Is waist circumference more strongly associated with metabolic risk factors than waist-to-height ratio in Asians?

OBJECTIVES: Differential distribution of fats can vary among ethnic groups and thus have varying effects on metabolic risk. Measuring metabolic risk of individuals using simple anthropometric measurements is essential to replace current invasive methods of obtaining blood samples. Waist-to-height ratio (WHtR) has been advocated as the best simple anthropometric measurement, but, because of the high visceral fat of Asians, there has been speculation as to the possibility of using only waist circumference (WC) to measure metabolic risk. The aim of this study was to compare the performance of WC and WHtR in terms of their association with measures of obesity and metabolic risk factors (e.g., homeostasis model assessment for insulin resistance, low-density lipoprotein, triacylglycerol, and ratio of triacylglycerol to high-density lipoprotein) and to obtain an optimal cutoff value for one anthropometric measurement. METHODS: The study was performed on healthy Asian Chinese (N = 527) men (n = 209) and women (n = 318) who participated in a cross-sectional study conducted at the Clinical Nutrition Research Centre located in Singapore. Association of WC and WHtR with metabolic risk factors was obtained using Spearman's rank correlation coefficient. Optimal cutoff value was obtained using receiver operating characteristic curve. RESULTS: WC and WHtR performed equally well in both sexes in terms of their strength of association between metabolic risk factors. Receiver operating characteristic curve analysis showed that 73.5 cm (in women) and 82.5 cm (in men) were the optimal WC cutoff values to identify insulin resistance. CONCLUSION: It is suggested that WC is a simpler anthropometric measurement that has strong association with an individual's metabolic risk level.

The glycaemic index and insulinaemic index of commercially available breakfast and snack foods in an Asian population.

A low-glycaemic-index (GI) breakfast has been shown to lower blood glucose levels throughout the day. A wide variety of breakfast foods are consumed, but their GI values are largely unknown, hence limiting consumers' ability to select healthier options. This study investigated the GI values of ten common breakfast (five Asian and five Western) foods in this region using a randomised, cross-over study design. Participants arrived after an overnight fast, and fasting blood sample was taken before participants consumed test foods. Next, blood samples were taken at fixed intervals for 180 min. Glycaemic and insulinaemic responses to test foods were calculated as incremental AUC over 120 min, which were subsequently reported as glycaemic and insulinaemic indices. In all, nineteen healthy men (nine Chinese and ten Indians) aged 24·7 (sem 0·4) years with a BMI of 21·7 (sem 0·4) kg/m2 completed the study. Asian breakfast foods were of medium (white bun filled with red bean paste=58 (sem 4); Chinese steamed white bun=58 (sem 3)) to high GI (rice idli=85 (sem 4); rice dosa=76 (sem 5); upma=71 (sem 6)), whereas Western breakfast foods were all of low GI (whole-grain biscuit=54 (sem 5); whole-grain biscuit filled with peanut butter=44 (sem 3); whole-grain oat muesli=55 (sem 4); whole-grain oat protein granola=51 (sem 4); whole-grain protein cereal=49 (sem 3)). The GI of test foods negatively correlated with protein (r s -0·366), fat (r s -0·268) and dietary fibre (r s -0·422) (all P<0·001). GI values from this study contribute to the worldwide GI database, and may assist healthcare professionals in recommending low-GI breakfast to assist in lower daily glycaemia among Asians who are susceptible to type 2 diabetes mellitus.