Insufficient sleep in teenagers linked to overweight, obesity

Teenagers who sleep less than eight hours a night are more likely to be overweight or obese compared to their peers with sufficient sleep, finds a new study.

The study, presented at the ESC Congress 2022, showed that shorter sleepers were also more likely to have a combination of other unhealthy characteristics, including excess fat around the middle, elevated blood pressure, and abnormal blood lipid and glucose levels.

"Our study shows that most teenagers do not get enough sleep, and this is connected with excess weight and characteristics that promote weight gain, potentially setting them up for future problems," said researchers Jesus Martinez Gomez from Spanish National Centre for Cardiovascular Research (CNIC), Madrid.

For the study, the team examined the association between sleep duration and health in 1,229 adolescents. Participants had an average age of 12 years at baseline with equal numbers of boys and girls.

Sleep was measured for seven days with a wearable activity tracker three times in each participant at ages 12, 14 and 16 years. For optimal health, the American Academy of Sleep Medicine advises sleeping 9 to 12 hours a night for 6 to 12-year-olds and 8 to 10 hours for 13 to 18-year-olds.

To simplify the analysis, the study used 8 hours or more as optimal. Participants were categorised as very short sleepers (less than 7 hours), short sleepers (7 to 8 hours), and optimal (8 hours or more).

Overweight and obesity were determined according to body mass index.

The researchers calculated a continuous metabolic syndrome score ranging from negative (healthier) to positive (unhealthier) values that included waist circumference, blood pressure, and blood glucose and lipid levels.

At 12 years of age, only 34 per cent of participants slept at least 8 hours a night, dropping to 23 per cent and 19 per cent at 14 and 16 years of age, respectively.

Boys tended to get less sleep. Teenagers who got the most sleep also had better quality sleep, meaning they woke up less during the night and spent a higher proportion of the time in bed than those with shorter sleep.

The prevalence of overweight/obesity was 27 per cent, 24 per cent and 21 per cent at 12, 14 and 16 years of age, respectively.

Associations between sleep duration, overweight/obesity and metabolic syndrome score were analyzed after adjusting for parental education, migrant status, moderate-to-vigorous physical activity, smoking status, energy intake, city (Madrid or Barcelona) and school.