Metabolic Features of Individuals with Obesity Referred for Bariatric and Metabolic Surgery: a Cohort Study

Prevalence, Risk Factors, and Metabolic Characteristics of Metabolically Healthy Obesity in Patients Seeking Bariatric Surgery: A Cohort Study

BACKGROUND

Bariatric surgery is an effective treatment for morbid obesity. However, a subset of individuals seeking bariatric surgery may exhibit a metabolically healthy obesity (MHO) phenotype, suggesting that they may not experience metabolic complications despite being overweight.

OBJECTIVE

This study aimed to determine the prevalence and metabolic features of MHO in a population undergoing bariatric surgery.

METHODS

A representative sample of 665 participants aged 14 or older who underwent bariatric surgery at our center from January 1, 2010 to January 1, 2020 was included in this cohort study. MHO was defined based on specific criteria, including blood pressure, waist-to-hip ratio, and absence of diabetes.

RESULTS

Among the 665 participants, 80 individuals (12.0%) met the criteria for MHO. Female gender (P = .021) and younger age (P < .001) were associated with a higher likelihood of MHO. Smaller weight and BMI were observed in individuals with MHO. However, a considerable proportion of those with MHO exhibited other metabolic abnormalities, such as fatty liver (68.6%), hyperuricemia (55.3%), elevated lipid levels (58.7%), and abnormal lipoprotein levels (88%).

CONCLUSION

Approximately 1 in 8 individuals referred for bariatric surgery displayed the phenotype of MHO. Despite being metabolically healthy based on certain criteria, a significant proportion of individuals with MHO still exhibited metabolic abnormalities, such as fatty liver, hyperuricemia, elevated lipid levels, and abnormal lipoprotein levels, highlighting the importance of thorough metabolic evaluation in this population.

Management and outcomes of gastric leak after sleeve gastrectomy: results from the 2010-2020 national registry

BACKGROUND

Management of gastric leak after sleeve gastrectomy (SG) is challenging due to its unpredictable outcomes. We aimed to summarize the characteristics of SG leaks and analyze interventions and corresponding outcomes in a real-world setting.

METHODS

To retrospectively review of 15,721 SG procedures from 2010 to 2020 based on a national registry. A cumulative sum analysis was used to identify a fitting curve of gastric leak rate. The Kaplan-Meier method and log-rank tests were performed to calculate and compare the probabilities of relevant outcomes. The logistic regression analysis was conducted to determine the predictors of acute leaks.

RESULTS

A total of 78 cases of SG leaks were collected with an incidence of 0.5% (78/15,721) from this registry (6 patients who had the primary SG in non-participating centers). After accumulating 260 cases in a bariatric surgery center, the leak rate decreased to a stably low value of under 1.17%. The significant differences presented in sex, waist circumference, and the proportion of hypoproteinemia and type 2 diabetes at baseline between patients with SG leak and the whole registry population ( P = 0.005, = 0.026, <0.001, and = 0.001, respectively). Moreover, 83.1% (59/71) of the leakage was near the esophagogastric junction region. Leakage healed in 64 (88.9%, 64/72) patients. The median healing time of acute and non-acute leaks was 5.93 months and 8.12 months, respectively. Acute leak (38/72, 52.8%) was the predominant type with a cumulative reoperation rate >50%, whereas the cumulative healing probability in the patients who required surgical treatment was significantly lower than those requring non-surgical treatment ( P = 0.013). Precise dissection in the His angle area was independently associated with a lower acute leak rate, whereas preservation ≥2 cm distance from the His angle area was an independent risk factor.

CONCLUSIONS

Male sex, elevated waist circumference, hypoproteinaemia, and type 2 diabetes are risk factors of gastric leaks after SG. Optimizing surgical techniques, including precise dissection of His angle area and preservation of smaller gastric fundus, should be suggested to prevent acute leaks.

Comparing Effects of Bariatric Surgery on Body Composition Changes in Metabolically Healthy and Metabolically Unhealthy Severely Obese Patients: Tehran Obesity Treatment Study (TOTS)

BACKGROUND

Among two popular obesity phenotypes, metabolically healthy severely obese (MHSO) and metabolically unhealthy severely obese (MUSO), it is important to clarify whether or not those with MHSO phenotype would benefit from bariatric surgery in terms of an improvement in body composition parameters.

METHODS

A prospective cohort was conducted on a total of 4028 participants (1404 MHSO and 2624 MUSO) who underwent bariatric surgery; MHSO was defined as having abnormalities in none or one of these four parameters: systolic blood pressure and/or diastolic blood pressure, triglycerides, fasting plasma glucose, and high-density lipoprotein. Otherwise, the definition of MUSO was met. Body composition analysis was performed at the baseline and 6-, 12-, 24-, and 36-month post-surgery using bioelectrical impedance analyzer.

RESULTS

Both phenotypes showed a significant decrease in fat mass (FM) and fat-free mass (FFM) and a significant increase in EWL% and TWL% (P_trend < 0.05). FFM, FM%, and excess weight loss (EWL%) were significantly different between the two phenotypes (P_between < 0.05) during the follow-up. Multivariate linear regression demonstrated that compared to MUSO patients, MHSO individuals experienced a greater increase in total weight loss (TWL%) and EWL% at 12- and 24-month and in EWL% at 36-month post-surgery and also a lower decrease in the FFML/WL% after 12 months.

CONCLUSION

Despite a lower decrease of FFML/WL% and a greater increase in TWL and EWL in MHSO phenotype at some time points, there were no clinically significant differences between the study groups in terms of body composition changes throughout the follow-up period.

Reducing the 10-year risk of ischemic cardiovascular disease to receive early cardiovascular benefits from bariatric surgery for obesity in China

Background

Cardiovascular risk due to obesity can be improved greatly by bariatric surgery. However, there is no research involving appropriate model for evaluating cardiovascular disease risk reduction in bariatric surgery for obesity in China. We selected the ischemic cardiovascular disease (ICVD) risk score that accurately predict cardiovascular risk in Chinese adults to evaluate the 10-year risk of ICVD and estimated early cardiovascular benefits of bariatric surgery in obese Chinese patients through its reduction.

Methods

From 2017 to 2019 we followed up 107 patients 6 months after surgery and measured the ICVD 10-year risk and other cardiovascular factors before and after surgery.

Results

There were significant reductions in the ICVD total score (p < 0.001) and ICVD 10-year risk (%) (p < 0.001) 6 months post-operation compared with baseline. Furthermore, we found significant reductions in body mass index (BMI), body adiposity index (BAI), low-density lipoprotein (LDL), small dense-low-density lipoprotein (sd-LDL) and triglycerides (TG) 6 months after surgery compared with pre-operation (all p < 0.05). The decrease in ICVD total score was correlated with excess BMI loss (%EBMIL), reduced BAI, reduced LDL, reduced sd-LDL and reduced TG respectively (all p < 0.05) at 6 months post-operation. Moreover, there were significant reductions in the ICVD total score in the male subgroup [3 (3, 5) vs. 2.5 (2, 4), p < 0.001] and female subgroup [3 (2, 4) vs. 2 (1, 3), p < 0.001] 6 months post-operation compared with baseline. At last there were also significant reductions in the ICVD total score in the diabetic subgroup [5 (4, 6) vs. 4 (3, 5), p < 0.001] and non-diabetic subgroup [2 (2,3) vs. 2 (1, 2), p < 0.001] 6 months post-operation compared with baseline.

Conclusions

Bariatric surgery could provide early cardiovascular benefits for patients with obesity in China by reducing the 10-year risk of ICVD. Both men and women with obesity achieved cardiovascular benefits according to bariatric surgery, so did diabetic and non-diabetic patients.

Comparison of preoperative and postoperative Lipid Profile changes in obese and morbidly obese patients after mini gastric bypass surgery

Background & Objective:

Obesity has become a serious health problem that has become increasingly important in recent years. Since patients with high levels of obesity have dyslipidemia and an unbalanced lipid profile, they have a high risk of both diabetes mellitus and cardiovascular disease. This study aimed to evaluate the short (3 months) and long term (12 months) effects of mini-gastric bypass surgery from the current bariatric surgical techniques on the lipid profile.

Methods:

Of the patients undergoing Mini-gastric bypass operation between January 2016 to December 2018 at the General Surgery Clinic of Private Samsun Büyük Anadolu Hospital, demographic data and changes in lipid concentrations at 3 and 12 months were analyzed. Patients were grouped according to age, sex, body mass index (BMI), cardiologic risk groups, bypass lengths, and obesity classes. Total cholesterol, triglyceride, LDL-cholesterol, and HDL cholesterol values of the patients were examined at the time of admission to the outpatient clinic before the operation, at the postoperative third month and at the post-operative twelfth-month. Patients who did not go for a checkup during the one-year follow-up and whose data could not be reached or missing were excluded from the study.

Results:

There was no significant difference in terms of age, sex, and cardiovascular risk (p> 0.05). Although the HDL-C level was initially low (p <0.001), it significantly increased 12 months after surgical treatment (p <0.001). While serum concentrations of LDL cholesterol, total cholesterol, and triglycerides were high preoperatively, they significantly decreased at 12 months postoperatively (p <0.001). When compared with values in the 3rd- and 12th-month, there was a significant decrease in the class-3 obesity group but not in the class-2 obesity group. When serum HDL cholesterol concentrations were compared with preoperative baseline and postoperative 12th-month those, no statistically-significant difference was found in serum concentrations in the 3rd month, although there was a significant increase in both class 2 and 3 obesity groups.

Conclusion:

In patients undergoing mini-gastric bypass surgery, serum LDL cholesterol, total cholesterol, and triglyceride concentrations decreased in the 12th postoperative month, but serum HDL cholesterol concentrations increased.

How much abdominal fat do obese patients lose short term after laparoscopic sleeve gastrectomy? A quantitative study evaluated with MRI

Background

This study aimed to elucidate the changes in the amount of abdominal adipose tissue after laparoscopic sleeve gastrectomy in obese Chinese patients over a relatively short follow-up period and to analyze the differences in the effects of surgery between genders.

Methods

Ninety-one patients were enrolled in the study, including 18 males and 73 females. These patients underwent laparoscopic sleeve gastrectomy between November 2017 and November 2019. Before and short term after surgery, the areas of subcutaneous/visceral adipose tissue and the liver proton density fat fraction were calculated with upper abdominal magnetic resonance (MR) examinations.

Results

Approximately 100 days after surgery, the median values of weight loss and body mass index reduction were 23.1 kg and 8.1 kg/m², respectively. The patients achieved a greater absolute loss of subcutaneous adipose tissue index than of visceral adipose tissue index (3.2×10^-3 vs. 1.6×10^-3, P<0.001). The amount of weight loss, body mass index loss and absolute/relative reduction in visceral adipose tissue index were much greater in males than in females (31.7 vs. 21.7 kg, P<0.001; 9.8 vs. 7.9 kg/m², P=0.016; 2.5×10^-3 vs. 1.3×10^-3, P=0.007; 28.2% vs. 20.9%, P=0.029). There was a correlation between decreased amounts in subcutaneous and visceral adipose tissue in sum and weight loss (r=0.282, P=0.032). The absolute/relative reduction in visceral adipose tissue index was also correlated with absolute/relative reduction in liver proton density fat fraction (r=0.283, P=0.013; r=0.372, P=0.001).

Conclusions

The reductions in body weight and visceral fat were more significant in male patients. The sum of absolute reduction in subcutaneous and visceral fat deposits was correlated with weight loss, in all patients enrolled. For severely obese patients, an upper abdominal MR examination could assess the body tissue composition and how it changes after bariatric surgery.

Effectiveness of Bariatric Surgery in Patients with the Metabolically Healthy Obese Phenotype

BACKGROUND

To evaluate the effectiveness and safety of bariatric surgery in metabolically healthy obese (MHO) patients.

METHODS

In this retrospective, observational study, we reviewed the medical records of patients who underwent bariatric surgery at a tertiary care hospital between January 2007 and March 2015. Patients who underwent revisional surgery and patients with type 1 diabetes were excluded from the analysis. MHO patients were defined as those without a previous diagnosis of diabetes or atherogenic dyslipidemia and absence of hypoglycemic treatment or treatment with fibrates.

RESULTS

A total of 188 patients were included (mean age 48.97 ± 10.32 years, 68.6% of women). Sleeve gastrectomy was performed in 121 patients (64%) and a gastric bypass in 67 patients (36%). Prior to surgery, 36 patients (19%) were MHO. In the second- and third-year post-surgery, MHO patients presented a higher percentage of total weight loss (%TWL) (35.16% vs. 30.34%; p = 0.02 and 33.97% vs. 27.78%; p = 0.013 respectively). Multiple regression analysis showed that MHO was associated with a higher weight loss irrespective of age, sex, baseline BMI, and type of surgery. We did not detect any differences in acute complications between patients with and without MHO after bariatric surgery.

CONCLUSIONS

Bariatric surgery in MHO patients in our study was associated with higher weight loss than that in MUHO patients. There were no differences between the two groups in respect to acute complications following surgery.

The Appropriateness Criteria of Abdominal Fat Measurement at the Level of the L1-L2 Intervertebral Disc in Patients With Obesity

BACKGROUND

In this study, we proposed to use MR images at L1-L2 (lumbar) intervertebral disc level to measure abdominal fat area in patients with obesity. The quantitative results would provide evidence for the individualized assessment of the severity of obesity.

METHODS

All patients in the IRB-approved database of Beijing Friendship Hospital who underwent bariatric surgery between November 2017 and November 2019 were recruited. We retrospectively reviewed upper abdominal magnetic resonance (MR) data before surgery. We analyzed the correlation and consistency of the area of abdominal subcutaneous adipose tissue (ASAT) and visceral adipose tissue (VAT) measured at the L1-L2 and L2-L3 levels on MR images. We randomly distributed the cases into prediction model training data and testing data at a ratio of 7:3.

RESULTS

Two hundred and forty-five subjects were included. The ASAT and VAT results within the L1-L2 and L2-L3 levels were very similar and highly correlated (male^ASAT: r=0.98, female^ASAT: r=0.93; male^VAT: r=0.91, female^VAT: r=0.88). There was no substantial systematic deviation among the results at the two levels, except for the ASAT results in males. The intraclass correlation coefficients (ICCs) were 0.91 and 0.93 for male^ASAT and female^ASAT, and 0.88 and 0.87 for male^VAT and female^VAT, respectively. The ASAT/VAT area at the L2-L3 level was well predicted. The coefficient β of linear regression that predicted L2-L3 ASAT from L1-L2 ASAT was 1.11 for males and 0.99 for females. The R-squares were 0.97 and 0.91, respectively. For VAT prediction, the coefficient β was 1.02 for males and 0.96 for females. The R-squares were 0.82 and 0.77, respectively.

CONCLUSION

For patients with obesity, the L1-L2 intervertebral disc level can be used as the substitution of L2-L3 level in abdominal fat measurement.

Prevalence of NASH/NAFLD in people with obesity who are currently classified as metabolically healthy

BACKGROUND

While metabolic health in obesity may confer a protective status, recent studies indicate that nonalcoholic fatty liver disease (NAFLD) or even nonalcoholic steatohepatitis (NASH) may exist in this category of individuals. Although cardiovascular and diabetic risks have been well described, the risk of NAFLD and NASH among this population requires further investigation.

OBJECTIVE

Our goal was to compare the prevalence of steatosis, NAFLD, and NASH between individuals with metabolically healthy obesity (MHO) and individuals with metabolically abnormal obesity (MAO) and to identify preoperative risk factors for these conditions in a prospective cohort with morbid obesity scheduled for bariatric surgery.

SETTINGS

Tertiary referral university hospital in France.

METHODS

The prospective cohort included 837 bariatric patients who also had an intraoperative liver biopsy between 2002 and 2015. Obese individuals fulfilling none of the criteria in the strict definition of metabolic syndrome were considered metabolically healthy. Preoperative blood samples and liver pathology examinations were reviewed. Steatosis, NAFLD, and NASH were carefully identified allowing comparison of prevalence and risk factors between the 2 cohorts.

RESULTS

In total, 149 patients (17.8%) had MHO and the remaining 688 (82.2%) had MAO. The cohort with MHO was significantly younger, had a significantly lower glycosylated hemoglobin, a lower homeostasis model assessment of insulin resistance, and increased C-reactive protein. In individuals with MHO, 44 patients (29.5%) had at least moderate steatosis (>33% macrovesicular steatosis) and 5.4% had NASH. Using logistic regression, waist circumference was positively associated with NASH, whereas body mass index and alanine aminotransferase were significantly associated with severe steatosis (>66%).

CONCLUSION

Our study indicates that obese individuals without metabolic syndrome may develop subclinical liver involvement. Therefore, the occurrence of NAFLD and NASH in this population needs further investigation.