The thyroid gland’s importance in the body is essentially related to its regulation of many aspects of the body’s functions. Dysfunction of the thyroid, either overactive or underactive, is a common problem experienced by many women. Low thyroid, or hypothyroidism, can occur after removing the thyroid, simply low functioning of the thyroid, or autoimmune diseases such as Hashimoto’s thyroiditis.
Low thyroid function can affect mood, metabolism, weight, heart rate, brain function, hair, and ovulation. It is therefore a stretch to hypothesize if hypothyroidism affects sexuality? In other words, is hypothyroidism linked to female sexual dysfunction (FSD)?
TSH (Thyroid stimulating hormone) is the common blood test used to screening for hypothyroidism. When TSH levels are abnormally high, this suggests low circulating thyroid hormone from an underactive thyroid. TSH production from the pituitary gland will increase to try to “rev up” the sluggish thyroid gland if it’s underactive in order to push it to produce more thyroid hormone. Usually, TSH above 5 is considered “high/abnormal”, but it’s important to note that if the patient “feels normal” and has a slightly elevated TSH, then thyroid hormone replacement may not necessarily be warranted. Conversely, if the TSH is within the “normal range” (<5), but the patient appears sluggish or “clinically hypothyroid”, then thyroid hormone replacement may actually be warranted. This goes to the point of “treating the patient, not the number”.
A study was recently published looking at three groups of women, comparing their thyroid status, to see if it links to female sexual dysfunction. The three groups were:
1. Women who were clinically hypothyroid, 2. Women with TSH <> 10 but not overtly hypothyroid, 3. Control group with “normal thyroid” women.
FSD was diagnosed in 56 percent of women who were clinically hypothyroid, and 54.6 percent of women with a TSH > 10. By contrast, the control group of women, and the group of women with a TSH <> 10, but not so in the other two groups of women. Other hormone levels, such as estradiol, free testosterone, FSH, LH were all normal across the board.
As a sidebar, prolactin is a pituitary hormone that is linked to lower sexual function as well. Lactating women post-pregnancy will have elevated prolactin levels, a “protective mechanism” to allow nurturing of the infant and avoidance of early sexual interest that may be a distraction during this time.
The importance of this study, which was quite simple and straightforward in design and results, should help us remember to screen for female sexual dysfunction in women with hypothyroidism. It may be simply overlooked when busy physicians are concerned with fixing one problem, to not neglect secondary conditions which may co-exist.