Effect of EGLN1 Genetic Polymorphisms on Hemoglobin Concentration in Andean Highlanders

Targeting HIF-1α in sickle cell disease and cancer: unraveling therapeutic opportunities and risks

INTRODUCTION

HIF-1α, a key player in medical science, holds immense significance in therapeutic approaches. This review delves into its complex dynamics, emphasizing the delicate balance required for its modulation. HIF-1α stands as a cornerstone in medical research, its role extending to therapeutic strategies. This review explores the intricate interplay surrounding HIF-1α, highlighting its critical involvement and the necessity for cautious modulation.

AREAS COVERED

In sickle cell disease (SCD), HIF-1α's potential to augment fetal hemoglobin (HbF) production and mitigate symptoms is underscored. Furthermore, its role in cancer is examined, particularly its influence on survival in hypoxic tumor microenvironments, angiogenesis, and metastasis. The discussion extends to the intricate relationship between HIF-1α modulation and cancer risks in SCD patients, emphasizing the importance of balancing therapeutic benefits and potential hazards.

EXPERT OPINION

Managing HIF-1α modulation in SCD patients requires a nuanced approach, considering therapeutic potential alongside associated risks, especially in exacerbating cancer risks. An evolutionary perspective adds depth, highlighting adaptations in populations adapted to low-oxygen environments and aligning cancer cell metabolism with primitive cells. The role of HIF-1α as a therapeutic target is discussed within the context of complex cancer biology and metabolism, acknowledging varied responses across diverse cancers influenced by intricate evolutionary adaptations.

Individual variations and sex differences in hemodynamics and percutaneous arterial oxygen saturation (SpO2) in Tibetan highlanders of Tsarang in the Mustang district of Nepal

Background

Many studies have indicated specific low-hemoglobin (Hb) adaptation to high altitude in the Tibetan population, but studies focusing on physiological variations within this population are limited. This study aimed to investigate the relationships between SpO₂ and related factors, including individual variations and sex differences, to assess the generality of high-altitude adaptation in the Tibetan population of Tsarang.

Methods

The participants were 31 male and 41 female community-dwelling people aged ≥18 years living in Tsarang, in the Mustang district of Nepal. Height, weight, SpO₂, Hb concentration, finger temperature, heart rate, and blood pressure were measured. Lifestyle information was obtained by interview.

Results

Men had significantly higher systolic blood pressure (p = 0.002) and Hb (p < 0.001) than women. There was no significant correlation between SpO₂ and other parameters in men. In women, SpO₂ was negatively correlated with heart rate (p = 0.036), Hb (p = 0.004), and finger temperature (p = 0.037). In multiple regression analysis, a higher SpO₂ was marginally correlated with lower age (β = −0.109, p = 0.086) and higher Hb (β = 0.547, p = 0.053) in men. In women, higher SpO₂ was significantly correlated with lower heart rate (β = −0.045, p = 0.036) and Hb (β = −0.341, p = 0.018). Mean hemoglobin (95% confidence interval) was 13.6 g/dl (13.1–14.0 g/dl), which is lower than that found previously in Andeans and almost equal to that in Japanese lowlanders measured using the same device. In some participants of both sexes, hemoglobin was >17.0 g/dl.

Conclusion

Higher SpO₂ was marginally correlated with younger age and higher Hb in men and with lower heart rate and lower Hb in women. Hemoglobin concentration was similar to that found previously in lowlanders, but higher in some individuals. These results indicate individual variation and sex differences in the hemodynamics of high-altitude adaptation in Tibetan highlanders of Tsarang, as well as low-Hb adaptation to high altitude equal to that of other Tibetans.

Insight into the Effects of High-Altitude Hypoxic Exposure on Learning and Memory

The earth land area is heterogeneous in terms of elevation; about 45% of its land area belongs to higher elevation with altitude above 500 meters compared to sea level. In most cases, oxygen concentration decreases as altitude increases. Thus, high-altitude hypoxic stress is commonly faced by residents in areas with an average elevation exceeding 2500 meters and those who have just entered the plateau. High-altitude hypoxia significantly affects advanced neurobehaviors including learning and memory (L&M). Hippocampus, the integration center of L&M, could be the most crucial target affected by high-altitude hypoxia exposure. Based on these points, this review thoroughly discussed the relationship between high-altitude hypoxia and L&M impairment, in terms of hippocampal neuron apoptosis and dysfunction, neuronal oxidative stress disorder, neurotransmitters and related receptors, and nerve cell energy metabolism disorder, which is of great significance to find potential targets for medical intervention. Studies illustrate that the mechanism of L&M damaged by high-altitude hypoxia should be further investigated based on the entire review of issues related to this topic.

Hematological Reference Values According to Geographical Region in Jujuy, Argentina

Armella, Flavia Noelia, and Sandra Stella Lazarte. Hematological reference values according to geographical region in Jujuy, Argentina. High Alt Med Biol 00:000-000, 2022. Background: Hematological values vary with altitude above sea level. The purpose of this work was to determine the ranges of hematological reference, and the prevalence of anemia and erythrocytosis in adult blood donors from Jujuy, discriminated according to the geographical region, who assisted at the Centro Regional de Hemoterapia from 2016 to 2018. Materials and Methods: A cross-sectional retrospective study was carried out. Men and women donors belonging to the regions of Valles, Yungas, Quebrada, and Puna were analyzed. The percentiles 2.5 and 97.5 were obtained for the hemoglobin (Hb), hematocrit (Ht), red blood cell count (RBCC), and hematimetric indices, according to sex and region. Results: A total of 4,707 men and 3,326 women, ranging from 18 to 65 years of age, who met with the expected clinical criteria in donors, were studied. The anemia prevalence was 2.5% (95% confidence interval [CI] = 2.2%-2.8%), while the erythrocytosis was 4.9% (95% CI = 4.4%-5.4%). The RBCC, Hb, and Ht increased with altitude above sea level. Conclusions: The Hb and Ht were similar to those observed in the Andean populations living at similar altitudes. The anemia prevalence was lower than the global prevalence reported by the World Health Organization, while that of erythrocytosis increased with the altitude above the sea level. The evidence indicates the necessity for laboratories to obtain reference values for their target population. Registro Nacional de Investigaciones (Renis, Ministerio de Salud de Argentina) IS002323.