Waist to Height Ratio: An alternative anthropometric indicator for early detection of health risk for Malaysia Health and Morbidity Survey (NHMS)

Introduction Waist-to-height ratio (WHtR) recently received much attention as an indicator for early health risk (diabetes, hypertension and cardiovascular). Many Asian countries such as India, China, and Korea have proposed that WHtR 0.5 be used for screening in other population. The data also confirmed that the cut off value of WHtR 0.5 for increased risk is appropriate across age, gender and ethnic population in adults. The purpose of this study was to identify the prevalence of adults who are at risk by WHtR but missed by BMI screening from the Malaysia NMHS 2015 Study. It is also to investigate whether WHtR is an independent anthropometric predictor for diabetes, hypercholesterolemia, high systolic and diastolic blood pressure.

Materials and Methods Recent data of the Malaysia National Health and Morbidity Survey (NHMS) 2015 was used. The sampling design used two staged stratified random sampling. WHtR is defined as waist circumference in centimetres divided by height in centimetres. Data collection was from Mac 2015 till June 2015. A descriptive analysis for socioeconomic and anthropometric variables was carried out. Correlations between the variables BMI, WHtR, systolic blood pressure(SBP), diastolic blood pressure (DBP), Total cholesterol and Diabetes were checked using Pearson correlation test. The analysis of ROC curve (receiver operating characteristics) was used to assess the accuracy of BMI,WC and WHtR as early health risk indicators for diabetes, high systolic and diastolic blood pressure, and high cholesterol.

Results A total of 20767 adults were recruited for this study. 18373 selected after considering exclusion criteria. Data from Table 1 shows the summary of anthropometry data of the study. Results from NHMS 2015 reported a mean ration for WHtR of 0.53 for Malaysian population regardless of gender, ethnicity and age. Findings from this study ( Table 2) showed 19.4% ( 1 in 5) of adults with ‘normal weight by BMI’ have WHtR greater than 0.5 and therefore are at health risk.

Discussion / Conclusion This study showed that there were certain percentage of Malaysian population that were missed by BMI screening but found to be at risk by WHtR. Areas under ROC curve showed WHtR was the predictor for the best performance for diabetes and high cholesterol but not systolic pressure and diastolic pressureLimitation of this study was that three blood pressure measurements were taken almost simultaneously. In view of considering NHMS 2015 survey as one of the largest population-based survey, it can be concluded that a cut-off point of 0.5 for WHtR should be sufficient and acceptable to indicate Malaysian population that are at risk or increased health risk regardless of ethnicity, gender and age.