S.C. Ho

Association between simple anthropometric indices and cardiovascular risk factors.

OBJECTIVE: To identify which of the three simple anthropometric indices, body mass index (BMI), waist-to-hip ratio (WHR) and waist circumference (WC), best predicts cardiovascular risk factors, and to determine if the association between the anthropometric indices and cardiovascular risk factors varies with gender.DESIGN AND METHODOLOGY: A cross-sectional population-based survey was carried out during 1995–1996. One thousand and ten Chinese people (500 men and 510 women) aged 25–74u2005y were recruited as subjects for the study. Metabolic profiles and anthropometric indices were measured.RESULTS: Partial correlation and co-variance analyses showed that WC exhibited the highest degree of association with almost all of the studied metabolic profiles for both men and women. We observed significant gender differences in the association between central or general obesity with cardiovascular risk factors. BMI had an independent and significant association with metabolic risks in men, but not in women, whereas WHR was more strongly correlated with metabolic risks for women than for men. Logistic regression analysis further confirmed the magnitude of the association between the obesity indices and metabolic risks. Among the studied metabolic variables, serum insulin showed the highest degree of association with the obesity indices, followed by plasma glucose, triglyceride, HDL and blood pressure. Total cholesterol and LDL-cholesterol had a small but significant correlation with obesity. No threshold values in the relation between either the anthropometric indices and metabolic values, or with hypertension, diabetes and dislipidemia were observed.CONCLUSION: The association of central or general obesity and metabolic syndrome varied with gender. In addition, the useful anthropometric predictors for cardiovascular risk factors were BMI and WC for men, and WC and WHR for women.

Social Determinants of Frailty

Background: Frailty represents a body-wide set of a linked deterioration that occurs with ageing, but is susceptible to active intervention and is reversible. The concept of frailty should include broader environmental factors. A quantitative measure of frailty, the frailty index (FI), developed for elderly Canadians and shown to be valid for an elderly Chinese population, was examined for its association with socioeconomic, lifestyle, and social support network factors in an elderly Chinese cohort. Objective: 2,032 people aged 70 years and over recruited by stratified random sampling of the population were surveyed in 1990–1991, and information obtained regarding physical and functional health, psychological factors, lifestyle, socioeconomic and social support factors. The FI was constructed from 62 variables covering cognitive, psychological and physical health, and tested for association with socioeconomic, lifestyle and social support factors using ANOVA and t test. Results: The mean FI for women was higher than for men (0.16 ± 0.08, n = 1,033 vs. 0.13 ± 0.08, n = 999, p < 0.001, t test). For men, increasing frailty was observed with non-white collar occupations, inadequate expenses, no or little exercise, abstinence from alcohol, few relatives or neighbours and no or infrequent participation in helping others. For women, little contact with relatives (rather than number of relatives), and absence of participation in community/religious activities were additional factors. Conclusion: FI is influenced by social and environmental factors in keeping with the concept of frailty being multi-dimensional. Such a quantitative measure may be a useful indicator of the health of elderly populations as well as for public health measures to combat frailty.

Genetic and environmental risk factors for Parkinson’s disease in a Chinese population

An epidemiological study of the environmental and genetic factors as well as the possible interplay between them was conducted among 215 patients with Parkinson’s disease and 313 controls in a Chinese population in Hong Kong. In univariate analysis, a regular tea drinking habit was found to be a protective factor, which had not been reported before. Smoking (a protective factor), family history, duration of pesticide exposure (in years) in farming and pesticide exposure during farming in women (both risk factors) have been reported previously. In multivariate analysis, current smoking reached borderline significance at the 5% level and the variables, years exposed to pesticides and family history were significant at the 10% level. By contrast with the common occurrence of polymorphism of the CYP2D6 gene (a gene involved with xenobiotic metabolism) in white people, it is very rare in China and is not thought to be a significant factor contributing to Parkinson’s disease in Chinese people.

Is waist circumference a useful measure in predicting health outcomes in the elderly

OBJECTIVE: To examine the effect of age on the relationship between body mass index (BMI) and waist circumference (WC), and the usefulness of BMI, WC and waist–hip ratio (WHR) in predicting mortality and cardiovascular risk in the elderly population.DESIGN: Longitudinal observational study of 36 months duration.SUBJECTS AND METHOD: A stratified random sample of 2032 Chinese subjects (990 male, 1033 female) mean age (s.d.) 80.1 (7.5), interviewed and examined at baseline and after 36 months. Deaths and presence of diabetes mellitus and hypertension were documented. A younger data set of 1010 subjects (500 male, 510 female), mean age (s.d.) 45.5 (11.6), was used for comparison of the BMI–WC relationship between younger and older subjects. In predicting outcomes using different values of BMI, WC and WHR, receiver operating characteristic curve analysis was used to derive cut-off values with optimal sensitivity and specificity, and the likelihood ratios for mortality, diabetes and hypertension for different anthropometric values were plotted.RESULTS: The waist circumference values corresponding to BMI values of 25 and 30u2005kg/m2 were higher in elderly (92 and 103u2005cm for men; 88 and 99u2005cm for women) compared with younger subjects (85 and 97u2005cm for men; 78 and 88u2005cm for women). BMI and WC are inversely associated with mortality, in both men and women, positively associated with diabetes in men but not in women. WC was positively associated with hypertension in men and women. WHR was not associated with any outcome measures. The anthropometric measurement at the point of intersection of the likelihood curves for mortality and diabetes may be considered the optimum value, being BMI=21u2005kg/m2 for men and 25u2005kg/m2 for women, WC between 80 and 85u2005cm, and WHR 0.88–0.90.CONCLUSION: Waist measurement values for predicting health outcomes in elderly people aged 70u2005y and over are different compared with younger subjects, and have similar predictive accuracy compared with body mass index. Waist–hip ratio is not a useful predictor.

Bone mineral density in Chinese elderly female vegetarians, vegans, lacto-vegetarians and omnivores

Objectives: To compare the bone mineral density and dietary intake of elderly Chinese vegetarian women with omnivores, to compare the bone mineral density of Chinese `vegans and `lactovegetarians, and to study the relationship between nutrient intake and BMD in vegetarians.Design: A cross-sectional survey.Setting and subjects: A community-based study. The vegetarian women (aged 70–89u2005y) (n=76) were non-institutionalized subjects. All of them were Buddhists. Their bone mineral density were compared to normal elderly volunteers (aged 70–89u2005y) (n=109) who were recruited to establish normal BMD ranges. Their dietary intake was compared to omnivorous subjects from a previous dietary survey (n=250).Methods: Dietary assessment was by the 24u2005h recall method, and bone mineral density was measured by dual-X-ray-densitometry. The analysis of co-variance was used to compare the BMD between vegetarians and omnivores, with adjustment for potential confounders. The BMD in `vegans and `lactovegetarians were compared by similar methods. The t-test was used to compare dietary intake between omnivores and vegetarians. The relationship between nutrient intake and BMD was studied by correlation and multiple regression.Results: The dietary calorie, protein and fat intake were much lower, but the sodium/creatinine ratio was much higher in vegetarians than omnivores. The BMD at the spine was similar between vegetarians and omnivores. However, the BMD at the hip was significantly lower in vegetarians at some sites (P<0.05). There was no significant difference in BMD between `vegans and `lactovegetarians. BMD in vegetarians appeared to be positively correlated with energy, protein and calcium intake; and negatively associated with urinary sodium/creatinine levels.Conclusions: There is a relationship between diet and BMD. The BMD at the hip was lower in vegetarians than omnivores, but no difference was observed between `vegans and `lactovegetarians. There is a complex relationship between the intake of various nutrient and BMD in vegetarians.Sponsorship: None

Influence of educational level and marital status on dietary intake, obesity and other cardiovascular risk factors in a Hong Kong Chinese population

Objectives: To examine the influence of education and marital status on dietary intake, body mass index, waist hip ratio, blood pressure, fasting and 2u2005h glucose, and lipid profile in adult Hong Kong Chinese.Design: Randomized age and sex stratified surverySubjects: One thousand and ten subjects aged 25–74u2005y (500 men, 510 women) recruited for the 1995–96 Hong Kong Dietary and Cardiovascular Risk Prevalence Survey.Measurements: Dietary intake was estimated using a food frequency method. Information on education level and marital status was included in the questionnaire. Anthropometry and biochemical parameters were measured using standard methods.Results: After adjustment for age, higher levels of education are associated with higher percentage protein intake in men, higher percentage fat intake in women, higher nutrient density of fibre and calcium in both men and women, and higher nutrient density of protein, fat, niacin, vitamin D, and polyunsaturated fatty acid in women. Consumption of fruits was also higher in women, and that of dairy products higher in men. Body mass index and waist-hip ratio were lower with increasing levels of education in women, while lower mean systolic BP was observed in men. Single women had lower nutrient densities of vitamin D and iron, and lower consumption of vegetables and fish, compared with married women. Body mass index was lower in both single men and women. Single men had a better cardiovascular risk factor profile, in that diastolic BP, triglycerides and cholesterol/HDL ratio were lower, in addition to a lower body mass index.Conclusion: Higher education level is associated with a healthier diet and lower prevalence of overweight.Sponsorship: Hong Kong Health Services Research Grant.

Age-Associated Gait Changes in the Elderly: Pathological or Physiological?

AIMnTo examine the role of disease-related factors and age-related physiological changes in affecting gait speed and stride length in the elderly.nnnSUBJECTSn925 men and 890 women aged 70 years and above who were ambulant, recruited by random sampling stratified according to age and sex, from all recipients of Old Age and Disability Allowance in Hong Kong.nnnDESIGNnGait was assessed by measuring the time taken and the number of steps required to complete a 16-foot walk. Information on health and functional status, cognitive function, and depressive symptoms was collected, and anthropometric indices obtained. Factors affecting walking speed and stride were examined in the overall population and also after excluding those with physical disability or diseases.nnnRESULTSnResults were analyzed separately for men and women since mean walking speed was slower in women, who also took a larger number of steps. Age, coexisting disease, leg or back pain, poor vision, low level of physical activity, functional and cognitive impairment, high depressive symptom score, and anthropometric indices were all negatively associated with walking speed. Fallers also had slower speed. After excluding those with diseases or physical impairment, multivariate analysis showed that the only factors affecting speed were age in men, and age, height, and level of physical activity in women. Age and height were factors associated with stride length in men, and height only for women.nnnCONCLUSIONnBoth disease-related factors as well as age-related physiological changes contribute to the decline in walking speed and stride length.

Lifestyle Factors and Health Outcomes in Elderly Hong Kong Chinese Aged 70 Years and Over

Background: Although increasing emphasis is being placed on strategies for successful aging, few studies have examined the relationship between lifestyle factors and mortality and other health outcomes in the old-old population. Objective: To examine the impact of physical activity, dietary habits, smoking, and alcohol consumption on 3-year mortality and other health outcomes. Methods: 2,032 Chinese subjects aged 70 years and older (mean age 80 years) were recruited territorywide by proportional random sampling and followed for 3 years. Baseline information was obtained by interview on level of physical activity, dietary habits (frequency of consumption per week of major food groups), alcohol consumption, and smoking habits. Outcome measures include mortality, self-perceived health status, frequency of hospitalization, geriatric depression score, and development of new diseases (stroke, heart disease, hypertension, diabetes mellitus, fractures). Logistic regression was used to examine the effects of lifestyle factors on each health outcome, with and without adjustment for age and baseline health status. Results: The mortality risk is reduced with increasing physical activity, daily fish intake and moderate alcohol consumption, and avoidance of smoking; hospitalization is inversely associated with increasing activity; better self-perceived health is associated with moderate alcohol consumption and a non-smoking status, and there is an inverse relationship between depressive symptoms and increasing activity and moderate alcohol consumption. After adjustment for age and baseline health status, higher levels of physical activity are associated with decreased mortality and hospitalization; non-smokers have reduced mortality and a better self-perceived health, and moderate alcohol consumption is also associated with better self-perceived health. Conclusion: Lifestyle factors may influence health outcomes even in the old-old population.

Dietary intake and practices in the Hong Kong Chinese population.

OBJECTIVES: To examine dietary intake and practices of the adult Hong Kong Chinese population to provide a basis for future public health recommendations with regard to prevention of certain chronic diseases such as cardiovascular disease, hypertension, and osteoporosis. PARTICIPANTS: Age and sex stratified random sample of the Hong Kong Chinese population aged 25 to 74 years (500 men, 510 women). METHOD: A food frequency method over a one week period was used for nutrient quantification, and a separate questionnaire was used for assessment of dietary habits. Information was obtained by interview. RESULTS: Men had higher intakes of energy and higher nutrient density of vitamin D, monounsaturated fatty acids and cholesterol, but lower nutrient density of protein, many vitamins, calcium, iron, copper, and polyunsaturated fatty acids. There was an age related decrease in energy intake and other nutrients except for vitamin C, sodium, potassium, and percentage of total calorie from carbohydrate, which all increased with age. Approximately 50% of the population had a cholesterol intake of < or = 300 mg; 60% had a fat intake < or = 30% of total energy; and 85% had a percentage of energy from saturated fats < or = 10%; criteria considered desirable for cardiovascular health. Seventy eight per cent of the population had sodium intake values in the range shown to be associated with the age related rise in blood pressure with age. Mean calcium intake was lower than the FAO/WHO recommendations. The awareness of the value of wholemeal bread and polyunsaturated fat spreads was lower in this population compared with that in Australia. There was a marked difference in types of cooking oil compared with Singaporeans, the latter using more coconut/palm/mixed vegetable oils. CONCLUSION: Although the current intake pattern for cardiovascular health for fat, saturated fatty acid, and cholesterol fall within the recommended range for over 50% of the population, follow up surveys to monitor the pattern would be needed. Decreasing salt consumption, increasing calcium intake, and increasing the awareness of the health value of fibre may all be beneficial in the context of chronic disease prevention.

Prevalence of Cognitive Impairment and Associated Factors among Elderly Hong Kong Chinese Aged 70 Years and Over

The prevalence of cognitive impairment was determined in a random age- and sex-stratified sample of 2,011 elderly Hong Kong Chinese, aged 70 years and over, consisting of subjects living in the community and in institutions. The Information/Orientation Section of the Clifton Assessment Procedure was used as the screening instrument using a cutoff point of 7. The overall age-adjusted prevalence was 5% for men and 22% for women, and 15% for both sexes combined. Univariate analysis identified the following associated factors in order of magnitude of the odds ratio: age; history of Parkinsons disease; functional disability; female sex; low educational level; low social class; history of stroke, and low monthly income. Other diseases, such as heart disease, hypertension, chronic lung diseases or diabetes, were not associated factors. In multivariate analysis, all the above factors remained significant with the exception of a history of stroke. The prevalence figures are comparable to other Caucasian and Chinese studies, and the associated factors identified suggest that there may be room for prevention.