Blunting of Colon Contractions in Diabetics with Gastroparesis Quantified by Wireless Motility Capsule Methods

<div><p>Generalized gut transit abnormalities are observed in some diabetics with gastroparesis. Relations of gastric emptying abnormalities to colon contractile dysfunction are poorly characterized. We measured colon transit and contractility using wireless motility capsules (WMC) in 41 healthy subjects, 12 diabetics with gastroparesis (defined by gastric retention >5 hours), and 8 diabetics with normal gastric emptying (≤5 hours). Overall numbers of colon contractions >25 mmHg were calculated in all subjects and were correlated with gastric emptying times for diabetics with gastroparesis. Colon transit periods were divided into quartiles by time and contraction numbers were calculated for each quartile to estimate regional colon contractility. Colon transit in diabetics with gastroparesis was prolonged vs. healthy subjects (P<0.0001). Overall numbers of colon contractions in gastroparetics were lower than controls (P = 0.02). Diabetics with normal emptying showed transit and contraction numbers similar to controls. Gastric emptying inversely correlated with overall contraction numbers in gastroparetics (r = -0.49). Numbers of contractions increased from the 1^st to 4^th colon transit quartile in controls and diabetics with normal emptying (P≤0.04), but not gastroparetics. Numbers of contractions in the 3^rd and 4^th quartiles were reduced in gastroparetics vs. healthy controls (P≤0.05) and in the 4^th quartile vs. diabetics with normal emptying (P = 0.02). Numbers of contractions were greatest in the final 15 minutes of transit, but were reduced in gastroparetics vs. healthy controls and diabetics with normal emptying (P≤0.005). On multivariate analyses, differences in numbers of contractions were not explained by demographic or clinical variables. In conclusion, diabetics with gastroparesis exhibit delayed colon transit associated with reductions in contractions that are prominently blunted in latter transit phases and which correlate with delayed gastric emptying, while diabetics with normal emptying show no significant colonic impairments. These findings emphasize diabetic gastroparesis may be part of a generalized dysmotility syndrome.</p></div

Subject Characteristics for Each of the Three Groups.

<p>Subject Characteristics for Each of the Three Groups.</p

Numbers of Colon Contractions.

<p>Overall numbers of colon contractions are plotted for the three groups. Diabetics with gastroparesis showed reductions in overall numbers of contractions compared to healthy subjects (P = 0.02). Overall contractions in diabetics with normal gastric emptying were not different than in diabetic patients with gastroparesis or in healthy controls (P = NS).</p

Representative WMC Recordings.

<p>Representative WMC recordings are shown from a healthy volunteer (A, C) and a diabetic with gastroparesis (B, D). In the complete recording from the healthy subject, there is an abrupt pH decrease (red) at 10 hours and 15 minutes reflecting ileocecal (IC) transit (A). The capsule is expelled at 37 hours and 39 minutes. In the diabetic, IC transit occurs at 33 hours and 15 minutes and the capsule is expelled at 97 hours and 14 minutes (B). Pressure activity (blue) increases prior to WMC expulsion in the healthy subject, but not in the diabetic with gastroparesis. In the final 15 minutes of colon transit, contractions (blue) are frequent and intense in the healthy volunteer (C) but are reduced in the diabetic (D).</p

Correlation of Colon Contraction Numbers with Gastric Emptying.

<p>The correlation of overall numbers of colon contractions with gastric emptying times is plotted for diabetics with gastroparesis. There was a moderately good inverse correlation (r value -0.49) with patients with the most severe emptying delays exhibiting lower numbers of contractions.</p

Regional Differences in Numbers of Colon Contractions.

<p>Numbers of colon contractions are plotted as a function of colon transit quartile (A) and for the final 15 minutes of colon transit (B). Healthy volunteers (P<0.0001) and diabetics with normal gastric emptying (P = 0.04) showed increased numbers of contractions from the first to fourth quartiles, while contractions did not increase from the first to fourth quartiles in diabetics with gastroparesis (P = NS). Compared to healthy controls, diabetics with gastroparesis exhibited reduced numbers of contractions in the third (P = 0.05) and fourth (P = 0.0006) quartiles. Diabetics with gastroparesis also showed lower numbers of contractions in the fourth quartile than diabetics with normal emptying (P = 0.02). Diabetics with normal emptying exhibited numbers of contractions that were no different from those of the healthy volunteers in any quartile of colon transit (all P = NS). Numbers of contractions in the final 15 minutes were reduced in diabetics with gastroparesis compared to healthy subjects (P = 0.0005) and diabetics with normal gastric emptying (P = 0.005). Numbers of contractions in the final 15 minutes were no different in diabetics without gastroparesis and healthy volunteers (P = NS).</p