Study links TV viewing in childhood to metabolic syndrome as adult

Key takeaways:

• A study found an association between frequent TV viewing in childhood and metabolic issues in adulthood.
• Childhood behaviors can still have an impact into older age if TV-watching is curbed by 32 years.

A long-running cohort study found an association between frequent television viewing as a child and developing metabolic syndrome as an adult, according to results reported in Pediatrics.

The study originated with a group of 1,037 children born in 1972 and 1973 at the same hospital in Dunedin, New Zealand.

“We've been following this group of children [starting] when they were born,” Robert J. Hancox, MD, a respiratory physician and head of the department of preventative and social medicine at the University of Otago in Dunedin, told Healio. “Most of the research is looking at what the early life influences are on later health, and we're looking at changes in how they live.”

One such health issue Hancox and co-author Nathan MacDonell, BBiomedSc, wanted to examine was the extent of TV use or other sedentary behavior on later life health outcomes.

“Age 45 is still a bit young to actually develop diagnosable heart disease and diabetes and other things that tend to happen a decade later in life, but there's this collection of risk factors which tend to go together called metabolic syndrome, which actually has become quite common in midlife adults,” Hancox said. “We wondered how much sedentary behavior predicted the long-term risk of metabolic syndrome.”

Up until the cohort turned 15 years old, the researchers asked them on six occasions how much time they spent watching TV.

“We’ve got multiple measures of TV use between the ages of 5 and 15, when they would have been in school,” Hancox said.

Additionally, once the cohort members turned 45 years old, the researchers measured their blood pressure, blood sugar levels, body weight, waist circumference, blood cholesterol and triglycerides to put together their metabolic syndrome. Data were available for 87% of 997 surviving participants in the cohort.

Ultimately, the authors found that mean TV viewing time between ages 5 and 15 years was associated with metabolic syndrome at 45 years of age, even after adjusting for factors like sex, socioeconomic status and body mass index at age 5 years (OR = 1.3; 95% CI, 1.08-1.58).

It also persisted after adjusting for adult TV viewing (OR = 1.26; 95% CI, 1.03 to 1.54).

“It is actually the amount of time you spend watching TV or using a screen as a child that predicts long-term adult health,” Hancox said.

The authors also found that childhood TV viewing was associated with lower cardiorespiratory fitness and higher BMI at 45 years of age.

The study was accompanied by an editorial authored by Pooja S. Tandon, MD, MPH, a pediatrician and researcher at the Center for Child Health, Behavior and Development at Seattle Children’s Research Institute.

“A significant body of literature reveals the known child health risks of excessive and/or inappropriate screen time, including unhealthy diet, sleep problems, excessive adiposity, poor cardiometabolic health, and increased mental health concerns,” Tandon wrote. “What is less well characterized are the long-term consequences of media use in childhood.”

“Notably and disappointingly,” Tandon continued, the authors found that the relationship between childhood TV viewing and metabolic syndrome at age 45 years persisted after they adjusted for TV viewing at age 32 years.

“Although the benefits of decreasing sedentary behaviors and media use certainly exist in adulthood, as well, these findings underscore the critical and potentially disproportionately larger influence of the childhood years on cardiometabolic health risks,” Tandon wrote. “If early media use is, in fact, causally related to adult metabolic syndrome, the mechanism, however elusive, has important public health consequences. Some emerging evidence reveals that the ‘exposome’ early in childhood creates epigenetic changes that predispose to obesity. Seen in this light, limiting screen time in young children takes on even greater urgency.”

Hancox said research on modern-day screen media such as smartphones and tablets and their effects on children’s development is “desperately” needed.

“We're going to have to wait a long time for us to be able to look at long-term effects,” Hancox said. “It would be really good to get some research done on what can be done about it to limit the amount of time that kids engage in screens. That's not an easy thing to do, because the environment out there is heavily based on screens now. But it will be interesting to see what could be done at a population level to actually limit kids’ recreational use of screens.”

References:

MacDonell N, et al. Pediatrics. 2023;doi:10.1542/peds.2022-060768.

Tandon PS, et al. Pediatrics. 2023;doi:10.1542/peds.2023-062183.