The Impact of Living at Moderate Altitude in the USA: Epidemiology and Key Research Questions

BACKGROUND: Over the last 20 years, the USA has seen a significant population migration into moderate elevation locations (defined as elevations 1,800-2,500 m for the purposes of this review). While considerable research has investigated how chronic diseases are impacted on acute ascent to high altitude, little research has examined how residing at high altitude impacts longer term health including risk of various disease states and long-term morbidity, with even fewer studies examining moderate altitude specifically. SUMMARY: This review investigated how living at moderate elevation impacts seven different disease states/health issues pertinent to the aging individual. Overall, this review reveals a limited literature in this field, though with interesting findings that warrant the need for further studies. While limited studies have documented a potential protective effect of moderate altitude on ischemic heart disease and obesity prevalence, current evidence suggests worse outcomes for chronic obstructive pulmonary disease, possibly increased rates of pulmonary hypertension and low birth weight (which increases risk of chronic diseases later in life), negative impacts on sleep, and increased association with risk of mental health issues including suicide. KEY MESSAGES: Residing at moderate altitude appears to be beneficial for some disease states but detrimental to others. Further research is needed to solidify these associations, particularly for aging populations, and more importantly to understand the mechanisms that might explain these associations. Understanding the role of mild hypoxia in health resulting from living at moderate altitudes guides improved care delivery and the design of public health interventions.