Non-Communicable Diseases

Non-communicable diseases (NCDs) pose a threat to sub-Saharan Africa (SSA), but there is little research to address this challenge. We have shown that NCD manifest differently in SSA. For example, mental illness is often seen with chronic infections (eg HIV). Similarly, type 2 diabetes occurs in lean individuals Africa, unlike in the West where it associates with obesity. Solutions from elsewhere may therefore not be necessarily effective in SSA. The unique NCD presentations are likely shaped by local factors, such as genetic susceptibility and other exposures, including infections and malnutrition. We aim to do rigorous research to uncover the fundamental underlying mechanisms, and to find best ways to prevent and treat these disorders in Africa. We will carefully characterise diabetes to see if it is caused either by lack of insulin (eg because the pancreas is small from previous malnutrition or infection) or because the insulin produced is not working well. We will test if drugs used to treat diabetes in the obese work in thin Africans. Building on our studies that have strongly linked HIV and depression, particularly in young people, we will design and test psychological intervention(s), delivered by lay health workers, to manage depression in young people living with HIV. As combination of infection and NCDs can cause huge disability, we will study how to improve the quality of life of people with disabilities, including through better access to healthcare.

Non-communicable diseases (NCDs) will soon overtake infectious diseases as major causes of morbidity and mortality in sub-Saharan Africa (SSA), but the region is ill-prepared to respond to this challenge, both in terms of research and health systems readiness. Our research on diabetes and mental health has shown that these conditions manifest differently in SSA, compared to high-income countries. For example, mental illness is commonly seen in people with chronic infection (such as HIV), and type 2 diabetes occurs in young and lean individuals (rather than its classic association with obesity).

We hypothesis that these unique manifestations of NCDs in SSA are shaped by local genetic and environmental exposures, such as interactions with infection and the impact of malnutrition, particularly in early life; this can affect organ growth and/or function. We have assembled a multidisciplinary team of epidemiologists, social scientists, clinicians and basic scientists to unravel the underlying mechanisms and to find the best ways to prevent and manage these conditions in SSA. We will undertake detailed characterisation of diabetes to assess the contribution of insulin resistance versus pancreatic beta cell deficiency, quantify pancreatic size suing MRI, and investigate associations with nutrition patterns and infection/inflammation. We will undertake clinical trials to assess the efficacy of different therapeutic agents. We hypothesize that thin patients will respond better to secretagogue (sulphonylurea) therapy, while metformin will be more effective in those with obesity and insulin resistance.

Our mental health work builds on a track record of research that has revealed high prevalence of emotional disorders (depression and anxiety) in the youth living with HIV. We will adapt and validate relevant tools (such as the RCADS-25) to rigorously assess the prevalence of these disorders, and carefully investigate potential mediating mechanisms, including the role of inflammation. Based on an approach (the PRIDE) that has been effective in India , we will develop and evaluate an intervention, delivered by lay health worker, to address the reinforcing mental health and psychosocial challenges facing the youth living with HIV.

The convergence of infectious diseases and NCDs in SSA is likely to cause significant emotional stress and disability. Our research also incorporates studies on the social and structural drivers of morbidity, including studies to improve health and quality of life of people with disabilities through better access to health care. We also have research on the relationships between these chronic conditions, emotional stress and violence, particularly in adolescents and the youth.