BackgroundWaist circumference (WC) is an indicator of intra-abdominal adipose tissue, high levels of which confer an increased risk of cardiometabolic disease. Population data on WC should be more informative than data on body mass index (BMI), which is a general indicator of body size. This study aimed to evaluate the importance of WC relative to BMI in cross-sectional relationships with blood pressure (BP), glucose, and total cholesterol (TC) in the adult population of Vietnam.MethodsThe data were collected in a population-based survey conducted during 2009–10 using the “WHO STEPwise approach to surveillance of risk factors for non-communicable disease” (STEPS) methodology. The survey participants (n = 14 706 aged 25 to 64 years) were selected by multi-stage stratified cluster sampling from eight provinces representative of the eight geographical regions of Vietnam. All measurements were performed in accordance with the STEPS protocols. All analyses were performed using complex survey methods.ResultsThe measurements of WC and BMI were highly correlated (men r = 0.80, women r = 0.77). For men, the strongest and predominant associations with BP, glucose, and TC were for WC or an index based on WC. For women, this was true for glucose but BMI was more important for BP and TC. WC or an index based on WC provided better discrimination than BMI of hypertension and elevated glucose, and of raised TC for men. Information on four new anthropometric indices did not improve model fit or subject discrimination.ConclusionFor BP/hypertension, glucose/elevated glucose, and TC/raised TC, WC was more informative than BMI for Vietnamese men, but both WC and BMI were important for Vietnamese women. Both WC and BMI need to be assessed for estimation of CVD risk in Vietnam.

BackgroundTo estimate the prevalence of non-communicable disease (NCD) risk factors at a provincial level in Vietnam, and to assess whether the summary estimates allow reliable inferences to be drawn regarding regional differences in risk factors and associations between them.MethodsParticipants (n = 14706, 53.5 % females) aged 25–64 years were selected by multi-stage stratified cluster sampling from eight provinces each representing one of the eight geographical regions of Vietnam. Measurements were made using the World Health Organization STEPS protocols. Data were analysed using complex survey methods.ResultsDifferences by sex in mean years of schooling (males 8.26 ± 0.20, females 7.00 ± 0.18), proportions of current smokers (males 57.70 %, females 1.73 %), and binge-drinkers (males 25.11 %, females 0.63 %), and regional differences in diet, reflected the geographical and socio-cultural characteristics of the country. Provinces with a higher proportion of urban population had greater mean levels of BMI (r = 0.82), and lesser proportions of active people (r = −0.89). The associations between the summary estimates were generally plausible (e.g. physical activity and BMI, r = −0.80) but overstated, and with some anomalous findings due to characterisation of smoking and hypertension by STEPS protocols.ConclusionsThis report provides an extensive description of the sex-specific and regional distribution of NCD risk factors in Vietnam and an account of some health-related consequences of industrialisation in its early stages. The STEPS protocols can be utilized to provide aggregate data for valid between-population comparisons, but with important caveats identified.

Alcohol use and harmful consumption were common among Vietnamese men but less pronounced than in Western nations. Self-reports of quantity of alcohol consumed in terms of standard drinks had predictive validity for blood pressure and hypertension even in rural areas. However, using detailed measures of consumption resulted in only minor improvements in prediction compared to simple measures.

IntroductionOur aims were to provide the first national estimates of physical activity (PA) for Vietnam, and to investigate issues affecting their accuracy.MethodsMeasurements were made using the Global Physical Activity Questionnaire (GPAQ) on a nationally-representative sample of 14706 participants (46.5% males, response 64.1%) aged 25−64 years selected by multi-stage stratified cluster sampling.ResultsApproximately 20% of Vietnamese people had no measureable PA during a typical week, but 72.9% (men) and 69.1% (women) met WHO recommendations for PA by adults for their age. On average, 52.0 (men) and 28.0 (women) Metabolic Equivalent Task (MET)-hours/week (largely from work activities) were reported. Work and total PA were higher in rural areas and varied by season. Less than 2% of respondents provided incomplete information, but an additional one-in-six provided unrealistically high values of PA. Those responsible for reporting errors included persons from rural areas and all those with unstable work patterns. Box-Cox transformation (with an appropriate constant added) was the most successful method of reducing the influence of large values, but energy-scaled values were most strongly associated with pathophysiological outcomes.ConclusionsAround seven-in-ten Vietnamese people aged 25–64 years met WHO recommendations for total PA, which was mainly from work activities and higher in rural areas. Nearly all respondents were able to report their activity using the GPAQ, but with some exaggerated values and seasonal variation in reporting. Data transformation provided plausible summary values, but energy-scaling fared best in association analyses.

Smoking prevalence is declining in recent cohorts of men, and continues to decline in successive cohorts of women, possibly in response to anti-tobacco initiatives commencing in the 1990s. Low proportions of quitters mean that Vietnamese smokers accumulate high exposures despite moderate quantities of cigarettes smoked per day.