Altered glucose profiles and risk for hypoglycaemia during oral glucose tolerance testing in pregnancies after gastric bypass surgery

Abstract

Aims/hypothesis A history of gastric bypass surgery can influence the results of the OGTT recommended during pregnancy. Therefore, we compared OGTT glucose kinetics and pregnancy outcome between pregnant gastric bypass patients and BMI-matched, lean and obese controls. Methods Medical records were used to collect data on glucose measurements during the 2 h 75 g OGTT as well as on pregnancy and fetal outcome for 304 women (n = 76 per group, matched for age and date of delivery). Results Women after bariatric surgery had lower fasting glucose levels compared with lean, obese and BMI-matched controls, and showed altered postprandial glucose kinetics, including a rise at 60 min followed by hypoglycaemia with serum glucose of <3.34 mmol/l (which occurred in 54.8%). Moreover, their risk of pre-eclampsia or gestational hypertension was reduced, with an increased risk of delivering small for gestational age infants. Conclusions/interpretation Alternative strategies to accurately define impaired glucose metabolism in pregnancies after bariatric surgery should be explored.

Pregnancy after bariatric surgery: Maternal and fetal outcomes of 39 pregnancies and a literature review

“…However, OGTT is poorly tolerated in women after malabsorptive procedures because it can cause symptoms of early or late dumping, including hypoglycemia, which can lead to invalid results . The pathophysiological mechanisms leading to hypoglycemia in gastric bypass patients are not fully understood, but it seems that altered gastric glucose transit, with an accelerated appearance of systemic glucose after an oral glucose load, as well as a shortened period of postprandial hyperglycemia, is secondary to increased incretin peptide release and exaggerated insulin secretion from pancreatic beta cells …”

“…A study that evaluated the glucose profiles during OGTT in pregnancies after gastric bypass surgery revealed a rise in plasma glucose levels at 60 min followed by hypoglycemic episodes in more than half of the cases . Therefore, capillary blood glucose profiles and continuous glucose monitoring over 1–2 around 24–28 weeks of gestation might represent diagnostic alternatives to patients after RYGB or if they do not tolerate OGTT .…”

“…A study that evaluated the glucose profiles during OGTT in pregnancies after gastric bypass surgery revealed a rise in plasma glucose levels at 60 min followed by hypoglycemic episodes in more than half of the cases . Therefore, capillary blood glucose profiles and continuous glucose monitoring over 1–2 around 24–28 weeks of gestation might represent diagnostic alternatives to patients after RYGB or if they do not tolerate OGTT . One proposed alternative is to use home glucose monitoring to record four measurements per day (fasting and 1‐h postprandial intercalated with 2‐h postprandial for approximately 1 week) between 24 and 28 weeks of gestation .…”

“…One proposed alternative is to use home glucose monitoring to record four measurements per day (fasting and 1‐h postprandial intercalated with 2‐h postprandial for approximately 1 week) between 24 and 28 weeks of gestation . These alternatives also offer the possibility of detecting postprandial hyper‐ or hypoglycemic episodes, which can be missed by a single OGTT . The diagnostic or intervention thresholds would be fasting glucose ≥95 mg/dL, 1‐h postprandial glucose ≥140 mg/dL, and 2‐h postprandial glucose ≥120 mg/dL …”

Rodent vertical sleeve gastrectomy alters maternal immune health and fetoplacental development

“…These negative outcomes include an increased risk for abnormal glucose kinetics and hypoglycemia during pregnancy (17), increased risk for miscarriage (20), small-for-gestational age babies (SGA) or intrauterine growth restricted infants (IUGR) (2, 19, 38), birth at a reduced gestational age (20, 27), preterm birth (19, 51) and still-birth or neonatal death (21, 27). These adverse events may be due to maternal micronutrient deficiencies following surgical weight loss or the timing of pregnancy with respect to the bariatric surgery (24, 33).…”