Inflammation throughout the body from various diseases often goes along with cardiovascular disease, prediabetes-metabolic syndrome and poor nerve health to the feet.
Healthcare providers will examine areas of psoriasis and many other inflammatory diseases visible to the eye, but systemic inflammatory conditions, and their comorbidities, like psoriatic arthritis, for example, are more than skin deep. In addition to arthritis there are also potential neurovascular conditions that accompany these systemic inflammatory diseases that should not be ignored. One area that continues to be a source of active investigation involves the apparent association between many systemic inflammatory diseases, metabolic syndrome and type 2 diabetes. There is also a well-documented connection between psoriasis and an increased risk for cardiovascular disease (CVD) in the literature. Patients with psoriasis are more prone to:
- Cardiovascular disease risk factors – hypertension, obesity, dyslipidemia and smoking
- Non-cardiac vascular diseases – carotid, peripheral artery and chronic kidney disease
- Metabolic dysfunction – type 2 diabetes mellitus, metabolic syndrome, non-alcoholic fatty liver disease and obstructive sleep apnea
The associations are even greater in patients with severe psoriasis and in those with psoriatic arthritis. The common pathophysiologic mechanism linking psoriasis with cardiovascular and metabolic disease appears to be,
Insulin resistance, endothelial dysfunction and obesity induced by several adipokines and inflammatory cytokines.”
There has been a growing presence of the psoriasis-poor metabolism connection in the literature. A recently released investigation into this connection found,
The severity of psoriatic arthritis is independently associated with metabolic syndrome and insulin resistance with clinical connections to cardiovascular risk factors, including hypertension (74%), elevated waist circumference (56%), and high triglycerides (44%)” – These cardiovascular risk factors may dictate psoriatic arthritis severity.”
As with these metabolic syndrome components of: hypertension, an increased waistline and elevated triglyceride levels, another component – insulin resistance – also appears to be linked with more severe psoriatic arthritis. It has been suggested that,
Providers should routinely screen for metabolic syndrome and insulin resistance among patients with psoriasis and psoriatic arthritis.”
Peripheral nerve health and insulin resistance
The insulin resistance and pre-diabetic metabolism of some psoriasis patients may be producing peripheral neuropathy that would otherwise be labeled “idiopathic.” It may not be “idiopathic” in that some believe the etiology is the metabolic dysfunction and insulin resistance in these patients.
It has been reported that idiopathic neuropathy accounts for up to 40% of all neuropathies in a neurology practice. And although the nature of the relationship between impaired glucose tolerance and neuropathy is a subject of active debate, there may be an increased prevalence of impaired glucose tolerance in idiopathic neuropathy patients (although others have suggested another component of metabolic dysfunction – elevated triglycerides – may be a more important risk factor).
Regardless, there is evolving science suggesting metabolic syndrome, particularly dyslipidemia and obesity, are potent neuropathy risk factors for both idiopathic and diabetic neuropathy. Insulin resistance often accompanies obesity and dyslipidemia, and some experts in the field believe obesity, hypertension, dyslipidemia, inflammation and insulin resistance may be contributory to T2DM diabetic polyneuropathy to an equal if not greater degree than hyperglycemia.
Where there is systemic inflammation, especially in immune-mediated systemic diseases such as psoriasis, there is often at least some degree of metabolic dysfunction. And whether or not it is immediately clinically relevant, where there is metabolic dysfunction there is bound to be at least some degree of neurovascular dysfunction that is especially prone to impacting the feet and legs.