The Need for Weight Loss and Weight Gain in the ILD Clinic Save

Hi everyone. I'm Richard Conway from Dublin, Ireland, and I'm here to talk to you as part of the obesity campaign on RheumNow. I'm going to talk to you today about the rheumatology interstitial lung disease clinic. This is one of my special interests in rheumatology and I run a multidisciplinary clinic in this with one of my respiratory colleagues.

So why are we talking about this during obesity month? I mean, that's great to know that you do that, but I think it is a topic that is highly relevant in that clinic and a bit of a double-edged sword as well. Certainly in our patients we do see sometimes the need for weight loss and we do use agents such as GLP-1 analogues in these patients, and that comes in a variety of scenarios. We do have patients who are overweight and obese and this has impacts on their lungs and their exercise ability and tolerance, and they can have things like sleep apnea, obesity hypoventilation syndrome, and just be generally limited in the activity they can do because of the obesity rather than their lung function. So in these patients we do utilize our existing weight loss drugs if we feel that we need to achieve weight loss. Another factor in that is if we have somebody potentially going for a lung transplant — the lung transplant people won't even look at them unless their BMI is less than 30. So there can be a relatively urgent need to reduce somebody's weight sometimes.

So I think it is true we definitely do need weight loss in some of our patients, but what I really want to bring to your attention is the other side of the coin — the need to potentially increase people's weight. There is, like everything in medicine and in life, a happy medium, and if you're either side of that, things may not be as good. And this again ties into GLP-1 analogues and the perhaps overuse of these in people who are not overweight trying to achieve lower body weights by the use of these agents.

It is very well shown now that if you have ILD, being of low body weight or losing weight is not a good thing. Patients who are underweight have worse prognosis both in terms of mortality and also in terms of decline in lung function, compared to patients who are of normal body weight, and this also applies to patients who are losing weight. Patients who lose as little as 2 kilos in a year have worse outcomes, and this is such a strong effect that there is this obesity paradox where patients who are overweight and obese actually end up with better lung function and respiratory mortality outcomes than those who aren't.

This can be exacerbated by other factors, particularly antifibrotic drugs — nintedanib, pirfenidone, naloxolast — they all potentially can cause GI upset including anorexia and weight loss, and so there is another kind of added impact of that. As can our drugs — our immunosuppressant drugs — we often utilize mycophenolate mofetil in particular, which can be associated with weight loss.

So I think it is important that when we're all congratulating ourselves for weight loss, we don't forget the patients who need a bit of a push the other way and a bit of weight gain to improve their outcomes. I'm Richard Conway, and tune into RheumNow for all the action over this obesity campaign.