What is functional hypothyroidism?

You won’t find the term functional hypothyroidism in the medical literature, or at least not yet. Primarily due to clinical hypothyroidism being bound to a rigid assessment usually diagnosed by the blood test thyroid stimulating hormone or TSH.

TSH secretion is controlled by synthesis of thyroid releasing hormone or TRH in the supraortic and supraventricular nuclei of the hypothalamus. TRH is transported to the anterior pituitary by the hypothalamo- hypophysial portal system where it stimulates synthesis of TSH. T4, T3 and TRH control the secretion of TSH (Gardner et al., 2011).

TSH production can also be affected by TSH receptor damage, medical drugs, disease states, iodide, blood glucose levels and other circulating hormones TSH may also be affected by environmental pollutants and heavy metals (Llop et al., 2015).  Metabolic disease and increases in Body Mass Index appear to be correlated with an increase in TSH levels (Ruhla et al., 2010).

Often, you will see clear links and studies to key micronutrients such as zinc, selenium, iodine and other important co-factors. These deficiencies can exist demographically but usually in westernised societies, there deficiency can be linked to impaired absorption rates, perhaps linked to digestive dysfunction and other factors.

“Measuring the amount of thyroid in the blood isn’t a good way to evaluate adequacy of thyroid function, since the response of tissues to the hormone can be suppressed (for example, by unsaturated fats) (Peat, R.1999).

 Dietary factors such as unsaturated fatty acids in the diet may potentially be one of the most overlooked factors that supress thyroid function. Other factors such as caloric restriction, stressful environments, over exercising and other factors are some of the others. It’s well known that in certain areas of hormone dysregulation such as menstrual cycle irregularities, oligoamenorrohea (loss of cycle), anovulation (failure to ovulate) and lack of libido and fertility in both men and women,  can be attributed to poor energy intake and environmental factors (Nieuwenhuijsen et al., 2014) (Skakkebæk, 2003). Dietary factors have synergy with hormonal imbalances perpetuating high levels of estrogen.

The functional suppression of thyroid function by unsaturated fats, eating a so-called healthy diet (full of uncooked brassica vegetables, nuts and seeds) orthorexic states and other factors is largely ignored by physicians.

I can say with some certainty, after completing postgraduate studies at university with a number of Doctors, that diet and inhibitory factors of diet rarely get assessed when it comes to assessing energy and thyroid function.

A persistent functional hypothyroid state, induced by unsaturated fats may lead to the pre-diabetic and diabetic states induced by an inability to utilise carbohydrate and the preferential shift to use of fats instead of sugars as suggested in the Randle or glucose fatty acid cycle (Randle, Garland, Hales, & Newsholme, 1963). Increased cortisol, oxidation, decreased carbon dioxide and an increased stress on the oxidative system, could potentially lead to glycolysis and an increase in lactic acid, further increasing damage, stress and further suppression of thyroid function.

Measurement of thyroid blood tests remains inaccurate and problematic without the inclusion of a variety of symptoms and previously accurate assessment, such as basal metabolic rate, body temperature and pulse. The suppression of both thyroid and adequate energy states will always remain.

As the common approach for diagnosing hypothyroidism is having TSH above 4 or 5 mmUL and the preferred treatment is to supplement with synthetic levothyroxine. How much change can you realistically achieve if you fail to address the supressed metabolism induced by diet, an individuals susceptibility to stress and their own environment?

 

References:

Gardner, D. G., Shoback, D. M., Greenspan, F. S. et al .(2011). Greenspan’s Basic and Clinical Endocrinology. McGraw Hill.

Llop, S., Lopez-Espinosa, M. J., Murcia, M., Alvarez-Pedrerol, M., Vioque, J., Aguinagalde, X., … Ballester, F. (2015). Synergism between exposure to mercury and use of iodine supplements on thyroid hormones in pregnant women. Environmental Research, 138, 298–305. http://doi.org/10.1016/j.envres.2015.02.026

Nieuwenhuijsen, M. J., Basagana, X., Dadvand, P., Martinez, D., Cirach, M., Beelen, R., & Jacquemin, B. (2014). Air pollution and human fertility rates. Environment International, 70, 9–14. http://doi.org/10.1016/j.envint.2014.05.005; 10.1016/j.envint.2014.05.005

Peat, R. (1999). Thyroid Therapies, Confusion and Fraud. Retrieved from www.raypeat.com/articles/articles/thyroid.shtml

Randle, P. J., Garland, P. B., Hales, C. N., & Newsholme, E. A. (1963). The glucose fatty-acid cycle its role in insulin sensitivity and the metabolic disturbances of diabetes mellitus. The Lancet, 281(7285), 785–789. http://doi.org/10.1016/S0140-6736(63)91500-9

Ruhla, S., Weickert, M. O., Arafat, A. M., Osterhoff, M., Isken, F., Spranger, J., … Möhlig, M. (2010). A high normal TSH is associated with the metabolic syndrome. Clinical Endocrinology, 72(5), 696–701. http://doi.org/10.1111/j.1365-2265.2009.03698.x

Skakkebæk, N. E. (2003). Testicular dysgenesis syndrome. In Hormone Research (Vol. 60, p. 49). http://doi.org/10.1159/000074499

 

Can a bad smell create pain, dysfunction and weakness?

Over the last few years I have found that nothing ceases to amaze me when it comes to the human body. As it becomes possible to dissect systems and assess interactions of specific stimulus, observing the input/output relationship between stimulus and body.

Pain is observed to be chemical, thermal or mechanical in nature. Please bear with the technicalities before I explain the simplified mechanisms or skip to the last part of the blog, if you get bored!

There are many factors that contribute to a patient’s perception and physical feeling of pain. Pain is the central nervous systems response to an event that has the capacity to injure the tissues of the body. Nociception or pain can be qualified from the following pathways.

The ‘First’ pain is usually a withdrawal mechanism (Nociceptive Withdrawal Reflex or NRA) mediated by the neurotransmitter glutamate and utilises the neospinalthalmic (new pain) tract in the anterolateral system or ALS. This typically lasts less than 0.1 of a second and the signal, suggested to be dampened in the substantia gelatinosa, an area found in the dorsal aspect of the spinal cord. Think about that sharp initial pain experienced causing you to move away from a stimulus, which has been detected by free nerve endings.                               Trigeminal nocicpetion/pain pathway

The ‘Second’ pain is also part of the ALS but is part of the paleospinalthalmic tract (old pain). It typically takes over from the initial first pain/neo. It is mediated by the compound substance P and can be associated with that long, lingering pain experienced from an injury.

In addition to pain, we have the capacity to assess many other features of mechanical distortion such as pressure, stretch and touch. The Dorsal Column Medial Lemniscus or DCML, allows the nervous system to provide adequate feedback to tasks and environmental stimulus.

Another part of the pain detection system is the trigeminal chemosensory system, which has nociceptive/pain and temperature pathways that feedback to cranial nerve five, called the Trigeminal nerve (CNV). When a noxious or toxic substance is processed by the neurons in the mucosal areas of the nose, mouth, eyes and lips it is relayed into the thalamus. The VPMN (or ventral posterior medial nucleus) relays signals to the sensory cortex and provides responses, such as watery eyes, sneezing and withdrawal

When we inspire air with small particles of pollutants, they pass from the lungs into the blood stream. Although the blood brain barrier is supposed to prevent any unwanted chemicals, crossing from the blood to the brain; the Circumventricular organs present an area that does not have the capacity to restrict compounds that can create dis-organisation of neurological signals entering and leaving the brain. The area postrema, also has a chemosensory role to initiate vomiting to deal with exposure to harmful compounds

So let’s have something a little easier on the eyes and brain to read now. For example:

Perhaps you are walking across the road in heavy traffic. Sucking up all the pollutants such as benzene, carbon monoxide and other waste products of burning fossil fuels into your lungs as you find your way from one side of the road to another.

For a few seconds your brain, exposed to the onslaught of pollution, has a hard time processing the compounds that have made their way into areas such as the pineal gland or chemoreceptors that can induce vomiting in response to a noxious stimulus.

You are in a rush and bump into someone, his or her shoulder hitting you firmly in the chest. It was slightly painful but you don’t really notice it, the pain pathway, along with pressure, stretch and touch receptors provided some form of feedback. The brain, perhaps still not capable of processing this feedback due to the short exposure of increased pollutants, is just trying to get on with the milieu of everything else that your body demands of it.

Meanwhile the pectoralis muscle, which is being used with each step that you take, has been exposed to increased pressure, a state of contraction or small window of pain that necessitated a withdrawal reflex. The intrafusal muscle fiber that monitor both stretch and contraction now have increased signal towards sustained contraction due to the chaos of external compounds that entered areas of the brain.

So now we might have some level of muscle dysfunction. We probably don’t even know about it. That level of muscle dysfunction now increases and decreases tension demands to receptors found in the ligaments and tendons. The joint mechanoreceptors have a different signal. The skin exteroreceptors perhaps have a different signal. There’s no pain to remind us of the event. In fact we have now gone to the gym and started doing a bunch of push-ups or gone shopping for food and simply carrying the bag home with that hand and shoulder. This doesn’t create pain, but simply sets the foundation for increased areas of dysfunction from distorted neurological signalling.

The concept of this neurological/chemical chaos is often referred to as ‘brain fog’. It seems to be in the literature for many reasons, blood sugar issues, gluten, estrogen (PMS and menopausal females are particularly susceptible) and other factors. It’s also possible that brain fog can be created from specific food stressors, once again eliciting the same response, proposed in the heavy traffic.

Some might say, how can the body be so fragile? Surely we are more robust than that? But it is possible to create these specific dysfunctions but they can be unravelled. Understanding specific stimulus can give us a solution to what dysfunction exits. We might never find out how it came about but a thorough history taking can help to influence where we assess and how to treat it. This is where a technique like P-DTR or Proprioceptive Deep Tendon Reflex, developed by Dr Jose Palomar is unique and effective at uncovering specific neurological dysfunction.

If emotions, visual, auditory, mechanical, chemical and pain factors perpetuate dysfunction, then using those stimulus can pose an effective form of assessment and treatment.

  1. Palomar, J. Proprioceptive Deep Tendon Reflex: Course Notes.
  2. Purves D et al Neuroscience 5th edition. Sinauer Associates 2012
  3. http://www.neurology.org/content/77/12/1198.short