What is cortisol sleep?

Dr Yatin Sagvekar, Consultant Neurology at Kokilaben Dhirubhai Ambani Hospital, Navi Mumbai, explained the intricate relationship between cortisol, the stress hormone, and sleep. With its pivotal role in maintaining our circadian rhythms and overall health, cortisol is a hormone of significant influence in sleep-wake cycles.

The cortisol clock: A 24-hour cycle

Cortisol follows a daily rhythm, peaking in the morning around 8 am. It begins to rise during the latter half of sleep, helping to stimulate wakefulness as you transition out of sleep. Throughout the day, cortisol levels gradually decline, reaching their lowest point near midnight, coinciding with your body’s natural sleep drive, said Dr Sagvekar.

Cortisol production is regulated by the hypothalamic-pituitary-adrenal (HPA) axis, which operates at low levels during the evening to prepare the body for sleep. (Source: Freepik)

This rhythm is a cornerstone of sleep health, ensuring you remain alert during the day and relaxed enough for restorative sleep at night. Disruption to this rhythm, such as through stress or lifestyle factors, can significantly impact your sleep quality.

HPA axis and its impact on sleep

Cortisol production is regulated by the hypothalamic-pituitary-adrenal (HPA) axis, which operates at low levels during the evening to prepare the body for sleep. However, disturbances to the HPA axis—whether due to stress, clinical sleep disorders like obstructive sleep apnea (OSA), or poor sleep habits—can alter this balance.

• HPA Dysfunction and Insomnia: An overactive HPA axis can contribute to chronic insomnia by inducing sleep fragmentation and perpetuating the cycle of disrupted rest.
• Cortisol Overload: Sleep deprivation leads to elevated cortisol levels, which not only impair sleep architecture but also result in broader health issues.

According to Dr Sagvekar, chronic sleep loss and HPA axis hyperactivation have been linked to obesity and type II diabetes. Elevated cortisol levels can interfere with glucose metabolism and insulin sensitivity, contributing to these conditions. Cortisol’s immunosuppressive effects can lead to increased susceptibility to infections.

Maintaining cortisol balance for sleep hygiene

To optimise cortisol rhythms and promote restful sleep:

• Maintain a consistent sleep schedule, going to bed and waking up at the same time each day.
• Create a calm evening environment to naturally reduce cortisol levels, such as dimming lights and avoiding screens.
• Engage in stress management techniques like yoga, meditation, or deep breathing exercises.
• Avoid caffeine and heavy meals close to bedtime.

DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.