michigan hypertension core curriculum - State of Michigan

Vital signs
suggestive of OSAHS. 20 The prevalence of sleep apnea in hypertensive populations
ranges between 30 – 40%. Men are 2 to 3 times more likely to be affected than women. 21
Population-based studies have associated OSAHS with cardiovascular
disease, stroke and hypertension. In the Sleep Heart Health Study, 6,424 patients
were longitudinally studied with in-home polysomnography. 20 In the highest quartile of
apnea-hypopnea frequency (>11/hr) the adjusted odds of self reported cardiovascular
disease was 1.42 (95% confidence interval, 1.13 – 1.78). 22 The strongest links were to
congestive heart failure and stroke. 21
Strong evidence for an association of OSAHS and hypertension comes
from the Wisconsin Sleep Cohort Study. Subjects underwent serial in-laboratory
polysomnography. A dose-dependent like between apnea-hypopnea frequency at
baseline and the development of hypertension was identified. For a baseline apneahypopnea
frequency of 15/hr the odds ratio for hypertension at 4 years was 2.89
(confidence interval, 1.46 – 5.64). 23
Intermittent hypoxia, negative intrathoracic pressure variations and arousal
characteristics of apneas and hypopneas lead to acute increases in BP and the
termination of disordered breathing events, evolving into sustained hypertension via
chronically heightened sympathetic nervous system activity and arterial baroreceptor
dysfunction. 21
History should focus on breathing disturbances during sleep, unsatisfactory sleep
quality, daytime dysfunction, and OSAHS risk factors. A collateral history should be
obtained from the patient’s bed partner. Reports of habitual, socially disruptive snoring
and witnessed apneas terminated by snorts or gasps increase diagnostic accuracy.
Sleepiness, per se, however, lacks diagnostic sensitivity and specificity. 20,21
Physical examination focuses on craniofacial and soft tissue conditions
associates with increased upper airway resistance, such as retrognathia, deviated
nasal septum, low-lying soft palate, enlarged uvula, and base of tongue. Obesity and
neck circumference over 43cm (17.5inches) correlates with an increased likelihood of
OSAHS. 20
Treatment of OSAHS may, though not invariably, result in improvement of
hypertension. However, treatment of sleep apnea does lower cardiovascular risk. 22
164 Hypertension Core Curriculum
Physical Examination 1,4-10,20,21
General appearance
A Retinopathy
B Neck/chest
C Cardiac
i. Inspection of precordium
ii. Palpation of PMI
iii. First sound
iv. S 3 Gallop
v. S 4 Gallop
vi. Murmurs
D Abdomen
vii. Renal bruits
viii. Bladder distention