What’s Up Doc?

OK so regular readers may have noticed it’s been quiet around here for a while, so firstly sorry about that, I haven’t  disappeared! You may remember way back in March I said that I’ve been accepted onto a PhD studying endometriosis, well now I have officially started so it’s probably a good time to give you all an update on what’s happening.

I’m going to be researching the different roles of an enzyme and a signalling molecule in endometriosis, the role they play and maybe even new ways to approach treatment of endo.

So let’s get down to specifics, the enzyme I’m going to be looking at is named, rather unpoetically, AKR1C3. This is one of the enzymes involved in producing estrogen in the body. Specifically this enzyme converts a weak estrogen, called estrone, to a more potent estrogen called estradiol. In addition this enzyme is also involved in the breakdown of progesterone. Recent studies have shown that the level of AKR1C3 is higher in endometriotic lesions than in the normal endometrium. As many of you will know, estrogen is very important to the survival of endometriosis, so any enzyme involved in the production of estrogen will play a significant role in the disease. So part of my research is going to be looking at whether AKR1C3 is important for the survival of endometriosis and whether inhibiting this enzyme with drug treatment would help to regress the disease.

The signalling molecule I’m looking at is called prostaglandin E2 (or PGE2 for short). This acts like a messenger in your cells, telling them to perform certain actions.  Previous research has shown that PGE2 is very important for many aspects of endometriosis. For example, PGE2 has been implicated in controlling pain, inflammation, hormone production, and altering the function of the immune system, all processes that are altered in some way in endometriosis. Therefore, I’ll also be looking at how inhibiting or attenuating the production of PGE2 may be beneficial to women with endometriosis.

Most drugs for the treatment of endometriosis are hormone based which is why women can get so many side effects from them, some of which can be very unpleasant. However my research will focus on non-hormonal ways of treating endometriosis, which may one day lead to drug treatments with fewer side effects (although that day could be a long way off).

So that’s what will be keeping me busy for the next four years and hopefully the foreseeable future after that. I’ll keep you all updated on how things progress and also get back to posting regular updates on what other endo research is going on the world.

June Roundup in July

Unfortunately I’ve been a bit behind this month, but I always keep my eye on what going on in the world of endo research.

So with that in mind let’s have a look at what’s been going on

Firstly, a study into surgical treatment for endometriosis of the bladder. This form of the disease isn’t particularly common, but it does add another layer of misery to the sufferer so knowing the optimal treatment is important. This study took sixty nine patients with bladder endometriosis and recorded what surgical procedures they had and how this affected their symptoms afterward. After follow up period of between 4 and 92 months, 92.7% of the women either had no symptoms, or a reduction in symptoms. What this study highlighted was the need for surgeons with specialist training in different types of endo (i.e. bladder, bowel etc) as they may require a different surgical approach.

Speaking of bladder and bowel surgery, up next is a report on the use of robotic assisted surgery for the treatment of just those conditions. This study included 19 cases of bowel surgery and 5 cases of bladder surgery, all of which occurred without complications. Now, robot-assisted surgery is a hot topic at the moment because it is a new and growing technique. But we are also stuck in a catch-22 situation with robotic surgery. You see, people are reluctant to support robotic surgery until there are more studies into its effectiveness, but you can’t have more studies until you support wider use of robotic surgery. Either way it looks like robotic surgery is here to stay and it is a safe and effective tool with a skilled surgeon at the helm.

Speaking of robot-assisted surgery, there are many different types of surgical procedure the robot can be utilised for in the treatment of endometriosis. In severe cases of the disease, doctors may opt for hysterectomy and our next study examines the safety and effectiveness of using the robot for such a procedure. In summary this study looked at 43 cases of women with severe endo (19 with stage III and 24 with stage IV). The results of which were -  operating times averaged at 145 minutes (with a variation of 67-325 mins); 41 out of 43 women only had a 1day hospital stay, with one woman needing to stay for 5days due to needing a laparotomy and one woman staying 3days because of a bowel obstruction that cleared. There were no reported complications during surgery though after surgery one woman had to be readmitted with a vaginal cuff abscess which was treated with antibiotics and drained. The authors of this study make some good points about the pros and cons of robotic surgery, namely – “The robotic platform improves the depth of perception and facilitates the resection of deep infiltrating lesions. In addition, the robotic system improves dexterity, filters the surgeon’s tremor, and improves intuitive movements”; however they also say “Robotic surgery has several disadvantages compared with traditional laparotomy. These include increased cost; the lack of tactile feedback to the surgeon [i.e the ‘feel’ of the toughness or resistance of tissues]; the presence of bulky robotic arms, as well as long and thick cords; the inability to move the surgical table once the robot arms are attached; and a limited range of motion with respect to operating in different quadrants in the same case”.

Sticking with a surgical theme is a study from the US looking at the effectiveness of surgical excision of endometriosis across five different medical centre’s. All the women included in this study were suffering endometriosis associated pain, of which 90 had operative information. Once these women were operated on, 65 were confirmed to have endometriosis and 25 had no confirmation of endo. Interestingly, of all the patients who had endometriosis confirmed at these centres, 84.6% had previously been given hormonal therapy or ablation (burning away of endo) surgery, indicating that these treatments are not very effective at reducing endo pain symptoms.  After their surgeries, all of the women in the different centres noticed a significant reduction in all but bowel symptoms (bowel symptoms were reduced though, but the amount of reduction wasn’t considered statistically significant). Interestingly the authors of this study found there was no significant difference in the pain and quality of life scores between women who were given hormonal therapy after excision surgery and those who weren’t. However, the post-operative information was collected 6 months after surgery, so long term effectiveness couldn’t be gauged. In any case this study shows that excision of endometriosis is still the preferred method of treatment for the disease where possible.

It is rapidly becoming apparent that endometriosis is a disease that begins to present itself in adolescence. This is extremely important to know because it means general practitioners need to be able to spot the signs of endometriosis in young girls and make sure they get treatment as soon as possible. But what are the major signs of endo? A new study looking at diagnosis of endo in adolescent girls found that 75% of girls with chronic pelvic pain (which is any pain in the pelvic area that lasts more than six months) that did not respond to medical treatment and 70% of girls with dysmenorrhoea (excessively painful/heavy periods) were later diagnosed with endometriosis. All doctors need to be aware of these ‘red flags’ and act on them quickly.

Next up is copper, which is great for electrical wiring and making cheap jewellery, but also may be important for endometriosis. Our bodies need miniscule amount of copper to function properly, but as with so very many things in this world, there is fine balance to be kept. In your body copper can float around by itself, but is also carried around by a protein called ceruplasmin and this latest study looked at the levels of both of these in the blood of women with advanced stage endometriosis compared to disease free women. What they found was that levels of copper and ceruplasmin were much higher in the blood of women with endo, but what does this mean? That’s a tricky question to answer because we’re still not sure what role copper might play in endo. Excess levels of copper are known to be a marker for oxidative stress and oxidative stress certainly seems to be elevated in women with endo. Oxidative stress, as the name suggests, is not something you want happening to excess in your body; prolonged exposure to oxidative stress can make you run down and generally feel like crap, in addition localised oxidative stress can actually promote the survival of endometriosis. Further study is needed to find out if copper is a cause or effect of oxidative stress, but as an interesting aside, elevated levels of copper in the blood could possibly be used as an indicator of advanced stage endometriosis.

Finally is a study from Denmark about the risk of endometriosis and fertility problems in the daughters of women with the disease. This was quite a large study, including information from 12,389 women with endometriosis and 52,371 without. Overall daughters of women with endometriosis were just over two times more likely to be diagnosed with endo. However, daughters of women with endo had no difference in the rate of deliveries, risk of miscarriage and ectopic pregnancy compared to the daughters of women without endo.  

The Size of the Problem

There has been some buzz lately about a new study into endometriosis - it’s been in news reports on a number of blogs and websites (such as this one and this one), you may have already heard about it. From the headlines in the news article you’ve probably gathered this new study is about the relationship between body size and endometriosis, specifically leaner women were found to be more at risk.

So, this study has found that thinner women are more likely to have endo; does this mean, in order to decrease your endo risk, you should all start reaching for the cakes and pies, forgo the use of even the most rudimental cutlery and just shovel food in your mouths with your hands like a mad combine harvester ploughing through a buffet?

Well no, definitely don’t do that. Most of the news outlets have done a pretty decent job of explaining the findings, but this month I’ll be looking over the original study and finding out exactly what was done, what was discovered and what we can learn from it.

Before we start though I know this study is controversial to some, so I will say I'm not going to comment on the worthiness of this study. I'm only going to give you an explanation of the findings and my interpretation thereof, then let you make up your own mind.

To start with it’s always a good idea to see if any other research like this has been done in the past and it turns out it has, and I’ve written about it before, way back in the dark murky past of 2010. So the finding that women with a low BMI are more likely to have endo isn’t a particularly new discovery. 

What’s different about this latest study? For a start it’s bigger, much bigger. The same US research group conducted a similar study in 2010 with 1,817 women with endo, this latest study includes 5,504 women with endo and the more people you have in your study, the more accurate your results. So where did they get all these women from? Well in the US since 1989, 116,430 female nurses from 14 different states have been filling in questionnaires about their health every 2 years. All this information together forms the Nurses’ Health Study II – a vast mine of information available to researchers looking into relationships between lifestyle and environment factors and the risk of all manner of illnesses.

This current study looked at all the questionnaires from 1989 to 2011, picked out the information from women who were diagnosed with endo and compared it to women who weren’t. The major factor being examined here was BMI, which is a ratio of height to weight. My BMI is around 20, which is classified as normal, but I’m a gangly leviathan, so someone who was a foot shorter than me but the same weight, would have a BMI of 28 and be classified as overweight (in my last post on this subject I air my grievances about BMI as a measure of body size).

BMI on its own isn’t a very reliable measure of body size, basically because a body builder and a fat guy could have the same BMI as it doesn’t take into account body shape. Fortunately BMI wasn’t the only factor these researchers were looking at; in order to get a better picture of body size they also took measurements of waist/hip ratio and waist circumference.

Anyway, enough of the methods, onto the results. The central finding of this study was that women with a higher BMI were less likely to be diagnosed with endometriosis – in fact morbidly obese women (i.e. with a BMI over 40) were 39% less likely to have a diagnosis of endometriosis than women with a BMI between 18.5 and 22.4.

What the researchers found was that there was an inverse correlation between endometriosis and BMI. What this means is that as BMI went up, endometriosis risk went down. Below is a graph from the paper which shows that relationship (the solid black line is the important one, don’t worry about the dashed lines).

Source:

http://humrep.oxfordjournals.org/content/early/2013/05/09/humrep.det120/F1.large.jpg 
(click to enlarge)

Interestingly this study found that this association was stronger in women who were also infertile, but there is an important point to take into consideration first. The average age of women at the time this information was collected was around the mid-thirties, so it is very likely they’ve been living with endo for a long time. BMI tends to increase with age and, more importantly, many women who have suffered endo long term take medications that cause weight gain. Therefore, wouldn’t it be better to look at the BMI of these women when they were younger? Yes, and that is exactly what the researchers did - they looked at the BMI of these women aged 18. Below is the graph of the result.

Source: http://humrep.oxfordjournals.org/content/early/2013/05/09/humrep.det120/F2.large.jpg
(click to enlarge)

As you can see it looks pretty much the same and, despite the fact that the result was slightly attenuated, morbidly obese women were still 25% less likely to be diagnosed with endo.

Now, one thing we must be careful of here is not to assume this means women with a higher BMI can’t get endometriosis, it just suggests they are less likely to have it when they are younger. For example, if we look at the results of this study, women with a BMI of around 21 had the ‘average’ rate of endo, which is 1 in 10. However women with a BMI of over 40 had a 39% reduction in their endo rate, which is equivalent to about 0.6 in 10. So, in women with a normal BMI, around 10 in 100 would be expected to have endo, however in women who are morbidly obese, 6 in 100 of them would be expected to have endo.

So what of the other body size factors being investigated? The results of this study showed that a larger waist circumference was also associated with a lower risk of endo, but only for infertile women and there was no association with height and endo. Waist-to-hip ratio was a harder result to call as a lot of women didn’t have that information recorded. Although the researchers found that women with the smallest waist-to-hip ratio had a 3 fold increased risk of endo, this was only based on data from eight women, so it’s probably best not to pay much attention to that result until it can be verified.

Now we know the results, the next big question is, why might this be the case? At first appearance it doesn’t make sense, fat cells can produce estrogen, so the more fat cells you have the higher levels of estrogen you have. Being as endometriosis is an estrogen dependant disorder, shouldn’t women with more fat (and therefore a higher BMI) be more susceptible to the disease? Similarly, being underweight as a child is associated with later menarche and less menses, yet women with endo are known to have, on average, and earlier menarche so that doesn’t seem to add up either.

There are several ideas as to why we are seeing these results. It is known that obese women are more likely to have Polycystic Ovarian Syndrome (PCOS) and some researchers think that PCOS may be ‘protective’ against endo due to a reduced number of menstrual cycles and higher levels of androgen hormones which could suppress endo lesions. Although without knowing which women had PCOS in this study we can’t tell if this is the case. The androgen link may be important though. Studies have suggested that androgen hormones are elevated in obese young girls and women regardless of them having PCOS. Therefore, a higher level of androgens in obese girls and women may suppress endo and explain why we see a lower risk of endo in the high BMI group.

The authors of this study also suggest there may be a diagnostic bias for obese and morbidly obese women. Surgeons may be less likely to want to perform a laparoscopy on these women as it is just more difficult, therefore they would be less likely to be confirmed with endo. However, the authors point out that if this were the case there wouldn’t be such a strong association between endo and BMI in infertile women compared to women with pain symptoms alone.

There are several other factors that can modify BMI, such as medications, lifestyle factors and co-morbid conditions and these all need to be considered when examining a relationship between endo and BMI, which as far as I can see, this present study did not take into account. Another consideration about this study is the population of women from which it was drawn. All the women from whom the information was taken were nurses employed in that profession for at most 20 years. As endometriosis presenting with severe symptoms would hinder a woman’s ability to maintain long-term employment (especially a physically demanded job, like nursing), then it is likely that women with severe endo symptoms were not proportionally represented in this study, which may skew the results to favour women with less severe forms of the disease, who in turn would be more physically active and hence, have a lower BMI.

Of course it could be that whatever makes a woman susceptible to endo also makes her more likely to have a lower BMI at a younger age. A growing body of evidence suggests that endometriosis is condition you are born with and is hereditary - so it may, or may not, be that whatever genetic/epigenetic factors result in a woman developing endo, also affect her metabolism or fat deposition resulting in her having a lower BMI before she started taking hormonal medication. Unfortunately there are still a lot of questions that need to be answered before we can make any definite conclusions here, but when we eventually answer those questions, we will have a better understanding of this paradoxical disease.

This is my interpretation of the current study, as ever though I encourage everyone to do their own research and draw their own conclusions, so below is a link to the study I have been talking about this month, which you can read and download, in full, for free.

http://humrep.oxfordjournals.org/content/early/2013/05/09/humrep.det120.full.pdf+html