Weight Loss and Health Status 5 Years after Adjustable Gastric Banding in Adolescents

Abstract

Objective:

This prospective cohort analysis describes changes in weight, cardiometabolic health, and weight related quality of life (WRQOL) following adolescent LAGB.

Methods:

Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) collected demographic, anthropometric, micronutrient, cardiometabolic risk and WRQOL data for 242 adolescents. Data through 5 years were analyzed for 14 participants who underwent LAGB with 2 patients lost to follow up.

Results:

Participants (mean age 18.2±0.4 years) were mostly female (86%) and white (71%) with a median body mass index (BMI) of 48.7 kg/m² (45.5–54.1). Preoperatively, 100%(13/13), 62%(8/13), 57%(8/14), and 7%(1/14) had elevated high sensitivity C-reactive protein (hs-CRP), dyslipidemia, elevated blood pressure (EBP) and type 2 diabetes (T2D), respectively. At 5 years, mean BMI decreased by 3.3% (51.0 vs. 49.3 kg/m², p=0.6), 43%(6/14) had BMI values exceeding baseline and 21% (3/14) underwent band removal. Postoperative prevalence of hs-CRP, dyslipidemia, EBP and T2D was 45%(4/11), 36%(5/11), 33%(4/12), and 0%(0/11), respectively.

Conclusion:

Adolescents undergoing LAGB experienced modest initial weight loss and improvements in cardiovascular risk factors with later weight regain and frequent need for band removal. Despite the small sample size, this prospective study highlights long-term outcomes with high rates of participant retention over time.

INTRODUCTION

Severe or Class 2 obesity, defined as a body mass index (BMI) ≥ 120% of the 95^th percentile for sex and age, or BMI ≥ 35kg/m², threatens the long-term health of 4–7% of the pediatric population overall and in particular, has been reported to affect nearly 10% of adolescents (12–19 years of age) in the U.S.[1, 2]. An increase in the use of metabolic and bariatric surgery (MBS) in severely obese adolescents has been documented [1, 3, 4], driven at least in part by the recognition of the early morbidity and mortality faced by adolescents who are severely obese [5]. In addition, increasing evidence has emerged supporting the use of MBS as a safe and effective strategy in the treatment of severe adolescent obesity [3, 6, 7] and while the majority of recent reports have been focused on Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (SG), the majority of data overall is on the use of LAGB. While several investigators have concluded that LAGB use results in significant weight loss with accompanying comorbidity resolution (i.e. type 2 diabetes and metabolic syndrome), with meta-analyses demonstrating an average BMI decrease of at least 10kg/m² at 3 years [8–11], procedural prevalence has markedly diminished similar to current trends in the adult population undergoing MBS[12, 13]. The reasons for this decline are likely multifactorial and may be related to the inability to provide appropriate follow-up and band management and/or the higher than expected number of revisional procedures along with decreased weight loss when compared to outcomes following RYGB and SG[9, 14, 15].

In an effort to address knowledge gaps related to the use of LAGB in adolescents, data from the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study were used with the objective to examine changes in weight, health outcomes, including post-surgical complications, and quality of life up to 5 years following LAGB insertion.

METHODS

Study Design and Subjects

Methodology and design of the multicenter prospective Teen-LABS study (NCT00465829) have been previously described [16]. Consecutive adolescents (<19 years of age and Tanner Stage 4 or greater) with BMI ≥ 35kg/m² who met accepted consensus eligibility guidelines[17] for MBS were offered enrollment into Teen-LABS at one of five U.S. centers (February 28, 2007- December 30, 2011). Informed consent was obtained from all individual participants included in the study. The study protocol, data and safety monitoring plans, and assent and/or consent forms were approved by all institutional review boards and an independent data and safety monitoring board. Only participants who underwent LAGB insertion as a primary bariatric operation at one of the three Teen-LABS centers that offered LAGB were included in the current analysis (N=14). Two patients were lost to follow up after 24 and 36 months. These patients had a higher baseline median BMI as well as higher median BMI scores at last follow up. All subjects underwent insertion of available adjustable gastric band systems. In accordance with the prospective observational nature of Teen-LABS, there was no clinical coordination between centers and/or use of a specified band adjustment protocol. All band adjustments were performed by the operative surgeon or advanced practice providers, depending on the institution’s practice.

Data Collection

Data were collected at baseline (≤30 days prior to LAGB insertion), 6 months, 1 year, 2 years, 3 years, 4 years, and 5 years post-operatively. The majority of follow-up research visits occurred at Teen-LABS centers (89%), while the remaining visits were comprised of “in-home” evaluations by trained field examiners at participants’ homes or via telephone and/or electronic communication. All relevant laboratory data were obtained from a central laboratory (Northwest Lipid Metabolism and Diabetes Research Laboratories, Seattle, WA). One central database was utilized to store all collected data, which was maintained in a single center.

Data points and Definitions

Demographic data: Age (years) at the time of MBS, race (white or non-white) and gender (male or female) were provided for each study participant.

Weight Loss Outcomes: Weight and height were measured and BMI calculated at each pre- and post-operative visit. Weight change was reported as percent BMI change from baseline post-operatively. Previously reported definitions for prevalence, remission, and incidence of cardiovascular disease risk factors (i.e. dyslipidemia, elevated blood pressure ([18], and type 2 diabetes mellitus (T2D)) were used [3, 19]. In the case of longitudinal determination of dyslipidemia and EBP, definitions were adjusted to account for each participant’s age during follow-up using age-specific cut-points (pediatric versus adult) based on current published clinical guidelines.[1]

T2D: prevalence of T2D was either self-reported, diagnosed by a provider as determined by medical record review (EMR), diagnosed through standard laboratory assessment (glycosylated hemoglobin (A1C) ≥ 6.5%, impaired fasting glucose (IFG) ≥100 mg/dL or 2-hour oral glucose tolerance test glucose ≥200 mg/dL), or determined through usage of medications for diabetes management (with the exception of metformin if being used to treat polycystic ovarian syndrome).

Dyslipidemia: Participants were determined to have dyslipidemia if s/he had elevated low-density lipoprotein cholesterol (LDL-C) or fasting triglycerides (TG), or low high-density lipoprotein cholesterol (HDL-C) or using lipid-lowering medications. For participants < 21 years, TG ≥ 130 mg/dL, or LDL-C ≥ 130 mg/dL, or HDL-C < 40mg/dL were considered abnormal. For those > 21 years, TG ≥ 200 mg/dL, or LDL-C ≥ 160 mg/dL, or HDL-C < 40 mg/dL (males) and < 50mg/dL (females) were considered abnormal. Dyslipidemia remission for participants < 21 years was defined as TG<130 mg/dL, and LDL-C<130mg/dL and HDL-C ≥ 40mg/dL and absence of lipid-lowering medications. Remission for participants >21 years was defined as TG <200mg/dL, and LDL-C<160 mg/dL, and HDL-C ≥40 mg/dL (males) or HDL-C ≥50 mg/dL (females) and absence of lipid-lowering medication. Abnormal thresholds for TG/HDL ratio were defined as ≥ 3.0 for non-blacks and ≥ 2.5 for blacks.[20–22]

Elevated Blood Pressure (EBP): Average systolic blood pressure (SBP) and diastolic blood pressure (DBP) (≥ two separate measurements) were obtained using a Welch Allyn-Spot Vital Signs monitor (4200B). EBP was defined as SBP or DBP ≥ 95th percentile for age/sex/height for subjects <18 years, or SBP ≥ 140mmHg or DPB ≥ 90mmHg for those ≥ 18 years. Irrespective of age, EBP was assigned to those using anti-hypertensive medications. Since measurements were obtained at one rather than multiple separate occasions, the term hypertension was replaced by EBP. Normalization of EBP was defined as SBP and DBP within the defined “normal range” for age without antihypertensive medications. Nutritional Status: serum albumin(g/dL), ferritin(ug/L), transferrin(mg/dL), as well as vitamin B1 erythrocyte transketolase (activity coefficient), B9(ng/mL), B12 (pg/mL), D (ng/mL), A (ug/L) were obtained at each time point. Quality of life assessment: the impact of weight on quality of life score (IWQOL) was obtained at each time point and is reported as mean ± standard deviation. Follow-up Surgical Procedures: subsequent bariatric surgical procedures and/or revisional surgeries during the five-year follow-up period were documented for each participant as well as associated indications. Surgical Complications: post-operative complications noted within 30 days of the index bariatric procedure were recorded and analyzed. In addition, complications requiring reoperation or readmission over the 5 years were analyzed.

Statistical Methods

Given the small number of participants in Teen-LABS who underwent LAGB insertion (n=14), in-depth comparative and predictive analyses were not performed. Descriptive statistics were reported as either mean ± standard deviation (SD) or median and interquartile range (IQR) for continuous variables or frequencies and percentages for categorical variables. Pair-wise comparison between baseline and 5 year outcomes were compared using Wilcox signed rank test, paired t-test, and Fisher’s exact test as appropriate. BMI change outcomes, quality of life assessment, and comorbidity resolution was determined for the entire cohort and included sub-analyses designed to differentiate between participants who underwent revisional bariatric surgery. Calculations for percent excess weight loss and percent total body weight loss were as follows:

$$\%\text{total body weight loss}=\left\{\text{Weight}\left(\text{post-op}\right)-\text{Weight}\left(\text{BL}\right)/\text{Weight}\left(\text{BL}\right)\right\}\ast 100$$

$$\%\text{excess weight loss}=\left\{\text{Weight}\left(\text{post-op}\right)-\text{Weight}\left(\text{BL}\right)\right\}/\left\{\text{Weight}\left(\text{BL}\right)-\text{Ideal weight}\right\}$$

RESULTS

Participant Characteristics and Anthropometric Changes

Participants (mean age at time of surgery 18.2 ± 0.4 years) were mostly female (86%) and white (71%) with a mean BMI of 51.0 ± 8.8 kg/m². Initially, participants demonstrated a mean BMI loss of 10%, but this diminishes to 3% at 5 years (Figure 1). Nearly half of the cohort (42.9%; 6/14) had BMI values that exceeded their baseline. Three patients underwent band removal. One of these three patients underwent concurrent conversion to RYGB (Figure 1) (Reviewer #2, comment #1). In the band retention group, there was no change in BMI at five 5 years (Table 1). These BMI changes corresponded to a median ‒0.2 (IQR ‒4.4 to 3.2, p=0.7) percent total body weight loss and median 0.009 (IQR ‒0.29 to 0.8, p=0.52) percent excess weight loss in the total cohort (Table 1).

Figure 1:

BMI change over 5 years for each participant

Table 1:

Longitudinal Changes in Anthropomorphic and Comorbidity Outcomes

	Baseline Total Cohort (n=14)	5-Year Total Cohort (n=12)	Change from baseline to 5th year for total cohort (N=14) (p-value)	Baseline LAGB Retention Cohort (n=11)	5-Year LAGB Retention Cohort (n=9)d	Change from baseline to 5th year for ABG retention cohort (N=11) (p-value)
*BMI (kg/m2)a,e,f			0.60			0.91
Median (interquartile range)	48.8 (45.5–54.1)	44.1 (42.1–54.6)		49.8 (44.0–55.6)	44.6 (42.4–55.5)
Mean (standard deviation)	51 (8.8)	49.3 (14.9)		51.6 (9.7)	51.4 (16.0)
Median Percent Total Body Weight Loss		−0.2 (−4.4 – 3.2)	0.7		0.4 (−4.4 – 3.2)	0.8
Median Percent Excess Weight Loss		0.009 (−0.3 – 0.8)	0.5		0.009 (−0.2 – 0.9)	0.6
EBP, n (%)c	8/14 (57)	4/12 (33)	0.99	7/11 (64)	4/9 (44)	0.99
T2DMc	1/14 (7)	0/11 (0)	-	1/11 (9)	0/9 (0)	-
Dyslipidemiac	8/13 (62)	5/11 (45)	0.99	7/10 (70)	5/9 (56)	1.0
LDL >130	1/13 (8)	0/11 (0)	-	1/10 (10)	0/9 (0)	-
HDL <40	6/13 (46)	3/11 (27)	0.44	6/10 (60)	3/9 (33)	1.0
TG >130	7/13 (54)	4/11 (36)	0.08	6/10 (60)	4/9 (44)	1.0
Abnormal	7/7 (100)	4/4 (100)	0.25	5/6 (83)	4/4 (100)	1.0
TG/HDL ratioc
IWQOLb,f
Total	72.3 (15.0)	82.5 (19.9)	<0.01	69.9 (15.3)	81.0 (20.0)	0.01
Physical	59.7 (16.5)	81.4 (19.2)	0.02	56.9 (17.3)	77.6 (20.2)	0.02
SF-36b,f
Mental	51.7 (8.2)	51.5 (11.7)	0.94	50.7 (9.0)	53.3 (6.4)	0.42
Physical	48.5 (8.0)	48.4 (9.5)	0.37	47.9 (7.9)	47.5 (9.7)	0.40

^aWilcox signed rank test was used;

^bPaired t-test was used;

^cFisher’s exact test was used;

^dBand retention cohort is the group of participants that did not have the band removed during the study period

^emedian and interquartile range

^fmean and standard deviation

^*Difference between mean and median suggests that BMI is skewed and normality assumption for parametric test is violated.

Thus, non-parametric approach was used for significance testing. Abbreviations: EBP, elevated blood pressure; IWQOL, Impact of Weight on Quality of Life-Kids

Comorbidities

As shown in Table 1, the baseline prevalence of dyslipidemia, EBP and T2D was 62% (8/13), 57% (8/14), and 7% (1/14), respectively. In addition, baseline mean IW-QOL total score was 72.3±15, and the mean SF-36 was 51.7±8.2 for the mental portion and 48.5±8.1 for the physical portion. Five years following LAGB insertion, the prevalence of dyslipidemia, EBP and T2D decreased to 45% (5/11, p=0.99), 33% (4/12, p=0.99) and 0% (0/11) respectively, while mean IW-QOL total score improved to 82.5±19.9 (p<0.01).

Analysis of the 11 participants who maintained an LAGB in place throughout the five-year study period showed baseline prevalence of dyslipidemia, EBP, and T2D at 70% (7/10), 64% (7/11), 9% (1/11), respectively with a mean IW-QOL total score of 69.9±15.3, and mean SF-36 score of 50.7±9 for the mental portion and 47.9±7.8 for the physical portion (Table 1). At five years the prevalence of dyslipidemia, EBP, and T2D decreased to 56% (5/9), 44% (4/9), and 0% (0/9), while the mean IW-QOL total score improved to 81±20 (p=0.01).

Micronutrients

Micronutrient levels remained largely unchanged over the five-year study period. Median vitamin B12 concentrations were 438 pg/mL at baseline and 405.0 pg/mL at year 5 (p=0.08) while parathyroid hormone levels were a mean of 40 pg/mL at baseline to 63 pg/mL at five years (p=0.21; Table 2).

Table 2:

Longitudinal Changes in Micronutrient Deficiencies

	Baseline n (%)	5 year n (%)
Elevated Parathyroid Hormone	1/12 (8.33)	1/11 (9)
Vitamin B1	11/11 (100)	10/10 (100)
Vitamin D	6/12 (50)	4/11 (36)
Vitamin A	1/12 (8)	1/11 (9)

Complications

Band removal included participants who experienced weight loss failure at 29 months (n=1), malposition at 34 months (n=1) and band intolerance at 37 months (n=1). Additional complications included pulmonary embolism; 7.1% (1/14), postoperative ileus; 7.1% (1/14), gastritis; 7.1% (1/14), hiatal hernia; 7.1% (1/14), and umbilical hernia; 7.1% (1/14) while 35.7% (5/14) experienced soft tissue infections related to skin abscess (2/14), cellulitis (2/14), and/or port site infection (1/14). Two participants underwent cholecystectomy after developing symptomatic cholelithiasis and chronic cholecystitis. One of these patients had gallstones without symptoms at their baseline assessment.

DISCUSSION

We report outcomes related to a small but important cohort of severely obese adolescents who underwent LAGB. The study used rigorous methodology and uniform definitions to measure changes in weight, physiological parameters, and quality of life. This report directly addresses the relative paucity of prospective data evaluating long-term outcomes of LAGB in the adolescent population. Despite minimal change in weight and cardiometabolic risk factors, of importance is the sustained improvement in post-operative quality of life. This suggests that improvement in quality of life may not be solely related to percentage weight loss and should be examined further. Participants had unusually good baseline QOL scores in the SF-36, which may be related to adolescents having higher QOL scores in comparison to adult cohorts as demonstrated by Dixon et al [23].

An expanding body of evidence demonstrates that severe obesity, including numerous related co-morbid diseases, are difficult to reverse, and outcomes following various lifestyle modification strategies (i.e. diet, exercise and behavior modification) are associated with only modest improvements; which are often not durable[1]. While previous reports have concluded that metabolic and bariatric surgery is a safe and effective treatment modality for severe obesity in adolescents [3], and advances in pharmacotherapy, such as topirimate and phentermine, serve as additional weight loss tools, consensus regarding which treatment(s) are most appropriate or best suited for the adolescent population remain in question. Substantial, but decreased, weight loss outcomes following LAGB in adults compared to other contemporary bariatric procedures (i.e., RYGB and SG), coupled with high reoperation rates and/or or the need for device explantation, have resulted in a precipitous decline in LAGB utilization in adult and adolescent populations with adult data demonstrating a decrease from 35% to 5% [12, 24, 25]. The current analysis differs from previous studies regarding weight loss outcomes in LAGB in both adolescents and adults, as evidenced by data showing no weight loss among participants who retained their band at 5 years [26–28].

Although there has been increasing focus on the use of various bariatric procedures in the pediatric and adolescent age groups, a single operation that offers optimal results remains elusive. Bondada et al. performed a retrospective review of bariatric surgery in adolescents and found a rising use of LAGB in the early 2000s, which has subsequently decreased with concerns regarding long term outcomes in adults[24]. At its inception, LAGB was considered an attractive option due to the technical ease of the procedure, reversibility, short hospital length of stay, and “reasonable” weight loss. However, other studies have demonstrated that re-interventions required for pouch revision, band complications, explantation due to intolerance, other complication, or weight loss failure are associated with a higher morbidity than was anticipated [14]. Most studies examining LAGB in adolescents have found excess body weight loss percentages ranging from 35–60% (approximately 15–30% total body weight loss), but at the cost of a high reoperation rate (5–20%)[9, 24, 29]. The American Society for Metabolic and Bariatric Surgery’s most recent guidelines[30] state that they do not feel the LAGB should be the preferred weight loss procedure in adolescents. This statement was based on the high reintervention rate as supported by a randomized control trial comparing LAGB and lifestyle intervention where the LAGB group had a 30% revisional procedure rate[26].

In a recent review of outcomes after LAGB, RYGB, SG in adolescents, LAGB use has decreased over the last 10 years and is associated with lower weight loss percentages compared to either RYGB or SG[8, 11, 25]. Similarly, our study demonstrated no weight loss at 5 years in the LAGB cohort that retained the band, which is significantly less than the 27% weight loss at 3 years that we have observed with SG and RYGB [3]. Likewise, while participants in this cohort did exhibit resolution in hypertension and dyslipidemia (50% and 38%, respectively), reported comorbidity resolution after SG and RYGB is much higher (5). Interestingly, improvement in quality of life in this cohort was similar to that seen after SG and RYGB (5), suggesting that these parameters may not be solely dependent on weight loss outcomes.

There is a relative paucity of robust and uniform prospective data looking at LAGB in adolescents. This area of study requires further attention as it is an area of public health interest to determine the best bariatric surgery for adolescents. This study does have some limitations. Details regarding specific reasons for band removal are restricted by the study design, and the analysis has limited power due to the small sample size. Data regarding post operative band management should also be taken in the context that there was no clinical coordination between centers and/or use of a specified band adjustment protocol in accordance with the observational structure of the study. However, the prospective nature along with the uniformity of data collection, standardized definitions, and high subject retention make this study an important contribution to the literature.

CONCLUSION

Adolescents who underwent LAGB experienced modest weight reduction initially, but weight regain occurred by five years following implantation of the device suggesting that the LAGB may not be the optimal weight loss procedure in adolescents.

Table 3:

Longitudinal changes from baseline to 5 years in dyslipidemia, LDL, HDL, triglycerides, and abnormal TG/HDL ratio

	Baseline	6 months	12 months	24 months	36 months	48 months	60 months
Dyslipidemia	8/13 (62)	8/12 (67)	5/11 (46)	6/12(50)	7/11 (64)	5/9 (56)	5/11 (46)
LDL >130	1/13 (8)	1/12 (8)	1/11 (9)	0	1/11 (9)	0	0
HDL <40	6/13 (46)	5/12 (42)	5/11 (45)	3/12(25)	5/11(45)	2/9 (22)	3/11 (27)
TG >130	7/13 (54)	5/12 (42)	1/11 (9)	4/12 (33)	2/11(18)	5/9 (56)	4/11 (36)
Abnormal TG/HDL ratio	7/7 (100)	5/5 (100)	3/3 (100)	6/6 (100)	4/4 (100)	3/3 (100)	4/4 (100)

n/n (%)