Ageing and disease burdens: Our present and future Martin Prince and co-collaborators, Lancet Series on Ageing (2014) In low- and middle-income countries (LMICs), the epidemiological transition will result in growing exposure to cardiovascular risk factors in older people, particularly in those who are poor; an increase in the incidence and prevalence of cardiovascular diseases; and a surge in health inequalities. Addressing this issue should be a global health priority. In high-income countries (HICs), socioeconomic gradients, once established, tend to become entrenched, with poor people and people with lower levels of education failing to benefit from subsequent improvements in public health. Hence, there are two crucial and related public health challenges for LMICs: can we improve the health of successive cohorts of older people as life expectancy increases (compression of morbidity), and can this be achieved equitably? Overview and risk exposures In LMICs, the age-specific prevalence of dementia (Llibre Rodriguez et al., 2008) and depression (Guerra et al., 2009) is similar to that in HICs, with numbers increasing particularly rapidly given the pace of population ageing. Impact on disability (Sousa et al., 2009), needs for care and carer strain (Honyashiki et al., 2011) is There is a lot of scope for intervention to promote health and prevent disease in older people 42 Commonwealth Health Partnerships 2015 considerable. Dementia is the leading contributor to disability for older people in LMICs, while depression is fifth after stroke, limb impairment and arthritis (Sousa et al., 2009). Nevertheless, older people with cognitive and mental disorders are underserved by public health services. The diagnosis and treatment gap for dementia in LMICs exceeds 90 per cent (Prince, Bryce and Ferri, 2011), much higher than the 40–60 per cent in HICs that lack access to evidence-based treatment and care. While depression, alongside physical illness, predicts use of health care services, dementia is inversely correlated (Albanese et al., 2011). Informed policy-making and planning necessitates an understanding of the present and probable future distribution of morbidity and its effect on mortality, disability and dependence.1 Several effects need to be considered: demographic and epidemiological transitions, and secular changes in the effectiveness and coverage of disease control measures. Effects will vary between disorders and regions. However, a globalisation of risk behaviours – including diets rich in saturated fats, increase of tobacco use and underactivity, with consequent obesity – partly causes the rapid increase in burden of chronic diseases in low- and middle-income regions. After the transition, in HICs, cardiovascular risk factors and diseases are typically associated with economic disadvantage and low levels of education, but the opposite trend is often true for LMICs. The profile of lifestyle-related risk factors is much the same across the most burdensome disorders for older people. Dyslipidaemia, hypertension, diabetes, smoking and obesity are the major modifiable risk factors for cardiovascular diseases. Smoking is also the main modifiable risk factor for cataract- and age-related macular degeneration, COPD and lung cancer in old age. A review (Barnes and Yaff, 2011) of risk factors for Alzheimer’s disease identified consistent evidence from cohort studies to accord with a causal role for smoking, physical inactivity, midlife hypertension, obesity and diabetes. Cardiovascular diseases The profile of cardiovascular diseases develops gradually with the epidemiological transition. As mortality decreases, nutrition improves and infections are controlled, and hypertension, ischaemic heart disease and stroke become more prevalent. As HICs advance into the so-called age of delayed degenerative diseases, age-adjusted mortality due to cardiovascular diseases decrease with effective primary and secondary prevention and better acute hospital management. This article draws extensively on a Lancet Series on Ageing (2014) article ‘The burden of disease in older people and implications for health policy and practice’ co-written with Fan Wu, MD; Yanfei Guo, MD; Luis M. Gutierrez Robledo, PhD; Martin O’Donnell, PhD; Richard Sullivan, MD; and Salim Yusuf, DPhil. Adapted by kind permission. For full references and further information see www.thelancet.com/series/ageing Accessed 1 April 2015.
Commonwealth Health Partnerships 2015
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