This was a prospective study of 180 severely obese patients with biopsy-proven NASH.
NASH: At 5 years after bariatric surgery, NASH was resolved, without worsening fibrosis, in samples from 84% of patients (n = 64; 95% confidence interval, 73.1%-92.2%).
Fibrosis: Fibrosis decreased, compared with baseline, in samples from 70.2% of patients (95% CI, 56.6%-81.6%). Fibrosis disappeared from samples from 56% of all patients (95% CI, 42.4%-69.3%) and from samples from 45.5% of patients with baseline bridging fibrosis.
My take: This study showed that patients with NASH who underwent bariatric surgery had resolution of NASH in liver samples from 84% of patients 5 years later. The reduction of fibrosis was progressive, beginning during the first year and continuing through 5 years.
A recent study (LMS Carlsson et al. NEJM 2020; 383: 1535-43) was summarized in a quick take. Essentially, obese subjects who underwent bariatric surgery survived three years longer than a control group who had not undergone surgery but lived 5 years shorter than a reference group without obesity.
The authors speculate on the reasons why the bariatric subjects continued to have a lower life expectancy than controls after surgery:
Above-normal BMI even after surgery
Irreversible effects of obesity-related metabolic dysfunction
Higher risk of alcohol abuse, suicide, and trauma (including fall-related); these factors were identified in the SOS study more often than in those who had not undergone bariatric surgery
Since there have been improvements in bariatric surgery since the time of this cohort underwent surgery (1987-2001), it is possible that the average gain in life expectancy would be greater.
A recent policy statement (SC Armstrong et al. Pediatrics 2019; 144 (6): e20193223) outlines current evidence regarding adolescent bariatric surgery and makes recommendations for practitioners & policymakers. There is also an accompanying technical report which provides more detail and supporting evidence. Thanks to Ben Gold for this reference.
This policy statement uses “adolescent” to refer to a person from age 13 years to age 18 years.
Background: “Although nearly 4.5 million US adolescents have severe obesity, current estimates suggest that only a small faction undergo metabolic and bariatric surgery…Many providers prefer a “watchful waiting” approach, or long-term lifestyle management.50 However, current evidence suggests that pediatric patients with severe obesity are unlikely to achieve a clinically significant and sustained weight reduction in lifestyle-based weight management programs53 and that watchful waiting may lead to higher BMI and more comorbid conditions…In addition, comparative data examining
postoperative outcomes along the severely obese BMI spectrum (low, middle, and high) suggest that adolescents within a lower BMI range (BMI <55) at the time of bariatric
surgery have a higher probability of achieving nonobese status when compared with individuals with a higher starting BMI (BMI ≥55).”
From Table 2 -Indications for Bariatric Surgery:
Class 2 obesity, BMI ≥35, or 120% of the 95th percentile for age and sex, whichever is lower along with clinically significant disease, including obstructive sleep apnea (AHI .5), T2DM, IIH, NASH, Blount disease, SCFE, GERD, and hypertension
Class 3 obesity, BMI ≥40, or 140% of the 95th percentile for age and sex, whichever is lower. Clinically significant disease is not required but commonly present
Recommendations for practitioners:
Seek high-quality multidisciplinary centers that are experienced in assessing risks and benefits of various treatments for youth with severe obesity, including bariatric surgery, and provide referrals to where such programs are available.
Identify pediatric patients with severe obesity who meet criteria for surgery and provide
timely referrals to comprehensive, multidisciplinary, pediatric-focused metabolic and bariatric surgery programs.
Monitor patients postoperatively for micronutrient deficiencies and consider providing iron, folate, and vitamin B12 supplementation as needed.
Monitor patients postoperatively for risk-taking behavior and mental health problems.
Advocate for increased access for pediatric patients of all racial, ethnic, and socioeconomic backgrounds to multidisciplinary programs
Consider best practice guidelines, including avoidance of unsubstantiated lower age limits, in the context of potential health care benefits and individualized patient-centered care.
For insurers: Provide payment for care (pre-operative, operative & post-operative). Reduce barriers to pediatric metabolic and bariatric surgery (including inadequate payment, limited access, unsubstantiated exclusion criteria, and bureaucratic
delays in approval requiring unnecessary and often numerous appeals) for patients who meet careful selection criteria.
My take: These recommendations are in general agreement with previous guidelines. I think having the stamp of approval from the AAP is likely to help in getting coverage and may shift attitudes.
Among 505,258 obese individuals, 49,977 had bariatric surgery.
Overall mortality rates were lower in the surgery group during the first 14 years but higher after 15 years (HR 1.20 with CI 1.02-1.42). Thus, overall, obese patients who underwent bariatric surgery had longer survival times than obese patients who did not have surgery. Both groups had higher mortality than the general population
The improved survival compared to those without surgery was related to decreased mortality from cardiovascular mortality, diabetes and cancer. However mortality due to suicide was increased.
Limitations: lack of detailed data including BMI, smoking and alcohol consumption
Studies have shown that adults with obesity who were obese as adolescents have worse medical outcomes than persons who became obese in adulthood (Nat Rev Endocrinol 2018; 14: 183-8; NEJM 2011; 365; 1876-85). Thus, the question is whether earlier intervention would improve outcomes.
A recent study (TH Inge et al. NEJM 2019; 380: 2136-45, editorial TD Adams, pgs 2175-7) compares the 5-year outcomes of adolescents (n=161) and adults (n=396) who underwent Roux-en-Y gastric bypass (RYGB). The two prospectively enrolled cohorts were participants in two related but independent studies.
There was similar weight loss in both groups at the 5-year mark: -26% in adolescents and -29% in adults
Adolescents had greater remission in both type 2 diabetes (86% vs 53%) and in hypertension (68% and 41%).
Three adolescents (1.9%) and seven adults (1.8%) died in the 5-years after surgery. Two of the adolescents deaths were consistent with overdose.
Reoperations were significantly higher in adolescents than adults (19 vs 10 reoperations per 500 person years). The authors comment that the reason for this finding is unclear, possibly related to recall bias or closer monitoring of the adolescents.
Nutrient deficiencies were common in adolescents at followup. After 2 years, 48% of adolescents had low ferritin compared with 29% of adults (98% of participants had normal ferritin prior to RYGB. The authors note that this is likely related to adherence to vitamin/mineral supplementation (which is needed lifelong).
Limitations: observational study design
The associated commentary::
“Almost 6% of adolescents in the U.S. are severely obese and bariatric surgery is now the only successful long-term management…Negative health outcomes of bariatric surgery reported in adolescents mirror those reported in adults — including, for example, potential for self-harm (including suicide) and increased risk of alcohol or drug abuse.”
“Adolescent patients may not have fully developed the capacity for decision making, especially about a procedure that will have lifetime consequences.”
My take: This study and commentary point out some clear health benefits for adolescents who undergo RYGB. Given the lifelong need for monitoring and adherence with medical treatment as well as some of the negative health outcomes, it is also clear how challenging it is to proceed with RYGB in teenage years.
A recent systematic review and meta-analysis (Y Lee, et al. Clin Gastroenterol Hepatol 2019; 17: 1040-60) included 32 cohort studies with 3093 liver biopsy specimens from patients with nonalcoholic fatty liver disease (NAFLD).
Bariatric surgery resulted in a biopsy-confirmed resolution of steatosis in 66%, inflammation in 50%, ballooning degeneration in 76%, and fibrosis in 40%.
Bariatric surgery resulted in worsening features of NAFLD in 12%.
The authors note that Roux-en-Y Gastric Bypass (RYGB) “showed greater reduction of liver side effects and higher: resolution of NAFLD.”
Jejejnoileal bypass (JIB) and biliopancreatic diversion (BPD) “both have been associated with higher liver function morbidity.”
The overall GRADE quality of evidence was considered very low.
My take: Though better studies are needed, the majority of patients’ livers appear to benefit from bariatric surgery.
According to a recent study (EL Yu et al. J Pediatr 2019; 207: 64-70), about one-third of boys and one-fourth of girls with obesity have nonalcoholic fatty liver disease (NAFLD).
This study from San Diego with 408 children aged 9-17 years (mean 13.2 years) with obesity evaluated for NAFLD with laboratories (to exclude other etiologies) and with liver MRI proton density fat fraction (PDFF), with ≥5% considered the threshold for NAFLD.
Prevalence of NAFLD was 26% in this population, with 29.4% in males and 22.6% in females
The optimal cut offs of ALT for detecting NAFLD in this study were ≥30 U/L for females and ≥42 U/L for males. These are much lower than NASPGHAN guidelines which proposed ≥80 U/L or twice the ULN as thresholds for further investigation. (The NASPGHAN recommendations are likely to have higher specificity in identifying children at greater risk for nonalcoholic steatohepatitis (NASH).)
77% of this cohort were hispanic, thus prevalence may vary significantly in other populations.
MRI-PDFF -the exact cut off is unclear. The authors note that if 3.5% were chosen, the NAFLD prevalence jumped to 49.3% (according to Table II –though the discussion stated 53.2%)
My take: Understanding the likelihood of NAFLD in children at risk is a helpful first step. This study points to the growing use of non-invasive diagnosis with MRI.
On a related topic, briefly noted: “Obesity in Adolescents and Youth: The Case for and against Bariatric Surgery” (A Khattab, MA Sperling. J Pediatr 2019; 207: 18-22). In this review, the authors refer frequently to endocrine society guidelines (J Clin Endocrinol Metab 2017; 102: 709-57). These guidelines generally recommend bariatric surgery only under specific conditions (eg. completion of Tanner 4 or 5 along with a BMI of 40 kg/m-squared or BMI of 35 with significant extreme comorbidities after failure of lifestyle modifications & without untreated psychiatric illness). This review predicts increasing use of bariatric surgery in adolescents “as more data on long-term outcomes in larger cohorts become known.”