AHI 5 = fine. AHI 1.5 = tired. Why?

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
User avatar
Steve of Cornubia
Posts: 73
Joined: Tue Mar 12, 2013 10:19 pm
Location: Brisbane, Australia

AHI 5 = fine. AHI 1.5 = tired. Why?

Post by Steve of Cornubia » Mon Jul 29, 2013 11:09 pm

I've been using CPAP since February and I think I've got the hang of it, more or less. However, I have had a suspicion for some time now that there is something funny going on. Now though, I have seen enough data to convince me it's real.

Whilst getting my AHI as low as possible seems like the right thing to do, there seems to be a 'sweet spot' for my AHI and it isn't the lowest number. That sweet spot seems to be between 4 and 6. Any higher and I'll be noticeably sleepier - no surprise there. However, and more surprisingly, whenever I get a value <2 I tend to be tired the next day.

Has anybody else seen this?

I haven't looked closely at the data, to pick out any correlation between the individual components of the AHI and my tiredness (OA, CA, Hypopnea) but I'm going to keep an eye of that, just out of interest, but I nevertheless wonder why I feel tired when my AHI is nice and low.

User avatar
kteague
Posts: 7768
Joined: Tue May 16, 2006 8:30 pm
Location: West and Midwest

Re: AHI 5 = fine. AHI 1.5 = tired. Why?

Post by kteague » Mon Jul 29, 2013 11:23 pm

Don't have an answer for that, but can throw out some things for you to consider. Have you looked at your hours of sleep as you make the comparison? Just thinking - less time spent asleep could account for lower AHI, but not enough sleep to feel rested. Is your sleep schedule consistent? Timing can make a difference if we are working with or against the ebb and flow of hormones related to sleep. Also, are some nights more restless or seem less sound than others? Not getting the right proportion of the different sleep stages can leave one feeling less than optimal too. Maybe keeping a chart for a while could help you see if there's a trend.

EDIT: Hey, just for the fun of it, maybe you could keep that journal with everything except the AHI, and include how you feel each day. At the end of whatever time frame you choose, go back and fill in the AHI data and see if it matches up with what you expect. I used to think I wanted to do that, then somewhere along the way forgot. Sure would love if someone did that little experiment and shared their results, even if it's not you.

_________________
Mask: TAP PAP Nasal Pillow CPAP Mask with Improved Stability Mouthpiece
Humidifier: S9™ Series H5i™ Heated Humidifier with Climate Control
Additional Comments: Bleep/DreamPort for full nights, Tap Pap for shorter sessions

User avatar
robysue
Posts: 7520
Joined: Sat Sep 18, 2010 2:30 pm
Location: Buffalo, NY
Contact:

Re: AHI 5 = fine. AHI 1.5 = tired. Why?

Post by robysue » Tue Jul 30, 2013 12:08 am

steve,

I've noticed something similar, although my sweet spot is lower than yours. In three years of PAPing I've noticed that I'm most likely to feel best when the AHI is around 1.5. To feel really well, however, my insomnia must be under control: I have to have slept for more than 5.5 hours, I have to remember no more than 2 short wakes, AND my sleep efficiency needs to be above 90%. (In other words, I have to have been asleep 90% of the time I was in bed with the mask on.)

The days where my AHI is below 1.0 are typically days where some part of the insomnia is not under control. It could be total sleep time. Or it could be number of wakes. Or it could just be sleep efficiency---one really long wake is enough to matter sometimes.

And sometimes the battle to reduce the AHI to below 1.0 involves costs that are just not worth it. For example, I could probably get that AHI to be consistently below 1.0 by running in straight BiPAP and increasing my pressures to either 8/6 or 9/6. But the cost? A lot more aerophagia. And aerophagia triggers wakes and wakes trigger aerophagia, so once the aerophagia cycle gets going, it also aggravates the insomnia. Doesn't take much aerophagia to make me have a miserable night and it doesn't take much pressure to trigger the aerophagia. But my current settings limit the time that I'm at 8/6 if I'm having a decent night apnea-wise: On nights where my AHI is around 1.5, the EPAP seldom gets above 5 and usually stays at 4 cm for almost the whole night. The IPAP will be at 8 for long periods due to flow limitations mostly, but there's usually enough time with IPAP = 7 to take the edge off the aerophagia. Hence I do better with not raising my pressure all the way up to 9/6 even though my first titration indicated I needed a pressure of 9 to keep the airway open.

I've concluded that it is much better to Feel good with an acceptable AHI than it is to Feel so-so with a near perfect AHI.

_________________
Machine: DreamStation BiPAP® Auto Machine
Mask: Swift™ FX Nasal Pillow CPAP Mask with Headgear
Additional Comments: PR System DreamStation and Humidifier. Max IPAP = 9, Min EPAP=4, Rise time setting = 3, minPS = 3, maxPS=5

Fizzled
Posts: 71
Joined: Thu Jul 04, 2013 11:23 pm

Re: AHI 5 = fine. AHI 1.5 = tired. Why?

Post by Fizzled » Tue Jul 30, 2013 12:40 am

Steve of Cornubia wrote:I've been using CPAP since February and I think I've got the hang of it, more or less. However, I have had a suspicion for some time now that there is something funny going on. Now though, I have seen enough data to convince me it's real.

Whilst getting my AHI as low as possible seems like the right thing to do, there seems to be a 'sweet spot' for my AHI and it isn't the lowest number. That sweet spot seems to be between 4 and 6. Any higher and I'll be noticeably sleepier - no surprise there. However, and more surprisingly, whenever I get a value <2 I tend to be tired the next day.

Has anybody else seen this?

I haven't looked closely at the data, to pick out any correlation between the individual components of the AHI and my tiredness (OA, CA, Hypopnea) but I'm going to keep an eye of that, just out of interest, but I nevertheless wonder why I feel tired when my AHI is nice and low.
I'm a CPAP novice, but my understanding is that REM causes more events than other stages of sleep.

Your body may be happier with more REM and related events than lower events with less REM.

ddk
Posts: 165
Joined: Mon Aug 27, 2012 4:11 am
Location: Australia

Re: AHI 5 = fine. AHI 1.5 = tired. Why?

Post by ddk » Tue Jul 30, 2013 2:37 am

I'm starting to think that AHI means a lot less than I've been led to believe by the doctors. I had an AHI of 4.67 last night and felt pretty ratty today, but it was made up of centrals and hypopneas, not just OA's. Whereas I had a 5.4 the night before that but it was mostly OA's and I felt OK.

_________________
Mask: Swift™ FX Nasal Pillow CPAP Mask with Headgear
Additional Comments: SleepyHead Mac User

User avatar
Steve of Cornubia
Posts: 73
Joined: Tue Mar 12, 2013 10:19 pm
Location: Brisbane, Australia

Re: AHI 5 = fine. AHI 1.5 = tired. Why?

Post by Steve of Cornubia » Tue Jul 30, 2013 2:49 am

As some have suggested (thanks), the bad days might follow nights where my sleep was poor and/or disturbed for reasons other than apneas. A diary would indeed help to answer that. I might consider a diary though, to be honest, I generally try NOT to keep 'health' diaries as I find I can become fixated on my health and how I feel. I'm not a hypochondriac by any means, but since I had a heart attack in 2008, I find too much time thinking about my health, and my apnea, makes me a little depressed. Nevertheless, this issue intrigues me so......

Last night my AHI was 1.5 and I had a pretty solid 8 hours with only one trip to the bathroom that I can recall, so I have no explanation for my fatigue today. It felt like good deep sleep, too - though I can't be sure that was really the case.

User avatar
Sheriff Buford
Posts: 4080
Joined: Mon Aug 09, 2010 8:01 am
Location: Kingwood, Texas

Re: AHI 5 = fine. AHI 1.5 = tired. Why?

Post by Sheriff Buford » Tue Jul 30, 2013 5:05 am

You should feel good about yourself! Not only are you starting to get the "hang" of things, you are starting to be sensitive to how you're body is responding (or not responding) to the cpap therapy. What you are referring to happens to me all the time. I average a .2 - .3 AHI with a .2 - .3 apnea incidents and centrals every night. I'll get a zero across the board 2-3 times a month. I find that I don't feel as well with all the zero's as I do with numbers of .2 - .3. I don't know why my body responds that way... but it does.

What I have to watch out is that I record my nightly numbers in a tablet soon after I awake. If I see those zeros.... I have to tell myself that my day will not be all that bad. I can't let it get to my head. I can't let the machine dictate what my day will be like and let those dang numbers run my day! I have decided to let the numbers indicate and "steer" cpap treatment, but not run my life.

Sheriff

User avatar
Goofproof
Posts: 16087
Joined: Mon Dec 05, 2005 3:16 pm
Location: Central Indiana, USA

Re: AHI 5 = fine. AHI 1.5 = tired. Why?

Post by Goofproof » Tue Jul 30, 2013 12:27 pm

Steve of Cornubia wrote:I've been using CPAP since February and I think I've got the hang of it, more or less. However, I have had a suspicion for some time now that there is something funny going on. Now though, I have seen enough data to convince me it's real.

Whilst getting my AHI as low as possible seems like the right thing to do, there seems to be a 'sweet spot' for my AHI and it isn't the lowest number. That sweet spot seems to be between 4 and 6. Any higher and I'll be noticeably sleepier - no surprise there. However, and more surprisingly, whenever I get a value <2 I tend to be tired the next day.

Has anybody else seen this?

I haven't looked closely at the data, to pick out any correlation between the individual components of the AHI and my tiredness (OA, CA, Hypopnea) but I'm going to keep an eye of that, just out of interest, but I nevertheless wonder why I feel tired when my AHI is nice and low.
Maybe the data you are seeing if faulty. If the leak rate it too high the data becomes useless, by using the software to read the data you can see the full picture for the night not just the machines avg guess. Jim
Use data to optimize your xPAP treatment!

"The art of medicine consists in amusing the patient while nature cures the disease." Voltaire

User avatar
Steve of Cornubia
Posts: 73
Joined: Tue Mar 12, 2013 10:19 pm
Location: Brisbane, Australia

Re: AHI 5 = fine. AHI 1.5 = tired. Why?

Post by Steve of Cornubia » Fri Aug 02, 2013 4:53 am

I use sleepyhead and my leaks are well managed most nights. I see the occasional bad night because of leaks, but not so many that explain this phenomenon.

User avatar
cobra4x4
Posts: 272
Joined: Tue Mar 23, 2010 10:44 pm

Re: AHI 5 = fine. AHI 1.5 = tired. Why?

Post by cobra4x4 » Sat Aug 03, 2013 12:08 am

believe it or not you may actually be mouth breathing a tiny bit and therefore you feel like hell even though your AHI is great.
This happens to me all the time, sometimes low AHI is great then other nights low AHI and I'm very tired. Low AHI for me is anywhere from 0.0 to 0.6, there are days where I feel like a million bucks and my AHI is 2.0 to 2.5

There is too much going on in ones brain or body to have consistent perfect nights and I believe that plays a big part in why every night differs.

_________________
Mask: Wisp Nasal CPAP Mask with Headgear - Fit Pack
Humidifier: S9™ Series H5i™ Heated Humidifier with Climate Control
Additional Comments: Secondary Mask: Swift FX

FattyMagoo
Posts: 73
Joined: Thu Jun 27, 2013 11:20 am

Re: AHI 5 = fine. AHI 1.5 = tired. Why?

Post by FattyMagoo » Sat Aug 03, 2013 10:17 am

Is mouth breathing be detected by the machine in any way, say by accounting for any pressure variations or inbalances it may cause?

I feel like saying this stuff is frustrating to figure out, but I guess that applies to every person on the forum so maybe it doesn't bear repeating.

Thanks
cobra4x4 wrote:believe it or not you may actually be mouth breathing a tiny bit and therefore you feel like hell even though your AHI is great.
This happens to me all the time, sometimes low AHI is great then other nights low AHI and I'm very tired. Low AHI for me is anywhere from 0.0 to 0.6, there are days where I feel like a million bucks and my AHI is 2.0 to 2.5

There is too much going on in ones brain or body to have consistent perfect nights and I believe that plays a big part in why every night differs.

_________________
Mask: Aloha Nasal Pillow CPAP Mask with Headgear
Humidifier: S9™ Series H5i™ Heated Humidifier with Climate Control
Additional Comments: Quattro FX full face mask, and Aloha Nasal Pillow mask

Country4ever
Posts: 1373
Joined: Wed Oct 31, 2007 6:22 pm

Re: AHI 5 = fine. AHI 1.5 = tired. Why?

Post by Country4ever » Sat Aug 03, 2013 11:36 am

Is your leak rate acceptable? I've noticed that I can't believe my AHI number at all, if my leak rate was high.

_________________
MachineMask
Additional Comments: Resmed HumidAir 11 for humidifier