Office and Ambulatory Arterial Hypertension in Highlanders

Abstract

Millions of people worldwide live at high altitude, being chronically exposed to hypobaric hypoxia. Hypertension is a major cardiovascular risk factor but data on its prevalence and determinants in highlanders are limited, and systematic studies with ambulatory blood pressure monitoring are not available. Aim of this study was to assess the prevalence of clinic and ambulatory hypertension and the associated factors in a sample of Andean highlanders. Hypertension prevalence and phenotypes were assessed with office and ambulatory blood pressure measurement in a sample of adults living in Cerro de Pasco, Peru (altitude 4340 m). Basic clinical data, blood oxygen saturation, hematocrit, and Qinghai Chronic Mountain Sickness score were obtained. Participants were classified according to the presence of excessive erythrocytosis and chronic mountain sickness diagnosis. Data of 289 participants (143 women, 146 men, mean age 38.3 years) were analyzed. Office hypertension was present in 20 (7%) participants, while ambulatory hypertension was found in 58 (20%) participants. Masked hypertension was common (15%), and white coat hypertension was rare (2%). Among participants with ambulatory hypertension, the most prevalent phenotypes included isolated nocturnal hypertension, isolated diastolic hypertension, and systodiastolic hypertension. Ambulatory hypertension was associated with male gender, age, overweight/obesity, 24-hour heart rate, and excessive erythrocytosis. Prevalence of hypertension among Andean highlanders may be significantly underestimated when based on conventional blood pressure measurements, due to the high prevalence of masked hypertension. In highlanders, ambulatory hypertension may be independently associated with excessive erythrocytosis.

Blood Pressure Response in Miners Exposed to Chronic Intermittent Hypoxia in Chile

“…This so-called masked uncontrolled hypertension phenotype was even more frequent during HA exposure. This confirms the importance of ABPM in determining the real effectiveness of an anti-HT antihypertensive therapy over 24 h, especially in relatively young individuals in whom work-related BP elevation may have a considerable impact on overall BP burden ( 16 , 27 – 29 ).…”

Global REACH 2018: the adaptive phenotype to life with chronic mountain sickness and polycythaemia

“…Future work in humans will be required to elucidate these time-dependent adaptations. Indeed, epidemiological studies have seen evidence of systolic and masked hypertension in Andeans with CMS at Cerro de Pasco (Corante et al, 2018;Bilo et al, 2020), suggesting that time may be key and as CMS pathology progresses, the functional adaptations we observed herein are lost and hypertension develops. In addition to these physiological changes, vascular remodelling in terms of greater conduit artery diameter was a prominent feature in CMS+ (Tremblay et al, 2019a, b), which contributed to the normalization of in vivo conduit artery anterograde and retrograde shear stress despite elevated blood viscosity.…”

Effect of acetazolamide on obstructive sleep apnoea in highlanders: protocol for a randomised, placebo-controlled, double-blinded crossover trial

“…20 21 These findings were confirmed and extended by Bilo et al, showing a higher prevalence of nocturnal hypertension in highlanders. 22 Acetazolamide, a carbonic anhydrase inhibitor with diuretic effects, is the recommended pharmaceutical measure to prevent acute mountain sickness in trekkers ascending to high altitudes. 23 24 Apart from the preventive effect of acetazolamide against acute mountain sickness, this medication has been shown to reduce blood pressure in healthy persons and patients with OSA at low and high altitude.…”