Download Winter`s Hibernation (From Winter 2006 newsletter)

Dr. Kimberly Hindman, ND, LAc.
1820 SW Vermont, Suite C
Portland, OR 97219
(503) 784-1027
Thyroid and Adrenal (From Autumn 2007 newsletter)
Thyroid and adrenal disorders are very common, and are often occur in conjunction with each other.
The thyroid increases metabolic rate, stimulates synthesis of proteins, increases fat breakdown and
use of sugar to make energy, increases cholesterol excretion, accelerates growth and contributes to
normal nervous system development. The thyroid produces two hormones, T4 and T3, from iodine
and the amino acid tyrosine. T4 is produced in much greater quantities, but must be converted to
T3, the active form, to exert its effects. Approximately 40% of the T4 is converted to T3, and
another 20% is converted into an inactive form, reverse T3. The remaining 20% is converted into
two other hormones, which are activated by enzymes in the intestines. These enzymes are dependent
on healthy gut bacteria.
Secretion of thyroid hormone is controlled by the level of iodine and the feedback loops with the
pituitary and hypothalamus. Low levels of T3 and T4 in the blood stimulate the hypothalamus to
release thyrotropin releasing hormone (TRH), which stimulates the pituitary to release thyroid
stimulating hormone (TSH). TSH then stimulates the thyroid to trap more iodine and create and
secrete more T3 and T4.
There are several imbalances of thyroid functioning. Hypothyroidism occurs when the thyroid isn’t
producing enough T4 and T3. This may be caused by the thyroid not responding, the pituitary not
producing TSH, or the hypothalamus not producing TRH. If the thyroid is not responding, lab tests
will show a high TSH and low to normal T4 and T3. If this is the case, anti-thyroid antibodies
should be checked to rule out Hashimoto’s thyroiditis, an autoimmune condition that destroys the
thyroid. If the TSH is low, it may be more likely to be a pituitary cause, which is may be associated
with high cortisol and stress, post-partum hormone changes, heavy metal toxicity, or inappropriate
thyroid hormone replacement.
Hyperthyroidism is the exact opposite: the thyroid is producing too much thyroid hormone, which
can have significant consequences, especially during periods of acutely high hormone production. In
this case, TSH will be low and the T3 and T4 may be elevated. Hyperthyroidism can be induced by
over-prescribing thyroid hormone or ingesting too much iodine.
There are also patterns of overconversion and underconversion of T4 to T3. The TSH will be
normal with both of these, but the T3 will be high with overconversion, and low with
underconversion. Overconversion is usually seen with high testosterone exposure, which is
commonly seen in insulin resistance and polycystic ovary syndrome. Underconversion is often seen
with high levels of cortisol, inflammation, or low antioxidants.
Thyroid hormone travels in the blood stream attached to thyroid-binding proteins, which increase
with estrogen exposure (e.g., pregnancy, hormone replacement therapy, or birth control pills). An
increased protein level can cause low levels of free T3 and T4 on labwork. In this case, the thyroid is
functioning normally, but more of the hormone is being bound up by the binding protein. Thyroid
resistance presents with completely normal lab results but the person experiences symptoms of low
thyroid functioning. This is most often seen with high cortisol levels.
Adrenal dysfunction presents as hyperfunctioning and/or adrenal fatigue. High stress places a
demand on the adrenals for more cortisol, which requires the pituitary to produce more stimulating
hormone. While high cortisol is beneficial for acute stress, chronically high cortisol will
downregulate the digestive and immune systems, the thyroid conversion enzymes, and the thyroid
hormone detoxification pathways, as well as imbalance other hormones, including insulin.
Therefore, adrenal function should always be examined with any thyroid disorder.
Adrenal fatigue usually results after periods of high stress. High and low cortisol level can also occur
at different times of the same day. Low cortisol may be seen with morning fatigue and insomnia may
be caused by high nighttime cortisol.
© Kimberly Hindman, 2007