Thyroid Hormones and Heart Disease (expanded version)
Tuesday, August 13, 2013
1. Introduction: This review addresses the possibility of using traditional thyroid medication, desiccated thyroid, as a strategy for an effective prophylaxis for heart disease. There is a considerable amount of studies carried out on this subject that, for some reason, aren’t very well-known despite their notable results.In addition to describing these studies conducted mostly in the middle of the 20th century, some parts regarding diagnosis, causes and treatment of hypothyroidism are included.
2. Regarding the current CVD treatments
In the last decades, a large part of the discussion related to heart disease (CVD) has been about cholesterol levels. According to modern knowledge, some of the LDL cholesterol in the blood causes atheroma plaques to the intima part of blood vessels.
This is also the reason why low-fat or low-SFA diets are recommended for the prevention of heart disease. Saturated fat is supposed to cause CVD by increasing the serum concentration of LDL cholesterol. It’s also the reason why a large amount of the western human population uses cholesterol-lowering drugs, statins.
These two methods, however, haven’t proved very effective. Especially, if we look at the recent meta-analyses compiling evidence from a large amount of fat-modification trials, they don’t support the view that saturated fat is an important cause of CVD. (Hooper 2011, Ramsden 2010, Skeaff&Miller 2009)
Statins, on the other hand, have proved effective. Meta-analysis published in 2012 revealed that in the context of secondary prevention, statins can decrease total mortality by 20 per cent in men, though no significant benefit was seen in women. Also, Cochrane review published in 2011 showed that in primary prevention statins can decrease total mortality by 16 per cent, and heart attacks by a few dozen per cent. Gutierrez et al. 2012, Taylor et al. 2011
These results are quite good, but of course we want to maximize the effectiveness of medications and even statins do leave a majority of people vulnerable to CVD deaths. That’s the reason why we should consider if some other treatment could give better results than the statins.
3. Desiccated thyroid and CVD, part I: William B. Kountz
In 1951, physician William B. Kountz published his monograph Thyroid function and its possible role in vascular degeneration, in which he introduced his 5-year study with 268 subjects.
As study subjects, Kountz had specifically chosen people with low basal metabolic rate (BMR; on average, 10 to 18 percent below normal). For the intervention groups he prescribed desiccated thyroid to raise their metabolic rate to the normal level. The control group did not get thyroid. Both groups got some B vitamins as well.
There were three intervention groups plus their corresponding control groups. Group 1 consisted of middle-aged businessmen, Group 2 consisted of middle-aged office workers and Group 3 consisted of elderly infirmary patients.
The study results were promising. The rates of heart attacks were 85, 76 and 44 per cent lower in the intervention groups (group 1, 2 and 3). The reductions in mortality were similar, and are shown below.
The absolute values are shown here: Figure 6
4. Desiccated thyroid and CVD, part II: James C. Wren –Two decades after Kountz’ research, physician James Wren conducted two studies which gave additional support to Kountz’ results.
The first study, Thyroid function and coronary atherosclerosis, was published in 1968. During the two years, 74 CVD patients were given desiccated thyroid plus some vitamins. Forty-six controls were matched for the same number of intervention subjects.
The results were positive. The thyroid treatment decreased subjects’ pains, improved their ECGs and lowered their cholesterol levels 17 per cent on average. 95 per cent of the subjects reported subjective benefit from the treatment. The difference in the mortality rates between the intervention and control group was six-fold (2 vs 12).