The effect of acarbose on the colonic transit time of elderly long-term care patients with type 2 diabetes mellitus

Background. Constipation is common in elderly patients with diabetes mellitus (DM); its prevalence is estimated as up to 60% among patients with diabetic neuropathy. Acarbose, an α-glucosidase inhibitor, has a beneficial role in controlling DM, although one of its side effects is diarrhea. This study evaluates the efficacy of acarbose in improving constipation using transit time (TT) studies in elderly long-term care (LTC) patients. Methods. Twenty-eight patients with type 2 DM and constipation were recruited for the study. TT was measured by radiopaque markers and was calculated separately for the four segments of the colon (ascending, transverse, descending, and rectosigmoid) and for the total colonic transit time (CTT). Segmental TT and CTT were evaluated in each patient before and after 1 week, and again after 4 weeks of treatment with acarbose. Results. The mean baseline CTT measured in patients was 202 ± 136 hours. After 1 and 4 weeks of acarbose treatment, the baseline CTT significantly decreased to 149 ± 107 hours and 161 ± 97 hours, respectively (p < .002). For each segment studied, the TT was shortened, but it reached significance for the ascending and transverse colon only (p < .02 and p < .03, respectively). The effect of diet composition was examined. The amount of fiber consumed correlated with shortened CTT, while fat tended to be in negative correlation with TT. Conclusions. Acarbose therapy reduced the extremely prolonged CTT in LTC diabetic persons with constipation. The drug could be useful in relieving constipation in these patients, in addition to its beneficial effect in the control of diabetes.