Rate of post-bariatric hypoglycemia using continuous glucose monitoring: A meta-analysis of literature studies

Postbariatric surgery hypoglycemia: Nutritional, pharmacological and surgical perspectives

Post-bariatric hypoglycaemia (PBH) is a metabolic complication of bariatric surgery (BS), consisting of low post-prandial glucose levels in patients having undergone bariatric procedures. While BS is currently the most effective and relatively safe treatment for obesity and its complications, the development of PBH can significantly impact patients' quality of life and mental health. The diagnosis of PBH is still challenging, considering the lack of definitive and reliable diagnostic tools, and the fact that this condition is frequently asymptomatic. However, PBH's prevalence is alarming, involving up to 88% of the post-bariatric population, depending on the diagnostic tool, and this may be underestimated. Given the prevalence of obesity soaring, and an increasing number of bariatric procedures being performed, it is crucial that physicians are skilled to diagnose PBH and promptly treat patients suffering from it. While the milestone of managing this condition is nutritional therapy, growing evidence suggests that old and new pharmacological approaches may be adopted as adjunct therapies for managing this complex condition.

Glycemic variability and hypoglycemia before and after Roux-en-Y Gastric Bypass and Sleeve Gastrectomy - A cohort study of females without diabetes

BACKGROUND

Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) lead to lower fasting glucose concentrations, but might cause higher glycemic variability (GV) and increased risk of hypoglycemia. However, it has been sparsely studied in patients without preoperative diabetes under normal living conditions.

OBJECTIVES

To study 24-hour interstitial glucose (IG) concentrations, GV, the occurrence of hypoglycemia and dietary intake before and after laparoscopic RYGB and SG in females without diabetes.

SETTING

Outpatient bariatric units at a community and a university hospital.

METHODS

Continuous glucose monitoring and open-ended food recording over 4 days in 4 study periods: at baseline, during the preoperative low-energy diet (LED) regimen, and at 6 and 12 months postoperatively.

RESULTS

Of 47 patients included at baseline, 83%, 81%, and 79% completed the remaining 3 study periods. The mean 24-hour IG concentration was similar during the preoperative LED regimen and after surgery and significantly lower compared to baseline in both surgical groups. GV was significantly increased 6 and 12 months after surgery compared to baseline. The self-reported carbohydrate intake was positively associated with GV after surgery. IG concentrations below 3.9 mmol/L were observed in 14/25 (56%) of RYGB- and 9/12 (75%) of SG-treated patients 12 months after surgery. About 70% of patients with low IG concentrations also reported hypoglycemic symptoms.

CONCLUSIONS

The lower IG concentration in combination with the higher GV after surgery, might create a lower margin to hypoglycemia. This could help explain the increased occurrence of hypoglycemic episodes after RYGB and SG.

Dasiglucagon Treatment for Postprandial Hypoglycemia After Gastric Bypass: A Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVE

Postbariatric hypoglycemia affects >50% of individuals who have undergone Roux-en-Y gastric bypass surgery. Despite the often debilitating nature of this complication, existing treatment options are limited and often inefficient. Dasiglucagon is a stable glucagon analog available in a ready-to-use formulation and was recently shown to mitigate postbariatric hypoglycemia in experimental settings. Here, we aimed to evaluate the hypoglycemic hindering potential of dasiglucagon in an outpatient trial.

RESEARCH DESIGN AND METHODS

We conducted a randomized, double-blind, placebo-controlled, crossover, proof-of-concept study at the Center for Clinical Metabolic Research at Gentofte Hospital in Denmark. The study included 24 individuals who had undergone Roux-en-Y gastric bypass surgery (n = 23 women) with continuous glucose monitor-verified postbariatric hypoglycemia (≥15 min at <3.9 mmol/L three or more times per week) randomly assigned to two treatment periods of 4 weeks of self-administered subcutaneous dasiglucagon at 120 μg or placebo. The primary and key secondary outcomes were continuous glucose monitor-captured percentage of time in level 1 and 2 hypoglycemia (<3.9 and <3.0 mmol/L), respectively.

RESULTS

Compared with placebo, treatment with dasiglucagon significantly reduced time in level 1 hypoglycemia by 33% (-1.2 percentage points; 95% CI -2.0 to -0.5; P = 0.002) and time in level 2 hypoglycemia by 54% (-0.4 percentage points; 95% CI -0.6 to -0.2; P < 0.0001). Furthermore, dasiglucagon corrected hypoglycemia within 15 min in 401 of 412 self-administrations, compared with 104 of 357 placebo self-administrations (97.3% vs. 29.1% correction of hypoglycemia rate; P < 0.001). Dasiglucagon was generally well tolerated, with mostly mild to moderate adverse events of nausea.

CONCLUSIONS

Compared with placebo, 4 weeks of self-administered dasiglucagon effectively reduced clinically relevant hypoglycemia in individuals who had undergone Roux-en-Y gastric bypass surgery.

Use of Continuous Glucose Monitoring in Patients Following Bariatric Surgery: A Scoping Review

The objective of this scoping review was to summarize the emerging literature on the use of continuous glucose monitoring (CGM) in post-bariatric surgery patients, with a focus on its features (e.g., device, mode, and accuracy), as well as purposes and outcomes of utilization. Three databases (PubMed, EMBASE, and Web of Science) were searched to obtain relevant studies. Results suggested that most studies used CGM for 3-7 days under blinded mode. Accuracy data were available in only one study, which reported a mean absolute relative difference of 21.7% for Freestyle Libre. The primary applications of CGM were for elucidating glucose patterns and assessing glycemic treatment outcomes. No study has tested the effect of CGM as an intervention strategy to enhance glucose control.

Mixed Meal Tolerance Test Versus Continuous Glucose Monitoring for an Effective Diagnosis of Persistent Post-Bariatric Hypoglycemia

Gastric bypass determines an increase in incretin secretion and glucose excursions throughout the day and may sometimes entail the development of severe post-bariatric hypoglycemia (PBH). However, there is no consensus on the gold standard method for its diagnosis. In this study, we evaluated the usefulness of a mixed meal tolerance test (MMTT) and continuous glucose monitoring (CGM) for the diagnosis of PBH, defined as glucose levels <54 mg/dL (3.0 mmol/L). We found that hypoglycemia occurred in 60% of patients after the MMTT and in 75% during CGM, and it was predominantly asymptomatic. The MMTT confirmed the diagnosis of PBH in 88.9%of patients in whom surgery had been performed more than three years ago, in comparison to 36.4% in cases with a shorter postsurgical duration. CGM diagnosed nocturnal asymptomatic hypoglycemia in 70% of patients, and daytime postprandial hypoglycemia in 25% of cases. The mean duration of asymptomatic hypoglycemia was more than 30 min a day. Patients with ≥2% of their CGM readings with hypoglycemia exhibited a higher degree of glucose variability than those with <1% of the time in hypoglycemia. Our results show that the MMTT may be a useful dynamic test to confirm the occurrence of hypoglycemia in a large number of patients with persistent and recurrent PBH during long-term follow-up after gastric bypass. CGM, on its part, helps identify hypoglycemia in the real-world setting, especially nocturnal asymptomatic hypoglycemia, bringing to light that PBH is not always postprandial.

Persistent post-bariatric-surgery hypoglycemia: A long-term follow-up reassessment

BACKGROUND AND AIM

Post-bariatric-surgery hypoglycemia (PBH) is a serious complication of bariatric surgery (BS). In our previous study about three quarters of the patients developed PBH. However long-term follow-up data is lacking to determine whether this condition improves with time. The aim of the current study was to re-assess post-BS patients who participated in our previous study and determine whether there are changes in the frequency and/or severity of hypoglycemic events.

METHODS AND RESULTS

Twenty-four post-BS, post Roux-en-Y gastric-bypass (RYGB = 10), post omega-loop gastric-bypass (OLGB = 9) and post sleeve-gastrectomy (SG = 5) individuals were reevaluated in a follow-up study 34.4 ± 4 months after their previous assessment and 67 ± 17 months since surgery. The evaluation included: a dietitian assessment, a questionnaire, meal-tolerance test (MTT) and a one-week masked continuous glucose monitoring (CGM). Hypoglycemia and severe hypoglycemia were defined by glucose levels ≤54 mg/dl and ≤40 mg/dl, respectively. Thirteen patients reported questionnaire meal-related complaints, mainly non-specific. During MTT, hypoglycemia occurred in 75% of the patients, and severe hypoglycemia in a third, but none was associated with specific complaints. During CGM, 66% of patients developed hypoglycemia and 37% had severe hypoglycemia. We did not observe significant improvements in hypoglycemic events compared to the previous assessment. Despite the high frequency of hypoglycemia, it did not necessitate hospitalizations or lead to death.

CONCLUSIONS

PBH did not resolve within long-term follow-up. Intriguingly, most patient were unaware of these events which can lead to underestimation by the medical staff. Further studies are needed to determine possible long term sequela of repeated hypoglycemia.

The Interplay of Adipokines, Body Composition and Glucose Homeostasis in Pregnant Women with a History of RYGB Operation

Roux-en-Y gastric bypass operations (RYGB-OP) and pregnancy alter glucose homeostasis and the adipokine profile. This study investigates the relationship between adipokines and glucose metabolism during pregnancy post-RYGB-OP. (1) Methods: This is a post hoc analysis of a prospective cohort study during pregnancy in 25 women with an RYGB-OP (RY), 19 women with obesity (OB), and 19 normal-weight (NW) controls. Bioimpedance analysis (BIA) was used for metabolic characterization. Plasma levels of adiponectin, leptin, fibroblast-growth-factor 21 (FGF21), adipocyte fatty acid binding protein (AFABP), afamin, and secretagogin were obtained. (2) Results: The phase angle (φ) was lower in RY compared to OB and NW. Compared to OB, RY, and NW had lower leptin and AFABP levels, and higher adiponectin levels. φ correlated positively with leptin in RY (R = 0.63, p < 0.05) and negatively with adiponectin in OB and NW (R = -0.69, R = -0.69, p < 0.05). In RY, the Matsuda index correlated positively with FGF21 (R = 0.55, p < 0.05) and negatively with leptin (R = -0.5, p < 0.05). In OB, FGF21 correlated negatively with the disposition index (R = -0.66, p < 0.05). (3) Conclusions: The leptin, adiponectin, and AFABP levels differ between RY, OB, and NW and correlate with glucose metabolism and body composition. Thus, adipokines might influence energy homeostasis and maintenance of cellular health during pregnancy.

Benefits and Risks of Bariatric Surgery on Women's Reproductive Health: a Narrative Review

Bariatric surgery (BS) is escalating as the most efficient and endurable therapy for severe obesity. Women's reproductive health is essential to women's quality of life and is receiving increasing attention. However, despite the high prevalence of BS among women, the effect of BS on reproductive health remains underemphasis. The purpose of this narrative review is to provide an overview of BS on women's reproductive health, including their reproductive health before, during, and after pregnancy. Although limited attention has been given, current evidence highlights the substantial implications of bariatric surgery on reproductive health and reminds us of the importance of adopting decision-making conversations about reproductive health before bariatric surgery.

Pregnancy after Bariatric Surgery: Nutrition Recommendations and Glucose Homeostasis: A Point of View on Unresolved Questions

Obesity is increasing in all age groups and, consequently, its incidence has also risen in women of childbearing age. In Europe, the prevalence of maternal obesity varies from 7 to 25%. Maternal obesity is associated with short- and long-term adverse outcomes for both mother and child, and it is necessary to reduce weight before gestation to improve maternal and fetal outcomes. Bariatric surgery is an important treatment option for people with severe obesity. The number of surgeries performed is increasing worldwide, even in women of reproductive age, because improving fertility is a motivating factor. Nutritional intake after bariatric surgery is dependent on type of surgery, presence of symptoms, such as pain and nausea, and complications. There is also a risk of malnutrition after bariatric surgery. In particular, during pregnancy following bariatric surgery, there is a risk of protein and calorie malnutrition and micronutrient deficiencies due to increased maternal and fetal demand and possibly due to reduction of food intake (nausea, vomiting). As such, it is necessary to monitor and manage nutrition in pregnancy following bariatric surgery with a multidisciplinary team to avoid any deficiencies in each trimester and to ensure the well-being of the mother and fetus.

Post-Bariatric Hypoglycemia Is Associated with Endothelial Dysfunction and Increased Oxidative Stress

Post-bariatric hypoglycemia (PBH) is a potentially serious complication that may occur after bariatric surgery. Recurrent hypoglycemia may exert detrimental effects on vascular function. The aim of the present study was to evaluate endothelial function and oxygen reactive compounds in patients who experience PBH compared with controls. We performed a cross-sectional study on subjects with PBH (HYPO) and those without (NO-HYPO), detected by seven-day continuous glucose monitoring (CGM) performed at least twelve months after bariatric surgery. We enrolled 28 post-bariatric subjects (17.9% males, mean age 40.6 ± 10.7 years), with 18 in the HYPO group and 10 in the NO-HYPO group. In the two groups, we measured brachial artery flow-mediated dilation (FMD), oxidized low-density lipoproteins (oxLDL) and reactive oxygen metabolites (D-ROMs). The HYPO group had significantly lower FMD values than the NO-HYPO group (3.8% ± 3.0 vs. 10.5% ± 2.0, p < 0.001). A significant correlation was found between FMD and the time spent in hypoglycemia (rho = −0.648, p < 0.001), the number of hypoglycemic events (rho = −0.664, p < 0.001) and the mean glucose nadir (rho = 0.532, p = 0.004). The HYPO group showed significantly higher levels of D-ROMs (416.2 ± 88.7 UCARR vs. 305.5 ± 56.3 UCARR, p < 0.001) and oxLDLs (770.5 ± 49.7 µEq/L vs. 725.1 ± 51.6 µEq/L, p = 0.035) compared to the NO-HYPO group. In the multiple linear regression analysis, hypoglycemia independently predicted FMD values (β = −0.781, p < 0.001), D-ROMs (β = 0.548, p = 0.023) and oxLDL levels (β = 0.409, p = 0.031). PBH is associated with impaired endothelial function accompanied by increased oxidative stress.