Why are you highlighting this finding among the many in the study?
Because I thought that was a particularly interesting one with potential serious implications.
Why do you think there are serious implications of this finding as compared to other findings such as increased BMI or decreased VO2 output? What are the implications you are worried about?
The fact that covid has long term impact on testosterone production could mean that it impacts reproductive function, and it should be obvious why that’s a very serious problem.
Well, it’s not so simple. Testosterone operates within ranges. There’s a range we consider healthy when we’re considering the typical serum testosterone level. This biomarker has a rather large range (one which I believe needs to be refined, but for the most part is adequate). This study noted that there was a decrease in the amount, but not a shift in range. Most individuals are not at the extreme edges of this range, and in fact falling in or out of the range is not a marker of reproductive function.
In this same study they looked at other fertility markers such as FSH and LH (much more important for sperm function) as well as motility - these three are much better markers of fertility than testosterone is. There was no significant change in any of these, except as noted by the authors a short term (<6mo.) decrease in motility that seemed to disappear with time.
The reason I mention all this is that I believe there is good reason for the authors to not focus on these findings. In fact, they recognize their existence and call it out in the results and discussion section. There is a reason it was excluded from the main abstract and the conclusion - these findings aren’t particularly notable if you understand how we measure fertility and sex hormone levels considered normal. On the other hand, we have ample evidence that anything increasing BMI and decreasing VO2 max are unhealthy - while both of these are often binned for simplicity purposes, we happen to know that any absolute shift affects health, whereas this is not the case with testosterone.
Thanks, that’s actually a really good analysis. Sounds like I misunderstood the significance of the particular result in the study.
It appears to explicitly conclude that there is no long term impact on fertility. The main long term impacts of concern are metabolic disorders (eg chronic fatigue like), and cardiopulmonary complications.
From the results abstract:
There were no significant differences in psychosocial questionnaire scores, ophthalmological outcomes, sperm quality or motility between controls and those infected more than 6 months previously with SARS-CoV-2.
From the conclusions abstract:
However, the constellation of higher body mass index, dyslipidemia and lower physical endurance 6 months post COVID-19 is suggestive of a higher risk of developing metabolic disorders and possible cardiovascular complications.
That doesn’t actually say that fertility isn’t impacted, just that sperm quality doesn’t appear to be significantly effected. To be fair, it’s the main factor in fertility, but there are also questions of libido, sperm quantity, and so on that are regulated by testosterone.