Which came first, obstructive sleep apnoea or hypertension? A retrospective study of electronic records over 10 years, with separation by sex

Abstract

ObjectivesObstructive sleep apnoea (OSA) is a risk factor for hypertension (HTN), but the clinical progression of OSA to HTN is unclear. There are also sex differences in prevalence, screening and symptoms of OSA. Our objective was to estimate the time from OSA to HTN diagnoses in females and males.DesignRetrospective analysis of electronic health records (EHR) over 10 years (2006–2015 inclusive).SettingUniversity of California Los Angeles (UCLA) Health System in Los Angeles, California, USA.Participants4848 patients: females n=2086, mean (SD) age=52.8 (13.2) years; males n=2762, age=53.8 (13.5) years. These patients were selected from 1.6 million with diagnoses in the EHR who met these criteria: diagnoses of OSA and HTN; in long-term care defined by ambulatory visits at least 1 year prior and 1 year subsequent to the first OSA diagnosis; no diagnosis of OSA or HTN at intake; and a sleep study performed at UCLA.Primary and secondary outcome measuresThe primary outcome measure in each patient was time from the first diagnosis of OSA to the first diagnosis of HTN (OSA to HTN days). Since HTN and OSA are progressive disorders, a secondary measure was the relationship between OSA to HTN time and age (OSA to HTN=β1×Age+β0).ResultsThe median (lower and upper quartiles) days from OSA to HTN were: all −532 (−1439, –3); females −610 (−1579, –42); and males −451 (−1358, 0). Older age in both sexes was associated with less time to a subsequent HTN diagnosis or more time from a prior HTN diagnosis (β1 days/year: all −16.9, females −18.3, males −15.9).ConclusionsHTN was on average diagnosed years prior to OSA, with a longer separation in females. Our findings are consistent with underscreening of OSA, more so in females than males. Undiagnosed OSA may delay treatment for the sleep disorder and perhaps affect the development and progression of HTN.

Characteristics of hypertension and arterial stiffness in obstructive sleep apnea: A Scandinavian experience from a prospective study of 6408 normotensive and hypertensive patients

“…However, an alternative explanation, although less likely, for the lack of association between OSA and arterial stiffness/increased PP in our study may be the fact that polygraphy and brachial BP measurement were performed in the same setting and explored in a cross‐sectional fashion. It is known that following the OSA screening and diagnosis, it may take months or years until the development of incident hypertension, 23 and resultant targert arterial damage. It has been shown that patients diagnosed with OSA at an older age have longer time duration since the prior hypertension diagnosis and less time to a subsequent hypertension diagnosis 23 …”

“…It is known that following the OSA screening and diagnosis, it may take months or years until the development of incident hypertension, 23 and resultant targert arterial damage. It has been shown that patients diagnosed with OSA at an older age have longer time duration since the prior hypertension diagnosis and less time to a subsequent hypertension diagnosis 23 …”

“…The proposed mechanisms by which OSA leads to hypertension is believed to be apneas/hypopneas causing repetitive hypoxemia, nocturnal BP elevation and fluctuation and increased sympathetic activity, endothelial damage/dysfunction, oxidative stress, and hypertension target arterial damage; ie, increased arterial stiffness. 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 Recent studies have shown that nonmuscle myosin light chain kinase (nmMLCK) may be a key mechanism in intermittent hypoxia‐induced vascular oxidative stress and inflammation, both leading to functional and structural remodeling. 25 Furthermore, in hypertension, the presence of abdominal obesity or excessive fat deposition in the neck area, causes airway obstruction during sleep, and on molecular level leads to overproduction of adipokines, chronic low‐grade inflammation, and increased arterial stiffness.…”

“…An and associates assessed the time from OSA to hypertension diagnosis in a large retrospective study of electronic records over a period of 10‐years. 23 Hypertension was diagnosed years prior to OSA, and with a longer separation in females. However, no BP measurements or hypertension control data were reported.…”

“…In the literature, there are few large‐scale studies on hypertension control in OSA patients. An and associates assessed the time from OSA to hypertension diagnosis in a large retrospective study of electronic records over a period of 10‐years 23 . Hypertension was diagnosed years prior to OSA, and with a longer separation in females.…”