As practitioners, we know well how critically important adequate sleep is to our health. It’s essential to the healing process. Insufficient or disturbed sleep can slow recovery, compromise our immune function, increase inflammation, impair judgment and cognitive ability, and speed up the aging process, just to name a few negative outcomes.
Broadly speaking, sleep dysfunction comes in two flavors: those who struggle getting to sleep and those who fall asleep easily, but can’t stay asleep. Then there’s a hybrid of the two: those who can’t fall asleep OR stay asleep… Ouch.
Sleep is the darling of bio-hackers and functional practitioners of all stripes. There are many different things to consider, from proper sleep hygiene, stress management, exercise habits, to basic dietary strategies. These are always the places we address first, but what if they don’t work? What if you’ve addressed all of these fundamentals and you or your client is still struggling with sleep?
Time to bring out the functional testing! There are some key underlying physiological imbalances that can profoundly affect our sleep, and as functional health professionals it’s our job to ensure we’re investigating these areas for those clients who struggle with sleep.
Blood Sugar Imbalances
The first and most common type of sleep issue is poor blood sugar regulation. Specifically, a blood sugar crash in the middle of the night. When blood sugar levels dip too low and if the liver isn’t able to mobilize glycogen stores quickly enough, the adrenal glands will come to the rescue, secreting a rush of the hormones cortisol, adrenaline and noradrenaline to essentially force glycogen into the blood. These hormones are all very stimulating and thus can rouse one from sleep and then keep them up.
One very basic strategy for handling this night-waking is to eat a small protein-based snack before bed. If it resolves night-waking then it’s likely that low blood sugar levels are the culprit. But eating that snack doesn’t resolve the hypoglycemia itself – it’s simply a band-aid. Ultimately, we want to support and address the client’s hypoglycemia such that these middle-of-the-night crashes that require a nightly snack in the first place.
How do you identify whether it’s a blood sugar crash that’s causing the night waking? The first place to look is a fasting blood glucose test on waking, which will let you know what that morning glucose looks like, as well as looking at the client’s lactate dehydrogenase (LD), a serum marker that will be functionally depressed with reactive hypoglycemia. If the culprit is indeed hypoglycemia, then we address the glycemic imbalance with dietary adjustments and appropriate supplementation (something we teach in Level 3: Mastering the Art and Science of Nutritional Blood Chemistry).
Hypothalamus-Pituitary-Adrenal Axis dysregulation
Another common culprit for night wakings and a close companion to blood sugar dysregulation is Hypothalamus-Pituitary-Adrenal (HPA) Axis dysregulation, which is a breakdown somewhere in the chain of command between the hypothalamus, the pituitary and the adrenals. This can interrupt the body’s natural circadian rhythm and cause night wakings. The only way to know if this is a factor is to do either salivary or dried urine adrenal hormone testing (something we teach in Level 2: Mastering the Art and Science of Optimizing Hormones), and then support the imbalances via appropriate dietary, supplementation and lifestyle interventions.
Hormone dysregulation
Another close companion to both blood sugar dysregulation and HPA axis dysregulation is sex hormone dysregulation. This is because blood sugar dysregulation will negatively impact the HPA axis, and adrenal dysregulation impacts the whole endocrine system. So think of these as three amigos working hand-in-hand.
As any symptomatic post-menopausal woman will tell you, hormones (or the lack thereof) can wreak havoc on one’s sleep – both falling and staying asleep. But hormonally-driven sleep issues aren’t relegated to post-menopausal women. In men, low testosterone can compromise sleep, and in cycling women, low progesterone can do the same. Now, once again, the best way to understand how hormones are affecting sleep is to test, and we strongly recommend never manipulating hormones based on symptom presentation alone, as hormones are a two-partner dance: the imbalance can be in the amount of a hormone produced OR it can be in the inability of the cell receptor to receive that hormone. Thus one can display the symptoms of a lack of a given hormone in the presence of an excess of this hormone. This is a hard but important concept to grasp and we dive into this in depth in our Level 2: Mastering the Art and Science of Optimizing Hormone.
Immune activation
The fourth possibility is immune activation. We know that the immune system does the bulk of its work at night and this can have a stimulating effect. Consider that one of cortisol’s many roles is as an anti-inflammatory agent – if there’s inflammation, which is a process of the immune system, then cortisol will engage to anti-inflame, which can be stimulating. If you are trained in working with blood chemistries, you can get a sense of whether immune activation is a piece of your client’s puzzle by looking at their white blood cell levels and differential. Also, don’t forget that any gut infection will cause this kind of immune activity, and is one of the most common reasons the immune system is engaged, so by starting with the gut as we always advise, you’re necessarily addressing this piece at least in part.
Gut health
Speaking of gut health, there is fascinating research (1) showing that our intestinal microbes have their own circadian rhythms. When our microbiome is out of balance, it can affect our overall circadian rhythm. Discomfort from GERD (gastro-esophageal reflux disease), especially when triggered by late-night snacking, can disrupt sleep, especially in the early parts of the evening, as the symptoms are exacerbated by lying down. Also, parasites and the bruxism (teeth grinding) they potentially cause can also be an underlying contributor to sleep disturbances.
Vitamin D deficiency
Lastly, there’s new research [2] that has connected vitamin D deficiency to difficulty with sleeping – both falling asleep and staying asleep – and so testing your client’s vitamin D levels and ensuring sufficiency is a relatively easy and doable strategy for all your clients.
Clinically what all of this means is that when you’re supporting a client who struggles with sleep, not only should you consider their sleep hygiene and basic dietary strategies, but you also want to do some deeper digging to determine if any of these physiological factors can be contributing to the situation.
References
- Yuanyuan Li, Yanli Hao, Fang Fan, and Bin Zhang (2018). The Role of Microbiome in Insomnia, Circadian Disturbance and Depression.
- Qi Gao, Tingyan Kou, Bin Zhuang, Yangyang Ren, Xue Dong, and Qiuzhen Wang (2018) The Association between Vitamin D Deficiency and Sleep Disorders: A Systematic Review and Meta-Analysis.
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FAQ
These frequently asked questions expand on the key physiological concepts discussed in this article and provide additional clinical context for practitioners evaluating clients with sleep disturbances.
What physiological imbalances should practitioners consider when basic sleep interventions are not enough?
When sleep hygiene, stress management, exercise, and foundational nutrition have been addressed without success, practitioners should investigate underlying physiological dysfunction. This article highlights six areas that may contribute to persistent sleep disturbances:
- Blood sugar imbalances
- Hypothalamus-Pituitary-Adrenal (HPA) axis dysregulation
- Hormone dysregulation
- Immune activation
- Gut health disturbances
- Vitamin D deficiency
These underlying factors may require functional testing to identify and address appropriately.
Why is functional testing valuable for clients with persistent sleep problems?
Functional testing helps identify physiological contributors that may not be apparent through symptoms alone. Rather than relying solely on lifestyle interventions, testing can uncover underlying imbalances that interrupt normal sleep physiology and guide more targeted nutritional and lifestyle support.
How can blood sugar imbalances contribute to nighttime waking?
Nighttime hypoglycemia can trigger the release of cortisol, adrenaline, and noradrenaline to restore blood glucose levels, which may wake a person from sleep. These stimulating hormones can also make it difficult to fall back asleep.
A protein-rich bedtime snack may temporarily reduce nighttime waking, but it does not correct the underlying blood sugar imbalance.
How can practitioners evaluate whether nighttime waking is related to hypoglycemia?
The article recommends beginning with a fasting blood glucose measurement and evaluating lactate dehydrogenase (LD), which may be functionally depressed in reactive hypoglycemia. If blood sugar dysregulation is identified, dietary strategies and appropriate supplementation can then be used to support glycemic balance.
What role does HPA axis dysregulation play in sleep disturbances?
HPA axis dysregulation can disrupt normal circadian rhythms and contribute to nighttime waking. Because the HPA axis coordinates communication between the hypothalamus, pituitary gland, and adrenal glands, dysfunction anywhere along this pathway may affect normal sleep regulation.
The article recommends salivary or dried urine adrenal hormone testing to evaluate this possibility.
How are blood sugar, the HPA axis, and hormone balance connected?
Blood sugar regulation, HPA axis function, and sex hormone balance influence one another and often contribute to sleep disturbances together. Blood sugar dysregulation can negatively affect the HPA axis, while adrenal dysfunction may influence the broader endocrine system.
Evaluating these systems together may provide a more complete understanding of persistent sleep issues.
How can hormone imbalances affect sleep?
Hormone dysregulation may contribute to difficulty falling asleep or staying asleep in both women and men. The article notes examples including:
- Low progesterone in cycling women
- Hormonal changes after menopause
- Low testosterone in men
Hormonal contributions should be confirmed through testing rather than assumed from symptoms alone.
Why shouldn’t hormone therapy be based on symptoms alone?
Symptoms do not always reflect actual hormone availability. According to the article, hormone-related symptoms may result from either altered hormone production or impaired cellular receptor responsiveness.
Testing helps distinguish these possibilities before clinical decisions are made.
Can immune activation interfere with healthy sleep?
Yes. Immune activation may stimulate cortisol production because cortisol serves as one of the body’s anti-inflammatory hormones. Increased nighttime immune activity may therefore contribute to disrupted sleep.
The article also notes that blood chemistry, including white blood cell levels and differentials, may provide insight into immune activation.
How does gut health influence sleep quality?
Gut health may influence sleep through several mechanisms described in the article. These include:
- Circadian rhythms of the intestinal microbiome
- GERD symptoms that worsen when lying down
- Gut infections that promote immune activation
- Parasites that may contribute to bruxism and disrupted sleep
Because gut dysfunction can affect multiple physiological systems, it may represent an important contributor to chronic sleep problems.
Can vitamin D deficiency contribute to sleep disturbances?
Yes. The article cites research associating vitamin D deficiency with difficulty both falling asleep and staying asleep.
Testing vitamin D status and supporting sufficiency is presented as a practical clinical strategy when evaluating clients with sleep concerns.
What is a comprehensive functional medicine approach to evaluating chronic sleep disturbances?
A comprehensive approach begins with foundational strategies such as sleep hygiene, stress management, exercise, and dietary support. If symptoms persist, practitioners should investigate underlying physiological contributors using appropriate functional testing to identify imbalances in blood sugar regulation, HPA axis function, hormones, immune activity, gut health, and vitamin D status.
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ABOUT THE AUTHOR
Margaret Floyd Barry, FNTP MRHP is owner and Executive Director of the Institute of Restorative Health. She’s a functional nutritionist, author, speaker, educator, and real food advocate. Through years of experience working with the most complex client cases, including reversing her own autoimmune condition, Margaret uses a powerful system for restoring health by addressing the root cause of illness.
Today, Margaret teaches fellow practitioners the same proven system she uses to get her clients life-changing results through the Institute of Restorative Health – a two-year comprehensive functional nutrition certification program for qualified health professionals. Margaret also runs Restorative Corporate Wellness, a team of Restorative Health Practitioners facilitating health transformations with corporate clients. She is the author of Eat Naked and its follow-up cookbook The Naked Foods Cookbook. She’s also the host of the Clinician’s Corner podcast, where she interviews some of the world’s top experts in the fields of functional health and nutrition.
