Effects of acute hyperglycaemia on anorectal motor and sensory function in diabetes mellitus

Aims: To determine the effects of acute hyperglycaemia on anorectal motor and sensory function in patients with diabetes mellitus. Methods: In eight patients with Type 1, and 10 patients with Type 2 diabetes anorectal motility and sensation were evaluated on separate days while the blood glucose concentration was stabilized at either 5 mmol/l or 12 mmol/l using a glucose clamp technique. Eight healthy subjects were studied under euglycaemic conditions. Anorectal motor and sensory function was evaluated using a sleeve/sidehole catheter, incorporating a barostat bag. Results: In diabetic subjects hyperglycaemia was associated with reductions in maximal (P < 0.05) and plateau (P < 0.05) anal squeeze pressures and the rectal pressure/volume relationship (compliance) during barostat distension (P < 0.01). Hyperglycaemia had no effect on the perception of rectal distension. Apart from a reduction in rectal compliance (P < 0.01) and a trend (P = 0.06) for an increased number of spontaneous anal sphincter relaxations, there were no differences between the patients studied during euglycaemia when compared with healthy subjects. Conclusions: In patients with diabetes, acute hyperglycaemia inhibits external anal sphincter function and decreases rectal compliance, potentially increasing the risk of faecal incontinence.