Endocrine Abstracts

Purpose: Obesity is a chronic disease with a high risk of cardiovascular and metabolic comorbidities, hence a decrease > 5-10% of the initial body weight (BW) is essential to achieve improvement of cardiometabolic dysfunction. Bariatric surgery currently represents a valid therapeutic option in this clinical setting, especially in patients unresponsive to a dietary-nutritional approach. Obesity instigates adaptive hormone changes, yet the role of baseline hormone setting on postsurgical outcomes in terms of excess weight loss (%EWL) and post-nadir weight regain (%PNWR) remains unclear and warrants investigation.

Methods: Out of 202 patients with morbid obesity candidate to bariatric surgery enrolled between January 2017- December 2022, 79 patients (M/F: 16/63; age: 47.3±1.2 years; BMI: 44.2±0.5 kg/m²) eventually admitted to sleeve gastrectomy (n=72) or gastric bypass (n=7) after multidisciplinary assessment were retrospectively analyzed for clinical, and biochemical data at baseline and after 6, 12 and 24 months since surgery. Baseline hormone assessment included TSH, 24 h urinary free cortisol (UFC) IGF-I and prolactin levels.

Results: As expected, bariatric surgery caused a progressive reduction in BW, with nadir BW being reached after 12 months (ΔBMI -29±0.9%; %EWL, 70.3±2.9%) and 77% of patients achieving a %EWL ≥50%, regardless of the surgical technique. Surgical treatment resulted in remission of hypertension and type 2 diabetes mellitus in 62.5% and 64% of patients, respectively. Patients who did not go into complete remission achieved an improvement in disease that required a reduction in therapy. The glycolipid profile of the patients showed statistically significant differences at 12 months following surgery. At baseline, no abnormalities in hormone levels were observed. The influence of hormone setting on patients’ response in terms of %EWL ≥ 50% and %PNWR was null. Likewise, we failed to record associations between UFC, IGF-I or prolactin levels and post-surgical changes in BW or waist, although TSH was associated with 6-mo changes in BW (r=&minus;0.74, P<0.05) after controlling for age and gender. Alternatively, there were correlations between %EWL and baseline BMI (r&minus;0.39, P<0.001), %PNWR (r0.22, P=0.05), and age (r&minus;0.20, P=0.03). The inverse correlation between baseline BMI and %EWL was confirmed by stepwise multivariate regression analysis (β=&minus;0.45, P=0.002).

Conclusion: Bariatric surgery is an effective tool in inducing weight loss in adults with obesity and its effectiveness relates inversely to initial BMI. Baseline hormones play no role on postsurgical outcomes except for TSH, which potentially hints at the influence of the thyrostat on individual responsiveness to this weight-reducing approach.