London, UK – The number of deaths worldwide caused by noncommunicable “rich-country” diseases such as heart disease and stroke reached 34.5 million in 2010, outstripping the key global killers from two decades ago: infections, poor nutrition, and deaths associated with childbirth and early life.
In one of the studies, a survey of 235 causes of death across 20 age groups in 187 countries, Dr Rafael Lozano (Institute for Health Metrics and Evaluation, Seattle, WA) and colleagues report that although noncommunicable diseases caused 50% of deaths back in 1990, that number rose to almost two out of every three deaths in 2010 . Ischemic heart disease and stroke caused almost 13 million deaths in 2010—one in four deaths—worldwide, compared with just one in five back in 1990. Cancer deaths, likewise, have increased by 38%, causing a whopping eight million deaths in 2010. The number of deaths due to diabetes doubled over the study period, reaching 1.3 million in 2010.
In a second paper tracking the burden of disease related to 67 risk factors, Dr Stephen S Lim (Institute for Health Metrics and Evaluation, Seattle, WA) and colleagues report that the top two risk factors for disease in 2010 were high blood pressure and tobacco use . Back in 1990, these two risk factors held positions number 4 and 3, respectively, while the two most important risk factors 20 years ago were childhood underweight and household air pollution.
In 2010, write Lim et al, high blood pressure was estimated to be responsible for 9.4 million deaths, or 7% of disability-adjusted life-years (DALYs). Tobacco smoke (first- or secondhand) was estimated to have caused 6.3 million deaths and 6.3% of global DALYs.
Of note, while childhood underweight has dropped to eighth spot from its top seat, high body-mass index, which held the 10th position in 1990, rose to sixth place in the 2010 rankings. High total cholesterol, ranked 14th in 1990, actually dropped one spot, into 15th place. By contrast, high fasting plasma glucose levels occupied the ninth spot in 1990, rising to seventh over two decades.
Worldwide, life expectancies have risen by roughly 20% for both men and women (11.1 and 12.1 years, respectively) over the past two decades, reflecting the drop in conditions such as malnutrition and infectious disease, which tend to kill children and young adults . The rise also explains, in part, the increase in deaths from cardiovascular diseases and cancer, which typically occur later in life. Life-expectancy gains, not surprisingly, were seen primarily in the developing world, although notable exceptions included southern sub-Saharan Africa, Belarus, and Ukraine.
Speaking at a press conference Thursday, Lancet editor Dr Richard Horton called the series “an unprecedented issue in the Lancet‘s history,” likening its scope, and the efforts underpinning it, to the human genome project. In all, 486 authors from over 300 institutions in 50 countries participated in the GBD study, which was launched in 2007.
“Everyone concerned with health—health workers and policy makers, those working in technical agencies (across the UN system), development partners, civil society, and the research community—should use these latest findings to sharpen understanding of trends in disease, injury, and risk,” Horton writes .