Adults age 50 and older who don’t get at least five hours of sleep at night are 40% more likely to be diagnosed with two or more chronic diseases, compared to those who sleep for up to seven hours, a new study has found.

Researchers with University College London set out to analyze the impact of sleep duration on the health of nearly 8,000 British civil servants, ages 50, 60 and 70, over the course of 25 years.

Participants were asked “How many hours of sleep do you have on an average weeknight?” and whether they had been diagnosed with chronic diseases such as cancer, diabetes and heart disease.

After compiling the information collected at six different "data collection waves," researchers found that getting five hours of sleep or less in mid-to-late life was associated with "higher multi-morbidity risk." The findings were published in the journal PLOS Medicine in October.

Participants who reported getting five hours of sleep or less were 20% more likely to have been diagnosed with a chronic disease and 40% more likely to be diagnosed with two or more chronic diseases, compared to people who slept for up to seven hours.

"Multi-morbidity is on the rise in high-income countries and more than half of older adults now have at least two chronic diseases," the study’s lead author, Dr. Severine Sabia, said in a statement. "This is proving to be a major challenge for public health, as multi-morbidity is associated with high healthcare service use, hospitalizations and disability."

Previous research has found that sleeping less than seven hours could lead to individual chronic diseases.