for the Hologic QDR 2000 bone densitometer, to compare these values with the manufacturer’s reference ranges, to compare these values with population ranges for women obtained for the Norland X26 bone densitometer, and to examine variations between the two densitometers. The subjects were 164 men aged 40–79 years and 436 women aged 20–89 years, who were all ethnic Chinese, recruited from volunteers, social centers for the elderly and general practice clinics. BMD in women began to decline rapidly between ages 50 and 79 years, averaging about 10% loss per decade from the young adult (20–29 years) mean. The percentage losses from young adult mean values in the spine, femroal neck, trochanter and total femur were 23%, 30%, 31% and 33%, respectively, from 20 to 79 years. In the ninth decade no further decrease in BMD occurred with the exception of a further 4% at the hip sites. In men, no decrease in spine BMD occurred between 40 and 70 years. Compared with BMD in the fourth decade, 10%, 13%, and 11% of BMD was lost at the femoral neck, trochanter and total femur, respectively, by the seventh decade. These values show differences compared with the manufacturer’s reference ranges for Caucasians and Japanese. BMD values for the spine were comparable between Hologic and Norland densitometers, but Hologic values for femoral neck and trochanteric regions were lower than the Norland values. Data provided by this study may thus be used as normative values for the Hologic QDR2000 bone densitometer, instead of values provided by the manufacturer. BMD values at the hip sites are not interchangeable between Norland and Hologic bone densitometers, and estimation of numbers of the population with osteoporosis will depend on the model of densitometer used.

Association between serum uric acid and some cardiovascular risk factors in a Chinese population.

The association between serum uric acid concentration and some cardiovascular risk factors was examined in a working Hong Kong Chinese population (mean age 38 years), consisting of 910 men and 603 women. There was no significant age-related rise in serum uric acid concentration. Positive associations were found between serum uric acid concentration and body mass index, waist hip ratio, systolic and diastolic blood pressure, urea, creatinine, protein, glucose (fasting and 2 hours after 75 g oral glucose load), 2 hour insulin, triglycerides, and apolipoprotein B in men. Similar, but fewer, associations were seen in women, with the addition of a positive association with age. In both sexes, serum uric acid was negatively associated with high-density lipoprotein cholesterol. These findings complement the well-known clinical association between gout and cardiovascular and metabolic diseases, such as hypertension, hyperlipidaemia and diabetes mellitus, and suggest that serum uric acid may be a marker for the presence of an adverse cardiovascular risk factor profile.

Glycated haemoglobin and cardiovascular risk factors in Chinese subjects with normal glucose tolerance.

Increased plasma glucose concentration is a predictive factor for mortality in both diabetic and non‐diabetic subjects. Although glycated haemoglobin (HbA1c) is a useful index of mean blood glucose concentrations over the preceding 1 to 3 months, there are few data regarding its relationship to cardiovascular risk. We have examined the relationship between HbA1c and cardiovascular risk factors in 1280 subjects with normal glucose tolerance. Based on HbA1c tertiles (tertile 1: n = 427, 262 men and 165 women, HbA1c level: 2.9–4.7 % in men and 3.2–4.2 % in women; tertile 2: n = 426, 261 men and 165 women, HbA1c level: 4.7–5.1 % in men and 4.2–4.6 % in women; tertile 3: n = 427, 262 men and 165 women, HbA1c level: 5.1–6.7 % in men and 4.6–6.9 % in women), increasing HbA1c was associated with increasing age, blood pressure, waist–hip ratio, fasting and 2‐h plasma glucose, 2‐h insulin, cholesterol, low‐density lipoprotein cholesterol, apolipo‐ protein B and urate concentrations. When age and sex were included as covariates, increasing HbA1c remained associated with increasing fasting and 2‐h plasma glucose, 2‐h insulin, total cholesterol, and low‐density lipoprotein cholesterol concentrations. These findings emphasize the importance of hyperglycaemia, as reflected by HbA1c, as a continuum in the evaluation of cardiovascular risk. Furthermore, these findings support the hypothesis that cardiovascular disease risk commences with rising glucose concentrations before ‘conventionally‐defined’ glucose intolerance occurs.

Serum lipid profile and its association with some cardiovascular risk factors in an urban chinese population

&NA; The lipid profile of a Chinese population, which has a lower prevalence of coronary heart disease compared with Caucasians, is studied to determine whether lipid‐modifying disease prevention programs are necessary. The study population consisted of 910 men (mean age 36.7 ± 9.2 yrs) and 603 women (mean age 38.6 ± 9.1 yrs), who were employees of a public utility company and non‐medical staff of a district hospital. Indices of obesity, fasting cholesterol (TC), and its various subfraction, triglycerides (TG), apolipoprotein A‐1 (Apo A‐1), and apolipoprotein B (Apo B) concentrations were measured. Glucose tolerance was also estimated by measuring fasting and 2 h glucose after a 75 g oral glucose load. The lipid profile was similar to that of the North American population, with an overall prevalence of low density lipoprotein cholesterol (LDL‐C) ≥ 4.1 mmol/L of 21% and 11% in men and women respectively. Similar variations with age, sex, smoking and glucose tolerance compared with Caucasian populations were observed. The high prevalence of subjects with “undesirable” lipid values in this Chinese population, which at present has a coronary artery disease prevalence of one‐eighth to one‐quarter compared with that in Caucasians, suggests that the incidence of the disease may well rise in the future to pose a similar problem to that in Caucasian populations. Cut off values of lipids conferring increased cardiovascular risks need to be determined in this population, so that public health strategies may be formulated.