Clinical Hypothyroidism and Obesity

Quasita

I was doing some research for a member of a support group that I help run, and got to reading this clinical paper from the AACE/ATA (American Association of Clinical Endocrinology/American Thyroid Association)
It has a lot of interesting information about clinical guidelines for diagnosis, treatment and adjustments to the standards that have been traditionally used. I found a certain amount of the information to be actually surprising, and I thought I would share it here, as it may be valuable information for members here on MFP.

"Obesity.
Hypothyroidism and obesity are often linked at least in the consciousness of the lay public. However, appetite in those with marked hypothyroidism is often suppressed offsetting the impact of a decrease in metabolic rate, myxedema may present with weight loss, and overt hypothyroidism does not appear to be more common in the obese population than in the general population (240).
Nonetheless this impression dates back to early observations of significant weight loss following the resolution
of myxedema, an effect that was principally the result of fluid mobilization (241). This was recently confirmed in
a prospective year-long study of newly diagnosed patients with overt hypothyroidism whose mean TSH levels at the
onset of the study was 102 (242). Some observational studies correlate TSH levels with body mass index (243-245)
while others do not (246). However, obesity may have an impact on the hypothalamic-pituitary-thyroid axis as
evidenced by relatively elevated TSH levels in morbidly obese adults (247) and children (248) who have ultrasound
findings suggestive of chronic thyroiditis without either elevated anti-thyroid antibody titers or decreased T4 and T3
levels. Caution must therefore be exercised when diagnosing subclinical hypothyroidism in the setting of marked
obesity (249).
Apart from the mobilization of fluid and the ensuing diuresis in myxedematous states, however, the impact
of thyroid hormone therapy on waist-hip ratio (250) and weight loss (242), even in cases of profound hypothyroidism, appears at most to be modest. This is despite the fact that resting energy expenditure increases significantly in individuals who are rendered subclinically hyperthyroid after being subclinically hypothyroid (251). Clearly behavioral and other physiological factors apart from thyroid status have an impact on weight status. Because of the negative impact on nitrogen balance, cardiovascular factors, bone, and affective status, supraphysiological doses of thyroid hormone as used in the past (252,253) should not be employed as an adjunct to weight loss programs in patients with or without hypothyroidism (254). However, it
is advisable to counsel patients about the effect any change in thyroid status may have on weight control. This includes
thyroidectomy although recent studies concerning its effect are contradictory (255,256)."

For those unaware, myxedema is basically the swelling (edema) of subcutaneous tissues, often observed in patients with thyroid disease.

Basically, they are stating that while people have traditionally associated the two, there is no confirmed clinical evidence that suggests that hypothyroidism actually causes obesity, or that treatment of it would markedly reduce obesity. They are also saying that the extremely obese can, in essence, have elevated levels that in an average person would indicate hypothyroidism, but that the level is often due to the size of the person, and is not true hypothyroidism or subclinical hypothyroidism. In these cases, hormone treatment would be contraindicated due to the risks to the cardiovascular system as well as the bones.

I find the fact that they have concluded that if anything, hypothyroidism would cause weight loss at onset due to decreased appetite in correlation with the slowing metabolism to be on pointe and logical... But I had never really thought of it that way. My personal interpretation (which of course, with the exception of the quotation, all of this is) is that hypothyroidism can indeed cause things like depression (the next section of this paper discusses this in more detail) which could lead to environmental and behavioral changes such as malaise and food dependence, which then leads to weight gain... But as stated, this is not a universal truth in people with the condition. There is also the reduced energy metabolism to consider, which would render a person fatigued and less likely to participate in strenuous activities. Ultimately though, the conclusion is, in most cases, associated weight loss at the onset of treatment is actually the voiding of water weight due to the correction of the myxedema, and not fat loss, as many people believe.

I also found the paper's conclusions that T4 and T3 values cannot be definitively used for a clinical diagnosis on their own, but rather should be used as an addendum to testing when TSH levels fall into abnormal ranges to diagnose conditions and determine proper treatment, to be very interesting. All too often, I have read discussions where people have told inquirers who are *sure* they are hypo but have normal TSH values (according to this paper, this would be defined as .45-4.12 unless otherwise indicated by generational testing values) to have the T4 and T3 levels checked.
The paper also strongly advises that the majority of "thyroid support" supplements, particularly OTC formulations, have no marked positive effect on thyroid health/hormones, and some may actually cause adverse effects due to the ingredients being used, as well as apparent possible usages of altered thyroid hormone replacement chemicals.

I am by no means making any conclusions or suggestions to patients with this diagnosis, but rather interested in the discussion. Anyone care to weigh in? You can read the full paper and citations here: https://www.aace.com/files/final-file-hypo-guidelines.pdf

editorgrrl

MFP has a Hypothyroidism and Hyperthyroidism group: http://www.myfitnesspal.com/forums/show/770-hypothyroidism-and-hyperthyroidism

holly1283

I appreciated your article. I have been diagnosed with Hoshimoto's thyroiditis (hypo). I've been on thyroid hormone for 24 years. I finally lost weight in 2012 and then they reduced my med. and reduced it again. 2013. I was a mess. The 2nd reduction was too low and my depression was wacko. Gained weight because of the dpression. Now I have to re-lose those pounds. For anyone out there who has been diagnosed for years, stick to your guns and don't let the doctors only diagnose on the T3 and T4 and TSH numbers. You know how you feel.

Quasita

MFP has a Hypothyroidism and Hyperthyroidism group: http://www.myfitnesspal.com/forums/show/770-hypothyroidism-and-hyperthyroidism

That's cool, but I don't actually have a thyroid condition myself, I just thought I'd share the information for what it was worth. I don't think it would be appropriate for me to join a group about it.

Quasita

I appreciated your article. I have been diagnosed with Hoshimoto's thyroiditis (hypo). I've been on thyroid hormone for 24 years. I finally lost weight in 2012 and then they reduced my med. and reduced it again. 2013. I was a mess. The 2nd reduction was too low and my depression was wacko. Gained weight because of the dpression. Now I have to re-lose those pounds. For anyone out there who has been diagnosed for years, stick to your guns and don't let the doctors only diagnose on the T3 and T4 and TSH numbers. You know how you feel.

This is quite true. Hashimoto's Thyroiditis is considered the most common cause in the United States, and is diagnosed through testing for antibodies as well as the thyroid hormones, ultrasound, and clinical history. Diagnosed on average 1-2 in every 1000... So I wonder what that suggests for hypothyroidism on the whole?

The paper does discuss this topic as well. The conclusion tends to be the same, that the majority of weight gain experienced is fluid gain/retention due to subcutaneous edema. That's not to say that it's easy to lose by any means... But it does makes sense to me that one would gain this type of weight when reducing their medication intervention. I hope you get it worked out!!