USMLE Obstructive Sleep Apnea and Systemic Hypertension

[dotespalyer]

What's the mechamisn for the development of "systemic" hypertension in OSA?

In FA it says an increase in pulse pressure is seen in OSA due to increased sympathetic tone, shouldn't it be the vice versa because with an increased symp tone total peripheric resistance will increase...

Thanks in advance

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[Instatewaiter]

What's the mechamisn for the development of "systemic" hypertension in OSA?

In FA it says an increase in pulse pressure is seen in OSA due to increased sympathetic tone, shouldn't it be the vice versa because with an increased symp tone total peripheric resistance will increase...

Thanks in advance

Increased sympathetic tone increases your cardiac output and stroke volue. So even if you do increase your SVR, you are going to incrase your pulse pressure.

 

[Phloston]

What's the mechamisn for the development of "systemic" hypertension in OSA?

In FA it says an increase in pulse pressure is seen in OSA due to increased sympathetic tone, shouldn't it be the vice versa because with an increased symp tone total peripheric resistance will increase...

Thanks in advance

From UpToDate:

"Hypertension and OSA frequently coexist. OSA-related autonomic dysfunction is evidenced by elevated levels of plasma and urinary catecholamines and also peroneal microneurography."

"Some studies have also found that OSA is not as strongly related to isolated systolic hypertension as it is to isolated diastolic or combined systolic/diastolic hypertension."

Hope that helps.

 

[argatroban16]

I think the bottom-line is really that the relationship between OSA and systemic hypertension is complicated and while these two seem to coincide quite often, there just doesn't seem to be a clear causal (mechanistic) explanation as to why this is. The fact that age and obesity predispose you to both OSA and systemic hypertension certainly doesn't make this any easier. See http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3497224/ for reference.