Study links metabolic syndrome to a higher risk of NAION. Photo: Neil Miller, MD. Click image to enlarge.

Though individual components of metabolic syndrome were previously associated with non-arteritic anterior ischemic optic neuropathy (NAION), little is known about the direct association between the two. In a recent study, researchers sought to determine whether metabolic syndrome is a risk factor for NAION.

Patients with metabolic syndrome were included if three or more of the five standard criteria for diagnosing the condition were present: systemic hypertension, hyperglycemia, hypertriglyceridemia, reduced high-density lipoprotein cholesterol (hypoalphalipoproteinemia) and central adiposity defined by increased body mass index.

After adjusting for age, sex and race, metabolic syndrome was found to be associated with NAION, which did not come as a surprise to the researchers. For patients with NAION, though each individual component of metabolic syndrome was individually significantly associated with the condition, further analysis suggested that hypertriglyceridemia, hypoalphalipoproteinemia and hyperglycemia were likely the key drivers in the overall link between NAION and metabolic syndrome.

“Lipid derangements and insulin resistance indicators playing a significant role are in concordance with this pathophysiological explanation of metabolic syndrome,” the authors explained in their paper. “Furthermore, the atherogenic and deleterious effects on microcirculation of hypoalphalipoproteinemia, hypercholesterolemia and hypertriglyceridemia significantly contribute to vascular disease. Abnormal lipid profiles cause endothelial dysfunction and are hypothesized to affect the microvasculature of the optic nerve, increasing susceptibility to perfusion defects and ischemia.”

The association between metabolic syndrome and NAION highlights the importance of systemic disease management when it comes to ocular health, the authors concluded. Further studies are needed to determine whether treatment of metabolic syndrome may reduce the incidence of NAION.