Initially described in the mid-nineteenth century, endometriosis is an inflammatory, estrogen-dependent condition in which endometrial tissue grows outside the uterus, and is often associated with high levels of pelvic pain and fertility challenges. It’s estimated that 10% of women suffer from endometriosis, mostly between ages 25 and 35. Painkillers and hormonal contraceptives are typically used in an effort to manage the pain, and surgery as well, though its benefit is often temporary. But in a recent collaborative study, a potential new target for endometriosis treatment may have been found. 

A new genetic marker identified for endometriosis

After noticing that endometriosis can run in families, lead researchers from the University of Oxford, Bayer AG Pharmaceuticals, Baylor College of Medicine and the University of Wisconsin compared the complete set of genes from 32 families with at least three women who had endometriosis, and 105 women without endometriosis used as controls. They also consulted another genetic dataset of more than 3,000 endometriosis cases and 2,300 controls, in addition to the genomes of 849 rhesus monkeys, who can suffer from endometriosis and whose genetic makeup is similar to humans’.

The researchers found that DNA variations in a gene-encoding neuropeptide receptor occurs more often in people with endometriosis than in those who don’t have the condition, highlighting a potential genetic variant that may predispose certain people to the disease.

Previous research has shown that a person’s chance of inheriting endometriosis is about 50%.

The neuropeptide receptor identified is involved in the transmission of nerve signals and in inflammation—and can be found in certain regions of the brain affecting anxiety and behavior, possibly playing a role in how we perceive pain and in the anxiety that can accompany endometriosis. This discovery will hopefully help researchers find a drug that can be used to stop the activity of the protein neuropeptide. The key question? To determine if doing so reduces endometriosis symptoms without shutting down your period, offering a new option for treatment.

Causes of endometriosis

No one knows the exact cause of endometriosis, but two new studies have emerged indicating changes to the circadian rhythm could be a factor, and retrograde menstruation has been posited as another potential cause, too.

Circadian rhythm disruption linked to endometriosis onset

Circadian rhythms are the physical, mental and behavioral changes you experience that follow a 24-hour cycle and respond primarily to light and dark, serving to maintain balance in several of your bodily functions, like your sleep-wake cycle, body temperature, heart rate and hormone secretion. Researchers from the University of Rome, Italy, have found that disrupting your circadian rhythm can cause irregular periods by reducing the level of sex hormones you produce. This is important because of how it relates to another new, small study, in which researchers found that working the night shift is linked to irregular periods and an increased risk of developing endometriosis (and ovarian tumors).

The research, from the University of Athens, Greece, found altered expression of core “clock” genes in endometrial (period) tissues of women working the night shift, indicating a disturbance of biological timing. Although this is only the beginning of exploring this relationship, the researchers hope that with further investigation, they might deliver on the promise of strategies to reset or modify your biological clock to help restore balance to the disruption of biological rhythms caused by night shifts and other prolonged nighttime events.

Retrograde menstruation also linked to endometriosis development

According to the Mayo Clinic, one possible explanation for how endometriosis develops is retrograde menstruation

This happens when your period blood, containing endometrial cells, flows back through your fallopian tubes and into your pelvic cavity instead of out of your body. Just like they do in your womb each month, endometrial-like cells outside of the uterus thicken, break down and bleed with each period.

But these cells have no way to exit your body, so they become trapped and irritate the surrounding tissues, which eventually creates scars and adhesions that can cause pelvic tissues and organs to stick to each other, causing pelvic pain

A not-so-fun fact: Endometrial tissue has been found in nearly every organ system of the female body.

Symptoms of endometriosis

How much pain you experience is influenced mostly by the location and depth of your endometriotic tissues. But the severity of your pain may not be a reliable indicator of the extent of your endometriosis. You could have a mild case with severe pain, or you could have an advanced case with little or no pain.

Common symptoms of endometriosis include:

  • Painful periods that are far worse than usual and increase over time
  • Lower back, abdominal and pelvic pain and cramping that may begin before and extend several days into your period
  • Pain during or after sex
  • Pain with bowel movements or urination during your period
  • Heavy menstrual periods or bleeding between periods
  • Infertility
  • Other factors like fatigue, diarrhea, constipation, bloating or nausea, especially during your period.

Approximately one-third to one-half of women with endometriosis have difficulty getting pregnant. Endometriosis is also associated with a 50% increase in the risk of ovarian cancer. It is the third leading cause of gynecologic hospitalizations in the United States, and a leading cause of hysterectomy.

Unfortunately, a diagnosis of endometriosis may be overlooked in primary care, with a typical delay of 6.7 years between onset of symptoms and a surgical diagnosis. Interestingly, associations between endometriosis and autoimmune diseases have been noted, suggesting that doctors need to be aware of their potential coexistence when either is diagnosed. Ultimately, a comprehensive and higher level of awareness is needed to ensure women with endo symptoms are diagnosed in a timely manner.


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