Chronotype preferences of college students from varied altitude backgrounds in Ethiopia

Abstract

The purpose of this study was to compare chronotype preferences of college students from high- and low-altitude backgrounds living in a tropical setting of Ethiopia. Chronotype (morningness-eveningness) is a preference for a given time of day for physical or mental activities. The present cross-sectional study employed Horne and Osteberg Morningness-Eveningness Questionnaires to evaluate chronotype preferences. The chronotype preference of 264 male college students from varied altitude backgrounds indicated significant differences (p < 0.001). Our findings confirm our hypothesis, of the prevalence of M-types dominant chronotype among college students at low than high altitude. However, we did not confirm our second hypothesis, since students from high-altitude backgrounds were generally I-type dominant chronotype. Similarly, students' academic performances from low- compared to high-altitudes backgrounds also indicated significant differences (p < 0.003). Better academic performances were seen in students with I-type chronotype orientations from high altitudes.

Effects of altitude on chronotype orientations in relation to cardiorespiratory and hematological quantities of college students in Ethiopia

“…This is the first study to our knowledge that investigated the effects of altitude on chronotype orientations in relation to cardiorespiratory and hematological quantities of students from high and low altitude backgrounds living in a tropical setting. Our main finding confirmed that altitude is an independent predictor of chronotype orientations of the participants [36].…”

“…However, previous studies reported a better VO 2 max in E-types than M-types [68,70–72]. This might be reflective of better aerobic participation in energy metabolism during the evening time, leading to both mental and physical activeness among E-type than other chronotype [16,36,73]. Although our finding is not consistent with previous studies, but this might be due to absence of E-type among compared chronotype orientations.…”

“…The study was conducted in Arba Minch town South-West Ethiopia, with an elevation of 1286 meters above sea level [37,38], which is categorized as low altitude tropical setting [39]. It is located at 6.0206°N and 37.5641°E, latitude and longitude coordinates with an average annual temperature of 25.2°C, (average high and low temperature of 28.7°C and 21.8°C respectively) [36].…”

“…Therefore, based on the altitude classification by the Canadian Academy of Sport and Exercise Medicine (CASEM) [39], participants who originated and grew up from areas between 500–2000 meters above sea level were grouped under low altitude backgrounds. While those from areas above 3000 meters above sea level were grouped under high altitude backgrounds [36,39]. However, participants who reported to be from neither high nor low altitude backgrounds were excluded from the study.…”

“…In our previous study, we reported that the chronotype preferences of college students may vary according to their altitude backgrounds [36]. However, the underlying parameter by which altitudes may influence chronotype orientations is still unknown.…”