Metabolic and bariatric surgery can be safe and effective in adults, but can it be used in adolescents as well?
Obesity early in life is an independent risk factor for early cardiovascular disease (CVD). With increasing rates of pediatric and adolescent obesity, we must understand its long-term health risks, especially with regards to CVD. While the best way to see the effect of treating severe obesity and its impact on CVD events is to wait several decades, the effect of treating obesity on CVD can be predicted using algorithms. These algorithms use data such as serum lipids, systolic blood pressure, and diabetes status, among others. The Framingham Heart Study’s 30-year CVD risk estimate allows a validated prospective evaluation of CVD event risk over long periods. Evidence suggests childhood obesity is a risk factor for early CVD morbidity and mortality.
Currently, metabolic and bariatric surgery (MBS) is the only intervention that has high rates of sustained, significant weight loss among youth with severe obesity. MBS significantly reduced CVD events and mortality compared to other interventions. The long-term CVD event risk can be estimated using the Framingham methodology. This study hoped to examine the risk of a CVD event happening in the next 30 years in youth with severe obesity compared to those of a healthy weight. It also wanted to see the impact that MBS had on the 30-year CVD event risk and evaluate the cost-effectiveness of MBS in terms of CVD event reduction. Data was used from the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study, a longitudinal, multicenter observational study that enrolled those under 20 that were undergoing MBS, with data collected at baseline and annually up to 5 years postoperatively. At each assessment, each participant had their height, weight, systolic blood pressure, fasting total cholesterol, and high-density lipoprotein cholesterol measured, BMI calculated, and diabetes status assessed. For the nonsurgical arm, participants were aged 10-23 who enrolled in a study of obesity and type 2 diabetes. A third cohort was from a University of Minnesota cross-sectional, longitudinal study that looked at CVD risk factors in youth without diabetes whose weights ranged from average to severely obese. This study used two models to estimate CVD event risks, including coronary artery disease, myocardial infarction, stroke, intermittent claudication, and congestive heart failure. The first model included BMI while excluding lipids, sex, age, and systolic blood pressure, among other things. The second excluded BMI while including that which the first excluded.
After the surgery, weight loss was at its lowest after one year, with small increases from years 3 to 5. Systolic blood pressure and total cholesterol were lowered at one year, but increased every subsequent year. In contrast, high-density lipoprotein-cholesterol increased at both 1 and 2 years, with a sustained level at five years. Diabetes prevalence decreased from 13.5% at baseline to 2.2% in year 1. At baseline, 0.8% of youths with a healthy weight had a risk of CVD events over 5%, whereas 38.7% of the severe obesity groups and 13.0% of the obesity groups had the same risk when BMI was included in the model. Those with severe obesity had a statistically significant higher chance of 30-year CVD events (all P < 0.01). Following MBS, there was a substantial reduction in the 30-year CVD event risk seen at one year that extended out to 5 years after surgery (P < 0.0001 for all). The proportion of those with a 30-year CVD event risk of >5% was reduced, as well. In both models, the MBS showed a reduction in the 30-year CVD risk, though the model that included BMI showed a more significant reduction. The results seen in this study were very similar to those seen in studies that looked at the effects of MBS on adults. Previous studies that had an extended follow-up showed a reduction of total CVD events of 33%, whereas this study estimates that reduction to be 39% at 30 years. One previous study said the number needed to treat to prevent 1 CVD event was 50. This study found an even lower number, finding the number needed to treat was 36.5 persons.
MBS showed a significant reduction in the chance of CVD events happening in the long-term, even in those whose BMI remains very high after the surgery. The authors found that the reduction in CVD risk was due to a combination of improvements in dyslipidemia, blood pressure, and lowered diabetes prevalence. Previous studies have shown that MBS can help control diabetes, so it may be time to consider it, especially if a patient has a higher risk for CVD, regardless of the patient’s age.
- Metabolic and bariatric surgery was found to lower the 30-year CVD event risk significantly.
- MBS was shown to cause a reduction in diabetes prevalence, reducing it from 13.5% to 2.2% in the first year.
- MBS appears to be just as effective in young people as it is in adults.
Ryder, Justin R., et al. “Thirty‐Year Risk of Cardiovascular Disease Events in Adolescents with Severe Obesity.” Wiley Online Library, John Wiley & Sons, Ltd, 5 Feb. 2020, onlinelibrary.wiley.com/doi/abs/10.1002/oby.22725?af=R.
George McConnell, PharmD. Candidate, LECOM School of Pharmacy