Padrões de duração do sono entre a adolescência e a vida adulta e sua relação com o acúmulo de capital humano em uma coorte de nascimentos

Abstract

Sleep is an essential component of healthy development and is required for physical and mental health. Studies have shown that sleep problems may increase the risk of metabolic and cardiovascular diseases and contribute to all causes of mortality. Sleep plays a critical role in physical and intellectual development during adolescence, including memory and learning consolidation, and it is essential for school and work performance. However, the frequency of inadequate sleep duration in this age group is high, which may cause worse physical and mental health outcomes. Thus, the first aim of this thesis was to describe trajectories of sleep duration from adolescence to early adulthood (at ages 11, 18, and 22) and to characterize these individuals according to socioeconomic, demographic, and behavioral characteristics, using data from the 1993 Pelotas Birth Cohort. Three sleep duration trajectories were identified for males: “increase and maintenance” (3.4%), “fast reduction and maintenance” (45.0%), and “constant reduction” (51.6%). While for women, the identified trajectories were: “increase and decrease” (2.4%), “fast reduction and maintenance” (25.6%), and “constant reduction” (72.0%). Men and women who belonged to the longest sleep duration trajectories were more likely to present risky behaviors and worse socioeconomic status. The second objective of this thesis was to systematically review the literature on the relationship between sleep duration (as exposure) and human capital characteristics (cognitive function, school outcomes, and socioeconomic status). We observed that short and long sleep durations seem to be associated with worse cognitive outcomes in older adults. Only short sleep duration is likely to be associated with worse cognitive and school outcomes in children and adolescents. The last article developed in this thesis evaluated the relationship between sleep duration trajectories from adolescence to early adulthood (at ages 11, 18, and 22) and the following outcomes: working memory, years of schooling, and individual income at 22 years, using data from the 1993 Pelotas Birth Cohort. We observed that men and women who belonged to trajectories with longer sleep duration scored, on average, 1.6 and 1.8 lower in the memory test, respectively. They presented a median of 1.6 and 2.6 fewer years of schooling, respectively, compared to those from the “fast reduction and maintenance” trajectory who showed the best results. Regarding income, there was no significant association.