The day-night pattern of colonic contractility is not impaired in type 1 diabetes and distal symmetric polyneuropathy

Colonic contractility normally shows circadian variability regulated by sleep and especially food intake. However, individuals with type 1 diabetes have a reduced or even absent gastrocolic response to a meal, indicating that colonic contractility may be affected by the disease. We hypothesized that individuals with type 1 diabetes and distal symmetric polyneuropathy (DSPN) have decreased motility (expressed as the motility index) and contractility of the colon and a reduced increase in motility index from night to morning compared to healthy controls and individuals with type 1 diabetes without DSPN. Cohorts of 35 individuals with type 1 diabetes and DSPN, 40 individuals with type 1 diabetes without DSPN, and 28 healthy controls were included in this post-hoc, cross-sectional analysis. We investigated, using a wireless motility capsule that measures pH, temperature, and pressure throughout the gastrointestinal tract, whether individuals with type 1 diabetes with and without DSPN, compared to healthy controls, exhibit altered colonic contractility in the evening, night, and morning. Max amplitude, mean peak amplitude, mean contraction, and motility index of the colon were calculated at the afore-designated times. Motility index of the colon tended to be higher in individuals with type 1 diabetes and DSPN compared to controls in the evening (P = .064), but the effect size was small (1.74%). There was no difference in motility index between the groups in the morning or evening. Furthermore, there was no difference in max amplitude, mean peak amplitude, or mean contraction between groups in the morning, evening, and night. As expected, overall contractility increased from night to morning in all groups, but there was no difference between groups in the increase in contractility from night to morning. Colonic contractility generally peaked in the morning, decreased in the evening, and was almost absent at night. Type 1 diabetes and/or DSPN did not impair contractility of the colon at any time point. Contractility and motility increased from morning to night unaffected by type 1 diabetes and/or DSPN.