The number of people with peripheral artery disease (PAD) is on the rise, according to a study published in The Lancet.
PAD refers to diseases of the blood vessels outside of the heart and brain. Peripheral artery disease causes the blood vessels to narrow, restricting blood flow in the arms, legs, stomach and kidneys.
According to the Centers for Disease Control and Prevention, around 8 million people in the US suffer from PAD, with between 12-20% of these aged 60 and over.
But researchers from the UK and US have revealed that the number of people with peripheral artery disease worldwide has risen by 23.5% in the past 10 years, from 164 million in 2000, to 202 million in 2010.
Low-income countries more widely affected
The researchers analyzed data from 34 community-based studies worldwide, which identified PAD using the ankle brachial index. This is a test measuring the ratio of blood pressure at the ankle to that in the arm.
Of these studies, 22 were from high-income countries and 12 were from low-income or middle-income countries.
The studies were used to develop age-specific and sex-specific prevalence rates in these countries, as well as to determine the main risk factors for PAD development.
The estimates in this study reveal that peripheral artery disease is increasing worldwide, but 70% of people with the disease are living in low- or middle-income countries - with the majority living in southeast Asia and western Pacific regions.
Within the low- or middle-income countries, the number of people with PAD has gone up by 28.7%, while high-income countries have seen an increase of 13.1% in peripheral artery disease.
Additionally, the results showed higher rates of the disease in men in high-income countries, while in low-middle income countries PAD is more prevalent in women than men, particularly at younger ages.
Longer life expectancies
The researchers say that the dramatic increase in prevalence of peripheral artery disease over the last 10 years could be attributed to longer life expectancies and changing lifestyles.
They add that there has been a 35% increase in PAD occurrences in those aged over 80, and that peripheral artery disease now affects 1 in 10 people over 70 years of age and 1 in 6 people over 80.
The researchers note that the majority of key risk factors related to other major cardiovascular disorders, such as smoking, diabetes, high blood pressure and high cholesterol is the same for PAD, and can be treated and prevented.
Professor Gerry Fowkes, of the University of Edinburgh, says:
"Peripheral artery disease has become a global problem in the 21st century and can no longer be regarded as a disease that affects mostly high-income countries.
Prof. Fowkes adds: "As the world's population ages, peripheral artery disease will become substantially more common, and there is an urgent need to assess treatment and prevention strategies in both high-income countries and low- or middle-income countries."
Results "underestimate global burden"
Professor Alan Hirsch and Professor Sue Duval, of the cardiovascular division and Lillehei Heart Institute at the University of Minnesota Medical School, say in a comment piece following the study that this research underestimates the true burden of peripheral artery disease.
"The disease estimates were derived by use of the ankle-brachial index, without use of other methods that also detect the disorder (toe pressures, duplex ultrasound).
Future surveillance of peripheral artery disease will require development of better strategies to assess this burden fully."
They say that improvement of global health needs a global strategic plan for peripheral artery disease, adding: "When any disease affects more than 200 million people, it is time to take action to prevent and control its global burden."