Cardiac risk factors in Hong Kong adults

Abstract

(Uncorrected OCR) Abstract

Many studies have been conducted in Caucasian populations on the optimal body mass index cut-off for obesity, as well as the relationship between body mass index and percentage body fat and their associations with cardiovascular risk factors. However, few studies of this kind have been conducted in the Hong Kong Chinese population, This research is deemed to be important due to ethnic differences between Asians and Caucasians, Therefore, this dissertation aims to determine any ethnic differences from a sample of the local Hong Kong Chinese population, in order to advance health care policies controlling known cardiovascular risk factors.

A total of 800 subjects were randomly selected from a pool of subjects participated in a Hong Kong Cardiovascular Risk Factor Prevalence study conducted in 1994-1996. These subjects were contacted and 453 disease-free subjects (210 males and 243 females) consented to participate in the current study, Data collected included serum and blood pressure measurements, body mass index, percentage body fat measured by bioelectrical impedance analysis, and a self-completed cardiovascular risk factor questionnaire,

The mean age of the 453 subjects was 51.64 years (SD=12.3). When obesity was defined as percentage body fat ~ 25 and 2: 30 in males and females respectively, 23 kg/m2 was found to be the optimum cut-off value, with 78% correct classification (95% CI = 69%-87%). The corresponding sensitivity and specificity were 88% (95% CI = 81 %-95%) and 67% (95% CI = 57%-77%) respectively. On the other hand, if obesity was defined as percentage body fat ~ 25 and 2: 35 in males and females respectively, then 25 kg/m2 was found to be the best cut-off value with 82% correct classification

(95% CI = 74%-90%). The corresponding sensitivity and specificity were 78% (95% CI = 69%-87%) and 85% (95% Cl = 78%-92%) respectively.

Moreover, body mass index was found to be quadratically body fat. The quadratic relationship did not appear two genders, except that the percentage body fat of of females by 9.97 (SE=0.33).

Finally, except for total cholesterol, high density lipoprotein cholesterol, and fasting glucose, body mass index did not provide any substantial information additional to percentage body fat on serum and blood pressure measurements. was the only measure on which percentage body fat did additional to body mass index. When waist-hip body mass index and percentage body fat,. except for

body mass index did not have additional information on measurements when percentage body fat or/and

[n conclusion, the optimal body mass index cut-off for obesity in Hong Kong Chinese was lower than the 30kg/m2 recommended by the World Health Organization, a clear reflection of ethnic difference between Asians and Caucasians. The quadratic relationship between percentage body fat and body mass index was similar in Hong Kong Chinese as in Caucasians and Blacks. Moreover, percentage body fat together with waist-hip-ratio were found to be better indicators of cardiovascular risk factors in Hong Kong. This was the first time such findings were found in the Hong Kong Chinese population.

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