Is weight regaining significant post laparoscopic Roux-en-Y gastric bypass surgery? - A 5-year follow-up study on Indian patients.

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (RYGB) has been proven to induce significant weight loss and remission of related co-morbidities in patients with morbid obesity. The long-term follow-up data show weight regain or failure to achieve complete remission of type 2 diabetes mellitus (T2DM) in some patients. In this study, we report weight loss patterns and remission of T2DM in patients with morbid obesity during a 5-year follow-up after RYGB.
OBJECTIVE: The objective was to evaluate outcomes during the follow-up on excess weight loss (EWL) and remission of T2DM after laparoscopic RYGB among Indian patients.
SETTING: The study was conducted in a tertiary care hospital, Kerala, India.
MATERIALS AND METHODS: This is a retrospective study in patients who underwent surgery between 2007 and 2010. The patient demographics, pre- and post-operative body mass index (BMI), co-morbidities and EWL were recorded from the medical records. These data were compared between pre-operative and follow-up intervals till 5 years using statistical approaches.
RESULTS: The study included 157 patients (91 males and 66 females) having a mean pre-operative BMI of 47.91 ± 7.01 kg/m2. A significant reduction in the BMI was observed at each follow-up point (P < 0.01) till 5 years after the surgery. The mean percentage of EWL increased from 34.57% ± 12.62% to 71.50% ± 15.41% from 3 months to 5 years after the surgery. Twelve per cent (n = 19) of patients achieved normal BMI (<25 mg/kg2) by 3rd year after the surgery. However, the remission of T2DM was achieved in >50% of patients within a year of surgery. During the 5th year, weight regain (1-22 kg) was observed in 36.70% (n = 58) patients, and recurrence of T2DM was observed in two patients.
CONCLUSIONS: The long-term durability of RYGB in the study population was satisfactory with significant weight loss and remission of T2DM.

INTRODUCTION

Roux-en-Y gastric bypass (RYGB) is the 'gold standard' bariatric surgical procedure due to both restrictive and malabsorptive properties and offers superior results in resolution of obesity-related co-morbidities such as type 2 diabetes mellitus (T2DM) and hypertension.[12] The RYGB procedure increases the delivery rate of nutrients into the small intestine, with a fast glycaemic rise and increased secretion of glucagon-like peptide-1 (GLP-1), restoring the first-phase insulin response.[3] This leads to an improved insulin secretion after a meal, suggesting enhanced beta-cell function which makes RYGB as an effective treatment for patients with T2DM and morbid obesity.[4] RYGB offers advantage for the obese patients with T2DM through improvement in cardiovascular function, reduced inflammation and an improvement in the abnormal metabolic panel.[5]

Peak body mass index (BMI) reduction is generally achieved within 1–2 years after the surgery, and on long term, most patients maintain >50% weight loss and remission of co-morbidities.[4] In a recent 12-year follow-up study, long-term durability of weight loss and effective remission and prevention of T2DM after RYGB was found to be superior compared to medical management.[6] However, long-term durability of weight loss and remission of co-morbidities varied among individuals. Long-term outcome from the follow-up data after RYGB surgery is important to assess the performance of the patients, durability and sustainability of weight loss and/or T2DM remission pattern. Although bariatric or metabolic surgery is practiced by many centres, follow-up data on the outcome are relatively lesser. It has been shown in earlier reports that RYGB, although is an attractive procedure, often fails in maintaining or achieving satisfactory weight loss with weight regain in some patients.[78] Weight regain after RYGB often has a large negative impact on the bariatric quality of life index.[9]

Here, we report the long-term outcome from RYGB among morbidly obese Indian patients from a single centre using the post-surgery regular follow-up data.

MATERIALS AND METHODS

Patients and study design

This is a retrospective, single-centre, observational study using the data from the patients who had undergone RYGB for obesity/obesity-related metabolic disorders between 2007 and 2010. The data were reviewed from hospital medical records for pre- and post-operative details. The inclusion criteria were patients with morbid obesity (BMI >30 kg/m2) with or without co-morbidities and undergone RYGB with the follow-up data at 3 months, 6 months, 1 year, 3 years and 5 years.

Ethical clearance

This study was approved by the Institutional Ethical Committee - Moulana Hospital Ethical Committee, Mallapuram, Kerala (MH/EC/04/2017, dated 11th September, 2017). As this was a retrospective study, informed consent was not applicable.

Surgical technique and post-operative care

The RYGB was performed using the 6-port technique with standard pre-operative care and precautions. After gastroesophageal junction identification, the stomach was transected with a linear stapler entering the lesser sac 3–5 cm below the junction, creating a small gastric pouch with a volume of approximately 15 ml. A 50-cm biliopancreatic limb was measured, and an antecolic end-to-side gastroenterostomy was formed using a 45-mm vertical stapler. A stapled side-to-side jejunojejunostomy was formed 150 cm distally. Intermesenteric and Petersen spaces were closed with non-absorbable sutures. The standard post-operative care was given to all patients. Fluid and food intakes were monitored and discharged with dietary instructions by a bariatric dietician along with daily multivitamin and calcium supplements.

Data and study outcomes

Patient demographics, pre-operative weight, BMI, fasting blood sugar (FBS), HbA1c, co-morbidities and post-operative complications were recorded from the medical records. The end points such as percentage of excess weight loss (%EWL), changes in BMI and remission of T2DM were calculated with reference to the pre-operative data at every follow-up and between follow-ups. Standard conventions were followed for the assessment of prevalence, remission and incidence of coexisting conditions. Complete remission of T2DM was considered if the FBS level was <100 mg/dL (<5.6 mmol/L) and HbA1c was <6.0%. Interpretation of weight loss: the bariatric procedure was considered inadequate if the %EWL was between 30% and 50%, and failure if %EWL was <30%. Underweight was defined as BMI <20 kg/m2.

Statistical analysis

Continuous data were expressed in mean ± standard deviation, and categorical data were presented as frequency and percentages. Normality was tested using Shapiro–Wilk test, and paired t-test was used to compare quantitative variables across the time points. All statistical analyses were performed using IBM SPSS Statistics for Windows software (version 22.0, IBM Corp, Armonk, New York, USA).

RESULTS

Patient demographics

The pre-operative patient demographics and baseline data are given in Table 1. The study group included 157 patients (58% male and 42% females) with complete follow-up data. The mean age of the group was 35.64 ± 10.11 years (range: 17–63 years). At baseline, 2.5% (n = 4) of the patients were in the teenage age group (range: 17–19 years), 68.80% (n = 108) were in the age group of 20–40 years and 28.70% (n = 45) were above the age of 40 years.

Table 1

Patient demographics (n=157)

Details	Data
Male- n (%)	91 (58%)
Female-n (%)	66 (42%)
Mean age (Years)	35.64±10.11
Mean BMI (kg/m2)	47.91±7.05
No. DM cases -n (%)	43 (27.38%)
Mean BMI (kg/m2)	47.71±7.46
Mean FBS	125.88±16.99
Mean HbA1C	6.24±0.58
Other co-morbidities
HTN	46
OSA	75
GERD	04
Hyperlipidemia	03
Arthritis	63
Others	32

HTN- Hypertension, OSA- Obstructive sleep apnoea, GERD- Gastroesophageal Reflux Disease

Follow-up data

The patients were followed up at regular intervals for a period of 5 years (3 months, 6 months, 1 year, 3 years and 5 years).

Anthropometric changes

The mean weight of patients was 132.93 ± 22.46 kg at the baseline, and significant reduction in the mean weight was observed in the post-surgery follow-up period. The mean weight loss at the follow-up periods is given in Table 2. At 3 months after surgery, the mean weight reduction of the cohort was 22.71 ± 8.51 kg (range: 7–52 kg).

Table 2

Changes in the weight loss, BMI, %TWL and %EWL after RYGB in the study cohort (n=157)

Follow up	Mean weight loss	P	BMI	P	%TWL	P	%EWL	P
Pre operative	-	-	47.89±7.01	-	-	-	-	-
3 month	22.71±8.51	-	39.38±6.42	<0.001*	17.07±5.7	-	34.57±12.62	-
6 month	34.21±10.92	<0.001*	35.29±5.93	<0.001*	25.61±6.66	<0.000*	51.74±14.97	<0.001*
1 year	41.56±14.10	<0.001*	32.71±5.40	<0.001*	30.86±7.72	<0.000*	61.98±16.00	<0.001*
3 year	48.12±17.78	<0.001*	30.38±4.56	<0.001*	34.80±8.85	<0.000*	70.41±15.45	<0.001*
5 year	49.05±18.41	0.004*	30.04±4.52	0.003*	36.80±9.28	<0.007*	71.50±15.41	0.024*

**Significantly different from the respective previous follow-up data. BMI: Body Mass Index, TWL: Total Weight Loss, EWL: Excess weight loss

Within 3 and 6 months after surgery, 12.10% (n = 19) and 50.30% (n = 79) of patients achieved >50% EWL, and at the same time points, the mean %EWL of the study group was 34.13% and 51.36%, respectively. Within 1 year – 75.80% (n = 119), at 3 years – 91.10% (n = 143) and at 5 years – 93.06% (n = 147) patients achieved more than 50% EWL. Even at 5 years after surgery, one (0.63%) patient could not achieve satisfactory results (%EWL: 20.58%).

At 1 year, 3 years and 5 years of surgery, the mean %EWL of the study group was 61.98%, 70.41% and 71.50%, respectively [Table 2].

The mean pre-operative BMI was 47.91 ± 7.05 kg/m2 (range: 29.70–67.2 kg/m2). Significant reduction in mean BMI was observed throughout the follow-up period. Within a year after surgery, the mean BMI of the study group was 32.71 ± 5.40 kg/m2, and at the last follow-up (5 years), it was 30.04 ± 4.52 kg/m2, which was significantly lower than the pre-operative and previous follow-ups (P < 0.001) [Table 2]. About 1.90% (n = 3) of patients (initial BMI between 30 and 38 kg/m2) had achieved normal BMI (<25 kg/m2) as early as 6 months after the surgery. At 1-year follow-up, 5.7% (n = 9) of patients had attained normal BMI, in 29.30% (n = 46) of patients, the BMI was reduced to <30 kg/m2 (25 30 kg/m2 (range: 30.0–43.56 kg/m2). The distribution of BMI, weight and %EWL of the study cohort at different time points is given in Figure 1.

Figure 1

Distribution of BMI (body mass index), weight loss, % TWL (total weight loss) and % EWL (Excess weight loss) in the study cohort at different time points

Weight regain

Weight regain was observed in some patients post surgery. 12.73% (n = 20) of patients had regained a mean weight of 4.1 ± 1.97 kg (range: 1–9 kg) between 6 months and 1 year. However, 17 of these patients had achieved >50% EWL at 6 months, except three patients, others maintained >50% EWL [Table 3]. Between 1 and 3 years, 19.74% (n = 31) of patients showed weight regain (4.74 ± 2.80 kg; range: 1–11 kg); among them, 24 patients continued to maintain >50% EWL. Between 3 and 5 years, weight regain (2.57 ± 1.20 kg; range: 1–22 kg) was observed in 36.94% (n = 58) patients; 55 of these patients had achieved >50% EWL previously and they still maintained the weight loss at >50% EWL.

Table 3

Weight regain among the patients who had >50% EWL

Follow up	>50% EWL
	n (%)	Weight regain (n&%)
3 months	19 (12.1)	-
6 months	79 (50.3)	1 (5.3)
1 year	119 (75.8)	17 (21.51)
3 year	143 (90.9)	29 (24.36)
5 year	147 (93.6)	55 (38.46)

Weight regain as compared to the previous follow up is calculated. %EWL: Excess weight loss

Remission of co-morbidities

In the cohort at the baseline, T2DM was present in 27.38% (n = 43) of patients, having a mean FBS of 125.88 ± 16.99 mg/dL and the mean HbA1c of 6.24 ± 0.58%. The mean BMI of the diabetic patients was 47.71 ± 7.46 kg/m2 (range: 30–63 kg/m2), and at 5-year follow-up, it was 30.39 ± 4.36 kg/m2 (range: 23.15–43.56 kg/m2) [Table 4].

Table 4

Number of patients showing success after bariatric surgery (RYGB) in remission of diabetes (n=43)

Follow-up	%EWL >50%	Remission of T2DM (HbA1c <6.0%)	Improvement of T2DM (HbA1c <6.0-6.5%)
3 Months n (%)	19 (12.03)	26 (60.46)	14 (32.55)
6 Months	79 (50)	27 (62.79)	13 (30.23)
1 Year	119 (75.32)	32 (74.41)	7 (16.27)
3 Year	143 (90.51)	32 (74.41)	10 (23.25)
5 Year	147 (93.04)	36 (83.72)	5 (11.62)

EWL: Excess weight loss, T2DM: Type 2 diabetes mellitus

After surgery, a significant reduction in FBS was observed at 3 months, 6 months and 1 year compared to the baseline and also between the follow-ups (P < 0.001). Similarly, mean HbA1c levels decreased significantly after the surgery at 3 months (P < 0.001) without further increase in the levels in subsequent follow-ups. 60.46% (n = 26) of patients achieved remission at 3 months, 62.79% (n = 27) at 6 months and 83.72% (n = 36) at 5 years had complete remission of T2DM, and improvement in HbA1c levels (>6.0%–6.5%) was seen in 11.62% (n = 5) patients. However, two patients still had HbA1c levels above 6.5%.

DISCUSSION

Results from the follow-up data show satisfactory outcome from RYGB in terms of both weight loss and remission of T2DM among patients. Here, 50% of patients achieved satisfactory outcomes at 6 months after surgery and increased to 91.9% within 3 years after surgery. A small percentage of patients could attain normal BMI within a year (6.97%); however, absolute failure (<0% reduction in BMI) was not observed in this cohort. 9.30% of patients could not achieve satisfactory weight loss; still, these patients had complete remission of T2DM. Several studies have demonstrated improved glycaemic control in obese patients with T2DM after surgery independent of weight loss in procedures like RYGB.[1011] The diabetic remission is attributed to the calorie restriction and nutrient exclusion to the proximal gut. RYGB has been known to increase the delivery rate of nutrients to the small intestine, resulting in fast glycaemic rise and increased secretion of GLP-1 leading to insulin response. The metabolic surgery procedure has shown better disease management in patients with inadequate glycaemic control despite using the best available medical treatments.[1213141516]

Previous reports have shown weight reduction peak at 1–2 years after the surgery.[417] The long-term durability of weight loss depends on the patients' compliance with the post-surgery guidelines with respect to diet and physical activities. Long-term follow-up studies has shown favourable results in terms of the durability of weight loss after RYGB.[18]

The outcome from surgery in super-obese patients with respect to %EWL was appreciable, however, most of them could achieve ≥50% EWL within a year or 2 years after the surgery. Interestingly, in this study, 12.03% of super obese patients could attain normal BMI. Ideally, >50% EWL is a favourable outcome from any bariatric/metabolic surgery. The initial weight loss following the surgery will not be durable in a few patients, and they tend to regain weight after the initial weight loss. Here, 7.60% (n = 6) of patients who had initially lost >50% excess weight regained weight within a year after the surgery. One case of underweight (BMI 19.38 kg/m2) was seen in the cohort at 5-year follow-up.

Remission of diabetes in a subset of patients as early as 3 to 6 months after the surgery was observed. Remission of obesity-related co-morbidities is strongly associated with weight loss.[19]

The finding of this study is corroborated by many published works that although RYGB is a preferred, most commonly performed, highly efficient surgery in patients with morbid obesity, some patients regain a part of the weight loss, and to address this, alternative endoscopic therapies have been introduced.[20]

CONCLUSIONS

Long-term follow-up is necessary to explicate the effectiveness of RYGB surgery in terms of weight loss and remission of T2DM in morbidly obese patients. This long-term study indicates that although weight loss was observed post RYGB, some of the patients did not attain appreciable %EWL, and weight regain was also observed in a few cases. Hence, for morbidly obese patients, alternative procedures like minigastric bypass surgery can be considered. Physical exercise, diet and other lifestyle-associated factors also play an important role in the durability of weight loss.

Statement of Human and Animal Rights: This study was performed in accordance with the principles of the Declaration of Helsinki and was approved by the Institutional Ethical Committee.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.