Luteinising Hormone (LH)

Why take a Luteinising hormone blood test?

As LH plays an important role in the female menstrual cycle, an LH blood test gives a good insight into how the reproductive system is working. In females, the amount of LH circulating in the blood changes with age and throughout the menstrual cycle. For example, increases with reduced ovarian responsiveness approaching menopause. On the other hand, reduced LH levels can indicate an issue at the level of the control hypothalamic-pituitary axis. Measuring LH can give insights into why a woman maybe finding it hard to conceive.

In men, on the other hand, an LH blood test can help to identify testicular failure or if there is an issue with the control hypothalamic-pituitary axis.

You can test your LH levels along with other key fertility hormones by purchasing a simple at-home finger prick test kit which is then analysed at an accredited lab. Forth offers a number of blood tests which include LH such as Female Fertility, Male Hormones, Perimenopause & Menopause Health.

What function does Luteinising Hormone have in the body?

LH has vital roles in regulating the function of the male testes and female ovaries. The production and secretion of LH is a complex system which involves a variety of hormones produced by the hypothalamus and the sex organs.

Follicle stimulating hormone (FSH) and LH both work to stimulate the maturation of ovarian follicles and the release of an egg (ovulation).[2] LH has different roles in both halves of the female menstrual cycle. In the first two weeks of the cycle, LH stimulates the ovarian follicles to produce the hormone, oestradiol. Around the 14th day of the cycle, LH levels surge causing the ovarian follicle to rupture and release an egg from the ovary. For the remainder of the cycle, the remaining structure of the ovarian follicle forms a corpus luteum. LH stimulates the corpus luteum to produce the hormone, progesterone which is needed to sustain the early stages of pregnancy if the egg is fertilised.[3] If fertilisation doesn’t occur, the levels of FSH and LH fall and menstruation occurs, once this is over, a new cycle begins.

How do changes in Luteinising hormone affect health and wellbeing?

Because high levels of LH are associated with reduced responsiveness in the ovaries or testes, the effects can interfere with your everyday life, particularly as it may hinder your chances of having a baby. Increased levels of LH are associated with primary ovarian failure or testicular failure. Infertility is responsible for many psychological and social issues for both couples and individuals. As a result, failure to conceive has been associated with reduced sexual intimacy, depression and stress. [4]

In women, LH levels rise naturally around the time of the menopause, highlighting the reduced function of the ovaries as well as the reduction in oestrogen and progesterone production. The menopause can negatively affect wellbeing because of both the psychological and physical symptoms during the transition.[5]

If you are worried about your hormone levels or just want to check where you fall on the range, you can test your LH level with a simple at-home blood test.

What can cause Luteinising hormone to change?

A decreased sex steroid production can contribute to changing LH levels. For example, increased LH may be because of premature ovarian failure. Polycystic ovary syndrome, a condition where the body produces too much testosterone because of an imbalance between FSH and LH levels, is associated with increased LH levels.[6]

There are some genetic conditions which can cause an increase in luteinising hormone such as Turner syndrome and Klinefelter’s syndrome. The latter affects only males causing the testes to be small and as a result they do not release enough testosterone to produce sperm. Whereas, Turner syndrome only affects females and causes impaired ovarian function. As a result, LH levels increase to try to stimulate ovarian function.

A common reason for increased levels of LH and FSH in females is the menopause. FSH and LH are released to stimulate ovulation through the maturation of ovarian follicles. However, during the menopause, the ovaries stop working and no longer produce follicles. Usually, once a follicle matures and releases an egg, a structure called the corpus luteum forms which produces progesterone and suppresses the release of FSH and LH. However, because there are no follicles and subsequently no corpus luteum, levels of FSH and LH continue to rise.[7]

What are the most common symptoms?

The menopause causes differing levels of hormones in the system, which are responsible for various side effects, including:

• Hot flushes
• Mood changes
• Night Sweats
• Difficulty sleeping
• Headaches
• Stiff joints
• Urinary tract infections (UTIs)[8]

Primary ovarian failure can present with similar symptoms to the menopause. It is most commonly associated with:

• Periods stopping
• Irregular periods
• Hot flushes[9]

The symptoms of polycystic ovary syndrome usually become apparent in your late teens or early 20s. Some of the common symptoms include:

• Irregular or no periods
• Excessive hair growth
• Weight gain
• Thinning hair and/or hair loss
• Oily skin and acne
• Difficulty getting pregnant[10]

What Other Biomarkers Should I Test Alongside LDL?

As well as measuring total cholesterol, HDL, HDL ratio, and triglycerides alongside LDL, we also recommend:

• hs-CRP. This biomarker is a good indicator of low-grade inflammation in the body. It is also a good biomarker for heart health because it is released by smooth muscle cells in atherosclerotic arteries, the type where LDL-cholesterol has been deposited[13].

• Thyroid stimulating hormone (TSH) and Thyroxine. These biomarkers can give you an insight into your thyroid function, a small butterfly-shaped gland in the neck responsible for regulating metabolism. People with an underactive thyroid, hypothyroidism, often have increased LDL cholesterol levels, as the body is unable to clear the bad cholesterol appropriately. So, testing your thyroid health can indicate if high cholesterol is being caused by thyroid dysfunction.

• HbA1c. A HbA1c test provides an average glucose reading over a three-month period and is a good indicator of pre-diabetes. Type 2 diabetes increases the risk of high cholesterol levels. A HbA1c test may help to identify if diabetes is a contributing factor to high LDL levels.

How to keep Luteinising hormone in the healthy range

Making improvements to your lifestyle can help to reduce the symptoms associated with increased LH levels or may help with your fertility. A key factor in reproductive issues is obesity. Therefore, it is important to stay within a healthy weight range.

When menstruating, it is essential women keep their iron levels adequate to deal with the blood loss.  Foods which are good sources of iron include:

• green leafy vegetables
• red meat
• liver

You should aim to eat a healthy, balanced diet which incorporates essential fatty acids to help normalise hormone levels. Some research has shown that including omega-3 fatty acids in the diet can reduce hormone levels such as FSH which may prolong the reproductive lifespan.[11] Equally, other research has shown that some dietary fats can improve fertility.[12]

Exercise is also important. Controlled weight loss in overweight individuals has been shown to help restore reproductive function. Exercise is also great for psychological issues too, like depression and mood changes which have been linked to the menopause.