Moving into poverty during childhood is associated with later sleep problems.

OBJECTIVE

A social gradient in sleep has been demonstrated across the life span, but previous studies have been cross-sectional and used self-reported socioeconomic status (SES) indicators. Using registry-based data on family income trajectories, the current study examined the association between relative poverty in childhood and subsequent sleep in adolescence.

METHODS

Data on family income during 2004-2010 was obtained from the National Income Registry. Poverty was defined as household income <60% of the mean national income. Information on self-reported sleep was based the youth@hordaland-survey (n = 8873) conducted in 2012 when the adolescents were 16-19 years old. Latent class analysis (LCA) was used to identify trajectories of family household poverty, and analysis of variance and general linear models were used to examine associations between income trajectories and sleep, adjusting for confounders.

RESULTS

LCA identified four classes: 'never poor', two classes characterized by moving in or out of poverty, and 'chronically poor'. Compared to the 'never poor' group, adolescents from families in the 'moving into poverty' group displayed worse sleep across most sleep measures, including shorter sleep, lower sleep efficiency, and more nocturnal wake time (but not sleep onset latency). Neither adolescents from families who had moved out of poverty by increasing family income, nor the 'chronically poor' group differed significantly from the reference group.

CONCLUSIONS

The study found that downward socioeconomic mobility was associated with increased adolescent sleep problems. More studies are required on the mechanisms that may account for the association, to find targeted and effective strategies to prevent short sleep duration in adolescents from families with unstable financial circumstances.