Microvascular disease affects the small blood vessels, particularly in the kidneys and eyes, and is a common diabetic complication. Diabetic nephropathy causes the deterioration of kidney function and eventual failure; diabetic retinopathy can lead to vision loss and blindness. So, it’s crucial to stop microvascular disease before it progresses.
Studies have found that microvascular disease is associated with risk factors such as obesity, high blood pressure, physical inactivity and poorly controlled blood glucose. Now, a new study led by the Odense University Hospital in Denmark has identified another risk factor for microvascular disease in type 2 diabetics: sleep. Particularly too much or too little of it.
Previous research has demonstrated how important sleep is for maintaining optimal health. Too much or too little sleep has been linked to decreased cognitive performance, sleep deprivation has been found to increase pain sensitivity, and irregular sleeping patterns have been associated with obesity, high blood pressure, and other metabolic disorders.
For the current study, the researchers obtained data from a subset of participants involved in the Danish Center for Strategic Research in Type 2 Diabetes (DD2) study. Participants wore an accelerometer for 10 days to measure sleep duration, which was classified into short (less than seven hours), optimal (seven to less than nine hours), or long (nine hours or more). The researchers also looked at the presence of nephropathy and retinopathy as indicators of microvascular disease.
For 396 participants, whose median age was 62 and who’d had diabetes for an average of 3.5 years, 12% had short sleep duration, 60% were in the optimal range, and 28% had long sleep duration. The prevalence of microvascular damage was 38%, 18%, and 31%, respectively, for the short, optimal, and long sleep duration groups. Short sleep duration was significantly associated with a 2.6 times higher risk of microvascular disease compared with optimal sleep duration. Long sleep was independently associated with a 2.3 times higher risk.
The researchers found that age positively affected the association between short sleep duration and microvascular disease. In participants under 62, short sleep duration increased microvascular damage risk by 1.2 times compared to the optimal sleep duration group. Whereas for those aged 62 and over, short sleep was associated with a 5.7 times increase in small blood vessel damage. The effect of age on microvascular disease risk in the long sleep duration group was not statistically significant.
“In recently diagnosed [type 2 diabetic] patients, both short and long sleep durations are associated with a higher prevalence of microvascular disease compared to optimal sleep duration at night,” said the researchers. “Age amplifies the association between short sleep duration and microvascular disease, suggesting increased vulnerability among older individuals.”
The researchers say their findings suggest that sleep interventions, such as cognitive behavioral therapy (CBT), may be warranted to address this risk factor. Further study is needed to assess the effect that sleep quality has on diabetics’ risk of complications.
The study hasn’t been published yet. It will be presented at this year’s European Association for the Study of Diabetes (EASD) Annual Meeting in September.