Since the year 2000, the number of individuals experiencing poor health and premature death as a result of metabolism-related risk factors such as elevated blood pressure, high blood sugar, and high BMI, has surged by 50%, as indicated by a recent international study that was published on Thursday in The Lancet. Despite global declines, the burden of disease associated with malnutrition risk factors for children and mothers remains high in certain regions of the world, including sub-Saharan Africa.
The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides novel insights into health challenges and their underlying risk factors. According to the researchers, the increase in individuals experiencing metabolic risk factors, such as high systolic blood pressure, high fasting plasma glucose, high body mass index, high LDL cholesterol, and kidney dysfunction, reflects the impact of an aging population and evolving lifestyles worldwide.
The study revealed a 49.4% increase from 2000 to 2021 in the number of global disability-adjusted life years (DALYs) – years of healthy life lost due to ill health and premature death – attributable to metabolic risk factors. Notably, ill health in individuals aged 15-49 was increasingly linked to high BMI and blood sugar, which elevates the risk of diabetes. High blood pressure and LDL cholesterol were also among the top 10 risk factors for this age group.
“Although metabolic in nature, the development of these risk factors can often be influenced by various lifestyle factors, particularly among younger generations,” explained Michael Brauer, an affiliate professor at the Institute for Health Metrics and Evaluation (IHME). “They also serve as an indicator of an aging population that is more susceptible to developing these conditions over time. By focusing on reducing preventable, non-communicable diseases through modifiable risk factors, we have a significant opportunity to proactively alter the trajectory of global health through policy and education.”
Air pollution, smoking, low birthweight, and short gestation were also among the major contributors to DALYs in 2021, with significant variations across different ages, genders, and geographic locations. Commendably, substantial progress was made from 2000 to 2021 in reducing the global disease burden attributable to maternal and child health risks, unsafe water, sanitation and handwashing, and household air pollution from solid fuel cooking.
“Risk factors that currently lead to ill health, such as obesity and other components of metabolic syndrome, exposure to ambient particulate matter air pollution, and tobacco use, must be addressed through a combination of global health policy efforts and exposure reduction to mitigate health risks and improve population health,” said Emmanuela Gakidou, a professor of Health Metrics Sciences at IHME.
Greg Roth, the director of the Program in Cardiovascular Health Metrics at IHME, added, “With increasing exposure to risk factors such as high blood sugar, high blood pressure, low physical activity, and a diet high in sugar-sweetened beverages, there is an urgent need for interventions focused on obesity and metabolic syndromes.”
The most significant declines in disease burden were observed for maternal and child health and water/sanitation/handwashing risk factors, primarily due to decreased risk exposure and proportionally smaller youth populations. This suggests the effectiveness of recent public health measures and humanitarian initiatives, particularly in areas with lower socioeconomic conditions.
Despite global reductions, the disease burden from child and maternal malnutrition risk factors persisted in sub-Saharan Africa, South Asia, regions of North Africa and the Middle East, Southeast Asia, East Asia, and Oceania. Child and maternal malnutrition also remained a challenge in northern India in 2021.
Smoking’s disease burden increased moderately due to population aging, despite a decline in exposure. Ambient air pollution, high BMI, high blood sugar, and high blood pressure witnessed substantially increased disease burdens as exposure increased and populations aged. Emerging evidence suggests a recent peak in India’s ambient air pollution, coinciding with reduced household air pollution.
“GBD emphasizes that future trends may diverge significantly from past trends due to factors such as climate change, rising obesity rates, and addiction. However, simultaneously, there are immense opportunities to alter the trajectory of health for the next generation,” said Liane Ong, lead research scientist at IHME.
The findings also predict that by 2050, global life expectancy will increase by nearly 5 years for males and 4.2 years for females, despite geopolitical, metabolic, and environmental challenges. The most significant gains are anticipated in countries with lower life expectancies, contributing to a convergence of life expectancies across different regions. This is largely driven by public health interventions that prevent and improve survival from cardiovascular diseases, COVID-19, and communicable, maternal, neonatal, and nutritional diseases (CMNNs).
“As the disease burden continues to shift from CMNNs to non-communicable diseases (NCDs) and from years of life lost to years lived with disability, more people are expected to live longer, but with more years spent in poor health,” the forecast suggests. “Global life expectancy is projected to rise from 73.6 years in 2022 to 78.1 years in 2050. Global healthy life expectancy – the average number of years an individual can expect to live in good health – will increase from 64.8 years in 2022 to 67.4 years in 2050.”
