Teenagers who have low physical fitness, obesity, or a combination of the two are more likely to develop chronic disability later in life, according to a study published online today in Annals of Internal Medicine.
“[T]his population-based cohort study of more than 1 million male adolescents indicated that low cardiorespiratory fitness and obesity are strongly associated with receipt of a disability pension due to a wide range of diseases and causes later in life,” write Pontus Henriksson, PhD, Department of Biosciences and Nutrition, Karolinska Institute, Stockholm, Sweden, and colleagues.
Noncommunicable diseases such as cardiovascular diseases, musculoskeletal disorders, psychiatric disorders, and cancer are key causes of disability and premature death and impose a growing burden on society. Thus, identification of early-life and potentially modifiable risk factors holds great significance for public health efforts to help combat these chronic diseases, the authors write.
Obesity in adolescence has been linked to later receipt of a disability pension. However, few data assess the link between fitness in adolescence and later chronic disability, or between the combination of cardiorespiratory fitness and obesity with disability, report the researchers.
For the current study, Henriksson and colleagues examined data on cardiorespiratory fitness and weight among 1,079,128 male adolescents ages 16 to 19 years included in the Swedish Military Service Conscription Registry. They examined outcomes using data from other linked national registries to see who would later receive a medical disability pension.
According to the authors, over a median follow-up of 28.3 years, 54,304 men received a disability pension.
Low cardiorespiratory fitness was strongly associated with later-life disability. For example, adolescents in the lowest fitness decile had a 3.74-fold (95% confidence interval [CI], 3.55 – 3.95) greater risk for receipt of a disability pension due to all causes, compared with those in the highest decile.
Obesity was also associated with a risk for later-life disability, with the greatest risks observed for severe obesity (body mass index [BMI] ≥40 kg/m2). Adolescents with severe obesity had a 3.21-fold (95% CI, 2.49 – 4.15) greater risk for receipt of a disability pension due to all causes, compared with those with normal weight.
Conversely higher cardiorespiratory fitness reduced the risk for later-life disability in all BMI categories. For example, the risk for receipt of a disability pension due to all causes was similar among highly fit adolescents with obesity (hazard ratio [HR], 2.27 [CI, 1.94 – 2.66]) and unfit adolescents with normal weight (HR, 2.64 [CI, 2.53 – 2.76]). However, the risk was much higher for unfit adolescents with obesity (HR, 4.67 [CI, 4.21 – 5.17]).
While Henriksson and colleagues acknowledge that fitness is influenced by not only physical activity, but also by other environmental factors and genetics, they also stress the public health implications of this study.
The authors note several limitations, including an absence of data on smoking and alcohol intake. In addition, because the study population was all male, the generalizability to females may be limited.
“Although additional well-designed studies are required to provide further evidence, these findings emphasize the importance of high cardiorespiratory fitness and healthy body weight during adolescence,” they conclude.
This study was supported by a grant from the Karolinska Institute. The authors have disclosed no relevant financial relationships.
Ann Intern Med. Published online February 11, 2019. Full text