Is peak expiratory flow rate a predictor of complications in diabetes? TheWisconsin Epidemiologic Study of Diabetic Retinopathy

The objective of this study was to determine whether peak expiratory flow r ate is a predictor of complications of diabetes. Peak expiratory flow rate was measured at the 10-year follow-up (third examination) of a cohort of pe rsons with younger-onset diabetes. The relationships of progression of diab etic retinopathy by two steps, progression to proliferative retinopathy and of incidences of macular edema, sore or ulcers on feet or ankles, lower ex tremity amputation, proteinuria, and cardiovascular disease 4 years after t his examination with respect to peak expiratory flow rate were evaluated. S tudy procedures including measurements of blood pressure, height and weight , grading of fundus photographs, peak expiratory flow rate, urinalysis, and medical history were performed according to standard protocols. Peak expir atory flow rate was not associated in univariate analyses with progression of retinopathy, incidences of proliferative retinopathy, macular edema or l ower extremity amputation, sores or ulcers on feet or ankles, gross protein uria, or self-reported cardiovascular disease. However, when using multivar iable models to include the effects of other risk factors, peak expiratory flow rate was significantly associated with the combined incidences of sore s or ulcers on feet and ankles, or lower extremity amputations (OR = 0.61, 95% Cl 0.42-0.88). These data suggest that peak expiratory flow rate is a p redictor of subsequent complications in the lower extremities in those with long duration of younger-onset diabetes. Evaluating this association in an incipient cohort would illuminate whether the relationship we found is lik ely to be causal. (C) 2001 Elsevier Science Inc. All rights reserved.