Hypoglycemia after the Oral Glucose Tolerance Test in Participants With and Without Sleeve Gastrectomy

Abstract

Objective:

To evaluate the long-term effects of sleeve gastrectomy (SG) on glucose excursion and hypoglycemia in persons without diabetes during the oral glucose tolerance test (OGTT).

Methods:

This quasi-experimental study included persons undergoing body contouring surgeries, some of whom had a history of SG, while the remaining did not have a history of SG. An OGTT (75 grams) was undertaken at four time points (before body contouring surgery, immediate postoperative, short-term, and long-term postoperative). Glucose levels were measured at six time points (fasting, 15, 30, 45, 60, and 120 min). Glucose excursion was analyzed using Tai’s trapezoidal rule and Doi’s weighted average glucose (dwAG). Statistical models included linear and logistic regression.

Results:

The study evaluated 125 OGTTs. The SG group exhibited significantly higher rates of level 1 hypoglycemia (12.5%) compared to the non-SG group (3.2%). SG increased the odds of hypoglycemia 8-fold [OR: 8.11, (95% UI: 1.43–45.95)] compared to the non-SG group. Hypoglycemia occurred predominantly at 120 min. Logistic regression indicated no relationship of age, body fat, and gender on hypoglycemia odds. The unified measures (dwAG and Tai’s area) demonstrated that glucose excursion was less after SG then with participants without bariatric surgery.

Conclusions:

SG alters the OGTT responses, leading to increased risk of late post-load hypoglycemia in participants without diabetes. Data from this study will assist with OGTT management in post-SG patients, and it is suggested that use of unified measures like dwAG may be useful.