Natural history of gastrointestinal symptoms in diabetes mellitus
Community studies suggest that in the general population there is a considerable turnover of individuals reporting gastrointestinal symptoms. Moreover, longitudinal studies in the USA and Sweden, applying a postal questionnaire on two separate occasions, have demonstrated that the number of subjects who developed gastrointestinal symptoms in a given period of time paralleled the number of subjects who lost them. Unfortunately, almost no data exist on the natural history of gastrointestinal symptoms in diabetes, and whether factors such as glycaemic control or the development of autonomic neuropathy influence development and regression of motor dysfunction or disturbed sensation and symptoms is unknown. Indeed, it has been uncertain how many diabetic patients have gastrointestinal symptoms transiently and how many experience them for prolonged periods.
Talley et al. evaluated the natural history of lower gastrointestinal tract symptoms in diabetes, and assessed potential predictors of symptom change in 540 subjects with predominantly type 2 diabetes. The prevalence of abdominal pain, constipation, diarrhoea and faecal incontinence was stable over a three year period, but 4 – 27% in these symptom groups experienced symptom turnover. Change in symptom status was not associated with change in self-rated glycaemic control or the type or duration of diabetes. Baseline complications of diabetes and psychological factors were variably associated with turnover of symptom groupings, but a consistent pattern did not emerge. Studies of the natural history of upper gastrointestinal symptoms and their relationship to glycaemic control are not available but, based on cross-sectional studies, glycaemic control may be more important in this subset.