Socio-economic status and behavioural and cardiovascular risk factors in Papua New Guinea: A cross-sectional survey

BACKGROUND: Risk factors for cardiovascular disease (CVD) are negatively correlated with socio-economic status (SES) in high-income countries (HIC) but there has been little research on their distribution by household SES within low-and middle-income countries (LMICs). Considering the limited data from LMICs, this paper examines the association between behavioural and cardiovascular risk factors and household SES in Papua New Guinea (PNG). METHODS: Reported here are results of 671 participants from the 900 randomly selected adults aged 15-65 years. These adults were recruited from three socioeconomically and geographically diverse surveillance sites (peri-urban community, rural Highland and an Island community) in PNG in 2013-2014. We measured their CVD risk factors (behavioural and metabolic) using a modified WHO STEPS risk factor survey and analysis of blood samples. We assessed SES by education, occupation and creating a household wealth index based on household assets. We calculated risk ratios (RR) and their 95% confidence intervals (CI) using a generalized linear model to assess the associations between risks and SES. FINDINGS: Elevated CVD risk factors were common in all SES groups but the CVD metabolic risk factors were most prevalent among homemakers, peri-urban and rural highlands, and the highest (4th and 5th) wealth quintile population. Adults in the highest wealth quintile had high risks of obesity, elevated HbA1c and metabolic syndrome (MetS) that were greater than those in the lowest quintile although those in the highest wealth quintiles were less likely to smoke tobacco. Compared to people from the Island community, peri-urban residents had increased risks of increased waist circumference (WC) (RR: 1.67, 95%CI: 1.21-2.31), hypertension (RR: 2∙29, 95%CI: 1∙89-4.56), high cholesterol (RR: 2∙22, 95%CI: 1∙20-4∙10), high triglycerides (RR: 1∙49, 95%CI: 1∙17-1∙91), elevated HbA1c (RR: 5∙54, 95%CI: 1∙36-21∙56), and Metabolic syndrome (MetS) (RR: 2∙04, 95%CI: 1∙25-3∙32). Similarly, Rural Highland residents had increased risk of obesity (Waist Circumference RR: 1∙70, 95%CI: 1∙21-3∙38, Waist-Hip-Ratio RR:1∙48, 95%CI: 1∙28-1∙70), hypertension (RR: 2∙60, 95%CI: 1∙71-3∙95), high triglycerides (RR: 1∙34, 95%CI: 1∙06-1∙70) and MetS (RR: 1∙88, 95%CI: 1∙12-3∙16) compared to those in the rural Island site. INTERPRETATION: CVD risk factors are common in PNG adults but their association with SES varies markedly and by location. Our findings show that all community members are at risk of CVD weather they are part of high or low SES groups. These results support the notion that the association between CVD risk factors and SES differ greatly accordingly to the type of SES measure used, risk factors and the population studied. In addition, our findings contribute further to the limited literature in LMIC. Longitudinal studies are needed to monitor changes in rapidly changing societies such as PNG to inform public health policy for control and prevention of NCDs in the country