Morbidity and comorbidity

The National Psoriasis Foundation recently headlined a news article about the long term risks of psoriasis because of its highly inflammatory nature. At the recent Annual Meeting of the American Academy of Dermatology, Dr. Joel M. Gelfand (a dermatologist) explained:

that for the last two decades, research has shown that excessive inflammation is a critical feature of psoriasis... Excess inflammation also is present in other common conditions, such as hardening of the arteries, heart attacks, stroke, obesity and diabetes - which may explain why some psoriasis patients may be at an increased risk for developing these other serious conditions.

He goes on to say that people with severe psoriasis are likely to die 5-7 years earlier than those without.

Upon reading this, I went racing off to PubMed to try to locate some of this comorbidity research that Gelfand is talking about (especially the stuff that says I'm gonna croak soon), and ran across this 2008 article. Here are some highlights from the abstract (italics mine):

The risk factors of cardiovascular disease and other disease comorbidities appear to be more common in patients with psoriasis compared with the general population. To support this concept, the association between psoriasis and cardiovascular disease and other comorbidities was analyzed... from 1127 patients with psoriasis and a matched cohort of nonpsoriasis patients. Psoriasis patients were significantly more likely to have cardiovascular comorbidities... compared with nonpsoriasis patients. Other comorbidities significantly associated with psoriasis were arthritis, depression, sleep disorder/insomnia, chronic obstructive pulmonary disease, and gastroesophageal reflux disease. Responses to this large survey confirm that patients with psoriasis have a higher rate of cardiovascular risk factors and other comorbidities compared with patients without psoriasis.

Wait, wait... now I'm confused. Because I have psoriasis, I'm more likely to have arthritis? So...am I a patient with psoriasis, and the psoriasis is manifesting itself through the comorbidity of arthritis?

Or, am I a patient with psoriatic arthritis, which is an inflammatory condition similar to rheumatoid arthritis, but I also have some skin stuff going on too??

It's all just so blurry, and leads me back to questioning the diagnostic process again. I think I'm going to go back to reading those autoimmune books. While there's still time.