Blood Pressure in Andean Adults Living Permanently at Different Altitudes

Hypertension subtypes at high altitude in Peru: Analysis of the Demographic and Family Health Survey 2016-2019

BACKGROUND

The prevalence of hypertension in Peru has increased over the years. Approximately one third of the Peruvian population lives at high altitudes. This population presents particular physiological, genetic and environmental characteristics that could be related to the prevalence of hypertension and its subtypes.

OBJECTIVE

To assess the association between altitude and hypertension in the Peruvian population through an analysis of a nationally representative survey.

METHODS

We conducted a cross-sectional analysis of the Demographic and Family Health Survey for the period 2016-2019. We included 122,336 individuals aged 18 years and older. Hypertension was defined according to the JNC-7 guidelines. High-altitude location was defined as a residential cluster located above 2,500 meters above sea level. We utilized generalized linear models from the Poisson family with a log-link function to assess the magnitude of the association between high altitude and hypertension. Additionally, we employed multinomial regression models to analyze the association between high altitude and subtypes of hypertension, including isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and systolic-diastolic hypertension (SDH).

RESULTS

In the adjusted Poisson regression model, we found that the prevalence of hypertension among participants living at high altitudes was lower compared to those living at low altitudes (aPR: 0.89; 95% CI: 0.86-0.93). In the adjusted multinomial regression model, we observed a lower prevalence rate of ISH among participants residing at high altitudes (aRPR: 0.68; 95% CI: 0.61-0.73) and a higher prevalence rate of IDH among participants residing at high altitudes (aRPR: 1.60; 95% CI: 1.32-1.94).

CONCLUSIONS

Residents at high altitudes in Peru have a lower prevalence rate of ISH and a higher prevalence rate of IDH compared to those living at low altitudes. Further studies are needed to determine the influence of other biological, environmental, and healthcare access factors on this relationship.

Office and Ambulatory Arterial Hypertension in Highlanders: HIGHCARE-ANDES Highlanders Study

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.