Baseline TSH levels and short-term weight loss after different procedures of bariatric surgery.

BACKGROUND: Bariatric surgery is a valuable therapeutic option in the treatment of obesity but the outcomes show a large subject-to-subject variability yet to be explained. Thyroid function may represent an involved factor and we have only few controversial data about its influence. SUBJECTS/METHODS: We retrospectively assessed using a longitudinal approach the relation between baseline TSH levels and short-term (6 and 12 months) weight loss in 387 euthyroid patients who underwent laparoscopic gastric banding (LAGB; n = 187) or sleeve gastrectomy (SG; n = 200). RESULTS: After LAGB, patients with low-normal TSH levels (0.40-1.40 mUI/L) had higher percent total weight loss, ∆BMI and percent excess weight loss when compared to patients with normal (1.41-2.48 mUI/L) and high-normal (2.49-4.00 mUI/L) TSH (p < 0.05). Conversely, no association was detected after SG (p = 0.17). The multivariable regression analysis showed that also baseline BMI (6-12 months) and HOMA2-IR (only at 6 months) were independently associated with the outcomes. CONCLUSIONS: TSH levels may influence the short-term weight loss response after LAGB. The lack of association after SG suggests that the influence of baseline endocrine and metabolic factors may not be relevant for procedures with greater and more immediate calorie intake restriction.

Hypercortisolism and altered glucose homeostasis in obese patients in the pre-bariatric surgery assessment.

AIMS: Hypothalamus-pituitary-adrenal (HPA) axis hyperactivity was suggested to be associated with the metabolic syndrome (MS), obesity and diabetes. The aim of this study was to test whether hypercortisolism was associated with altered glucose homeostasis and insulin resistance, hypertension and dyslipidemia in a homogeneous population of obese patients. MATERIALS/METHODS: In retrospective analysis of a set of data about obese patients attending the outpatient service of a single obesity centre between January 2013 and January 2020, 884 patients with BMI >30 kg/m2 were segregated in two subgroups: patients with urinary free cortisol (UFC) higher than normal (UFC+; n = 129) or within the normal range (UFC-; n = 755). RESULTS: The overall prevalence of UFC+ was 14.6% and double test positivity (morning cortisol >1.8 mcg/dL following overnight dexamethasone suppression test, ODST) was detected in 1.0% of patients. Prediabetes (OR 1.74; 95%CI 1.13-2.69; p = 0.012) and diabetes (OR 2.03; 95%CI 1.21-3.42; p = 0.008) were associated with higher risk of UFC+ when analysis was adjusted for confounding variables. Conversely, hypertension and dyslipidemia were not related to UFC+. Within the individuals with normal FPG and HbA1c, those with higher estimated insulin resistance (HOMA2-IR) maintained a higher risk of UFC+ (OR 2.84, 95%CI 1.06-7.63; p = 0.039) and this relationship was weakened only when the body fat percentage was included into the model. CONCLUSIONS: In obese patients, hypercortisolism was more frequent across the entire spectrum of altered glucose homeostasis including the very early stages; this relation could not be detected for the other criteria of the MS, as waist, hypertension and atherogenic dyslipidemia.

Prevalence of Elevated Liver Stiffness Among Potential Candidates for Bariatric Surgery in the United States.

PURPOSE: Obesity represents a well-known risk factor for metabolic-dysfunction associated fatty liver disease (MAFLD) and its progression towards cirrhosis. The aim of this study is to estimate the proportion of potential candidates to a bariatric surgery intervention that has an elevated liver stiffness on vibration-controlled transient elastography (VCTE). MATERIALS AND METHODS: This is a cross-sectional study performed using data obtained during the 2017-2018 cycle of the National Health and Nutrition Examination Survey. Potential candidates for a bariatric surgery intervention from the general US population were identified by applying criteria from international guidelines. All included participants were evaluated by VCTE. A controlled attenuation parameter (CAP) value ≥ 288 dB/m was considered indicative of steatosis while liver stiffness measurement (LSM) was considered elevated if ≥ 9.7 kPa. Multivariable logistic regression models were fitted to identify independent predictors of both outcomes. RESULTS: A total of 434 participants were included (mean age 42.9 ± 0.6 years; 54.4% women). Among them, 76.7% (95% CI 71.7-81.0) had steatosis, while 23.1% (95% CI 17.8-29.3) had an elevated LSM. Male sex, older age, γ-glutamyltranspeptidase levels, and body mass index (BMI) were independent predictors of steatosis, while BMI was the only independent predictor of elevated LSM. Non-Hispanic black participants were protected from both outcomes, while other ethnicities were not. CONCLUSION: The prevalence of elevated LSM is high in potential candidates for a bariatric surgery intervention. Accurate screening for occult advanced liver disease might be indicated in this patient population.

Metabolic and Psychological Features are Associated with Weight Loss 12 Months After Sleeve Gastrectomy.

CONTEXT: Laparoscopic sleeve gastrectomy (LSG) is a recognized effective procedure of bariatric surgery, but a poor response in weight loss may still represent a clinical problem. To date there are no validated predictors useful to better perform patient selection. OBJECTIVE: To establish the association of baseline anthropometric, metabolic, and psychologic features with the percent total weight loss (%TWL) and percent excess weight loss (%EWL) 12 months after surgery. DESIGN: Retrospective longitudinal analysis of a set of data about obese patients attending the outpatient service of a single obesity center from June 2016 to June 2019. PATIENTS: A total of 106 obese patients underwent LSG with presurgery evaluation and follow-up at 12 months after surgery. MAIN OUTCOME: Weight loss 12 months after LSG. RESULTS: Patients who achieved a %TWL higher than the observed median (≥34%) were younger, with a lower fasting plasma glucose and glycated hemoglobin, with a lower prevalence of hypertension and with a lower score in the impulsiveness scale, compared with patients with a %TWL < 34%. Similar findings were found when %EWL was considered. Multivariable stepwise regression analysis showed that younger age, lower impulsiveness, higher-than-normal urinary free cortisol, and lower HbA1c were associated with higher %TWL, explaining about 31.5% of the weight loss. CONCLUSION: Metabolic and psychologic features at baseline were independently associated with weight loss and explained a non-negligible effect on the response to LSG. These data suggest that careful metabolic and psychologic profiling could help in sharper indications and personalized pre- and postsurgical follow-up protocols in candidates for LSG.

Resting Whole Body Energy Metabolism in Class 3 Obesity; from Preserved Insulin Sensitivity to Overt Type 2 Diabetes.

CONTEXT: Insulin resistance and diabetes may influence separately or in combination whole body energy metabolism. OBJECTIVE: To assess the impact of insulin resistance and/or overt type 2 diabetes on resting energy expenditure (REE) in class 3 obese individuals. DESIGN AND SETTING: Retrospective, cross-sectional analysis of a set of data about individuals attending the outpatients service of a single center of bariatric surgery between January 2015 and December 2017. PATIENTS: We screened 382 patients in which abnormal thyroid function was excluded, and segregated them in three groups of subjects: patients with type 2 diabetes (T2DM; n=70), non-diabetic insulin-resistant patients with HOMA-IR ≥ 3 (n=236), non-diabetic insulin-sensitive patients with HOMA-IR < 3 (n=75). MAIN OUTCOME MEASURE: Resting energy expenditure (REE), body composition and insulin resistance assessed using indirect calorimetry, bioimpedance and HOMA-IR. RESULTS: Non-diabetic insulin-sensitive patients resulted to be younger, with lower BMI and higher prevalence of female subjects; meanwhile, non-diabetic but insulin-resistant patients and T2DM patients were not different in terms of anthropometric parameters. REE was higher in T2DM than in non-diabetic insulin-resistant and insulin-sensitive individuals when expressed as percent of the predicted REE (based on Harris Benedict equation) (p<0.0001) or when adjusted for kg of free fat mass (p<0.0001) and was found to be higher also in insulin-resistant vs insulin-sensitive patients (p<0.001). The respiratory quotient was different between groups (0.87±0.11, 0.86±0.12 and 0.91±0.14 in T2DM, insulin-resistant and insulin-sensitive patients, respectively; p<0.03). Regression analysis confirmed that HOMA-IR was independently associated with the REE (R2=0.110, p<0.001). CONCLUSION: Class 3 obese patients with normal insulin sensitivity are characterized by reduced fasting REE in comparison to insulin-resistant obese patients and obese patients with short duration of diabetes supporting the hypothesis that down-regulation of nutrients' oxidative disposal may represent an adaptation of energy metabolism in obese individuals with preserved insulin sensitivity.

Resting Energy Expenditure in Obese Women with Primary Hypothyroidism and Appropriate Levothyroxine Replacement Therapy.

CONTEXT: Growing evidence suggests that appropriate levothyroxine (LT4) replacement therapy may not correct the full set of metabolic defects afflicting individuals with hypothyroidism. OBJECTIVE: To assess whether obese subjects with primary hypothyroidism are characterized by alterations of the resting energy expenditure (REE). DESIGN: Retrospective analysis of a set of data about obese women attending the outpatients service of a single obesity center from January 2013 to July 2019. PATIENTS: A total of 649 nondiabetic women with body mass index (BMI) > 30 kg/m2 and thyrotropin (TSH) level 0.4-4.0 mU/L were segregated into 2 groups: patients with primary hypothyroidism taking LT4 therapy (n = 85) and patients with normal thyroid function (n = 564). MAIN OUTCOMES: REE and body composition assessed using indirect calorimetry and bioimpedance. RESULTS: REE was reduced in women with hypothyroidism in LT4 therapy when compared with controls (28.59 ±â€…3.26 vs 29.91 ±â€…3.59 kcal/kg fat-free mass (FFM)/day), including when adjusted for age, BMI, body composition, and level of physical activity (P = 0.008). This metabolic difference was attenuated only when adjustment for homeostatic model assessment of insulin resistance (HOMA-IR) was performed. CONCLUSIONS: This study demonstrated that obese hypothyroid women in LT4 therapy, with normal serum TSH level compared with euthyroid controls, are characterized by reduced REE, in line with the hypothesis that standard LT4 replacement therapy may not fully correct metabolic alterations related to hypothyroidism. We are not able to exclude that this feature may be influenced by the modulation of insulin sensitivity at the liver site, induced by LT4 oral administration.