Kids with Sickle Cell Anemia are More Sedentary than Healthy Peers, Study Suggests

Children and adolescents with sickle cell anemia do less physical activity and have a more sedentary lifestyle than healthy controls, according to a study.

The study, “Objectively measured physical activity levels and sedentary time in children and adolescents with sickle cell anemia,” was published in PLOS ONE.

The red blood cells of patients with sickle cell anemia can obstruct the small blood vessels, leading to inflammation, pain, and impairment of the bones, muscles, and joints. This usually leads to reduced physical activity and a sedentary lifestyle that often starts at a young age.

However, physical activity is good for the health in the short and long term, and studies have shown that it may benefit people with sickle cell anemia.

A cross-sectional study performed at a Brazilian center evaluated the level of physical activity of children and adolescents with sickle cell anemia and compared it to that of healthy controls.

The study included 50 patients (60% male, mean age 12) and 50 controls matched for age and sex.

The patients were stable, had not experienced acute complications during the last month or received transfusions in the last three months, and had no orthopedic or neurological impairments.

All subjects answered a survey regarding physical activities, such as sports and games at school and in their free time, and used an accelerometer — a movement monitor that indicates activity levels — for seven consecutive days for at least 10 hours a day.

The researchers classified the overall activity as sedentary behavior and light, moderate, and vigorous physical activity depending on the number of counts per minute (an electrical measure that relates to the intensity of movement) on the accelerometer.

People with sickle cell anemia performed 19.2 minutes of moderate daily activity and 3.6 minutes of vigorous daily activity on average, while healthy controls performed 27.1 and 7.4 minutes, respectively. These significant differences were also observed in other measures, as the patients also took fewer steps and burned fewer calories than the controls.

In total, 8% of the patients and 30% of the controls performed the recommended amount of physical activity. Those with sickle cell anemia tended to spend more time doing sedentary activities than their healthy counterparts, but these values were not significant.

Overall, 62% of patients were considered very sedentary and the remaining 38% were considered sedentary. In the healthy group, 11% were sedentary, 75% moderately active, and 14% were active.

“The present study identified low [physical activity] levels and low energy expenditure in patients with SCA compared with healthy individuals, corroborating previous studies. Various factors, such as muscular hypotrophy, pulmonary and cardiac complications, may explain these findings,” researchers said.

This sedentary lifestyle might be encouraged by parents whoworry that exercise might worsen their children’s disease, but there are studies suggesting that moderate exercise can ameliorate the overall condition of people with sickle cell anemia, improving cardiac health and reducing oxidative stress.

“However, intense physical exercise induces metabolic and physiological changes that may be detrimental to individuals with [sickle cell anemia] and there is no consensus on the maximum intensity of safe exercise that these patients can tolerate,” researchers noted.

In future studies, researchers intend to determine which kind of exercise and intensity would provide more benefits to those with sickle cell anemia.