Patients with COPD often have multiple coexisting comorbidities, affecting quality of life, morbidity and mortality. However, the prevalence and impact of comorbidities on the efficacy of bronchodilators in COPD is poorly understood.In this post hoc analysis, pooled data from the 12-week, placebo-controlled GOLDEN 3 and 4 studies of nebulized glycopyrrolate (GLY) in individuals with moderate-to-very-severe COPD were used to quantify comorbidities and assess their impact on treatment efficacy and safety.Comorbidities that were most prevalent in the GOLDEN 3 and 4 study population were hypertension, high cholesterol and osteoarthritis. Participants were grouped based on their pre-specified comorbidity count into Group A (≤2 comorbidities; n=439) and Group B (>2 comorbidities; n=854). Treatment with GLY resulted in significant improvements in forced expiratory volume in 1 second (FEV1) and St George's Respiratory Questionnaire (SGRQ) total scores, independent of comorbidity prevalence. A higher prevalence of cardiovascular disease (CVD) comorbidities was observed among individuals in Group B, compared with Group A. In a sub-analysis based on prevalence of CVD, treatment with GLY resulted in significant FEV1 improvements independent of CVD prevalence, although values were numerically higher in the CVD group. GLY also led to higher improvements in SGRQ scores in the CVD group. GLY was well tolerated regardless of comorbidity or CVD prevalence, with a lower incidence of serious adverse events compared with placebo.A simple comorbidity count demonstrated that a majority of patients with COPD in the GOLDEN 3 and 4 studies had multiple comorbidities, with CVD being common in those with high comorbidity count. Results from this post hoc analysis demonstrate that GLY improved FEV1 and SGRQ scores in individuals with COPD, independent of their comorbidities or CVD status.