Objective: Hypoglycemia after bariatric surgery is an increasingly recognized metabolic complication. We sought to determine the sensitivity and specificity of a prior hypo-sx survey in detecting post-bariatric surgery hypoglycemia (PBSH) using a continuous glucose monitor (CGM).
Methods: Among the patients who underwent bariatric surgery at our institution and completed the hypo-sx survey, we enrolled 13 Roux-en-Y gastric bypass (RYGB, 7 with and 6 without hypo-sx) and 19 sleeve gastrectomy (SG, 9 with and 10 without hypo-sx) patients. Patients wore the CGM (Dexcom, San Diego, CA) for 72-120 hours at home. Hypoglycemia was defined as postprandial interstitial glucose (IG)<54 mg/dl. We used Kruskal Wallis test to compare the difference in hypoglycemia across groups.
Results: A total of 19 patients (59%) had hypoglycemia (Table 1), with a mean low glucose of 46.8 mg/dl. Two patients reported hypo-sx. The prevalence of hypoglycemia did not differ by the type of surgery (69% vs. 53%) or the presence of hypo-sx by survey (63% vs. 56%). The survey had a specificity of 53.8% and sensitivity of 52.6% for measured PBSH.
Conclusions: Asymptomatic postprandial hypoglycemia was common in post-bariatric patients regardless of surgery type. Assessments that focus on hypoglycemic symptoms may not adequately capture PBSH. Future studies should consider CGM to assess the true prevalence and impact of PBSH.
| Table 1. Baseline Characteristics and Results from continuous glucose monitoring on post-bariatric surgery patients who were categorized as with or without symptoms of hypoglycemia based on their survey responses | |||||||
| RYGB with Hypo-sx (N=7) | RYGB without Hypo-sx (N=6) | SG with Hypo-sx (N=9) | SG without Hypo-sx (N=10) | P ALL | P RYGB vs SG | P With vs Without Hypo-sx | |
| Mean Age, years | 52.9 (5.1) | 52.0 (10.0) | 41.9 (11.3) | 44.8 (11.9) | |||
| % Female | 67% | 56% | 89% | 82% | |||
| % Caucasian | 71% | 67% | 33% | 60% | |||
| Time since surgery (years) | 7.3 (3.2) | 4.8 (1.3) | 4.7 (0.7) | 4.2 (0.8) | |||
| Percent Patients with Postprandial Hypoglycemia (N) | 71% (5) | 67% (4) | 56% (5) | 50% (5) | |||
| Total Average IG (mg/dl, SD) | 97.0 (6.7) | 103.5 (12.5) | 93.0 (8.1) | 96.9 (6.4) | 0.373 | 0.227 | 0.228 |
| Average Minimum IG (mg/dl, SD) | 47.7 (10.9) | 45.8 (9.7) | 46.4 (5.6) | 47.0 (9.9) | 0.857 | 0.744 | 0.429 |
| Postprandial Minutes/day IG <54 mg/dl (SD) | 9.5 (12.7) | 4.7 (4.9) | 3.0 (3.9) | 11.3 (25.1) | 0.802 | 0.337 | 0.955 |
| Table 1. Baseline Characteristics and Results from continuous glucose monitoring on post-bariatric surgery patients who were categorized as with or without symptoms of hypoglycemia based on their survey responses | |||||||
| RYGB with Hypo-sx (N=7) | RYGB without Hypo-sx (N=6) | SG with Hypo-sx (N=9) | SG without Hypo-sx (N=10) | P ALL | P RYGB vs SG | P With vs Without Hypo-sx | |
| Mean Age, years | 52.9 (5.1) | 52.0 (10.0) | 41.9 (11.3) | 44.8 (11.9) | |||
| % Female | 67% | 56% | 89% | 82% | |||
| % Caucasian | 71% | 67% | 33% | 60% | |||
| Time since surgery (years) | 7.3 (3.2) | 4.8 (1.3) | 4.7 (0.7) | 4.2 (0.8) | |||
| Percent Patients with Postprandial Hypoglycemia (N) | 71% (5) | 67% (4) | 56% (5) | 50% (5) | |||
| Total Average IG (mg/dl, SD) | 97.0 (6.7) | 103.5 (12.5) | 93.0 (8.1) | 96.9 (6.4) | 0.373 | 0.227 | 0.228 |
| Average Minimum IG (mg/dl, SD) | 47.7 (10.9) | 45.8 (9.7) | 46.4 (5.6) | 47.0 (9.9) | 0.857 | 0.744 | 0.429 |
| Postprandial Minutes/day IG <54 mg/dl (SD) | 9.5 (12.7) | 4.7 (4.9) | 3.0 (3.9) | 11.3 (25.1) | 0.802 | 0.337 | 0.955 |
Abbreviations: SD: standard deviation , RYGB: Roux-en-Y gastric bypass, Hypo-sx: hypoglycemic symptoms, SG: sleeve gastrectomy, IG: interstitial glucose, Postprandial: within 3 hours of eating
C. Lee: None. T. Brown: Advisory Panel; Self; Merck & Co., Inc. M. Schweitzer: Consultant; Self; Ethicon US, LLC.. T. Magnuson: None. J. Clark: None.
