Climate-change danger for chronically ill

A ONE-DEGREE change in summer temperature could shorten life expectancy for elderly people with chronic disease, a study suggests.

Researchers from the Harvard School of Public Health looked at Medicare data from 1985 to 2006 to track the long-term health of 3.7 million chronically ill people aged more than 65 years.

They found that every one-degree increase in summer temperature increased the mortality rate by 4% for people with diabetes, 3.8% for post-myocardial infarct, 2.8% for people with heart failure and 3.7% for people with chronic lung disease. 

While previous research has focused on the short-term effects of heat waves, this is the first study to examine the longer-term effects of climate change on life expectancy.

PNAS 2012; online 9 April