Effect Of Hypothyroid Treatment On The Heart
Treatment with levothyroxine in those with overt thyroid dysfunction has been shown to improve LDL cholesterol, total cholesterol, triglycerides, hypertension, diastolic dysfunction, heart rate, and heart rate variability in exercise and to delay progression of atherosclerosis. Patients with cardiomyopathies may demonstrate improved cardiac contractility and stroke volume with levothyroxine treatment. One of the main concerns with starting levothyroxine replacement is the precipitation of myocardial ischemia or arrhythmias, which, although rare, are known to occur. The recommendation for these patients is usually to start with low doses and gradually escalate until euthyroid status is achieved.
How Do I Store And/or Throw Out Levothyroxine Tablets
- Store at room temperature.
- Protect from heat and light.
- Store in a dry place. Do not store in a bathroom.
- Some brands of this medicine come in a blister pack. If this medicine comes in a blister pack, do not take it out of the blister pack until you are ready to take it. Do not store the removed drug for future use.
- Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
- Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
Your Thyroid And Your Heart
Your thyroid is a butterfly-shaped gland located in your neck, and it manufactures and releases several hormones that influence your overall health and wellness. Your thyroid hormones play a big role in growth and development, and they also help regulate your metabolism.
One of their primary roles is to help regulate the way your organs function. While just the right amount of thyroid hormones keep your organs running smoothly, when the level of thyroid hormones is too high, it speeds up organ function, making your organs work harder than they should.
If you have an overactive thyroid, it can speed up your heart function, making your heart beat too quickly. Over time, hypothyroidism can wear out your heart, leading to whats known as high-output heart failure.
Read Also: What Causes High Ldl Cholesterol
Your Thyroid And High Cholesterol: The Connection
by Patient Advocate
According to the U.S. Centers for Disease Control and Prevention, almost 37 percent of the U.S. population has high cholesterol levels that put them at high risk for heart disease and stroke. What you are less likely to hear, however, is that a substantial subset of people with elevated cholesterol are hypothyroid, and proper diagnosis and optimal treatment for the underactive thyroid could resolve their cholesterol problems. Lets explore the important relationship between your thyroid and high cholesterol.
How Does Thyroid Hormone Affect Cholesterol Ldl And The Triglycerides
Having a thyroid hormone imbalance will have an effect on the lipids, which in turn can usually be seen on a lipid panel. As a result, balancing the thyroid hormone levels will almost always cause positive changes on a lipid panel, although there are times when other factors can lead to these deviations. What I plan on doing in this blog post is to talk about the impact of thyroid hormone on the total cholesterol, LDL, and some of the other basic lipid markers. Im not going to discuss the effect of thyroid hormone on other lipid markers such as LDL particles and lipoprotein a, but I probably will write a future article that talks about these markers.
Before talking about some of the individual markers on a lipid panel, Id like to briefly explain how thyroid hormones affect lipid metabolism. An enzyme called 3-hydroxy-3-methylglutaryl-coenzyme A reductase is important for the synthesis of cholesterol. In fact, when someone is given a statin to lower their cholesterol, these drugs inhibit this enzyme. Thyroid hormone plays an important role in regulating HMG-CoA reductase, and it also affects the metabolism of LDL and HDL.
How To Have A Healthy Lipid Panel
So if someone has elevated lipid markers, then what should they do in order to normalize them? Here are a few things that can help:
Exercise regularly. Doing aerobic exercise can decrease the triglycerides , although for optimal results its best to combine this with dietary changes.
Also Check: Where Is Cholesterol Made In The Body
Low Thyroid & High Cholesterol
One measurement of thyroid function is a hormone called thyroid-stimulating hormone . Made by a small gland at the base of the brain called the pituitary, TSH tells your thyroid how hard to work.
High TSH levels mean you have an underactive thyroid. Symptoms include:
- Weight gain
- Slow heart rate
Studies show that people with high TSH levels have much higher total cholesterol and LDL levels than people with normal thyroid tests.
Any of these can be fatal.
High cholesterol raises heart disease and stroke risk even more.
At Home Thyroid Blood Test
The inability of the body to properly metabolize cholesterol in hypothyroidism predisposes patients to the risk of heart disease. Thyroid disease not only increases cholesterol levels, but also leads to hypertension and the stiffening of major blood vessel walls, which all lead to increased cardiac disease risk.
Even with subclinical hypothyroidism, where the TSH is slightly elevated and Free T4 is within normal range, an increased risk of cardiac disease has been shown.
Do You Have Persistently High Cholesterol Even On Thyroid Medication
I’ll never forget this important lesson that I learned while in residency:
One old school but very smart attending physician told me that unexplained high cholesterol is almost always a sign of early hypothyroidism and is best treated by thyroid medications like NDT.
This flies in the face of conventional wisdom in the thyroid community but it’s something that has served me well.
Let me explain what she meant:
Medications, such as NDT, are often MUCH better at controlling cholesterol levels compared to levothyroxine even though almost EVERY doctor puts patients with low thyroid function on levothyroxine.
We even have studies showing that this is the case !
Take this study, for instance, which showed that thyroid patients taking levothyroxine did NOT have normal cholesterol levels even though they had a normal TSH.
The TSH is the test that most doctors use to determine whether or not you are taking ‘enough’ thyroid medication.
What can we infer from these results?
Well, for starters that using levothyroxine is probably not sufficient to help MOST thyroid patients feel better and to improve their thyroid function by itself.
If it were then we would see the cholesterol levels normalize as they started taking their medication.
If this doesn’t happen then we can only assume that their thyroid was not adequately treated by whatever therapy they were using.
This study just proves what my attending told me long ago:
That you are on the wrong type of thyroid medication.
Why Your Doctor May Miss This Connection
You would probably like to think that your doctor is the best and that they are infallible but you’d be wrong on both accounts .
Why is it that doctors miss this important connection between low thyroid and high cholesterol?
Well, there are a couple of reasons:
#1. They are trained to only test for the TSH.
The first big problem is how doctors diagnose thyroid conditions.
All doctors are trained to look only at the TSH test as a means to determine whether your thyroid is working or not.
If the TSH test is normal then you are said to have a normal thyroid.
There’s one big problem with this:
Focusing only on the TSH means you will miss PLENTY of patients who actually have thyroid problems but have a normal TSH.
Important patients who fall into this group are those women who have Hashimoto’s thyroiditis .
#2. They have become desensitized to high cholesterol because “everyone” has it.
Another big reason is just the fact that almost everyone nowadays has high cholesterol.
If you go back in time 20 or 30 years ago, high cholesterol wasn’t nearly as common as it is now.
But with obesity rates skyrocketing, with hormone imbalances running rampant , and insulin resistance rates soaring, it’s uncommon to find someone with NORMAL cholesterol.
Unsurprisingly, this leads many doctors to just automatically assume that high cholesterol in any patient is probably from a poor diet or from obesity without ever testing or giving thought to the thyroid.
But you’d be wrong…
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Taking Too Much Synthroid: Interindivdiual Variation In Dosing
Individuals undergoing treatment for hypothyroidism with synthroid are prescribed dosages aimed to optimize TSH levels. Excessively high TSH levels signifies that an individual is likely not getting enough synthroid. Since the severity of hypothyroidism is subject to individual variation and synthroid dosages necessitate patient-specific optimization, too much synthroid for one user may be a normal dose for another.
A person with severe hypothyroidism who weighs 200 lbs may take around 1.7 mcg/kg/day for a daily total dosage of ~154.22 mcg. Should the individual end up taking 175 mcg per day, he/she may exhibit subtle symptoms associated with too much synthroid. On the other hand, someone who weighs 140 lbs and is taking 1 mcg/kg/day for subclinical hypothyroidism, a total daily dosage may be just 63.5 mcg.
If the individual instructed to take 63.5 mcg of synthroid ends up taking 175 mcg per day, more severe symptoms are likely to emerge because the recommended dosage will have been surpassed by a significant amount. The lesser the extent to which an optimally calibrated dosage is surpassed, the less severe and/or numerous the symptoms of too much synthroid are likely to be. The greater the dosage over the optimal amount of synthroid needed for optimal function, the greater the symptomatic severity associated with the overdose.
Thyroid Hormone: How It Affects Your Heart
The thyoid gland, which wraps around the windpipe, releases hormones that have wideranging effects on the body.
Too little or too much of this crucial hormone can contribute to heart problems.
Located at the base your throat, the butterfly-shaped thyroid gland releases hormones that affect every organ in your bodyespecially your heart. Thyroid hormone influences the force and speed of your heartbeat, your blood pressure, and your cholesterol level. As a result, a malfunctioning thyroid gland can cause problems that masquerade as heart disease or make existing heart disease worse.
An estimated 6% of people in the United States have thyroid disease. Most of themabout 80% have an underactive thyroid, or hypothyroidism. When thyroid levels drop, all the systems in the body slow down, triggering a range of symptoms that include fatigue, weight gain, cold intolerance, constipation, and dry skin. But these symptoms are very common in people as they grow older, including those with normal thyroid levels.
Also Check: Does Seafood Have A Lot Of Cholesterol
Underactive Or Overactive Thyroid
The thyroid can produce too little or too many hormones sometimes.
A condition in which your thyroid is underactive is called hypothyroidism. When the thyroid is underactive, your whole body feels like its slowing down. You become tired, sluggish, cold, and achy.
You might get an underactive thyroid if you have the following conditions:
- Hashimotos thyroiditis, an autoimmune disease in which the body attacks and destroys the thyroid gland
- thyroid inflammation
Other factors that can result in an underactive thyroid include:
- removal of all or part of an overactive thyroid
- radiation for cancer or an overactive thyroid
- certain medications, such as lithium, interferon alpha, and interleukin 2
- damage to the pituitary gland from a tumor, radiation, or surgery
Hyperthyroidism is a condition that occurs when you have an overactive thyroid. When your thyroid is overactive, your body kicks into fast gear. Your heart rate speeds up, and you feel nervous and shaky.
You might get hyperthyroidism if you have:
- Graves disease, an immune system disorder that runs in families
- toxic nodular goiter, which involves lumps or nodules on the thyroid
- thyroid inflammation
How Can We Control Cholesterol Levels
Having hypothyroidism is not something we can control, so it may seem unfair that you also have to worry about having high cholesterol and an increased risk for cardiac related disease. Luckily, just as cholesterol is elevated with low thyroid function, once the thyroid is treated with appropriate hormone replacement, the cholesterol levels will likely fall.
Research shows that in 60% of people with a new diagnosis of hypothyroidism and high cholesterol, their elevated cholesterol levels resolve after thyroid function is restored. At least 75% of people who are treated with levothyroxine are able to go without cholesterol-lowering medications within one year after diagnosis.
In some cases, cholesterol levels may remain high, even after treatment with levothyroxine. These patients might try eating a nutrient-rich diet and exercising to reduce cholesterol levels. If this is not enough, cholesterol-lowering medications may need to be started with the supervision of your doctor in order to avoid cardiac disease.
As always, itâs important to discover the root cause before treatment is started. If you have elevated cholesterol on routine laboratory tests, talk to your provider about checking your thyroid function before taking cholesterol-lowering medications. Too many people go years without a clinical or subclinical hypothyroid diagnosis, leading to cardiac and other problems throughout the body.
Recommended Reading: How To Lower Vldl Cholesterol
Baseline Characteristics Of Subjects In The Statin Group And The Control Group
Table 1 presents the baseline characteristics of the participants in the statin group and the control group. Age, sex, TC, FT4, TSH, and thyroid antibodies were well matched between the two groups. Low-density lipoprotein cholesterol , FPG, ALT, AST, and follow-up time were comparable between the statin group and the control group. FT3, BMI, systolic blood pressure , and diastolic blood pressure were lower in the control group, and eGFR was lower in the statin group . For the comorbidities, there are more people accompanied with cardiovascular disease , hypertension , and diabetes mellitus in the statin group compared with the control group. Accordingly, the proportion of hypoglycemic medication use is also higher in the statin group . The characteristics of subjects in the statin group and the control group after follow-up were provided in Supplementary Table 1.
Table 1 Baseline characteristics of subjects in the statin group and the control group.
Association Between Thyroid Disease & Cholesterol
Association between thyroid disease and cholesterol
The composition and transport of cholesterol is severely disrupted with thyroid dysfunction. As discussed above, cholesterol is mostly synthesized in the liver. In order to ensure proper functioning, this process is heavily regulated by thyroid hormones. Thyroid-stimulating hormone increases the activity of an enzyme called HMG CoA reductase, which helps control the rate of cholesterol synthesis. Because you have increased TSH with hypothyroidism, the amount of cholesterol produced in the liver is increased. This is then taken out into the bloodstream via VLDL cholesterol.
VLDL travels in the bloodstream until it encounters an enzyme called lipoprotein lipase . T3 stimulates LPL to break down the VLDL, turning it into low-density lipoprotein , once the majority of triglycerides are removed. With hypothyroidism, there isnt enough T3, which will increase the amount of VLDL in the bloodstream as there wont be enough LPL enzymes available.
The VLDL-turned-LDL cholesterol circulates in the blood until it finds cells that have LDL receptors. Once it binds to the cell, the LDL is used for cell membrane maintenance or converted to other steroid hormones to be used elsewhere in the body. T3 increases the number of LDL receptors, which reduces the total amount of LDL cholesterol in the bloodstream. With hypothyroidism, the number of LDL receptors will be reduced, increasing the amount of LDL in the bloodstream.
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The Link Between Thyroid Disorder And Hypertension
Its well known that thyroid disorder can affect your metabolism, but people may not know that theres a link between thyroid problems and high blood pressure. If youve been diagnosed with either, you may want to discuss the other with your doctor.
At Heart & Vascular Institute, our experts have specialized knowledge about cardiology. We also have an endocrinologist on staff, Dr. Sablaa Ali. Taking a team approach to treating thyroid disorder and hypertension gives you the best of both specialties.
How Does The Thyroid Cause Cholesterol Problems
Your body needs thyroid hormones to make cholesterol and to get rid of the cholesterol it doesnt need. When thyroid hormone levels are low , your body doesnt break down and remove LDL cholesterol as efficiently as usual. LDL cholesterol can then build up in your blood.
Thyroid hormone levels dont have to be very low to increase cholesterol. Even people with mildly low thyroid levels, called subclinical hypothyroidism, can have higher than normal LDL cholesterol. A 2012 study found that high TSH levels alone can directly raise cholesterol levels, even if thyroid hormone levels arent low.
Hyperthyroidism has the opposite effect on cholesterol. It causes cholesterol levels to drop to abnormally low levels.
You might have an underactive thyroid gland if you notice these symptoms:
- weight gain
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Ruling Out Secondary Causes Of High Cholesterol And Triglycerides
If your doctor rules out the other causes of raised cholesterol and triglycerides listed above, then the next step is to look for other possible explanations. These include inherited causes. Tell-tale signs of inherited high cholesterol or triglyceride include:
- close family members with high cholesterol or high triglyceride
- early heart disease in close family members
- an inherited blood fat condition in close family members.
There are over 100 genes that can affect how our bodies handle blood fats. Sometimes just one small change in a gene is enough to raise cholesterol or triglycerides to very high levels. Sometime inheriting a number of genes that each have a small effect can add up to cause problems.
Inherited conditions that cause high cholesterol and triglycerides
Familial Hypercholesterolaemia raised cholesterol caused by a single gene
Familial Chylomicronaemia triglyceride levels can be extremely high, caused by a single gene
Familial Combined Hyperlipidaemia this causes raised cholesterol and triglycerides
Type 3 Hyperlipidaemia this also causes raised cholesterol and triglycerides
Polygenic Hypercholesterolaemia raised cholesterol caused by a number of genes