Oxygen Saturation Increases During Childhood and Decreases During Adulthood Among High Altitude Native Tibetans Residing at 3800–4200 m

Abstract

This report describes age differences in oxygen saturation throughout the life cycle in a sample of high altitude native Tibetans residing in villages at 3,800-4,200 m altitude in the Tibet Autonomous Region, China. Oxygen saturation of 3,812 Tibetans was measured by pulse oximetry and a subsample of 1,582 healthy, nonpregnant, nonsmokers from 1 week to 80 years of age was selected for analyses. Infants under 1 year of age had 5-6% lower oxygen saturation than the peak of 89.8% attained at 11 years of age. There was a steady increase in mean oxygen saturation-for-age during the first decade of life, but not during the second decade. Adult males exhibited a slight decrease starting in the 20-29 year age range. Adult females maintained the peak oxygen saturation through the 40-49 year age range, exhibiting a decrease in oxygen saturation beginning in the 50-59 year age range and as a result had higher oxygen saturation than males during the female reproductive span. Thus, developmental factors during infancy and childhood, but not adolescence, enhanced oxygen transfer in this high altitude native resident Tibetan sample. The age of onset of aging processes detrimental to oxygen transfer differed for females and males.

Oxygen Saturation in Healthy Children Aged 5 to 16 Years Residing in Huayllay, Peru at 4340 m

“…These levels were even lower than those found in other studies at midaltitude (Lozano et al, 1992;Gamponia et al, 1998;Beall, 2000;Graham et al, 2008;Subhi et al, 2009), suggesting a decreasing trend of Sao 2 when altitude increased. The reduction of normal Sao 2 found at this altitude become the reference values used in the coast inappropriate for this population and remarks the importance of determining accurate reference values for children residing at very high altitude.…”

“…This increase differs from that described in the Tibetan population, who typically experience a marked rise in Sao 2 levels during the first decade of life and then remaining stable after 11 yr (Beall, 2000). In other reports, Huicho and colleagues (2001) found a weak positive association between saturation and age from 4 to 18 yr.…”

“…In Tibet, a decreasing trend of Sao 2 with higher altitude was found; the average Sao 2 in the 0-to 9-yr age range was 89.3% at 3800 m and 85.5% at 4200 m, and in the 10-to 19-yr age range the average Sao 2 was 90.9% at 3800 m and 88.7% at 4200 m (Beall, 2000). A systematic review of 14 studies of Sao 2 in 1-5-yr-old healthy children living at high altitude found a threshold point for hypoxemia of 90% at 2500 m, which decreased to 85% at 3200 m (Subhi et al, 2009).…”

Higher offspring survival among Tibetan women with high oxygen saturation genotypes residing at 4,000 m

“…Everyone in each household was invited to participate in a survey of oxygen saturation of hemoglobin that also involved providing information on factors known to influence oxygen saturation, including age, sex, pregnancy status, self-reported health status, self-reported symptoms of chronic obstructive lung disease, medications, and smoking behavior (see ref. 4 for details). A total of 95% of those encountered (Ϸ63% of the total number of residents) agreed to participate, and a total of 3,812 people provided pulse oximetry.…”

Developmental Effects Determine Submaximal Arterial Oxygen Saturation in Peruvian Quechua

“…The examination of genetic and/or developmental origins of higher Sao 2 levels in highlanders contributes to the broader question of adaptation to high altitude Beall, 2000;Moore, 2001). Early studies conducted by Beall and colleagues (1994;1998) in Tibetans reported that Sao 2 showed significant heritability.…”