Anxiety and insomnia symptoms are associated with altered immune cell profiles in young women. Digest
Rising levels of anxiety and sleep disturbances in teenagers and young adults have raised questions about their broader biological and health consequences. A new cross-sectional study explored the relationship between these conditions and immune cell profiles.
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The study included 60 healthy female university students who were between 17 and 23 years old. They completed standardized questionnaires about generalized anxiety disorder and insomnia symptoms, and blood samples were collected to measure immune cell profiles. The researchers placed special focus on natural killer (NK) cells, which are part of the body's first line of defense and help detect and eliminate virus-infected or otherwise abnormal cells. Two major types of NK cells were examined, one mainly responsible for killing harmful cells (cytotoxic NK cells) and another type involved in coordinating immune signals.
- About 75% of participants reported at least mild anxiety symptoms, and 53.3% met the screening criteria for insomnia.
- Students with moderate anxiety, and particularly those with severe anxiety, had fewer NK cells circulating in their blood than students with normal anxiety levels.
- Students with insomnia had a lower proportion of the NK cell subtype involved in immune signaling.
- Among students with insomnia, anxiety was linked to lower levels of total and cytotoxic NK cells, a pattern that was not seen in students who slept well.
Together, these findings suggest that anxiety and disrupted sleep may interact to influence immune balance. One proposed explanation involves cortisol, a hormone released during prolonged stress that can suppress immune activity. Previous research has shown that people with anxiety often have elevated cortisol levels, which may reduce immune cell numbers or alter how immune cells are distributed. Sleep disturbances may prolong or intensify this stress response, whereas adequate sleep may mitigate the effects of psychological stress on the immune system.
Overall, the results point to mental health and sleep quality as factors that can shape immune resilience, even in otherwise healthy young adults. Future research in larger and more diverse populations could clarify whether these immune differences translate into higher risks of infection, inflammation, or other diseases. In this clip, Dr. Matthew Walker discusses how anxiety affects sleep and identifies ways to manage that stress to improve sleep.