Correlation to Keto- AHI has skyrocketed

[robtheironguy]

I've been using my BiPap with no issues for 5+ years. I went on Keto in October for the month and then I went back on Jan 3rd. There seems to be a direct correlation to my body's reaction to low Carb and my Sleep Apnea. Zero Stimulants (Beer/Caffiene) as I have had recent trouble with Arrythmia, including an episode yesterday. I finally looked to the CPAP data for anything and the data was shocking. I'm posting both the trend of AHI (Keto for October and stopped Oct 26th) and started again Jan 3rd. Would appreciate any feedback as well as comments on my settings prior to keto of Jan 2nd.

Sorry for omissions to question, I brand new and need to address asap. First step is to get off Keto which hopefully addresses my issue.

           

[robtheironguy]

I just did further digging and I discovered the same issue when I did an extended fast for 13 days- my AHI ramped up over that time.

[Geer1]

Interesting there does appear to be some correlation.

By chance have you noticed changes while on keto like less nasal congestion, significant weight loss etc? If keto is doing something to physically open up airway then that could be causing this treatment emergent type central apnea (usually see this with new CPAP users). If that is the cause then what you might find is that you can continue keto (if desired) by lowering PS (could try 3 to see if it helps).

If there have been no obvious physical changes I am not sure what exactly the mechanism would be and not sure if lowering PS would help or not. Lowering PS does help if central apnea is caused by low CO2 levels.

If lowering PS doesn't help then probably best to discontinue keto and see if things return to normal in which case I would just try a low carb diet but avoid ketosis to see if that solves issue and continues to help with weight loss etc you are seeking.

Edit: I was researching and typing while you made the fasting post. I think this is caused by something physical that the extra weight or perhaps bloating or something is causing you to need higher pressure support but without it the high pressure support causes apnea. Try lowering PS (3 would be a good first step).

[DaveCar]

Thats a wild increase in CA's
I wonder if they would settle out over time ?

One of the guys at my work is right into that keto stuff, went on about so many details of body/chemical changes that I dont remember any of it.. but I guess a takeaway is that there are significant changes. It's interesting to see this affect on CAs.

[robtheironguy]

Although from a science standpoint it would be interesting to see if lowering the PS made a difference-but I am diving into Carbs. I don't need to go back to the ER for another Atrial Fibrillation.

I will lower the PS though. Yes after 2 weeks in on my program I am down 17lbs and similar data from the Fasting. Although the physical changes are minimal at the start. By 48 hours in I was down 5lbs but AHI went up to 22.

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Sorry, what is CAs?

[Crimson Nape]

The 5lbs is water weight.   Dehydration can have some strange effects on the body.  Keto or fasting, you should hydrate.  This will reduce hunger symptoms as well. Being on one of these diets and added hydration can cause your potassium level to drop. This will cause cramps, usually in the legs.

[robtheironguy]

I was/am drinking a ton of water exactly for that reason. Carbonated water really satiates my hunger to fast longer, which I combined with Keto (Intermittent Fasting)

[Geer1]

CAs are what you are having, central apnea. It is when your body takes a break from breathing (rather than apnea caused by obstruction).

Some central apnea are driven by CO2 levels. If CO2 drops too low it drops below what is called the apneic threshold and your spontaneous breathing pauses until CO2 rises again. Pressure support (PS) drives down CO2 levels and so can aggravate/cause central apnea, we see this a lot in new cpap users but this is the first time I have seen CA correlate with fasting and keto.

If you are up for it I think it would be really good for you to know if lowering the PS solves or improves this issue, it would also confirm if these CA are CO2 based or something else. Ideally you would be able to lower your PS (current 6.5 is on higher side) and I could see it as being part of the issue. It might be keeping your CO2 just above apneic threshold until things like fasting, keto etc push it over the edge. The change from lowering PS would be instant (noticeable tonight, if it is going to help), I imagine going off Keto will actually be a slower process.

If you want to test the PS theory set it as low as you are comfortable (I figure that will be around 3). You can adjust while wearing the mask to see what feels most comfortable.

[robtheironguy]

Great, I'm going to change that setting and try tonight. I am actively going off keto right now due to the number of nights I've going through with issues. Once I've given a few weeks past my Atrial Fib I will experiment with Intermittent fasting to see results. Maybe I can get back to a more rigid approach. I'd like to see normalized sleep first.

[Geer1]

On the note of dieting I know some people disagree but I personally think going full keto isn't necessary. I think low carb without ketosis gives many of its benefits and unlike keto it is actually sustainable longer term. Imo based on a evolutionary standpoint ketosis is kind of a backup system and not meant to be used as primary source of energy, what is grey to me is if going into it every once in a while is good (intermittent fasting or brief keto diets).

What isn't clear in your case is if it is some sort of weight, bloating or something else changing or if it is ketosis related. Will be watching this to see if you are able to figure it out.