High‐altitude adaptations mitigate risk for hypertension and diabetes‐associated anemia

BACKGROUND: Human populations native to high altitude exhibit numerous genetic adaptations to hypobaric hypoxia. Among Tibetan plateau peoples, these include increased vasodilation and uncoupling of erythropoiesis from hypoxia. OBJECTIVE/METHODS: We tested the hypothesis that these high‐altitude adaptations reduce risk for hypertension and diabetes‐associated anemia among the Mosuo, a Tibetan‐descended population in the mountains of Southwest China that is experiencing rapid economic change and increased chronic disease risk. RESULTS: Hypertension was substantially less common among Mosuo than low‐altitude Han populations, and models fit to the Han predicted higher probability of hypertension than models fit to the Mosuo. Diabetes was positively associated with anemia among the Han, but not the Mosuo. CONCLUSION: The Mosuo have lower risk for hypertension and diabetes‐associated anemia than the Han, supporting the hypothesis that high‐altitude adaptations affecting blood and circulation intersect with chronic disease processes to lower risk for these outcomes. As chronic diseases continue to grow as global health concerns, it is important to investigate how they may be affected by local genetic adaptations.Accepted manuscrip

Same-sex sexual attraction does not spread in adolescent social networks

Peers have a powerful effect on adolescents' beliefs, attitudes, and behaviors. Here, we examine the role of social networks in the spread of attitudes towards sexuality using data from the National Longitudinal Study of Adolescent Health (Add Health). Although we found evidence that both sexual activity (OR = 1.79) and desire to have a romantic relationship (OR = 2.69) may spread from person to person, attraction to same sex partners did not spread (OR = 0.96). Analyses of comparable power to those that suggest positive and significant peer-to-peer influence in sexual behavior fail to demonstrate a significant relationship on sexual attraction between friends or siblings. These results suggest that peer influence has little or no effect on the tendency toward heterosexual or homosexual attraction in teens, and that sexual orientation is not transmitted via social networks