Purpose: We evaluated the predictors of the incidence of erectile dysfunction in patients with type 2 diabetes mellitus and identified subgroups of patients in whom the interaction between clinical and psychological characteristics determined an increase in the risk of erectile dysfunction.
Materials and methods: The study was based on 670 individuals. The presence of erectile dysfunction and the severity of depressive symptoms were investigated with a questionnaire filled in every 6 months for 3 years. Poisson regression was used to calculate incidence rates. To evaluate interactions among the different variables and identify distinct and homogeneous subgroups in terms of incidence of erectile dysfunction, RECursive Partitioning and AMalgamation method was used.
Results: Overall erectile dysfunction developed in 192 men with type 2 diabetes, with an incidence rate of 166.3 per 1,000 person-years. Age, insulin treatment, hemoglobin A1c greater than 8.0%, total cholesterol greater than 3.88 mmol/l and severity of depressive symptoms represented independent predictors of erectile dysfunction. RECursive Partitioning and AMalgamation analysis identified 5 classes with a marked variation in the risk of erectile dysfunction. Patients with low levels of depressive symptoms and hemoglobin A1c 8.0% or less showed the lowest risk of erectile dysfunction. Compared with this subgroup patients with higher levels of depressive symptoms and treated with insulin had a 3-fold risk of erectile dysfunction. Age, smoking, high cholesterol levels and neuropathy were globally predictive variables associated with an increased risk of erectile dysfunction.
Conclusions: The incidence of erectile dysfunction is predicted by modifiable risk factors. Even in diabetes, psychological problems can contribute to the pathogenesis of erectile dysfunction, in addition to organic causes.