I can completely understand your disappointment at being told to cut back on sports, being an avid sports person myself.
I shall attempt to break down and explain the situation for you:
1. The evidence about whether IgA nephropathy patients should completely avoid strenuous exercise is equivocal, to my knowledge. Data has shown that even though significantly increased levels of proteinuria are noted after intense exercise (maximal treadmill Bruce test), this lasts for less than 120 minutes. The study concludes that there is no need to reduce acute physical activity in patients with IgA nephropathy, but clearly a triathlon can be more strenuous.
2. IgA nephropathy is a disease with highly variable rates of progression, with no reliable way of predicting how the disease will progress in any one individual – some people will inevitably progress to kidney failure and require dialysis/transplantation, while others will be completely unaware that they have the condition, and their kidneys will continue to work normally in the long term.
3. Consequently, many doctors will advise patients to just “get on with life”. One patient has even competed for Team GB at the Olympics a few years after diagnosis! It is likely that before this incident, your nephrologist did not want to let IgA nephropathy define your entire life, especially knowing how how much sports and exercise means to you. Thus, he did not want to give you any hard limits for exercise, taking into consideration that exercise does have many benefits.
4. However, in this instance as there has been a precedent for your kidneys being unable to cope with one of your recent triathlon events, it’s a clear signal that you are pushing them too hard.
5. Your kidney’s primary function is to clear waste products, and maintain a normal blood pressure and fluid level. In triathlon and other endurance sports, it is not uncommon, even for healthy people, to see an increase in creatinine levels (a break down of waste products generated by exercise). This is further compounded by dehydration. In a normal person, his kidneys can generally cope with this additional stress.
6. In your case, your kidney has to be pushed doubly hard to cope with the extra stress, due to IgA nephropathy. The worst thing that could happen is that your kidney is tipped into acute kidney failure by the stress of the triathlon, and you end up on short/long-term dialysis. It is your nephrologist’s main goal to prevent kidney failure from happening, hence the warning to not do anymore endurance sports.
7. This is probably not the second opinion that you are hoping for – I’d strongly encourage you to have a proper discussion with him over your considerations, which would help you and him to establish parameters as to the limits of your exercise.
8. I’d also highly recommend consulting a Sport Medicine specialist, who is more attuned with the physical requirements and nature of various sports. Sport Medicine doctors are “exercise specialists”, and often look after endurance athletes such as yourself. Conceivably, both your Sport Medicine doctor and Nephrologist can work together to come up with an appropriate exercise programme for yourself.
Cheers
