Satiety testing in diabetic gastroparesis: Effects of insulin pump therapy with continuous glucose monitoring on upper gastrointestinal symptoms and gastric myoelectrical activity

Abstract

Background: Symptoms induced by caloric or non-caloric satiety test meals and gastric myoelectrical activity (GMA) have not been studied in patients with diabetic gastroparesis (DGP) before and after intense glucose management.

Aims: We determined the effects of continuous subcutaneous insulin infusion (CSII) with continuous glucose monitoring (CGM) on GI symptoms, volume consumed, and GMA induced by the caloric meal satiety test (CMST) and water load satiety test (WLST) in DGP.

Methods: Forty-five patients with DGP underwent CMST and WLST at baseline and 24 weeks after CSII with CGM. Subjects ingested the test meals until they were completely full. Visual analog scales were used to quantify pre- and postmeal symptoms, and GMA was recorded with cutaneous electrodes and analyzed visually and by computer. KEY RESULTS: At baseline and 24-week visits, nausea, bloating, abdominal discomfort, and fullness were immediately increased after CMST and WLST (Ps < 0.01). The meal volumes ingested were significantly less than normal controls at both visits in almost one-third of the subjects. After the CMST, the percentage 3 cycle per minute GMA increased and bradygastria decreased compared with WLST (Ps < 0.05). After treatment for 24 weeks meal volumes ingested, postmeal symptoms and GMA were no different than baseline. CONCLUSIONS AND INFERENCES: (a) Satiety test meals elicited symptoms of nausea, bloating, and abdominal discomfort; (b) CMST stimulated more symptoms and changes in GMA than WLST; and (c) CSII with CGM for 24 weeks did not improve symptoms, volumes ingested, or GMA elicited by the two satiety test meals in these patients with diabetic GP. Satiety tests in diabetic gastropresis are useful to study acute postprandial symptoms and GMA, but these measures were not improved by intensive insulin therapy.

Keywords: caloric and non-caloric test meals; diabetic gastroparesis; gastric dysrhythmias; gastric myoelectrical activity; gastroparesis cardinal symptom index; patient assessment of upper GI symptoms.

© 2019 John Wiley & Sons Ltd.

Figures

Figure 1.

Volumes ingested by subjects during the water load satiety test (WLST) and caloric meal satiety test (CMST) test meals until they were completely full. The X axis shows baseline and Week 24 visits and the Y axis shows the volume in milliliters (ml) ingested at baseline and 24 weeks after insulin pump therapy and continuous glucose monitoring. The volume of water ingested at baseline was 437 ml and 413 ml at 24 weeks (P=0.56). The average volume of caloric test meal ingested at baseline was 427 ml and 480 ml at Week 24 (p=0.44).

Figure 2.

Fullness, hunger, bloating, abdominal discomfort, and nausea scores are shown before and after the water load satiety test (WLST) test at baseline and at 24 weeks. The X axis shows time in minutes. Time 0 indicates the 10 minutes before the test meal and 10, 20, and 30 minutes indicate time after ingestion. The Y axis shows the symptom intensity on the visual analog scale (VAS) in millimeters (mm). Fullness increased significantly after the WLST and hunger decreased significantly at baseline and Week 24 visits. Symptoms of bloating and abdominal discomfort and nausea all increased significantly at the baseline visit, and bloating and abdominal discomfort increased significantly at 24 weeks. Compared with the baseline visit, there were no significant changes in symptoms at Week 24.

Figure 3.

Gastric myoelectrical activity (GMA) before and after the water load satiety test at baseline and at 24 weeks. Bradygastria (1.0–2.5 cpm), normogastria (2.5–3.5 cpm), tachygastria (3.5–10 cpm), and duodenal-respiration (10–15 cpm) frequency ranges are shown. The X axis indicates time in minutes with Time 0 indicating the 10 minutes before the test meal and the 10, 20, and 30-minute periods after ingestion. The Y axis indicates the percent distribution of GMA power in the four frequency ranges. Normogastria and tachygastria increased 20 and 30 minutes after ingestion at baseline and Week 24 visits, but changes were not statistically significant. Compared with baseline there were no significant changes in GMA at Week 24.

Figure 4.

Fullness, hunger, bloating, abdominal discomfort, and nausea scores are shown before and after the caloric meal satiety test (CMST) at baseline and 24 weeks. The X axis shows time in minutes. Time 0 indicates the 10 minutes before the test meal and 10, 20, 30, and 60 minutes indicates time after ingestion. The Y axis shows the symptom intensity on the visual analog scale (VAS) in millimeters (mm). Fullness increased significantly after the CMST and hunger decreased significantly, and symptoms of bloating, abdominal discomfort, and nausea all increased significantly at baseline and the Week 24 visits. Compared with baseline visits, there were no significant changes in symptoms at Week 24.

Figure 5.

Gastric myoelectrical activity (GMA) before and after the caloric meal satiety test (CMST) are shown at baseline and at 24 weeks. Bradygastria (1.0–2.5 cpm), normogastria (2.5–3.5 cpm), tachygastria (3.5–10 cpm), and duodenal-respiration (10–15 cpm) frequency ranges are shown. The X axis and Y axis are similar to Figure 3. After ingestion of the caloric meal, normogastria significantly increased and bradygastria significantly decreased at baseline and 24 weeks. At 24 weeks tachygastria increased significantly after the CMST. There were no differences in GMA at Week 24 compared with baseline.

Figure 6A.

GMA rhythm strips from the electrogastrogram recording from a subject with diabetic gastroparesis. Note the 3 cycle per minute (cpm) waves in GMA at baseline (before water load) and in the rhythm strips from Post stimulation period 1, 2, and 3 which are from the 10, 20, and 30-minute periods after the WLST. GMA rhythm strips from baseline (before WLST) and from 10, 20, and 30 minutes after the WLST (labeled Post stimulation period 1, 2, and 3, respectively) are shown. The X axis shows time in minutes and the Y axis shows microvolts. This is a normal 3 cpm GMA response to the WLST and reflects normal numbers of ICCs in this patient with diabetic GP.

Figure 6B.

Running spectral analysis of the GMA shown in 6A. Note the clear peaks at 3 cpm before and after ingestion of the water load. This is a very regular 3 cpm pattern in a patient with GP and suggests possible functional gastric outlet obstruction. The X axis shows frequency from 1–15 cpm. The Y axis shows time with each line representing 4 minutes of GMA with 75% overlap. The Z axis shows peaks that reflect the frequencies according to amplitude or power of GMA in the EGG signal. The two flat lines indicate the time of WLST in the EGG recording of GMA. The normal GMA range is 2.5–3.5 cpm.

Figure 7A.

GMA rhythm strips from an electrogastrogram recording from a subject with diabetic gastroparesis. In contrast to Figure 6A, note the lack of 3 cycle per minute (cpm) GMA at baseline and irregular GMA after the WLST in the post stimulation time periods. GMA rhythm strips from baseline (before WLST) and from 10, 20, and 30 minutes after the WLST (labeled Post stimulation period 1, 2, and 3, respectively). The upper channel is the EGG recording and the lower channel shows the respiration recording. The X axis shows time in minutes and the Y axis shows microvolts.

Figure 7B.

Running spectral analysis of the GMA shown in 7A before and after the WLST. In contrast to Figure 6B, note the multiple peaks in the gastric dysrhythmia frequencies (tachygastria 3.5–10 cpm; bradygastria 1–2.5 cpm) and the lack of 3 cpm peaks before and after the WLST. The X axis shows frequency from 1–15 cpm. The Y axis shows time with each line representing 4 minutes of GMA with 75% overlap. The Z axis shows peaks that reflect frequencies according to amplitude or power of the GMA in the EGG signal. The two flat lines indicate the time of ingestion of the water load.