Both the quantity and quality of sleep in adolescents had significant effects on aspects of cardiovascular health, such as blood pressure, cholesterol levels and abdominal fat deposition, according to a study.
Researchers made the conclusion after examining the amount of time that 829 now-adolescent participants spend sleeping, as well as the percentage of their sleep that is undisturbed.
The participants had both their nighttime sleep and daily physical activity measured over seven to 10 days by actigraphy, which records physical motion by a device worn on the wrist.
"While many studies have associated shorter sleep duration with increased obesity levels in children, few have examined effects on other risk factors, such as blood pressure, blood lipids and glucose metabolism, or examined associations of sleep quality with these outcomes," said Dr Elsie Taveras, chief of the Division of General Academic Paediatrics in Massachusetts General Hospital for Children and senior author of the study, which was published in medical journal Pediatric.
Results showed that the average sleep duration for all participants was 441 minutes, or 7.35 hours, per day; and only 2.2 per cent met or exceeded the recommended average sleep duration for their age group: nine hours per day for ages 11 to 13 and eight hours per day for those 14 to 17.
Sleep duration of less than seven hours was found in 31 per cent of participants, and more than 58 per cent had a sleep efficiency less than the 85 per cent that is considered sufficient for adults.
Both shorter sleep duration and lower sleep efficiency were also linked to higher levels of overall and abdominal fat deposition. This is despite having taken into account one's physical activity, television viewing and consumption of fast foods or sweetened beverages.
Longer sleep duration and higher efficiency were associated with reductions in cardiometabolic risk, which was based on factors such as smaller waist circumference, lower systolic blood pressure and higher high density lipoprotein cholesterol levels.
"Sleep quantity and quality are pillars of health alongside diet and physical activity," said the paper's lead author Elizabeth Cespedes Feliciano of the Kaiser Permanente Northern California Division of Research.
"Paediatricians should be aware that poor sleep quality, frequent awakenings and not just insufficient duration of sleep, is associated with increased cardiometabolic risk," she said.
XINHUA
