Presentation description

The spleen is an important lymphoid organ which filters blood and stores erythrocytes and ejects them into circulation upon stimulation. Studies have shown that spleens with a larger volume eject more erythrocytes into circulation, allowing for less physiological stress under hypoxic conditions; however, there are still gaps in our understanding of the factors that influence the spleen. An enlarged spleen phenotype (splenomegaly) has been identified in the Bajau population for suggested reasons such as apnea training, natural selection, or physiological factors. The Bajau are a seafaring people who live on the shores of the islands of Southeast Asia and dive regularly as part of their hunter-gather lifestyle. We hypothesize that splenomegaly in the Bajau population is due to the influence of natural selection and physiological factors such as thyroid hormones. We investigated these factors to elucidate the influences behind splenomegaly by comparing spleen volumes of Diver/Non-Diver in the Bajau, Tongan, and Haeyno populations, who are also populations who dive regularly. Our results presented that between Diver/Non-Diver in each population, the p-value was non-significant, supporting our hypothesis that the enlarged spleen phenotype presented in these populations are a result from natural selection. Future studies should consider the impact of physiological factors affecting the spleen and understand the implications it can have on personalized medicine affecting thyroid diseases and hypoxic conditions.