In addition to far greater prevalence of HIV/AIDS than elsewhere in the world, Sub-Saharan Africa (SSA) is expected to see cardiovascular and metabolic disease burdens more than double over the next 20 years. Little is understood about the nature of aging in this context, where many adults are now surviving with chronic diseases whether they are communicable or non-communicable. A February 2013 paper in Science by Bor et al. documented an increase in adult life expectancy of more than 10 years over the course of 8 calendar years due to the scale-up of antiretroviral therapy (ART) in a rural South African community with high HIV prevalence. However, there is little data on the effects of such dramatic ART-driven increases in population aging on the rates and composition of non-communicable diseases, functional status, and disabilities. Even less is known about the family and societal dynamics that will change as a result of growing numbers of older men and women surviving with chronic diseases.
Partnering with the University of Witwatersrand research team in Agincourt, this project focuses on Sub Saharan Africa and integrates the study of HIV and non-communicable diseases (including cardiovascular disease, diabetes, and cognitive impairments) and their interactions with population aging in order to understand the determinants of health and functional status in the elderly in South Africa, and the impact of ill health and functional limitations on their economic circumstances and well-being. Such research is especially important in the South African context where a) ART scale-up has reached millions of HIV-infected individuals leading to rapid changes in population age composition, b) health systems are strained and at present ill-prepared to effectively address changing disease patterns through screening, prevention and treatment, c) the high HIV-related mortality of the past has deprived families and communities of prime-age workers and has put significant economic burdens on the elderly to provide health care for younger family members, and d) private savings and government transfers to the elderly are limited.
We will establish a cohort of 4,000 men and women aged 50 and over in Agincourt, South Africa, who will be interviewed and tested for HIV infection and cardiometabolic disease risk factors. HIV-infected respondents will be oversampled to maximize the ability to study the combination of HIV and cardiometabolic disease. Survey questions, biomarker testing, and performance measures will assess HIV risks, biological, behavioral and structural risk factors for HIV and cardiovascular disease; economic assets, income and expenditure; subjective well-being; and social network structure and social supports. Dried blood spots will be collected to assess HIV morbidity, ART need and ART status. A sub-study of 400 respondents will be established who will have a clinic visit for more extensive HIV and cardiometabolic-related assessments. P01-collected data will be integrated with mortality data from the well-established INDEPTH Health and Demographic Surveillance System (HDSS) data at the Agincourt site, and also with longitudinal data (2006 and 2010) on functioning and quality of life from the WHO Study on Global Ageing and Adult Health (SAGE). To prepare for future longitudinal analysis in which accurate tracking of out-migrants is essential, all baseline participants will be followed to ascertain cause of death using standardized state-of-the-art verbal autopsy approaches. Our working hypothesis is that ill health and disability are major factors in determining household composition, labor force participation, household income and expenditure, and subjective well-being. Our project integrates the study of both chronic communicable and non-communicable diseases and their interactions. We aim to identify the ways in which behavioral and biologic risks are embedded in the social context of rural South Africa and are driven by social and economic conditions. Health policies, in the broadest sense, must rest on a strong evidence base and our study will provide critical assessments of phenotypic disorders and risk factors for guiding health policy.