Sleepless Nights, Sluggish Days: Insomnia Linked to Low Activity in Older Women with Diabetes

A bad night’s sleep may do far more than leave you groggy. For millions of people living with diabetes, new research from Norway suggests that troubled sleep could quietly erode one of the most powerful tools they have for managing their disease: physical activity. In a study of more than 1,300 adults with diabetes, researchers found that women over the age of 65 who reported insomnia symptoms moved substantially less than their well-rested peers, while men and younger women appeared largely unaffected. The findings, drawn from the Trøndelag Health Study (HUNT), one of the world’s largest population-based health cohorts, offer a striking reminder that sleep and movement are deeply intertwined, and that the relationship may look very different depending on who you are.

The study, published in the Journal of Activity, Sedentary and Sleep Behaviors, set out to answer a deceptively simple question: do people with diabetes who struggle to sleep actually move less? Previous research had already established that insomnia symptoms are remarkably common in this population, with roughly 39 percent of adults with type 2 diabetes reporting them. It was also known that poor sleep is linked to weight gain, disrupted glucose regulation, and impaired daytime functioning. But no one had yet measured, with objective devices, whether insomnia translates into measurably lower physical activity in people with diabetes. That gap mattered, because regular moderate-to-vigorous physical activity is a cornerstone of diabetes care, helping to control blood sugar, prevent complications, and reduce the risk of premature death.

To capture what participants actually did, rather than what they said they did, the researchers relied on a sophisticated measurement setup. Each participant wore two small tri-axial accelerometers for seven days, one strapped to the right thigh and another to the lower back. The devices sampled movement at 50 hertz, and a machine learning classifier built on eXtreme Gradient Boosting was trained to recognize specific activities in free-living conditions: walking at slow, moderate, or brisk speeds, running, cycling, sitting, standing, and lying down. From these data, the team calculated total physical activity, which includes all walking speeds, and moderate-to-vigorous physical activity, defined as brisk walking above 4 kilometers per hour, running, and cycling. This approach sidesteps the well-known biases of self-reported exercise questionnaires, which tend to overestimate how active people really are.

Insomnia was assessed through four questions covering difficulty falling asleep, repeated nighttime awakenings, waking too early, and impaired daytime functioning, each rated over the previous three months. Participants who reported at least one sleep symptom three or more nights per week were classified as having insomnia symptoms, while those who also reported daytime impairment at that frequency met the criteria for insomnia disorder, mirroring current diagnostic classification systems. Of the 1,354 participants analyzed, 36 percent had insomnia symptoms and 3 percent met the stricter threshold for insomnia disorder. The median age was 67 years, and the sample reflected the realities of living with diabetes: many participants with sleep problems were also more likely to be obese, to suffer from bodily pain, and to report moderate to severe physical impairment.

The headline result concerns older women. Among women aged 65 and above, those with insomnia symptoms accumulated 73 minutes less total physical activity per week than their peers without sleep complaints, a difference of roughly ten minutes a day. Their moderate-to-vigorous activity was reduced by 33 minutes per week, equivalent to only four to five minutes a day, but the gap in overall movement was substantial. Just 28 percent of older women with insomnia symptoms met the World Health Organization’s recommendation of at least 150 minutes of moderate activity per week, compared with 26 percent of those without symptoms in the same age band, and 43 percent among younger women. Men, by contrast, showed no meaningful difference in activity levels whether or not they reported insomnia symptoms, and neither did women under 65.

The picture sharpened dramatically for the small group with full-blown insomnia disorder. Regardless of age or sex, these participants moved far less than everyone else. Women with insomnia disorder logged 192 minutes less total physical activity per week than those sleeping well, while men logged 276 minutes less, a deficit of nearly an hour a day. Moderate-to-vigorous activity was lower by 37 minutes per week in women and 67 minutes per week in men. Because total physical activity includes slow walking while moderate-to-vigorous activity does not, the pattern suggests that people with insomnia disorder rely almost entirely on gentle movement, with the energetic activity that benefits glucose control largely absent from their weeks.

Why would sleepless nights hit older women hardest? The researchers point to a convergence of biological and social factors. Compared with men, older women tend to take longer to fall asleep, sleep for shorter periods, and report more daytime sleepiness. The postmenopausal stage of life brings its own burden of symptoms, including insomnia, fatigue, joint pain, and depression, any of which can make physical activity feel out of reach. There is also a broader context of inequity: women with type 2 diabetes appear to benefit less than men from lifestyle interventions and drug treatments, and are often undertreated. The authors caution that their cross-sectional design cannot determine whether insomnia causes inactivity, whether inactivity worsens sleep, or whether both stem from shared causes such as pain, obesity, or depression.

The clinical implications may be larger than the raw numbers suggest. Recent research has shown that even brief bouts of one to five minutes of vigorous daily activity, so-called vigorous intermittent lifestyle physical activity, can confer measurable health benefits, meaning that a few extra minutes of brisk movement each day could matter for glucose control, physical function, mood, and quality of life. Conversely, an experimental study in the general population found that a four-week behavioral treatment for insomnia improved sleep significantly but did not change device-measured physical activity, a sobering result that highlights how much remains unknown. Whether treating insomnia in people with diabetes would actually get them moving more is a question only prospective trials can answer, and the reverse possibility, that boosting activity improves sleep, is equally plausible.

The study has caveats worth keeping in mind. Only 37 participants met the criteria for insomnia disorder, so those estimates carry wide uncertainty, and the true prevalence is likely underestimated because the daytime impairment criterion was strict. Volunteers who agree to wear accelerometers for a week tend to be healthier than the general diabetic population, which may inflate measured activity levels. The researchers could not distinguish between types of diabetes, though type 2 accounts for 85 to 90 percent of cases in high-income countries, making the findings most relevant to that group. A single week of measurement may also not capture habitual behavior. Still, the overall adherence rate of about 40 percent to WHO activity guidelines matches similar studies in Denmark, lending credibility to the sample.

What emerges is a clear signal for clinicians and researchers alike: sleep deserves a place in the conversation about diabetes management, particularly for older women. With more than 60 million people in Europe living with diabetes, and only a minority meeting activity recommendations, identifying modifiable barriers is a public health priority. The Norwegian team suggests that future work should examine what distinguishes people with insomnia symptoms who still manage to stay active, and whether addressing insomnia, especially insomnia disorder, as part of routine diabetes care can lift activity levels and, with them, long-term health outcomes. For now, the message is that a restless night in an older woman with diabetes may be more than an inconvenience; it may be a quiet warning sign that her body is moving less than it needs to stay well.

Subject of Research: The association between insomnia symptoms and device-measured physical activity in adults with diabetes

Article Title: Assessing the level of device-measured physical activity according to insomnia symptoms in 1,354 individuals with diabetes: the HUNT Study, Norway

Article References: Mortensen, S. R., Mork, P. J., Skou, S. T., Kongsvold, A., Åsvold, B. O., Nilsen, T. I. L., & Skarpsno, E. S. (2024). Assessing the level of device-measured physical activity according to insomnia symptoms in 1,354 individuals with diabetes: the HUNT Study, Norway. Journal of Activity, Sedentary and Sleep Behaviors, 3(1), Article 27. https://doi.org/10.1186/s44167-024-00066-4

Image Credits: AI Generated

DOI: 10.1186/s44167-024-00066-4

Keywords: diabetes, insomnia, physical activity, HUNT Study, accelerometers, sleep, type 2 diabetes, moderate-to-vigorous physical activity, older women, WHO guidelines, Norway, cross-sectional study