Weight-loss Surgery May Help Reduce VOCs in Morbidly Obese SCD Patients

SCD is a rare genetic disorder caused by mutations in the HBB gene, which provides instructions to make hemoglobin, a protein responsible for blood oxygen transport. The red blood cells of SCD patients have an abnormal sickle-like shape and tend to stick to one another, forming blood clots that block blood circulation.

When these blockages occur and oxygen delivery is interrupted, patients undergo VOCs, a common, painful complication of SCD.

“For many years, SCD was stereotypically represented by an undernourished child with delayed growth and poor immunologic function. However, there has been a significant improvement in the
management of SCD patients over the past few decades. Early diagnosis coupled with introduction of disease-modifying therapy has significantly improved life expectancy of SCD patients. With increased longevity, SCD patients are susceptible to developing chronic medical problems such as obesity,” the researchers said.

In this study, a group of investigators from the Yale University School of Medicine and collaborators set out to assess the impact of weight-loss (bariatric) surgery on the clinical outcomes of morbidly obese patients with SCD. Bariatric surgery reduces the amount of food the stomach can hold, causing weight loss.

Patients were selected based on hospital discharge records stored at the United States Nationwide Inpatient Sample database containing the co-diagnosis of morbid obesity and SCD.

The study’s primary outcome was to evaluate patients’ in-hospital mortality rates. Secondary outcomes included the frequency of VOCs, acute chest syndrome (ACS), liver and pancreas complications, kidney and respiratory failure and other adverse events, hospitalization length and costs.

From the 2,549 patients with a discharge diagnosis of SCD and morbid obesity found in the database between 2004 and 2014, 42 (1.7%) underwent weight-loss surgery.

Further analysis demonstrated that patients who underwent the  surgery did not have a higher risk of mortality, or of developing other medical complications, including ACS, sepsis, and multi-organ failure. They were less likely to experience VOCs compared to those who did not have the surgery.

“We are hopeful that our results will motivate physicians to consider bariatric surgery as a safe and effective treatment option for SCD patients with morbid obesity. Although the results of this
study are narrowed based upon database and study design limitations, we hope our study encourages future exploration on the subject of sickle cell disease and bariatric surgery. Prospective studies, although difficult to design given the incidence of bariatric surgery and sickle cell disease, are needed to validate our findings,” they said.