Low and middle-income Asian countries are experiencing an increase in the number of NCD-related deaths. Rapid and unplanned urbanization in these countries has led to an increase in the number of urban poor, including slum dwellers. Worldwide, over a billion people currently live in urban slum settings and it is estimated that this figure will double by 2030. People living in urban slums often lack the basic amenities and are at a disadvantageous position compared to other urban inhabitants since they lack knowledge and information regarding health, and have poor access to healthcare due to socioeconomic constraints. There is growing interest, therefore, in (1) identifying major environmental, nutritional, and other multifactorial risks of NCDs among slum dwellers, and (2) forming a framework for future planning, policy-making, implementation, and evaluation of public health interventions, established to prevent and control such diseases.

BangladEsh Longitudinal Investigation of Emerging Vascular Events-Slum (BELIEVE-Slum) study, in this regard, has been designed as a large-scale prospective cohort investigation among South Asians living specifically in the slum areas. The study, in collaboration with Bangabandhu Sheikh Mujib Medical University (BSMMU) in Bangladesh, aims to recruit up to 10,000 inhabitants (age >18 years) from slum households in Bangladesh. The study population will be recruited through a household survey to ensure maximum and generalizable participation, particularly from individuals with shared environmental and genetic background.

The key objectives of the BELIEVE-Slum cohort study are to (1) identify unique, locally-relevant environmental (eg, indigenous diet, physical activity, smoking, consanguineous marriage, long-term arsenic exposure, concomitant water and air pollution) and biological (eg, iron deficiency, dyslipidaemia, metabolic dysfunction) NCD risk factors within slum settings; (2) assess reliably the synergy between the identified risk factors and subsequent NCD incidents such as cardiovascular, cancer, diabetes and kidney diseases (ascertained by clinical records and standardised validation); (3) allow genetic discovery, causal evaluation and functional genomics to determine the complex interplay between genes and environmental factors among South Asian slum dwellers and between different genes on disease risk; and (4) create a well-defined slum population platform to shape and establish scalable, cost-effective and context-specific interventions to control and prevent NCDs within slum communities of low- and middle-income countries.

The BELIEVE-Slum study (along with the BELIEVE-Urban and BELIEVE-Rural studies) has been underpinned by the Global Challenges Research Funds from the Research Councils UK.

Key people involved in the study:

Dr Rajiv Chowdhury (lead Principal Investigator)

Dr Md Khalequzzaman, Dr Emanuele Di Angelantonio and Professor John Danesh (co-Principal Investigators)

Dr Shariful Islam, Dr Sohel Choudhury, Dr Fazal Khan, Dr Meerjadi Sabrina Flora (co-investigators)

Ms Catherine Perry (data management)

Mr Richard Houghton, Ms Silvia Alonso Rodriguez