Original article
Fasting glycemia: A good predictor of weight loss after RYGB

https://doi.org/10.1016/j.soard.2013.11.005Get rights and content

Abstract

Background

Preoperative prediction of weight loss after Roux-en-Y gastric bypass (RYGB) could help surgeons in managing surgical lists and patients’ expectations. The objective of this study was to understand if preoperative metabolic control might improve surgical results.

Methods

Prospective cohort of 163 consecutive patients who underwent RYGB with at least 1 year of follow-up.

Results

Most patients were female (90.2%), with a mean age of 38 (19–60) and a BMI of 46.0 (34.3–59.9) kg/m2. After 12 months, the mean body mass index (BMI) was 29.7 kg/m2 (21.5–39.9) with a corresponding percentage of excess weight lost (%EWL) of 78.8% and a percentage of weight loss (%WL) of 35.1%.

Patients with the highest preoperative fasting blood glucose (FBG) were older (42 versus 36; P<.001); were more likely to have type 2 diabetes (T2 DM, 40% versus 6.8%; P<.001) and metabolic syndrome (89% versus 25%; P<.001), had a slightly higher BMI (30.8 versus 29.3 kg/m2; P = .03), and had achieved a significantly lower %EWL and %WL at 12 months (72.5% versus 81.2%; P = .004; 33.2 versus 35.9%; P = .03, respectively). We observed a dose-response effect with increasing FBG (<85 mg/dL, 85–100 mg/dL, and≥100 mg/dL, respectively), with 83.5%, 80.0%, and 72.5% (P = .009) of %EWL at 12 months. By multivariate logistic regression, initial BMI and FBG>100, were the only variables related (inversely) with the probability of achieving a %EWL>80 or %WL>35. This effect was not detected in patients receiving oral antidiabetic medications.

Conclusion

Higher preoperative FBG is independently related to a poorer weight loss 12 months after RYGB; this suggests the need to offer earlier surgical intervention for severely obese patients with impairment of glucose metabolism. The potential for less weight loss in patients with a higher FBG should not discourage RYGB, given the significant metabolic improvement after surgery.

Section snippets

Methods

After approval by the institutional ethics review board and written informed consent from all patients participating in the study, a prospective cohort of 163 consecutive patients who had laparoscopic RYGB were recruited at our Medical Center between January 2009 and June 2011. All patients met the inclusion criteria for bariatric surgery (having a BMI>40 kg/m2 or>35 kg/m2 with obesity-associated co-morbidities) and underwent a multidisciplinary preoperative evaluation and the same clinical and

Results

Most patients were female (90.2%) with a mean age of 38 years (19–60 yr) (Table 1). Follow-up was complete for 161 of 163 patients (98.8%), and the mean %EWL and %WL at 12 months was 78.8% and 35.1%, respectively, with 44% of the patients achieving a %EWL≥80 and 46.6% of the patients achieving a %WL≥35.

Perioperative complications occurred in 9 patients (5%): 3 anastomotic hemorrhages, 1 intraabdominal bleeding, 2 deep vein thrombosis, 1 intraabdominal abscess, 1 pulmonary infection, and 1

Discussion

Weight control (as low perioperative morbidity and co-morbid condition resolution) are the key factors to define a successful bariatric operation. Although there is a significant metabolic improvement after a modest weight loss, greater and long-term weight control are required to achieve all of the long-term benefits related with RYGB [17].

For this study, we selected a 1-year follow-up, because it usually represents the time at which the optimal weight loss is observed after bariatric surgery

Conclusion

Higher preoperative FBG was independently related to a poorer weight loss after RYGB. This association might explain why older patients and patients with T2 DM or insulin resistance have been reported to have a poorer weight loss.

Lowering FBG with antidiabetic medications was unrelated to an improvement in surgical outcomes. Our results suggest the need to offer surgical treatment to obese patients with insulin resistance earlier, before severe metabolic illness progresses. The potential for

Disclosures

The authors have no commercial associations that might be a conflict of interest in relation to this article.

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    This work was supported by Fundação Ciência e Tecnologia, through Programa Operacional Potencial Humano da EU (POPH); PEst-OE/SAU/UI0038/2011, and by a grant from the Harvard Medical School Portugal Program—HMSP-ICJ/SAU-ICT/0007/2009).

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