Author Archives: dnaserver

Men's Health, Women's Health

What is estradiol?

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Estradiol is the strongest of the three estrogen hormones and is one of the most important hormones in a woman for a healthy and normal menstrual cycle, ovulation, and fertility. Estradiol is naturally produced in both genders with much higher levels in females. It is predominantly produced within the ovarian follicles, but also in other tissues, such as the adrenal glands, fat, liver, breasts, brain, testes, and placenta (during pregnancy) (1).

What are the roles of estradiol in females?
The primary function of estradiol in females is to mature and maintain the reproductive system, including the mammary glands, uterus, and vagina. During each menstrual cycle, estradiol levels increase to trigger the maturation and release of the egg, and the thickening of the uterus lining to allow a fertilized egg to implant (1).

Other roles for estradiol include the development of female secondary sexual characteristics, (such as breasts, female fat distribution, and pubic hair) and increasing both bone and cartilage density. In addition, estradiol affects skin health, the brain, and the musculoskeletal and cardiovascular systems (2).

What are the roles of estradiol in males?
Although estradiol is considered a female sex hormone, it is also important in males. Within the testes, some testosterone is changed into estradiol to aid in the development of healthy sperm, as well as modulate libido, and for normal erectile function (3). It also has many of the same effects in males as it does in females, including an influence on skin health, the brain, and the musculoskeletal and cardiovascular systems (2).

What are normal estradiol levels?
Estradiol levels vary throughout a person’s lifetime, so there are wide variations in what is considered the normal reference levels.

Both girls and boys have low estradiol levels during childhood, although girls do have higher levels than boys even before physical signs of puberty. Prepubertal girls have estradiol levels of 1.6 +/- 2.6 pg/mL, while prepubertal boys have estradiol levels of 0.4 + 1.1 pg/mL (4). At puberty, estradiol levels gradually increase.

In females of reproductive age, estradiol levels rise and fall twice during each menstrual cycle. At the beginning of the follicular phase of the cycle (when menstruation occurs), estradiol levels are low (25–75 pg/mL). Levels gradually increase, until a rapid increase to 150–750 pg/mL just before ovulation occurs (when an egg is released), followed by a rapid decrease. During the luteal phase, estradiol levels gradually increase again to around 30–450 pg/mL, preparing the uterus for possible fertilization. If the released egg is not fertilized, estradiol levels decrease again to basal levels and menstruation begins (5). However, if the egg is fertilized for a pregnancy, estradiol levels keep increasing, until they reach levels as high as 40,000 pg/mL during the third trimester (6).

As females age, their estrogen levels slowly decrease, until a large decrease at menopause. Postmenopausal women generally have estradiol levels less than 20 pg/mL (5).

Normal estradiol levels in adult males are 10–50 pg/mL (5).

What happens if estradiol levels are too high?
In females, elevated estradiol is associated with (1):

  • Acne
  • Constipation
  • Decreased libido
  • Depression
  • Weight gain
  • Fertility issues
  • Increased risk of uterine and/or breast cancer

In males, elevated estradiol can cause (1):

  • Sexual dysfunction
  • Loss of muscle tone
  • Increased body fat
  • Development of breast tissue

What happens if estradiol levels are too low?
Low estradiol is associated with (1):

  • Skeletal issues (e.g., inadequate bone growth and osteoporosis)
  • Delayed puberty, disrupted menstrual cycle, and infertility in females
  • Fertility issues in males
  • Depression
  • Fatigue
  • Mood swings

How can I measure my estradiol levels?
We offer several different tests to measure your estradiol levels. These tests just require a small blood sample collected from a simple finger prick in the privacy of your own home. Test results are available through our online portal, thereby avoiding the need to make any doctor or lab appointments. Of course, you may also wish to discuss your results with your healthcare professional, and this is highly recommended if you receive any results that fall outside the normal range.

The Estradiol (E2) test measures just your estradiol levels. For females of reproductive age, it is helpful to know what stage of your menstrual cycle your sample was collected at, as normal levels vary throughout each cycle.

There are various combination tests available for females that include estradiol along with other important hormones:

Males may wish to order the Estradiol (E2) test (estradiol alone) or the Men’s Health Hormone Panel (6 biomarkers), which includes estradiol along with other hormones that are important for male health.

References:
1. Oestradiol. You and your Hormones, an education resource from the Society for Endocrinology. Reviewed Mar 2018.
2. Estrogen’s Effects on the Female Body. John Hopkins Medicine.
3. Schulster M, Bernie AM, Ramasamy R. (2016) The role of estradiol in male reproductive function. Asian J Androl. 18(3):435-40.
4. Janfaza M, Sherman TI, Larmore KA, Brown-Dawson J, Klein KO. (2006). Estradiol levels and secretory dynamics in normal girls and boys as determined by an ultrasensitive bioassay: a 10 year experience. J Pediatr Endocrinol Metab. 19(7):901-9.
5. Pagana KD, Pagana TJ, Pagana TN. Mosby’s Diagnostic & Laboratory Test Reference. 14th ed. St. Louis, Mo: Elsevier; 2019.
6. Speroff L, Glass RH, and Kase NG. (1994). The Endocrinology of Pregnancy. In: Mitchell C, editor. Clinical Gynecologic Endocrinology and Infertility, 5th ed. Baltimore: Williams and Wilkins. 251-289.

HIV

HIV Quick Facts

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What is HIV?
Human immunodeficiency virus (HIV) is a sexually transmitted disease (STD), which occurs by contact or transfer of blood, semen, pre-ejaculate, and vaginal fluids. HIV can also be transmitted from an infected mother to her infant during pregnancy, childbirth, or through breast milk. HIV targets the cells of the immune system and in the absence of effective treatment, it can develop into acquired immunodeficiency syndrome (AIDS) (1).

What causes HIV?
HIV is caused by infection with one of two types of HIV. HIV-1 is the most common and most contagious. HIV-2 is less infectious and is predominantly confined to infections in West Africa.

What are the symptoms of HIV?
Many people infected with HIV are unaware of the infection in the early stage (acute, stage 1), as they may not experience any symptoms or only mild symptoms (e.g. headache and sore throat) that can be easily confused with other illnesses (2). Other people experience more serious symptoms, including:

  • High fever
  • Swollen lymph nodes
  • Skin rashes
  • Diarrhea
  • Mouth ulcers
  • Muscle aches
  • Sore throat with persistent coughing
  • Chills
  • Night sweats

The second stage is called chronic HIV infection or clinical latency and generally doesn’t cause any symptoms.

AIDS is the third stage of an HIV infection when the virus has destroyed so many of the host’s immune system cells (2). The symptoms can include:

  • Rapid weight loss
  • Extreme fatigue
  • Pneumonia
  • Skin discoloration
  • Memory loss
  • Depression
  • Increased susceptibility to other infections such as tuberculosis, severe bacterial infections, and certain cancers

Who is at risk of HIV?
Populations that have an increased risk of HIV include men who have sex with men, injecting drug users, individuals in correctional facilities, sex workers (and their clients), and transgender individuals (3).

How is HIV diagnosed?
HIV infections are usually diagnosed by the detection of HIV antigens and antibodies in a blood sample. It is important to note that there is a window period of 45-90 days, during which HIV diagnostic tests may produce a negative result, although infected individuals can still transmit the virus to others. Follow-up testing is recommended for any individuals with a negative result who may have been exposed to HIV (3).

How is HIV treated?
Although there is no cure for HIV, effective antiretroviral therapy (ART) ensures that infected individuals can live relatively normal lives and prevents the transmission of HIV. Individuals at risk for HIV can also take HIV medication called pre-exposure prophylaxis (PrEP), which is highly effective for preventing HIV (3).

References:
1. Weiss RA. (1993) How does HIV cause AIDS? Science, 260 (5112), 1273-1279.
2. Symptoms of HIV. Clinical Info HIV.gov. July 2020.
3. HIV/AIDS. World Health Organization.

Posted in HIV
Heart Health and Diabetes, Inflammation and Stress

C-Reactive Protein (CRP) Quick Facts

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What is C-reactive protein (CRP)?
C-reactive protein (CRP) is a protein in the blood that non-specifically increases during inflammation and infection, as well as following a heart attack, surgery, or trauma. In many instances, tissue damage causes a significant spike in the blood concentration of CRP. However, even just minimal but persistent levels of inflammation result in small CRP increases.

Why measure CRP levels?
CRP is a very sensitive marker for inflammation and infection. It tends to rise before any other symptoms (e.g. fever and pain) occur, meaning it is an excellent option to detect underlying inflammation or an infection that is yet to cause any health issues.

What is the link between CRP and heart health?
There are numerous risk factors associated with heart (cardiovascular) disease, including high cholesterol, high blood pressure, being overweight, and diabetes. However, many individuals who develop cardiovascular disease do not appear to have any of the obvious risk factors (1).

The development of a high sensitivity CRP assay has allowed for the identification of individuals that have CRP levels within the higher end of the reference range (3-10 mg/L), who are not identified in standard wide-range CRP assays (2). These slightly elevated CRP levels in otherwise healthy individuals are indicative of the development of atherosclerosis (cholesterol deposits and plaque in the blood vessel walls) and help to predict the future risk of heart attack, stroke, and peripheral artery disease (3).

In addition, measurements of CRP are useful in patients who have already suffered a myocardial infarction. Elevated CRP in these patients is associated with subsequent risk of major adverse cardiovascular events and death (4).

Ways to lower CRP
Non-pharmacological methods for reducing CRP (and the risk of heart disease) include aerobic exercise, abstaining from smoking, losing excess body weight, and following a heart-healthy diet with whole grains, reduced unhealthy fats and sodium, and lots of fruits and vegetables. Various medications are also available that have been shown to reduce CRP levels, including statins, aspirin, and vitamin E (5).

Is CRP elevated in other health conditions too?
Yes, elevated CRP is not specific to just heart health. CRP values greater than 10 mg/L occur due to infections and diseases that cause inflammation, such as:

  • Cancer
  • Lupus (immune system disease)
  • Rheumatoid arthritis (swelling in the joints)
  • Inflammatory bowel disease
  • Osteomyelitis (bone infection)

It is important to note that although CRP tests are very useful to detect inflammation, they do not specify where the inflammation is located or what is causing it. Other tests will be required for additional information on the source and cause of the inflammation.

References:
1. Fonseca FAH, and de Oliveira MC. (2016). High-Sensitivity C-Reactive Protein and Cardiovascular Disease Across Countries and Ethnicities. Clinics (Sao Paulo). 71(4), 235-242.
2. Pearson TA, et al. (2003). Markers of Inflammation and Cardiovascular Disease, Application to Clinical and Public Health Practice, A Statement for Healthcare Professionals from the Centers for Disease Control and Prevention and the American Heart Association. 107(3), 499-511.
3. Kamath DY, et al. (2015). High sensitivity C-reactive protein (hsCRP) & cardiovascular disease: An Indian perspective. Indian J Med Res. 142(3), 261-268.
4. Carrero JJ, et al. (2019). hsCRP Level and the Risk of Death or Recurrent Cardiovascular Events in Patients with Myocardial Infarction: a Healthcare‐Based Study. JAHA. 8.
5. Prasad K. (2006). C-reactive protein (CRP)-lowering agents. Cardiovasc Drug Rev. 24(1): 33-50.

Inflammation and Stress

How does stress increase cortisol levels?

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Cortisol is widely known as the “stress hormone” and for good reason, as stress triggers a surge in cortisol. Cortisol also influences various other functions throughout the body too.

How are cortisol levels controlled?
Cortisol is a steroid hormone synthesized from cholesterol in the adrenal glands, with secretion controlled by the HPA axis. The HPA axis is a combination of glands that includes the hypothalamus, the pituitary gland, and the adrenal gland. This HPA axis follows a circadian rhythm, which means that cortisol levels are generally higher in the morning and lower at night (1).

When the hypothalamus detects low cortisol, low blood sugar, or times of stress, it releases corticotropin-releasing hormone (CRH), which signals for the pituitary to release adrenocorticotropic hormone (ACTH). ACTH then acts on the adrenal gland to trigger the synthesis and secretion of cortisol. Elevated cortisol levels inhibit the release of CRH and ACTH, providing a negative feedback loop to control cortisol levels (1).

What are the roles of cortisol?
Cortisol mediates the stress response, as well as helping regulate metabolism, the inflammatory response, and immune function. In times of stress, a surge in cortisol helps provide energy to the body by increasing blood sugar through gluconeogenesis (synthesis of ‘new’ glucose). Glucose is especially important as an energy source for the brain, helping to give that extra mental boost, such as when there is an important deadline approaching!

Cortisol is also involved in the metabolism of fat, protein, and carbohydrates. It helps control blood pressure and is even involved in memory formation. In addition, cortisol enhances the activity of epinephrine (adrenalin), which is what causes a faster heart rate and faster breathing in times of stress (1,2).

What happens if cortisol levels stay high for a long time?
Usually, cortisol only remains elevated for a few hours after a stressful event. However, in people who are suffering from chronic (long-term) stress, cortisol levels can remain elevated for several months. These persistently elevated levels of cortisol can increase the risk of various health complications, including anxiety, depression, digestive problems, weight gain, and insomnia (2).

References:
1. Thau L, Gandhi J, Sharma S. (2020). Physiology, Cortisol. [Updated 2020 May 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-.
2. What is Cortisol? (Nov 2018). Hormone Health Network, Endocrine Society.

Related Tests

Vitamins and Minerals, Women's Health

Pregnant? Here are the most important vitamins and minerals for your developing baby

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Pregnancy can be a demanding time for a mother-to-be. Many women suffer from morning sickness (or probably “all-day sickness” is more accurate for some!). Women can suffer from weird food cravings, which are more often than not an unhealthy food choice. Tiredness is often an issue, hip and back pain, and of course the constant need to pee too!

Despite all these obstacles, it is essential that women have a good nutritious intake during pregnancy. They need to not only maintain their own health and weight but also provide all the nutrients needed to grow another little person.

Should I “eat for two”?
“Eat for two” is a popular saying during pregnancy, but in reality, is not actually the best option. Now, doctors recommend instead eating twice as healthy. Yes, added calories are needed during pregnancy but definitely not twice as many calories as a pre-pregnancy diet. A woman carrying a single fetus requires an extra 340 calories per day in the second trimester and a bit more in the third trimester (1). That is equivalent to about a glass of skim milk and half a sandwich.

What are the most important vitamins and minerals during pregnancy?
Prenatal vitamins combined with a healthy diet are the best way to ensure adequate vitamin and mineral intake during pregnancy. The most important vitamins and minerals are folate (or the synthetic equivalent – folic acid), iron, calcium, vitamin D, choline, omega-3 fatty acids, B vitamins, and vitamin C. The table below shows the recommended amounts (obtained from The American College of Obstetricians and Gynecologists (1).

Nutrient Daily recommended amount Why it is required Best food sources
Folate (folic acid) 600 mg Helps prevent birth defects of the brain and spine (e.g. spina bifida)

Supports the general growth and development of the fetus and placenta

 Fortified cereal, enriched bread and pasta, peanuts, dark green leafy vegetables, orange juice, beans.

A daily prenatal vitamin with 400 mg of folic acid is also recommended during pregnancy.
Iron 27 mg Helps red blood cells deliver oxygen to the fetus Red meat, poultry, fish, dried beans and peas, iron-fortified cereals
Calcium 1000 mg (19+ years)

1300 mg (14-18 years)

 For strong bones and teeth Dairy products, sardines, green leafy vegetables
Vitamin D 600 international units Builds the fetus’s bones and teeth

Helps promote healthy eyesight and skin

 Sunlight, fortified milk, fatty fish such as salmon and sardines
Choline 450 mg Important for development of the fetus’s brain and spinal cord Milk, beef liver, eggs, peanuts, soy products
Vitamin B6 1.9 mg Helps form red blood cells

Helps body use protein, fat, and carbohydrates

 Beef, liver, pork, ham, whole-grain cereals, bananas
Vitamin B12 2.6 mg Maintains nervous system

Helps form red blood cells

 Meat, fish, poultry, milk (vegetarians should take a supplement)
Vitamin C 80 mg (14-18 years)

85 mg (19+ years)

 Promotes healthy gums, teeth, and bones Citrus fruit, broccoli, tomatoes, strawberries
Vitamin A 750 mg (14-18 years)

770 mg (19+ years)

 Forms healthy skin and eyesight

Helps with bone growth

 Carrots, green leafy vegetables, sweet potatoes
Iodine 220 mg Essential for healthy brain development Iodized table salt, dairy products, seafood, meat, eggs

References:
1. Nutrition During Pregnancy. ACOG. Updated March 2021.

Heart Health and Diabetes

“Bad” versus “good” cholesterol

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Most people have heard that high cholesterol is bad for heart health, but many people don’t actually realize that there is both “bad” cholesterol and “good” cholesterol.

What is cholesterol?
Cholesterol is a waxy type of fat (lipid), which travels around the body in the blood. It is an essential molecule, as it is required for building cells, producing bile for digestion, and making vitamins and hormones. Cholesterol is produced in adequate quantities in the liver, but can also be obtained from foods from animals (1).

Cholesterol can’t actually travel around the body by itself, and must instead be packaged with lipoproteins to move through the blood. “Bad” and “good” cholesterol refers to how the cholesterol is packaged.

“Bad” LDL Cholesterol
Most cholesterol in the body is carried around the body by low-density lipoproteins (LDL) and is referred to as LDL cholesterol. This is the “bad” cholesterol, as LDL deposits excess cholesterol in blood vessel walls, where it accumulates, leading to hardening of the arteries, atherosclerosis, and blood clots. LDL cholesterol levels are often considered to be the best predictor of the risk of heart disease (2).

Various factors can contribute to elevated LDL cholesterol, including a high intake of saturated fats (from red meat and dairy) and refined sugars, high alcohol consumption, physical inactivity, smoking, and being overweight or obese.

“Good” HDL Cholesterol
“Good” cholesterol refers to cholesterol carried around by high-density lipoproteins (HDL). HDL collects cholesterol from around the body and delivers it to the liver for recycling or excretion. HDL also carries cholesterol to other organs, where it is used to produce hormones. In addition, HDL cholesterol plays a role in protecting and maintaining the inner walls of the blood vessels by repairing damaged sites (2,3).

How can I lower my “bad” cholesterol and increase my “good” cholesterol?
A combination of losing weight, diet, and exercise is beneficial for improving your cholesterol. Specific changes include increasing fiber intake, limiting carbohydrate, alcohol, and fat intake, and choosing healthier unsaturated fats instead of saturated and trans fats. More information about food choices to improve cholesterol levels is available here. Abstaining from smoking and exercising for at least 30 minutes each day is also beneficial (4).

References:
1. What is Cholesterol? American Heart Association. (2020).
2. HDL (Good), LDL (Bad) Cholesterol and Triglycerides. American Heart Association. (2020).
3. Castelli WP, et al. (1977). HDL Cholesterol and other lipids in coronary heart disease. The cooperative lipoprotein phenotyping study. 55 (5), 767–72.
4. LDL and HDL Cholesterol: “Bad” and “Good” Cholesterol. CDC. Reviewed Jan 2020.

Men's Health

The wide influence of testosterone on male health

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What is testosterone?
Testosterone is the primary sex hormone in males, but it is also important in females. Testosterone is mainly secreted from the testes in males, and from the ovaries in females.

What does testosterone do in males?
Although males have much higher levels of testosterone than females, this androgen plays an important role during the life cycle of both genders. In this article, we focus on the role of testosterone in males.

Before birth, testosterone levels are associated with sex formation, with higher levels initiating the development of male reproductive organs. During puberty, testosterone plays a role in many of the typical changes that occur as boys grow into men. This includes increases in body and pubic hair, enlargement of the penis, testes, and prostate gland, deepening of the voice, teenage acne, and remodeling of the facial bones (1,2).

Other roles of testosterone include:

  • Increasing libido (sex drive)
  • Controlling fat distribution
  • Enhancing muscle and bone growth
  • Normal sperm production
  • Red blood cell production

How are testosterone levels controlled?
Testosterone levels can fluctuate slightly each day, with higher levels in the morning. However, strict control helps to maintain blood testosterone at normal levels. The hypothalamus in the brain releases gonadotrophin-releasing hormone (GnRH), which signals the pituitary gland (also in the brain) to produce luteinizing hormone (LH). LH travels through the blood to the testes to stimulate the synthesis and release of testosterone (1).

As the hypothalamus detects increasing levels of testosterone in the blood, it suppresses the production of GnRH, so in turn, there is less LH released, so less stimulation of testosterone production. This control system is known as negative feedback. As testosterone levels drop, the hypothalamus increases the production of GnRH, therefore more LH is produced, and testosterone synthesis is stimulated once again (1).

What are the symptoms of high testosterone in males?
In male children, elevated testosterone may cause a false growth spurt and early puberty (precocious puberty). This can contribute to infertility issues later in life.

Naturally elevated testosterone in adult males is rare and is not likely to cause any noticeable symptoms. However, males who take anabolic steroids (synthetic substances similar to testosterone) actually end up with lower levels of their naturally produced testosterone (3). Long-term use of anabolic steroids can result in:

  • Low sperm counts
  • Infertility
  • Decreased sex drive
  • Smaller testes
  • Breast development
  • Liver disease
  • Acne
  • Behavioural changes
  • Weight gain
  • Damage to heart tissue
  • Excessive body hair

What are the symptoms of low testosterone in males?
Low testosterone has differing effects depending on the age of the individual. Testosterone deficiency during fetal development can cause the incomplete development of male characteristics, while deficiency at puberty can slow growth and reduce the development of pubic hair, deeper voice, and penis and testes growth (1,4).

In adult males, testosterone levels naturally decline with age, and this can sometimes be called male menopause (or andropause) (1). However, unnaturally low testosterone can result in:

  • Reduced muscle tone and increased body fat
  • Loss of body hair
  • Weight gain
  • Depression
  • Reduced sex drive and performance
  • Memory loss
  • Irritability
  • Fatigue
  • Sleeping issues.
  • Increased risk of osteoporosis

References:
1. You and your Hormones, an education resource from the Society of Endocrinology. Reviewed May 2021.
2. Raggatt LJ, & Partridge NC. (2010). Cellular and molecular mechanisms of bone remodeling. J Biol Chem, 285 (33), 25103-25108.
3. Testosterone – What It Does And Doesn’t Do. (2019). Harvard Health Publishing, Harvard Medical School.
4. What is Low Testosterone? Urology Care Foundation.

Kidney, Liver, and Thyroid Health

Facts about thyroid-stimulating hormone (TSH)

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Do you have symptoms that suggest that your thyroid is not functioning quite right? Or just want to know more about thyroid health?

Firstly, what is the thyroid gland?
The thyroid gland is a small organ located just under the skin in the neck. This bow tie-shaped organ is usually only about 5 cm across and normally can’t be felt or seen. The thyroid releases specific hormones (chemical messengers) that act on almost every tissue in the body (1).

These thyroid hormones are called thyroxine (T4) and triiodothyronine (T3). T4 and T3 influence a whole range of bodily functions, including skin health, growth, heart rate, fertility, digestion, and weight control.

Normal thyroid hormone levels are very important for a healthy functioning body. But what controls the levels of T4 and T3?

That is where thyroid-stimulating hormone (TSH) comes into the picture. TSH is another hormone, but this one is produced in the pituitary gland, a small gland at the base of the brain. As the name suggests, TSH stimulates the thyroid to produce the T4 and T3 hormones that then go on to act on cells throughout the body (1).

When thyroid hormone levels in the blood are high, the pituitary gland slows the release of TSH, so fewer thyroid hormones are produced. When thyroid hormone levels fall, the pituitary gland speeds up the release of TSH, so it stimulates the thyroid to produce more thyroid hormones (1).

Why measure TSH levels?
TSH levels are usually the best indicator of thyroid function.

If TSH levels are high, it is generally indicative of an underactive thyroid (hypothyroidism), meaning it requires more stimulation (higher TSH) than normal.

If TSH levels are low, it usually indicates an overactive thyroid (hyperthyroidism), which requires less stimulation (lower TSH) than normal.

What are the symptoms of hypothyroidism?
Hypothyroidism means the thyroid is not producing as much T4 and T3 as normal. This effectively slows down functions throughout the body, leading to symptoms such as:

  • Fatigue
  • Puffy eyes and face
  • Slower heart rate
  • Constant feeling of cold
  • Confusion
  • Depression
  • Weight gain
  • Constipation
  • Dry and brittle hair and skin
  • Fertility issues

Treatment options for hypothyroidism include daily medications (e.g. levothyroxine), natural thyroxine hormone extracts, and reduced consumption of substances that affect levothyroxine absorption (2).

What are the symptoms of hyperthyroidism?
Hyperthyroidism means that the thyroid is overproducing T4 and T3. This overproduction speeds up lots of processes in the body, leading to symptoms such as:

  • Fast heart rate
  • High blood pressure
  • Excess sweating
  • Weight loss
  • Anxiety
  • Shaky hands
  • Sleeping issues
  • Increased bowel movements
  • Mood changes

Medication, radioactive iodine, or surgical removal of the thyroid gland are effective treatments for hyperthyroidism (2).

It is important to note that abnormal TSH levels sometimes do not accurately reflect thyroid function. For example, if there is a health issue with the pituitary gland that is interfering with the detection of thyroid hormones in the blood and/or the release of TSH. Additional tests may be required in some instances for an accurate diagnosis. These additional tests can include measuring the levels of T4 and T3, as well as measuring the levels of specific antibodies that are altered in certain health conditions.

Checking the function of your thyroid is simple with a range of tests offered by us. Take our simple Thyroid Stimulating Hormone (TSH) Test for TSH alone, our Thyroid Health Panel to also include T4 and T3 along with TSH, or opt for the Thyroid Health, Complete Panel to also include Anti-Tg and Anti-TPO.

References:
1. Hershnan JM. (Modified Oct 2020). Overview of the Thyroid Gland. Merck Manual Consumer Version
2. Rugge JB, Bougatsos C, & Chou R. (2014) Screening for and Treatment of Thyroid Dysfunction: An Evidence Review for the U.S. Preventive Services Task Force [Internet]. In Evidence Syntheses, No.118. Rockville, MD: Agency for Healthcare Research and Quality (US).

Sexual Health

I just had unsafe sex. Should I take an STD test immediately?

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There is no harm in taking an STD test shortly after a potential exposure. However, it is very likely that the test result will come back negative, even if you have been infected. This is because the molecules detected by laboratory assays must reach a specific level to actually be detectable.

This time between exposure and when a laboratory test can detect the infectious agent is called the window period.

Note: The window period differs from the incubation period, which is the time from exposure to the development of symptoms.

Window periods vary for different STDs and also for the laboratory test that is being used. We screen for chlamydia, gonorrhea, and trichomoniasis using nucleic acid amplification tests. The window period for these STDs is predicted to be around 5 days, but may be up to two weeks.

Our hepatitis B test detects the hepatitis B surface antigen (HBsAg) and antibodies to the hepatitis B core (anti-HBc), which can take 30 to 60 days to become detectable.

Antibodies to hepatitis C may be detected with our test as early as two weeks post-exposure, but are generally not detected until 8-11 weeks post-exposure, and can be longer in individuals that lack an adequate immune response.

We use a 4th generation test for HIV that can detect an HIV infection within 18 – 45 days, or sometimes as early as two weeks post-exposure. Individuals who have been potentially exposed to HIV should be tested immediately, and then tested again at six weeks, three months, and six months. In addition, if an individual is concerned about being exposed to HIV in the last 72 hours, they should be referred to a health care provider immediately for post-exposure prophylaxis (PEP) evaluation.

Syphilis can usually be detected with our laboratory assays around one month post-exposure but may take up to three months.

Women's Health

All about follicle-stimulating hormone (FSH)

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What is follicle-stimulating hormone?
Follicle-stimulating hormone (FSH) is a hormone produced in the pituitary gland in both females and males. It helps regulate development, growth, pubertal maturation, and reproductive processes (1).

What are the roles of follicle-stimulating hormone?
FSH plays important roles in both females and males (2):

  • In females, FSH stimulates ovarian follicular growth and production of estrogen and initiates the release of an egg at ovulation.
  • In males, FSH signals for the Sertoli cells of the testes to produce sperm (spermatogenesis).

What controls follicle-stimulating hormone levels in females?
Gonadotrophin-releasing hormone (GnRH) released from the hypothalamus (region of the brain) stimulates the synthesis and release of FSH from the pituitary along with another important hormone called luteinizing hormone (LH). FSH and LH travel through the blood to act on the ovaries (3).

The FSH stimulation of ovarian growth results in increased estrogen levels, which is detected by the hypothalamus and results in less GnRH release; hence less stimulation of FSH synthesis. However, when levels of estrogen reach a “tipping point”, it stimulates a surge in FSH and LH, which is what causes the release of an egg (ovulation). After ovulation, the ruptured follicle forms a corpus luteum that produces progesterone, which inhibits the release of any more FSH. During a normal menstrual cycle, this corpus luteum then breaks down, progesterone levels decrease again, and FSH starts to slowly increase once again (3).

How is follicle-stimulating hormone controlled in males?
In males, a similar negative feedback system occurs. FSH stimulates the production of testosterone in the testes, which is then detected by the hypothalamus. As testosterone levels increase, less GnRH is released and consequently, less FSH is synthesized and released. As testosterone levels fall, more GnRH is released to stimulate FSH synthesis to then act on the testes to initiate testosterone production (3).

What happens in females with low estrogen?
Low estrogen in females, can occur in primary ovarian failure, which is common in females with Turner syndrome. This low estrogen means there is no feedback loop to control FSH levels, and FSH can be significantly elevated (3).

There is of course also a perfectly natural estrogen decline in females too. As females age, their quantity and quality of eggs decrease. This means that the normal FSH stimulation of the ovaries doesn’t result in the same increases in estrogen that were occurring at a younger age. This is why FSH levels naturally rise around the menopausal period and remain higher during postmenopause (3).

Are FSH levels linked to male infertility?
Yes, FSH is required for proper sperm production. If FSH levels are too low, normal puberty and sperm production does not occur. In addition, elevated FSH levels are also a sign of infertility, as raised FSH is a sign of testicular failure, as there is not enough testosterone for the normal feedback control of FSH levels. This condition occurs in conditions such as Klinefelter’s syndrome in males (3).

How do FSH levels predict ovarian reserve?
Ovarian reserve refers to the quality and quantity of a woman’s eggs. Different tests are available to predict a women’s ovarian reserve, one of which is the day 3 FSH test. FSH levels fluctuate throughout the menstrual cycle with levels gradually increasing in the first half of the cycle until reaching a peak at ovulation before decreasing again. This is why measuring the basal FSH levels at day 3 (the third day of your period) is important to gain the most benefit from an FSH ovarian reserve test.

An FSH level of <10 mIU/mL at day 3 is considered normal for ovarian reserve testing. Higher basal FSH levels are indicative of a reduced ovarian response and lower ovarian reserve. However, a single elevated FSH reading may not be sufficient, so it is often recommended to also measure day 3 FSH levels in one or more subsequent cycles too (4).

References
1. Ulloa-Aguirre A, Reiter E, & Crépieux P. (2018). FSH Receptor Signaling: Complexity of Interactions and Signal Diversity. Endocrinol, 159 (8), 3020-3035.
2. Knudtson J. (2019) Female Reproductive Endocrinology. Merck Manual Professional Version.
3. Follicle-stimulating hormone. You and your hormones, an education resource from the Society for Endocrinology. (Reviewed Feb 2018).
4. Roudebush WE, Kivens WJ, Mattke JM. (2008) Biomarkers of Ovarian Reserve. Biomark Insights. 3, 259-268.