A newly released study finds that seniors who get less than five hours of sleep a night may be at higher risk for chronic diseases. More than 7,000 midlife and senior men and women were part of the study on sleep duration over the course of 25 years.

In high-income countries today, the researchers cite, more than half of seniors have been diagnosed with at least two chronic diseases. Having two or more chronic conditions at the same time, such as diabetes, dementia, cancer, or heart failure, is known as multimorbidity.

Higher multimorbidity, in turn, can reduce quality of life, put more pressure on the health care system, increase the need for prescription medications, and lower work productivity.

Study participants who reported sleeping less than five hours a night – compared with individuals who slept seven hours per night – were at consistently greater risk of developing more than one chronic disease.

For example, people aged 50 who slept five or fewer hours a night were 20 percent more likely to receive one chronic disease diagnosis. Worse still, individuals in this age range were 40 percent more likely to develop two or more chronic diseases.

Not getting enough sleep may negatively impact one's metabolic processes, level of inflammation, and circadian rhythm, the researchers suggest.