Why research the ageing process?
Life expectancy in the United Kingdom is increasing at a rate of approximately two years per decade; with 1 in 3 children born now expected to reach 100 years. This would be a cause for celebration if it were not for the fact that increases in health span, the years spent in good health, are not keeping pace with lifespan changes. Estimates from the World Health Organisation show a 10-year difference between healthspan and lifespan in the UK.
Supporting the continued need for a Centre of Excellence focussed on research in to musculoskeletal (MSK) ageing are the dramatic statistics concerning age-related compromise to the MSK system: 740,000 adults are admitted to A&E each year after a fall, which resulted in 89,000 hip fractures in 2015; 20% of the population consults their GP about an MSK problem each year and the NHS spends >£5 billion on MSK health; low muscle mass predicts all-cause mortality in older people; Arthritis affects over 10 million people in the UK and there are >175,000 joint replacements annually as a result; the indirect cost to the economy of arthritis, in terms of working time lost, is estimated at £14 billion.
These figures make it clear that doing nothing to improve the MSK health of our ageing population is an expensive choice and an untenable long-term position. Ageing is a complex process that results in the reduced functioning of most of the body’s organ systems, with the MSK system (muscle, bone, tendon and cartilage) significantly affected.
The MSK system is compromised not only by the loss of muscle, bone and cartilage with age but also by the decline in function of the nervous system which results in reduced control of movement and balance leading to frailty. Ageing is also often accompanied by weight gain which puts further strain on joints and contributes to the erosion of cartilage and bone, increasing the chances of developing osteoarthritis.
Importantly both ageing and obesity are associated with decreased physical activity levels, an increased level of systemic inflammation, an altered anabolic hormone milieu, muscle anabolic resistance to nutrition and exercise and insulin resistance, all of which affect the ability of the body to maintain a healthy MSK system and accelerate chronic disease progression. Therefore increased physical activity and interventions that are able to reduce inflammation, correct age- and obesity-related hormone and body composition changes, and sustain tissue metabolic health offer a way forward for delaying age-related changes in the MSK system and disease progression. Indeed, strong relationships exist between physical inactivity and chronic disease and all-cause and disease-specific mortality rates. The problem is we do not yet know the rate of change or mechanistic basis of these relationships.