Studies explore global burden of disease and heart disease in the United States

If you like numbers and statistics, especially those about health, two reports released this week should keep you occupied for days: the massive Global Burden of Disease study was published in The Lancet, and the American Heart Association released its annual “Heart and stroke statistics” report. Both contain good news, bad news, and sobering news.

The Global Burden of Disease project aims to gauge the health of the blue planet’s 7 billion inhabitants and determine the leading causes of death and disability. Funded by the Bill and Melinda Gates Foundation, the project is a collaboration between nearly 500 scientists from 50 countries; the Harvard School of Public Health is a leading research partner.

Here are a few highlights from the 200+ pages that The Lancet devoted to the findings:

Life expectancy. In 1970, a newborn boy could expect to live to age 56. Today it’s 67. For girls, the average life expectancy rose from 61 years in 1970 to 73 today. Those averages mask a huge variation, from a low in Haiti (32 years for boys and 44 for girls) to a high in Japan (79 years for boys and 86 for girls).

Shifting causes of death. Infectious diseases like malaria and tuberculosis long dominated world deaths. Today, so-called non-communicable causes account for two-thirds of world deaths. These include things like traffic accidents, violence and war, heart disease, cancer, and other chronic conditions.

DALY bread. Study investigators estimated disability-adjusted life years (DALYs)—a measure of years lost due to death, disability, or poor health. More than half of years lost are now due to non-communicable causes.

According to the American Heart Association’s annual report, the percentage of deaths due to heart attack, stroke, and other cardiovascular diseases has fallen by nearly one-third since 1999. That’s a bright spot. Even so, cardiovascular disease is still the leading killer in America, accounting for one in three deaths. Every day, more than 2,000 Americans die of cardiovascular disease.

Here’s the daunting news: if we as a population keep up our unhealthy habits and behaviors, look for cardiovascular disease rates to stop falling and start climbing. Why is that?

• Almost 78 million adults have high blood pressure—which the Global Burden of Disease study identified as the biggest global risk factor for disease.
• 32 million adults have high cholesterol, another precursor to cardiovascular disease.
• Diabetes is on the rise (20 million Americans have been diagnosed with it), and this chronic disease often leads to heart disease (and kidney disease, vision loss, limb amputations, and more).
• As a nation we are overweight and underactive.

High blood pressure and cholesterol, diabetes, and excess weight are most preventable problems—making cardiovascular largely preventable, too. “Americans need to move a lot more, eat healthier and less, and manage risk factors as soon as they develop,” said Alan S. Go, M.D., chairman of the report’s writing committee, in a statement. “If not, we’ll quickly lose the momentum we’ve gained in reducing heart attack and stroke rates and improving survival over the last few decades.”