Background. Hyperinsulinemic hypoglycemia with neuroglycopenia is a rare complication of Roux-en-Y gastric bypass (RYGB). We hypothesized that continuous glucose monitoring (CGM) would be useful to characterize glycemic variability after RYGB.
Methods. CGM and mixed meal tolerance testing (MMTT) were performed on sixteen post-RYGB subjects, ten with a history of neuroglycopenia on medical treatment and six asymptomatic controls.
Results. 9 of 10 subjects with neuroglycopenia developed hypoglycemia defined by glucose <70 mg/dL on CGM, and 3 of 9 on MMTT. In asymptomatic subjects, 3 of 6 had asymptomatic hypoglycemia during CGM, and 3 of 5 on MMTT. Therefore, the sensitivity and specificity to detect clinically significant hypoglycemia was 90% and 50% for CGM and 33% and 40% for MMTT.
Conclusions. Asymptomatic hypoglycemia after RYGB is more frequent than commonly recognized. For clinicians evaluating patients for postbypass neuroglycopenia, CGM may be a valuable diagnostic tool.
Symptomatic hypoglycaemia with related confusion, syncope, epilepsy or seizures is a newly recognised complication of gastric bypass surgery for obesity. The incidence of these conditions is not known. We therefore studied the incidence of post-gastric bypass hypoglycaemia and related symptoms in patients who have undergone gastric bypass and a reference cohort from the general population of Sweden.
This is a nationwide cohort study based on national registries with 5,040 persons who underwent gastric bypass, vertical banded gastroplasty or gastric banding for obesity in Sweden between 1 January 1986 and 31 December 2006 and a cohort of ten referents per patient matched for sex and age randomly sampled from the general population. The incidence rates of hospitalisation for hypoglycaemia, confusion, syncope, epilepsy or seizures before and after dates of surgery or inclusion in the reference cohort were studied.
Preoperative incidences of hospitalisation for hypoglycaemia were similar in the surgical and referent cohorts. After gastric bypass surgery, the adjusted hazard ratios were significantly elevated for hypoglycaemia (2.7 [95% CI 1.2-6.3]), confusion (2.8 [1.3-6.0]), syncope (4.9 [3.4-7.0]), epilepsy (3.0 [2.1-4.3]) and seizures (7.3 [5.0-10.8]). The proportions of gastric bypass patients and reference participants affected by hypoglycaemia were very low (0.2% and 0.04%, respectively). There was no increased risk of hypoglycaemia after vertical banded gastroplasty or gastric banding compared with the referent population.
Obese persons who have undergone gastric bypass have an increased risk of hospitalisation for diagnoses associated with post-gastric bypass hypoglycaemia, although few patients are affected.
Dumping syndrome is a serious complication occurring in 10% of patients after gastric surgery. Dumping symptoms are effectively reduced by subcutaneous application of the somatostatin analogue octreotide, but side-effects limit its use.
To evaluate the efficacy of depot long-acting release octreotide (Sandostatin-LAR) vs. octreotide subcutaneous on dumping symptoms, quality of life and side-effects.
Twelve patients (five females, age 58 +/- 3 years) with severe dumping symptoms, requiring daily use of octreotide subcutaneous, were included in an open study and changed from octreotide subcutaneous after a 2 weeks washout to Sandostatin-LAR 10 mg i.m., every 4 weeks for 6 months. Symptoms (diary), body weight, fat excretion, food intake and Gastrointestinal Specific Quality of Life Index were evaluated.
Gastrointestinal Specific Quality of Life Index increased significantly (P < 0.05) during Sandostatin-LAR treatment (88 +/- 4) compared with octreotide (74 +/- 4) and washout (75 +/- 6). During Sandostatin-LAR treatment, abdominal symptom score was lower compared with octreotide and washout, but not significantly. During Sandostatin-LAR treatment, body weight increased (66 +/- 4 to 70 +/- 3 kg; P = 0.19).
Sandostatin-LAR is at least as effective as octreotide subcutaneous in suppressing symptoms in patients with severe dumping syndrome and is more effective than octreotide subcutaneous in increasing body weight and quality of life.