Oral hypoglycaemic drugs and gastrointestinal symptoms in diabetes mellitus

Background: Gastrointestinal symptoms are commonly reported as side-effects of oral hypoglycaemic drugs. It may be very difficult to distinguish betwe en spontaneous and truly drug-related symptoms due to the high Background i ncidence of gastrointestinal symptoms. Gastrointestinal symptoms in diabeti c patients have also been linked to factors associated with long-standing d isease and suboptimal control. Aim: To explore the association between gastrointestinal symptoms and treat ment with oral hypoglycaemic drugs in a large cohort of subjects with type 2 diabetes. Patients and methods: 956 subjects with type 2 diabetes participated in the study. All subjects completed a validated, self-administered questionnaire on gastrointestinal symptoms, diabetes, drug use and various potential ris k factors for gastrointestinal symptoms. The association between oral hypog lycaemics and nine gastrointestinal symptom groups was assessed based on lo gistic regression. Results: 405 of the 956 patients used oral hypoglycaemic drugs. Metformin u se was independently associated with chronic diarrhoea (odds ratio 3.08, 95 % CI: 1.29-7.36, P < 0.02) and with faecal incontinence (odds ratio 1.95, 9 5% CI: 1.10-3.47, P < 0.05). Use of sulphonylureas was associated with less abdominal pain, but not with any other gastrointestinal symptom. Conclusions: Troublesome gastrointestinal symptoms do not appear to be caus ed by oral hypoglycaemics, except for diarrhoea and faecal incontinence, wh ich are strongly and independently associated with metformin use.