So, you’ve read everything you can find about XLH at various reliable websites, but you want to know more. One option is to read what your health care providers are (or aren’t) reading about current research and the overall scientific understanding of XLH. But perhaps you don’t know where to start, so here’s a quick primer for you.
Fortunately, there’s a single site that compiles information on a huge number of medical journals, with summaries (abstracts) and links, sometimes to the full article, sometimes just to the summary. It’s called Pubmed, and anything you find there has at least presumptive reliability (although you’ll need to judge for yourself the authors’ expertise).
To get started reading journal articles on your own, follow the link above and if the boxes aren’t already pre-filled, put XLH (or TIO or FGF23 or a researcher’s name or whatever other term you’re interested in) into the search box. I also like to choose the filter for listing the most recent article first, since there’s been a startlingly large amount of research into XLH in the last three years, so it can be overwhelming to know where to start without organizing it by date.
When you start reading the articles, you may feel like the jargon is too overwhelming, and that you don’t understand any of it. That’s okay. It’s how I felt when I first read the Clinician’s Guide to X-Linked Hypophosphatemia (now out of date in some respects, but not a bad place to practice reading medical journals), and I got better with practice.
I don’t think it ever gets easy, exactly, but you can improve your comprehension over time. I still need to read an article more than once to get the most out of it. The first time is just to get the gist of it, ignoring any terms you don’t understand, and focusing on the big picture. On second (or third, fourth, etc.) reading, you can look up terms that you don’t understand. I usually just Google the terms, and that will generate a definition that’s adequate for most purposes without being too technical. At first, you may need to look up terms in the definition too to understand the first word, but with practice, you’ll find it gets easier.
It’s important to know your limitations too. I don’t understand organic chemistry, or statistical analysis, and I’m never going to (I’d have to go back to school to get a PhD on top of my JD, and that just ain’t happening), so any article that gets too deep into those topics, I have to accept that I won’t understand the details. The abstract (summary) and the conclusion are usually simpler though, and I focus on what I can understand, not what I’m missing.
Even though the journals in the Pubmed database are generally reliable, you still need to read with a critical mind. There will be disagreement among articles, and information will become outdated and may or may not be supplanted with different, better information. To sort through conflicting information, you’ll want to consider the expertise of the article’s authors and editors. You’ll recognize some doctors in the list of authors, like Thomas Carpenter, Karl Insogna, Mike Econs, Erik Imel, Carolyn Macica, Suzanne Jan deBeur, and Agnes Linglart, all of whom are well-known for their work with XLH, so seeing their names on an article is a good indication of its reliability. (And apologies to the other experts out there whose names escaped me as I wrote this.)
Beyond recognizing the authors, pay attention to the focus of the journal where the article appears. Is it a big, general but prestigious journal like the New England Journal of Medicine? They’re very selective of what they publish, so anything in there is likely to be by top experts and very reliable. Or if it’s a journal like the one published by the Endocrine Society or ASBMR, both of which have many members with XLH expertise, the article is more likely to have been peer-reviewed by qualified experts in XLH. In contrast, since XLH affects so many different parts of the body, you may encounter articles in some specialized journals that are a bit more tangential to the disorder as a whole and therefore much less likely to have XLH experts as editors or on the peer review team, like those for dentists or surgeons. Those articles CAN have really useful information in them, but you may need to wade through some outdated information (like the persistent equating of XLH with rickets and ignoring adult symptoms), so it’s important to approach them with a critical mind and take the information that’s useful and ignore the problematic bits.
One other thing to watch for is articles written specifically for clinicians who ONLY work with children. Anything addressed to pediatricians is likely to use the old “rickets” nomenclature and to minimize or completely ignore the adult symptoms and sometimes the non-bone/teeth symptoms (i.e., muscle function and calcification issues). These articles may be very good with respect to pediatric bone issues, but keep in mind that there is a whole lot more to XLH than the pediatric bone issues, and ignore any implications that diagnosis and treatment end with adulthood.
And finally, if you search Pubmed for articles on FGF23 in general, as opposed to its manifestation in XLH specifically, you’ll find some interesting stuff, but you should be aware that it may not apply to XLH, so don’t panic if it sounds scary. A lot of FGF23 research is being done in the chronic kidney disease (CKD) community specifically, where FGF23 excess is a symptom rather than an underlying cause. In CKD patients, FGF23 excess is associated with poor outcomes, so understanding it is critical for better treatment of those patients, but no one really understands the correlation with poor outcomes yet. You can’t assume that just because the FGF23 causes a certain issue in CKD patients, it will also cause that issue in XLH patients. CKD has a number of poorly understood elements, and researchers are still trying to sort out how they all interact, and to date, as far as I can tell, there’s no way of knowing if the excessive FGF23 alone is causing an issue for CKD patients, or if it’s interacting with another element of the underlying disease. My guess (remember, not a doctor here) is that there’s more than one process going on, not the FGF23 acting on its own, so the effects in CKD patients are not necessarily the same in XLH patients.
I hope you’ll try reading some journal articles for yourself. If you do, and you hit a stumbling block or have questions about the article, I’d love to hear from you. If it’s something I do understand (or I can find someone to explain it to me), I’ll turn it into a future topic here, time and space permitting. You can send your question, with a link to the article, to Gin at GinJones.com.
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Please note that the author is a well-read patient, not a doctor, and is not offering medical or legal advice.
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