Lung health over the life course in Malawi

Lead Research Organisation: Liverpool School of Tropical Medicine
Department Name: Liverpool School of Tropical Medicine

Abstract

Non-communicable diseases (NCDs) present an increasing challenge for health care systems as the global burden of infectious diseases falls, due to improvements in disease prevention and treatment. NCDs are non-curable conditions, which require long-term management, to minimise symptoms and improve quality of life and reduce risk of future adverse events.
The WHO has identified the prevention and management of NCDs as a priority, emphasizing the importance of a life-course approach, with multi-stakeholder engagement and empowerment of people and communities. Poverty and NCDs are intertwined; health systems in low-income countries are ill-equipped to detect and manage chronic conditions, and there are high household costs associated with long-term treatment. The 2030 Agenda for Sustainable Development recognises NCDs as a major threat and includes a target (SDG 3.4) of reducing premature deaths from NCDs by one-third by 2030.
Non-communicable lung disease includes COPD and asthma; respiratory conditions associated with considerable morbidity and mortality. It is estimated that asthma affects 358 million people, and COPD 174 million people, worldwide. The Global Burden of Disease Study (GBD 2016) reported COPD in the top ten causes of both death and disability worldwide. Although a much rarer cause of death, asthma is a major cause of morbidity in childhood, ranking in the top ten causes of disability-adjusted life years (DALYs) in both younger and older children.
NCD-L is subdivided into obstructive and restrictive lung disease, with obstruction described as reversible (asthma) or irreversible (COPD). Obstructive lung disease is defined by a reduced ratio of forced expiratory volume in 1s (FEV1) to forced vital capacity (FVC). Restrictive lung disease is defined by a low FVC. However, there is considerable debate regarding disease definitions, and the most appropriate cut-off values to define abnormality, particularly as normal ranges vary with age and ethnicity.

Lung growth and development may be influenced by factors present across the life course; pre-natal, perinatal, infancy, childhood, adolescence and adulthood. Risk factors such as low-birth weight prematuriy, air pollution, respiratory infections are commonly encountered in low-income settings such as Malawi. Maternal exposure to biomass fuel smoke may have a detrimental effect on in-utero lung development, given the impact of other maternal environmental exposures, such as cigarette smoking, on infant lung function.
Clinically significant lung function impairment at preschool age has been associated with higher levels of maternal exposure to outdoor air pollution (benzene, NO2 and fine particulate matter) during pregnancy.


This thesis will explore NCD-L across the life course, in a low-income setting. The projects contributing to this thesis have all been conducted in Malawi (in both urban and rural settings), and have relevance to other low-income countries, particularly in sub-Saharan Africa.
Broad aims:
- Explore the decreased FVC phenomenon reported in Malawian adults
- Is this due to accelerated decline in lung function?
- Is this related to exposure to HAP
- Explore the prevalence on non-communicable lung disease in rural Malawian children
- Is asthma a problem in rural Malawi?
- Do the spirometric abnormalities seen in Malawian adults, originate in childhood?
- Explore the pathophysiology and response to treatment for children with a doctor-diagnosis of asthma

Publications

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