Table 2.

Comorbidity Interactions Using Diabetes as an Example of a Disease That Can Affect the Diagnosis, Treatment, or Prognosis of a Second Disease

Impact on Clinical ActivityExamples
    Made easier by coexisting diseaseMost diabetic patients undergo regular fundus examinations, making the diagnosis of unrelated retinal disease, such as age-related macular retinopathy, more likely
    Made more difficulty by a coexisting diseaseDiabetic patients may have altered pain sensation, thereby interfering with and making more difficult the diagnosis of coronary heart disease
    Indicated for existing and coexisting diseasePhysical exercise as recommended for a patient with chronic obstructive pulmonary disease can have a beneficial effect on diabetes
    Antagonistic effect on coexisting diseaseCorticosteroids prescribed for chronic obstructive pulmonary disease in the same patient will have an antagonistic effect on the diabetes treatment
    Positively modified by a coexisting diseaseMortality associated with diabetes is increased in the presence of peripheral vascular disease
    Not affected by a coexisting diseaseDiabetes is unaffected by the presence of hypothyroidism