CPAP vs APAP and heart disease

[hayeswildrick]

Here's an article that should be interesting:

Fixed and Autoadjusting CPAP Yield Different Cardiovascular Benefits

Information from Industry
NSCLC Treatment Strategies

By Will Boggs, MD

NEW YORK (Reuters Health) May 22 - Continuous positive airway pressure (CPAP) and autoadjusting CPAP (APAP) differ in their ability to reduce cardiovascular risk factors in patients with obstructive sleep apnea (OSA), according to a report in the May issue of Chest.

"CPAP and APAP do not seem to be interchangeable," Dr. Nicola Montano from University of Milan, told Reuters Health. "Indeed, even though they both reduce apneas and hypoxic events, they do not achieve this in the same way, and this fact seems to imply also a different effect on cardiovascular risk factors."

Dr. Montano and colleagues evaluated the benefits induced by CPAP or APAP on arterial blood pressure, insulin resistance, and inflammation in 40 patients with newly diagnosed OSA.

Apnea measures improved with both treatments, the authors report. Apnea-hypopnea index (AHI) was lower with CPAP, as was oxyhemoglobin desaturation index.

Systolic and diastolic blood pressure and insulin resistance were reduced in the CPAP group but not in the APAP group, the results indicate, whereas C-reactive protein levels were similarly reduced after both treatments.

"According to our results, we would say that so far there is still no solid evidence that APAP is as efficient as CPAP in correcting major cardiovascular risk factors," Dr. Montano concluded.

"We would like to underline that our results do not imply that APAP should be disregarded as a treatment option for OSA, based on its high potential in terms of cost-effectiveness," Dr. Montano said. "On the contrary, we believe that these devices should be tested not only in terms of efficacy on sleep and respiratory indexes, but also in reducing cardiovascular risk factors."

[roster]

This post has been here 14 hours and none of the apap fans have commented on it. Please step up to the plate and take a swing.

cpap rooster

[GoofyUT]

[quote="hayeswildrick"]Here's an article that should be interesting:

Fixed and Autoadjusting CPAP Yield Different Cardiovascular Benefits

Information from Industry
NSCLC Treatment Strategies

By Will Boggs, MD

NEW YORK (Reuters Health) May 22 - Continuous positive airway pressure (CPAP) and autoadjusting CPAP (APAP) differ in their ability to reduce cardiovascular risk factors in patients with obstructive sleep apnea (OSA), according to a report in the May issue of Chest.

"CPAP and APAP do not seem to be interchangeable," Dr. Nicola Montano from University of Milan, told Reuters Health. "Indeed, even though they both reduce apneas and hypoxic events, they do not achieve this in the same way, and this fact seems to imply also a different effect on cardiovascular risk factors."

Dr. Montano and colleagues evaluated the benefits induced by CPAP or APAP on arterial blood pressure, insulin resistance, and inflammation in 40 patients with newly diagnosed OSA.

Apnea measures improved with both treatments, the authors report. Apnea-hypopnea index (AHI) was lower with CPAP, as was oxyhemoglobin desaturation index.

Systolic and diastolic blood pressure and insulin resistance were reduced in the CPAP group but not in the APAP group, the results indicate, whereas C-reactive protein levels were similarly reduced after both treatments.

"According to our results, we would say that so far there is still no solid evidence that APAP is as efficient as CPAP in correcting major cardiovascular risk factors," Dr. Montano concluded.

"We would like to underline that our results do not imply that APAP should be disregarded as a treatment option for OSA, based on its high potential in terms of cost-effectiveness," Dr. Montano said. "On the contrary, we believe that these devices should be tested not only in terms of efficacy on sleep and respiratory indexes, but also in reducing cardiovascular risk factors."

[DreamStalker]

Well I’m certainly no expert but … with a background in science however, 31 samples (patients) to statistically evaluate the significance of both APAP and CPAP on blood pressure, heart rate, HOMA-IR (whatever that is?), and CRP is hardly a defensible study. There is insufficient information from the abstract regarding the methodology of the study to indicate otherwise. http://www.chestjournal.org/cgi/content ... 129/6/1403

I’m not willing to pay to get the full journal article text but if someone else is, they may well prove my thoughts on this study to be total bunk … would not be the first time that has ever happened.

I’m no doctor but I think that there are many many factors that contribute to the parameters being evaluated for cardiovascular health … did they successfully isolate all parameters for each patient for both groups as being directly the result of OSA and/or its treatment rather than of diet, exercise, genetics, etc.?

Sure CPAP may be better for some than APAP but lets face it, as long as AHI is lowered sufficiently enough to maintain proper O2 saturation, the cardiovascular system could care less whether the result of the O2 saturation is due to CPAP or APAP.

[tangents]

Very interesting post, thanks for the information!

I would like to see if anyone else has similar study data to share on this topic. I agree with DreamStalker that the sample number seems too small to make such sweeping conclusions. I'd also like some sort of hypothesis or data on WHY apap wouldn't treat anything except apneas and hypopneas. Just doesn't seem logical.

I'm eager to learn all things apnea. Thanks again for the post.
Cathy

[JohnMudie]

When I was on APAP, my AHI was running 1.7 or so. After the sleep study I switched to CPAP at 10 cm H2O and the AHI dropped to about 0.7. On the basis of the results from the APAP, I then dropped it to 9cm H2O and the AHI now seems to be about 0.2 . Last night I scored a 0.0 AHI.

But I am still feeing tired and get short of breath easily. So for me, good AHI's are not enough

John M

[Guest]

Perhaps they set apap on 4-20 instead of centering it around ones titrated pressure. I can't believe there is significant differences in results between a cpap of 10 and an apap of 8-12....based on the results I have seen. However there probably is a difference if the apap was set at 4-20. The lower setting would be too far from the titrated pressure to work effectively.

[GoofyUT]

[quote="DreamStalker"]Well I’m certainly no expert but … with a background in science however, 31 samples (patients) to statistically evaluate the significance of both APAP and CPAP on blood pressure, heart rate, HOMA-IR (whatever that is?), and CRP is hardly a defensible study. There is insufficient information from the abstract regarding the methodology of the study to indicate otherwise. http://www.chestjournal.org/cgi/content ... 129/6/1403

I’m not willing to pay to get the full journal article text but if someone else is, they may well prove my thoughts on this study to be total bunk … would not be the first time that has ever happened.

I’m no doctor but I think that there are many many factors that contribute to the parameters being evaluated for cardiovascular health … did they successfully isolate all parameters for each patient for both groups as being directly the result of OSA and/or its treatment rather than of diet, exercise, genetics, etc.?

Sure CPAP may be better for some than APAP but lets face it, as long as AHI is lowered sufficiently enough to maintain proper O2 saturation, the cardiovascular system could care less whether the result of the O2 saturation is due to CPAP or APAP.

[Joethespy]

I have said this before but auto-CPAP is no replacement for a good titration study. But if used to improve compliance then that is always a good thing.
The bottom line is that there are studies that show any type of pressure therapy greatly reduces mortality rates is sleep apnea patients, no matter what complicating factors there are.

Good Luck...Joe

[DreamStalker]

Well I’m certainly no expert but … with a background in science however, 31 samples (patients) to statistically evaluate the significance of both APAP and CPAP on blood pressure, heart rate, HOMA-IR (whatever that is?), and CRP is hardly a defensible study. There is insufficient information from the abstract regarding the methodology of the study to indicate otherwise. http://www.chestjournal.org/cgi/content ... 129/6/1403

I’m not willing to pay to get the full journal article text but if someone else is, they may well prove my thoughts on this study to be total bunk … would not be the first time that has ever happened.

I’m no doctor but I think that there are many many factors that contribute to the parameters being evaluated for cardiovascular health … did they successfully isolate all parameters for each patient for both groups as being directly the result of OSA and/or its treatment rather than of diet, exercise, genetics, etc.?

Sure CPAP may be better for some than APAP but lets face it, as long as AHI is lowered sufficiently enough to maintain proper O2 saturation, the cardiovascular system could care less whether the result of the O2 saturation is due to CPAP or APAP.

Roberto, though I mightily respect the wisdom that you've often shared here, in this case you are simply wrong. As a scientist, you'll know that statistics conducted with a sample of 25 or greater are considered to be parametric (representative of the population). The study cited exceeded that sample size.

And, no, the cardiovascular impact of SDB (and xPAP treatment) is NOT just a matter of maintaining acceptable O2 saturations. The damaging effects of SDB on the heart have to do, in part, with what the body has to do to attempt to maintain oxygen saturations in the face of SDB, such as releasing boluses of adrenaline and other angiotensins which are damaging to the heart over the long haul. This study suggests that there well may be a differential in those effects between CPAP and APAP.

So, I repeat: Attempting therapy for SDB with auto-titrating equipment is NOT a benign decision and MUST be discussed with a physician that you trust before it is undertaken. Be careful about offering advice here that you might not be able to fully and responsibly support.

Chuck

Chuck –

I too respect your wise and valuable contributions to the forum. However, my response above was only to the study and not “advice” as to whether one should use CPAP or APAP to treat their OSA. I do however think it is better to have an APAP machine rather than a CPAP machine (since APAP can be used in CPAP mode and not the other way around). As to whether to use it in CPAP or APAP mode should indeed be determined on an individual basis and I agree with you on that point … a different matter than the type of machine one should try to acquire.

Using proper parametric statistics on the other hand is based on specific underlying assumptions about the probability distributions of their study sample and relationships between the variables. I have yet to be completely satisfied that these assumptions and relationships have been made clear and are indeed valid based on the abstract alone. Again, if someone wishes to buy the article and post the full text, I may be convinced that the sample is representative of the population.

Finally, the study was an investigation into OSA (not SDB) on the cardiovascular system (not the heart). Please feel free to correct me but I thought that OSA was a subset of SDB and therefore not equivalent. The heart is also a subset of the cardiovascular system and therefore they are not equivalent. So let’s not mix terminology here and confuse what I said above. I don’t recall that they investigated the effects of OSA (and definitely not SDB) or its treatment on adrenaline or angiotesins with respect to damage to heart. In other words, I don’t doubt that there are many other parameters that affect the cardiovascular system (as I stated in my first post on this thread) … and all I am saying is that based on the information from the abstract, the study appears to be flawed for the very reasons you and I have just pointed out.

My background in science is not in the biosciences (only biology course I ever had was high school biology over 30 years ago … can you say mitochondria?). So perhaps I am way out on a limb on this one but I still think that based on the information provided so far, the study is likely flawed.

It is an Italian study ... pizza can't possibly be good for the cardiovascular system

[cwsanfor]

Is it possible for -SWS, SAG, or any of the Techs I ran into on chat at 2 AM the other night to weigh in on this? I can run my APAP as CPAP, but had been thinking that my BiPAP was the best bet. This bears examination by someone smarter than me, and does not need to be a flame war. So calm down.

[Guest]

Heh... predictable response pattern:

CPAP mode user: "Yeah baby, yeah!"

APAP mode user: "The study is flawed, there's not a big enough sample size, the analysis was shoddy, the moon wasn't in the right phase! etc. etc."

I must admit I feel a bit happier about my Remstar M-Series Pro CPAP machine now, though. I used to have APAP envy, but that faded awhile ago... and this news doesn't hurt that process much.

Oh, and for the person who said that O2 sat is all that matters to the heart, heck no. There's a lot more to it than just that.

Keep it civil though, folks. This isn't a "mode war". I'd love to see more data, however... fascinating stuff.

[roster]

[quote="Anonymous"]..........

Keep it civil though, folks. This isn't a "mode war". ..........

[DreamStalker]

Heh... predictable response pattern:

CPAP mode user: "Yeah baby, yeah!"

APAP mode user: "The study is flawed, there's not a big enough sample size, the analysis was shoddy, the moon wasn't in the right phase! etc. etc."

I must admit I feel a bit happier about my Remstar M-Series Pro CPAP machine now, though. I used to have APAP envy, but that faded awhile ago... and this news doesn't hurt that process much.

Oh, and for the person who said that O2 sat is all that matters to the heart, heck no. There's a lot more to it than just that.

Keep it civil though, folks. This isn't a "mode war". I'd love to see more data, however... fascinating stuff.

OK, let me clarify … again. I did not say that O2 is all that mattered to the heart or cardiovascular system … to the contrary, I said that there are “many many” factors that affect the health of the cardiovascular system. Hence, the sample size is likely inadequate to accurately represent the relationships between the variables of investigation and population parameters and assumptions.

Regarding the relationship of O2, AHI, and PAP treatment, I was pointing out that the primary purpose of PAP treatment is to maintain O2 saturation (thru lowered AHI) … are there other relationships between PAP treatment and cardiovascular health? … YES … as Chuck pointed out. I mean, I thought the main purpose of our treatment was to suck air. I may have been stoned the day the biology teacher talked about how O2 was a necessary ingredient for the success of aerobic life forms … but hey! -- let that be a lesson to all those young’ins out there contemplating the experimentation of recreational drug use.

So, maintain proper O2 saturation and body does not freak out causing all kinds of other unhealthy effects. Does it matter to the cardiovascular system whether or not it gets its O2 saturation thru CPAP or APAP (or tracheotomy for that matter)? … NO … I dare you to prove otherwise (in a civil manner of course ).

[Joethespy]

cwsanfor,

I was not on chat the other night but if you will allow, I will weigh in on Bi-Level pressure. For strickly OSA, standard Bi-Level therapy is not as effective. Here is why: Bi Level alternates between two set pressures, lets say 15 as the IPAP and 10 as the EPAP. So while you are inhaling, the machine delivers 15 and as you exhale the machine deliver 10cm of H2O. So when an OSA is taking place the pressure delivered is 10 since there in no inhalation. Since (in this case) 15 is the therapeutic pressure, the patient is not receiving this pressure when they need it most.

There are other modes of Bi Level therapy out here (S-T) and there is now an auto Bi Level(BiFlex). In my experience, CFLEX has proved a better alternative to standard Bi Level because CFLEX delivers the therapeutic pressure when it is needed. Also standard Bi-Level is not recommended for central sleep apnea or complex sleep apnea.

Thanks...Joe