With rising costs for gas and food, 2 years of the COVID-19 pandemic, global uncertainty, and the ongoing war in Ukraine, it is hardly a surprise that more than 70% of American adults report feeling stressed.
The Stress in America survey, which was conducted by the American Psychological Association in partnership with The Harris Poll, also found that a growing number of Americans report money as a source of stress, peaking at two thirds of adults in 2022, the highest reported level in 7 years.
Confronted with multiple stressors, many Americans have adopted unhealthy behaviors. More than half of Americans report weight gain, with an average of 26 pounds in the past year.
Stress affects our emotional and physical well-being. Let's examine the body's response to stress and review techniques to reduce cortisol, known as the stress hormone.
The Stress Response
In 1953, Lewis and colleagues developed the first protocol for the perioperative management of patients with adrenal insufficiency. We now have a more nuanced understanding of cortisol production and the effects of stress on the hypothalamic-pituitary-adrenal axis.
A 2020 study sought to determine the best treatment modality for patients with adrenal insufficiency exposed to major stress. The authors measured cortisol production in nearly 300 participants with normal adrenal function exposed to a variety of stressors, including sepsis, major trauma, elective surgery, and the war in Afghanistan.
Serum cortisol was highest and most variable in patients with sepsis. Cortisol levels were elevated in military personnel within 4 weeks of deployment, and production appeared similar to that of surgical patients, illustrating the body's response to both emotional and physical stress.
Cortisol and the Sleep-Wake Cycle
The COVID-19 pandemic has disrupted our lives and our sleep. Cortisol production is closely tied to the sleep-wake cycle. Levels increase in the early morning and decrease in the evening. This pattern is often disrupted in shift workers, with a blunted response upon waking and increased cortisol production in the evening.
This may have implications for long-term health. One study found higher levels of cortisol in the hair of young shift workers compared with their day worker peers. Cortisol levels correlated with BMI. Levels were lowest in participants with a BMI < 25 and highest in participants with a BMI > 30. This highlights the important relationship between disrupted sleep at a young age, cortisol production, and obesity, increasing the risk for cardiovascular disease later in life.
The Impact of Stress on Health
The Whitehall II study, a large, prospective cohort study in the United Kingdom, explores the relationship between the work environment, stress, and health. A subset of participants was selected to evaluate the relationship between stress and hypertension. Salivary cortisol was measured after participants completed stress-inducing activities. Approximately 40% of participants demonstrated a significant increase in cortisol production, highlighting variability in the stress response. Participants with a heightened stress response were more likely to develop hypertension during the 3-year follow-up period.
A separate study found that Whitehall II study participants with higher evening cortisol levels were more likely to develop diabetes.
What can your patients (and you) do to combat stress?
Get Active — Exercise Builds Resilience
Like many Americans, physicians report high rates of burnout. Many medical schools have tried to address this issue by developing curricula that teach skills to cultivate resilience, particularly among postgraduate trainees.
Exercise is key to maintaining physical and emotional well-being and has been shown to moderate the body's response to psychosocial stress. Engaging in regular exercise leads to a reduced stress response to physical activity.
Repeated activation of the hypothalamic-pituitary-adrenal axis appears to prime the body for future stressors.
Martikainen and colleagues explored the relationship between physical activity and the stress response in healthy 8-year-old children. Children participated in the Trier Social Stress Test, which reliably induces stress with storytelling and mental arithmetic activities. Children with the highest levels of physical activity exhibited the smallest increase in salivary cortisol in response to stress. These findings appear to persist across the lifespan.
College students and older adults who participate in high levels of physical activity develop an adaptive response to stress, producing lower levels of cortisol compared with their less-active peers (Gerber et al; Pauly et al). These studies highlight the role that exercise plays in moderating the stress response and building emotional resilience.
Be Mindful — Meditation Reduces Stress
Practicing mindfulness in everyday life has been shown to reduce stress, but the effects of mindfulness on the body's physiologic response, including cortisol production, is unclear.
Most medical schools in the United States offer mindfulness-related activities, according to Barnes and colleagues. Nearly a third of schools embed these activities in their curriculum.
A 2021 study assessed the impact of two mindfulness-based interventions on heart rate and cortisol secretion. In focused-attention meditation, participants were instructed to center their attention on their breath. This activity improved concentration and reduced distraction.
In open-monitoring meditation, participants were instructed to be aware of their physical sensations and explore the impact of distracting thoughts and emotions on the body. These mindfulness-based interventions appear to have affected the body in different ways: Salivary cortisol levels decreased significantly following open-monitoring meditation, and heart rate decreased significantly following focused-attention meditation. In contrast, there was no difference in salivary cortisol levels following focused-attention meditation and no difference in heart rate following open-monitoring meditation.
In the past 70 years, we've gained a better understanding of the hypothalamic-pituitary-adrenal axis and the impact of stress on health. How can we apply this knowledge in daily life?
A group of researchers at UCLA developed a smartwatch that can measure cortisol levels in sweat. A growing number of Americans use smartwatches to monitor their activity, sleep, and a variety of health parameters, including heart rate and function as well as oxygen saturation. Expanding these capabilities to include cortisol levels has implications for patient care and possibly for everyday life, allowing us to gain insight into our body's response to stress and learn techniques to effectively manage the stress hormone.