Incidence of sickle cell disease complications rise in cold weather
More vaso-occlusive episodes, acute chest syndrome from January to March
The incidence of vaso-occlusive episodes and acute chest syndrome in children with sickle cell disease (SCD) is elevated during January to March, a large nationwide, retrospective study in the U.S. suggests.
The findings reinforce the need for “recommendations for patients with SCD to take appropriate precautions in cold weather,” the researchers wrote. The study, “Influence of Weather on Sickle Cell Disease Vaso-Occlusive Episodes and Acute Chest Syndrome: A Nationwide Sample Analysis,” was published in Pediatric Blood & Cancer.
In SCD, a defective form of hemoglobin, which is the oxygen-carrying protein inside red blood cells, causes the cells to become stiff and take on a crescent-like shape. These abnormally shaped cells are prone to clumping and adhering to blood vessel walls, blocking blood flow and reducing oxygen delivery to tissues. Blood vessel obstruction can lead to painful vaso-occlusive crises and other complications, such as acute chest syndrome, a severe lung condition.
Cold weather and sudden changes in temperature have been observed to trigger these events, but follow-up studies that have assessed the impact of weather, specifically temperature, humidity, wind speed, atmospheric pressure, and precipitation, on the incidence of pediatric vaso-occlusive episodes have had inconsistent results.
More vaso-occlusive episodes, acute chest syndrome in cold weather
Here, researchers in the U.S. retrospectively analyzed clinical data from SCD patients from the Pediatric Health Information System (PHIS) between 2015 and 2022 to shed light on the association between weather and vaso-occlusive episodes. The PHIS is a U.S. database for clinical data obtained from more than 49 children’s hospitals. The data were organized according to seasons and regions in the U.S., and merged with weather information from the National Climatic Data Center.
Researchers found 84,774 occurrences, with 86% identified as vaso-occlusive episodes and 14% as acute chest syndrome. About 60% of the patients were hospitalized. Nearly half (48%) of these hospital visits occurred in the southern U.S.
Vaso-occlusive episode admissions were most frequent in the northeast, while emergency department visits for vaso-occlusive episodes and acute chest syndrome admissions were highest in the south. A seasonal trend also was identified: the highest rate of vaso-occlusive episode-related hospitalizations occurred between January and March.
Weather variables appeared to play a significant role in hospital admissions, with some key patterns emerging. Vaso-occlusive episode admissions were positively associated with increased wind speed and snowfall, while acute chest syndrome hospitalizations showed a positive correlation with average temperature and temperature changes.
Vaso-occlusive episode admissions were negatively associated with average temperatures. A negative correlation also was found between acute chest syndrome admissions and wind speed, as well as between vaso-occlusive episode-related emergency department visits and precipitation levels.
No single weather factor was found to impact all three clinical conditions — vaso-occlusive episode-related emergency department visits, vaso-occlusive episode-related admissions, and acute chest syndrome hospitalizations — but the study underscores the role of weather in triggering SCD complications.
“Prospective studies are needed to truly explore the association between the environment and SCD complications,” the researchers wrote.
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