Effect of EGLN1 Genetic Polymorphisms on Hemoglobin Concentration in Andean Highlanders.

The physiological characteristics of Andean natives living at high altitudes have been investigated extensively, with many studies reporting that Andean highlanders have a higher hemoglobin (Hb) concentration than other highlander populations. It has previously been reported that positive natural selection has acted independently on the egl-9 family hypoxia inducible factor 1 (EGLN1) gene in Tibetan and Andean highlanders and is related to Hb concentration in Tibetans. However, no study has yet revealed the genetic determinants of Hb concentration in Andeans even though several single-nucleotide polymorphisms (SNPs) in EGLN1 have previously been examined. Therefore, we explored the relationship between hematological measurements and tag SNPs designed to cover the whole EGLN1 genomic region in Andean highlanders living in Bolivia. Our findings indicated that haplotype frequencies estimated from the EGLN1 SNPs were significantly correlated with Hb concentration in the Bolivian highlanders. Moreover, we found that an Andean-dominant haplotype related to high Hb level may have expanded rapidly in ancestral Andean highlander populations. Analysis of genotype data in an ~436.3 kb genomic region containing EGLN1 using public databases indicated that the population structure based on EGLN1 genetic markers in Andean highlanders was largely different from that in other human populations. This finding may be related to an intrinsic or adaptive physiological characteristic of Andean highlanders. In conclusion, the high Hb concentrations in Andean highlanders can be partly characterized by EGLN1 genetic variants.

Individual variations and sex differences in hemodynamics with percutaneous arterial oxygen saturation (SpO2) in young Andean highlanders in Bolivia.

BACKGROUND: Many studies have reported specific adaptations to high altitude, but few studies have focused on physiological variations in high-altitude adaptation in Andean highlanders. This study aimed to investigate the relationships between SpO2 and related factors, including individual variations and sex differences, in Andean highlanders. METHODS: The participants were community-dwelling people in La Paz, Bolivia, aged 20 years and over (age range 20-34 years). A total of 50 men and 50 women participated in this study. Height, weight, SpO2, hemoglobin concentration, finger temperature, heart rate, and blood pressure were measured. Information about lifestyle was also obtained by interview. RESULTS: There were individual variations of SpO2 both in men (mean 89.9%, range 84.0-95.0%) and women (mean 91.0%, range 84.0-96.0%). On Student's t test, men had significantly lower heart rate (p = 0.046) and SpO2 (p = 0.030) than women. On the other hand, men had significantly higher SBP (p < 0.001), hemoglobin (p < 0.001), and finger temperature (p = 0.004). In men, multiple stepwise regression analysis showed that a higher SpO2 was correlated with a lower heart rate (ß = - 0.089, p = 0.007) and a higher finger temperature (ß = 0.308, p = 0.030) (r2 for model = 0.18). In women, a higher SpO2 was significantly correlated with a higher finger temperature (ß = 0.391, p = 0.015) (r2 for model = 0.12). A higher SpO2 was related to a higher finger temperature (ß = 0.286, p = 0.014) and a lower heart rate (ß = - 0.052, p = 0.029) in all participants (r2 for model = 0.21). Residual analysis showed that individual SpO2 values were randomly plotted. CONCLUSION: Random plots of SpO2 on residual analysis indicated that these variations were random error, such as biological variation. A higher SpO2 was related to a lower heart rate and finger temperature in men, but a higher SpO2 was related to finger temperature in women. These results suggest that there are individual variations and sex differences in the hemodynamic responses of high-altitude adaptation in Andean highlanders.

Self-perceived oral health status and influencing factors of the elderly residents of a peri-urban area of La Paz, Bolivia.

AIM: To assess the self-perceived oral health status of the elderly in Bolivia and explore the relationship between the socio-demographic and subjective factors that influence such perception. DESIGN: A cross sectional study. SETTING: Pampahasi, peri-urban area of La Paz, Bolivia. PARTICIPANTS: A 22.5% (300) sample was selected randomly from the total population (1,336) of 60 years and above. Of the participants, 293 agreed to participate in the survey. METHODS: Information was collected by interviews at home. RESULTS: The mean age was 70 years (SD = 7.7), with more females (57%) than males. Sixty per cent of subjects categorised their oral health as poor. Logistic regression analysis showed that poor self-perceived oral health was associated significantly with not going to school, no/ fair satisfaction with economic status, poor chewing ability, perception of need for dental treatment, and poor self-perceived general health status. CONCLUSIONS: Socio-economic factors seem to contribute to poor oral health among the elderly in Bolivia. Considering that these factors are associated with bad oral health behaviour and few visits to dental clinics, there is a need to design dental education programmes and enhance accessibility to dental clinics for elderly people living in the peri-urban areas of La Paz, Bolivia.