- A new study found that sleeping less than 6 hours a night can increase the risk of type 2 diabetes.
- If you don’t get enough sleep, the body’s ability to regulate glucose metabolism and appetite hormones is disrupted.
- Type 2 diabetes is defined by a buildup of glucose levels when the body cannot react to insulin effectively or is unable to produce enough of it.
People who sleep less than six hours a night are at considerably higher risk for type 2 diabetes than those who sleep seven to eight hours a night, a new study found. And even those with habitual short sleep who follow a healthy dietary regimen carry that risk, suggesting that sleep is a vital element in type 2 diabetes prevention.
The study was published March 5 in JAMA Network Open.
The study followed nearly 250,000 adults in the UK between May and September of 2023. The mean age of the participants was 55.9 years old, and the group had varying dietary habits ranging from “red meat, processed meat, fruits, vegetables, and fish, resulting in a healthy diet score ranging from 0 (unhealthiest) to 5 (healthiest).”
Type 2 diabetes is defined by a buildup of glucose levels when the body cannot react to insulin effectively or is unable to produce enough of it. Treatment for type 2 diabetes most commonly involves careful monitoring of blood sugar levels and medications like metformin or sulfonylureas. Additionally, diet, weight management, and exercise are part of a broader approach to treating the condition.
According to the Centers for Disease Control and Prevention, about 38 million Americans (one in 10, on average) have diabetes, and up to 95% of them have type 2 diabetes. The condition can significantly increase the risk for heart disease and heart attacks.
How does sleep affect the risk of type 2 diabetes?
Dr. Nuha Ali El Sayed, the senior vice president of Health Care Improvement at the American Diabetes Association, who was not involved in the study, told Healthline that dysfunctional sleep patterns have wide-ranging health consequences.
“Sleep disturbances are categorized into long-term and short-term issues, each with different implications for health,” El Sayed said. “Long-term disturbances, such as insomnia, sleep apnea, and restless leg syndrome, result in prolonged periods of inadequate or poor-quality sleep and have been linked to various health problems, including an increased risk of developing type 2 diabetes. Short-term disturbances caused by factors like stress or travel, lead to temporary discomfort or fatigue with less impact on long-term health.”
Melanie Murphy Richter, a registered dietitian nutritionist and the director of communications for the nutrition company Prolon, who was not involved in the study, told Healthline that without adequate and consistent sleep, the body becomes more vulnerable to inflammation, stress, impaired glucose metabolism, and imbalances to appetite hormones.
“Our body runs on circadian rhythms in which all of our organs, tissues and glands operate. When we disrupt these circadian patterns, our body becomes less responsive to insulin, the hormone needed to pull glucose into our cells to be used as fuel. When someone is insulin resistant, the body’s insulin receptors dull, and therefore more glucose floats freely in our blood, causing blood glucose imbalances,” Richter said.
Richter also explained that key hormones called ghrelin and leptin affect our appetites and can be impacted by inadequate sleep.
“Ghrelin, which increases appetite, increases when we lack sleep, likely due to evolutionary reasons for needing energy to continue to find or hunt for food,” Richter said. “This increase in appetite leads to increased eating, most especially sugary or sweet foods, which can exacerbate blood glucose levels.”
Too much or too little sleep linked to health risks
Disrupted sleep can occur at various points in life, for various reasons, but the chronic nature of habitual short sleep duration was the main focus of the study. El Sayed explained that the extremes — not enough sleep (less than 6 hours) or an excess of sleep (more than 9 hours) — contribute to a higher risk of type 2 diabetes.
“Short sleep duration can contribute to insulin resistance, impaired glucose tolerance, increased levels of HbA1c (indicating poor long-term glucose control), obesity (a key risk factor for type 2 diabetes), and disruptions in hormones that regulate appetite and metabolism, potentially leading to overeating and weight gain,” El Sayed said. “Conversely, long sleep duration may signal underlying health issues such as depression, sleep disorders, or chronic diseases, which are also risk factors for type 2 diabetes.”
“While research has shown that even one night of poor sleep can negatively impact health, acute phases of sleep deprivation as with new parents, for instance, may not always lead to the development of diseases like T2D,” Richter said. “Yes, the body will absolutely experience temporary disruptions to glucose metabolism and insulin sensitivity, but the greater risk associated with T2D is most prevalent in those who are chronically sleep deprived.”
Can napping offset poor sleep?
Brief naps can result in better energy and cognitive function during the day, but they don’t make up for chronic short sleep patterns, Richter said.
“Our bodies need a long stretch of sleep to really do the deep repair work it needs to function properly. It cannot do this as effectively in short bursts, as with napping,” Richter said. “If you are a new parent or in a phase of life where you are temporarily unable to get adequate sleep, naps can help to restore some of this sleep deficit to better support your energy levels, mood and brain health. But you cannot nap your way to better health. Only regular, consistent, and quality sleep every night can do that.”
Takeaway
Chronically inadequate sleep — less than six hours a night — can lead to type 2 diabetes even in people who follow a healthy dietary regime.
Without proper sleep, the body’s ability to regulate glucose metabolism and appetite hormones is disrupted.
Sleep also puts stress on the body and can lead to chronic inflammation, which in turn contributes to the development of type 2 diabetes.
