Cortisol is a stress hormone made by the adrenal glands. Cortisol levels are highest in the morning and normally go down during the day. Keeping balanced cortisol levels is important for optimal health. Low levels are associated with fatigue, low blood pressure, salt cravings, immune system dysfunction, and adrenal exhaustion. High levels are associated with hypertension, immune suppression, increased thirst, elevated blood sugar, abdominal weight gain, loss of verbal memory, insulin resistance, and type 2 diabetes.
In the context of cardiovascular disease, we are primarily concerned with the destructive effects of high cortisol. Cortisol breaks down muscle and fat to provide the body with glucose for energy. Cortisol also relocates fat deposits to around the internal organs and inhibits the formation of collagen. Collagen keeps our skin and joints young and healthy. Visceral fat is the fat around and between your organs. Excess visceral fat leads to the classic “beer gut.” Visceral fat is connected to insulin resistance, glucose intolerance, high cholesterol, high blood pressure, and heart disease. It’s worth saying again: “your gut should not be bigger than your butt.”
Changes in levels of stress hormones have been considered a central component of stress for many years. Cortisol also suppresses testosterone levels in men. A high cortisol-to-testosterone ratio is a biological indicator of chronic high stress.
There are plenty of problems with having elevated cortisol in comparison to testosterone. Cortisol is a catabolic hormone, meaning that it promotes muscle breakdown. In contrast, testosterone is an anabolic hormone that helps build muscle. As people lose muscle, their metabolic rate goes down and they need fewer calories per day. The last thing people who are already overweight need is to lose muscle mass and have their metabolic rate go down! Cortisol is often elevated in depression, particularly in people with heart disease. Depression has been associated with increased cortisol in medically healthy patients. Cortisol may play a role in linking depression and heart attacks (Otte et al. 2004).