Crunching the numbers - How does your pathology stack up?

We all know that a trip to the doctor often results in getting some kind of testing done. How often do you carry out the test and wait for a couple of days only to be told ‘the tests are all normal’? That’s great, but what about your symptoms? You know, the ones that led you to the doctor in the first place.

To understand why this happens and to make the most of your pathology results, you need to understand where, what and why of pathology – and here’s a tip, the reasons are different for naturopaths.

Let’s begin with where – blood, urine, saliva, stool. It’s a really important place to start because you wouldn’t test your saliva if you’re trying to identify a gut bug, at least not to begin with. To know where to test, you need to understand what information the results are going to provide. Let’s take blood as its probably the most common place to test and most of us have had a blood test done. Blood contains red blood cells, white blood cells and plasma. It’s also where nutrients like glucose and fats as well as minerals such as iron and calcium are transported to our organs and tissues. It receives these from our gut and transports them to our liver and also carries waste to our kidneys for excretion, so it’s a good place to assess how well these organs are functioning. Hormones such as oestrogen, testosterone and cortisol are also transported in our blood. It’s like a super highway! It does have limitations though, and part of this involves the why I mentioned earlier – blood contains all the things I mentioned above in various states but it’s not the best place to look if you’re trying to assess things like sex hormones because the results reflect total hormone production and most of this is inactive because it is bound to a protein carrier. Hormones such as oestrogen and progesterone also fluctuate throughout the month and so results are random without knowing which stage of the cycle is being tested. Some of the minerals and vitamins routinely measured are found in blood but plasma does not provide an accurate reflection. Magnesium and zinc, for instance, are found inside red blood cells and so testing plasma doesn’t reflect actual levels inside the cell.

Urine tests are also common and you have probably handed over the little container in a brown bag to your doctor at some point. It can also provide important information about your kidney function and is probably most well known for diagnosis of urinary tract infections or UTI’s. Urine can provide so much more though, it can flag high oxidative stress when there is increased excretion of calcium as well as how your body is metabolising hormones such as oestrogen, and whether you have a tendency towards forms that are less beneficial. If you were to use urine as a measurement of your total hormone production though, it would not be accurate.

Salivary tests are less commonly ordered by doctors and more the domain of naturopaths and other natural medicine practitioners. They really come into their own with hormones such as cortisol and sex hormones like oestrogen, because they reflect the level of active hormone available at cellular level. Sometimes this is measured at different times during the day, such as with cortisol, to provide better information about daily fluctuations. This can really help if someone experiences chronic, low energy in the morning or later in the afternoon. It can also provide more information about reproductive function and flag further areas for investigation.

So, as you can see; it’s really important to identify why you’re doing the test. If you want to find out gross amount of oestrogen being produced, blood is best. This will provide information about how well your ovaries are functioning, but It doesn’t tell you if it’s being converted to active hormone or if your body is efficiently metabolising and excreting it safely.

Often people experiencing long term fatigue or issues with weight gain come into clinic with a handful of ‘normal’ blood test results. All the markers are within range and the doctor has told them they are ‘just tired’. To understand how this can be the case, there needs to be an explanation about how the pathology reference ranges are established. Many of them are developed from a population distribution across the pathology company, meaning people who are having their blood tested. If you think about that, it’s probably not a population experiencing optimal health. An average is established with 2 standard deviations either side becoming the reference range for ‘normal’. If your results sit anywhere inside this range, you are considered normal. The problem with this is that if your result is at the very bottom of the range your body is far from functioning at optimal health and the same can be said for the top of the range. Some markers have limits beyond which they are considered out of range. Take active B12, for instance, normal levels are considered >30. Unfortunately, macrocytic anaemia is exhibited when levels fall below 30 and therefore using such a crude measurement is not really supporting optimal health for such an important nutrient.

Iron is another marker where there is a very large reference range and often younger females fall at the very low end of ‘normal’. In fact, often clients will come in with iron studies indicating adequate iron and very low iron stores. These are actually only 2 of the markers provided to assess iron and not the most accurate ones to use. Serum iron is really only an indication of recent dietary intake or supplementation and ferritin, stored iron, can be falsely increased during periods of inflammation as the body moves iron out of circulation. A more accurate way to assess a person’s iron status is with transferrin saturation and transferrin (iron transport protein). You can think about this as measuring the number of taxis available to transport iron around your body as well as the number of seats in the taxi. Iron deficiency is reflected in lots of taxis turning up but not enough iron on the seats.

The last point I’m going to mention here is that various factors can interfere with the accuracy of your results, the first being not fasting.

This is a contentious issue with many doctors advising it’s not necessary. While fasting may not alter the doctor's diagnosis, it will skew the results of your tests, particularly those relating to your metabolism such as glucose and cholesterol as well as minerals like iron. The other important behavioural factor to consider is exercise as it can alter some of your kidney function markers including creatinine. At the end of the day, isn't it best to get the most accurate results possible about your health? For the best results I recommend you fast overnight and get your test done early the next morning. Make sure you're well hydrated and avoid high intensity exercise for 24 hours in the lead up to your test.

Finally, as I mentioned earlier in this piece, pathology results provide different information depending on who is reading them.

As a naturopath, I specialise in assessing the function of your body and treating areas that require support with nutritional and herbal medicine. Your doctor uses them to diagnose or rule out specific disease states, an important skill, but it doesn’t help you when all your results sit within the reference range.

The most important part of the consultation is still what you tell me about your current health as well as how your body is functioning. Your pathology results help to put the picture together, but they are always used in conjunction with taking your case, they are not the whole story.

If you’d like more information about pathology testing or you’d like to book a consultation head over to the booking page to make a time.