Cortisol is a steroid hormone that helps maintain metabolism and energises the body in response to stress. To accomplish its important work, cortisol has an impact on every system in the body. This means that adequate levels must be maintained.
Balanced Cortisol Levels
Cortisol follows a circadian rhythm in which the levels are highest in the morning and lowest in the evening, to facilitate sleep. The levels of cortisol also increase in response to stress, boosting energy for the systems critical to survival (such as the brain) while decreasing the energy available to less important systems. Low levels of cortisol are rare in children; however, insufficiency needs to be identified to prevent a health crisis.
How Cortisol Works
Cortisol helps to maintain blood pressure by either decreasing absorption of water or by promoting water retention. It plays a role in stimulating epinephrine, which in turn stimulates cardiac output. During stress, this prevents potentially serious low blood pressure. It promotes the breakdown of proteins and lipids so that they are available for energy.
Causes of Low Cortisol in Children
The adrenal glands synthesise and release cortisol, so low levels are called adrenal insufficiency. Adrenal insufficiency can be "primary," meaning that there is something wrong with the adrenal gland, or "secondary," which means that some other mechanism or disease outside the adrenal gland is causing the problem. Primary adrenal insufficiency is rare and is caused by damage to the adrenal glands due to autoimmune disease or, rarely, by congenital adrenal hyperplasia (too many cells grow, causing enlarged adrenal glands). Secondary adrenal insufficiency is more common. It is usually caused by the sudden discontinuation of corticosteroid therapy or a disorder of the pituitary, which releases hormones required to stimulate cortisol.
Symptoms of Low Cortisol Levels in Children
Symptoms of ongoing cortisol insufficiency are nonspecific: weakness, fatigue, loss of appetite, weight loss, dizziness, nausea, vomiting and muscle aches. The symptoms often mimic a gastrointestinal illness or even a psychiatric disorder as low cortisol levels can cause depression or changes in behaviour. In primary adrenal insufficiency, hyperpigmentation (a darkening of the skin especially in creases, moles, scars or black freckles) and craving for salty foods is common. If not treated, the symptoms progress to include abdominal pain, extreme weakness, low blood sugar and low blood pressure. Often triggered by physical stress, adrenal insufficiency can elevate into a health crisis -- kidney failure, shock or even death by cardiovascular collapse.
Treatment and Outcomes
Low cortisol levels can be easily treated with medication to replace the cortisol and to maintain a balance of other hormones, sodium and potassium that are affected by cortisol. It is also important to be aware of stressful events as they often trigger a depletion of cortisol. A child who has been diagnosed with low cortisol levels needs to be carefully monitored for illness, emotional stress or prolonged physical activity. Circumstances that increase the stress level, whether physical or emotional, may require higher doses of medication to maintain the proper cortisol levels. Remember that while this condition is rare in children, they are less able to monitor their body's warning signs so parents need to take an active role. Parents should be equipped to manage a potential adrenal crisis, including injections, monitoring glucose, providing snacks and ensuring their child wears a medical alert bracelet.