In the news: Lutein & Artery Inflammation in CAD; CVD & Risk of Rapid Glaucoma Progression

Lutein and Artery Inflammation in CAD

Persistent, low-grade inflammation is widely recognized in patients with coronary artery disease (CAD), despite drug treatment, arterial by-pass surgery, or lifestyle modifications. 

Inflammation plays a prominent role in CAD, from the development of plaque to plaque destabilization. Elevated levels of inflammatory biomarkers like C-reactive protein and interleukin-6 (IL-6) have also been consistently shown to predict the risk of CAD.

Low plasma levels as well as low dietary intake of carotenoids have been associated with high cardiovascular disease risk, including CAD.  Further, inverse associations between circulating levels of carotenoids and inflammatory markers have been demonstrated in multiple studies.  This has led some to hypothesize that carotenoids exert anti-inflammatory effects.

To learn more about the anti-inflammatory potential of carotenoids, researchers assessed the relationship between IL-6 and individual carotenoids in CAD patients, then conducted ex-vivo experiments (1).  The results suggest that lutein could potentially reduce chronic inflammation in CAD.

Plasma lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha- and beta-carotene and IL-6 were measured in 134 patients with stable angina and 59 patients with acute coronary syndrome. Long term, low-level inflammation is predominant in stable angina, while acute inflammation is characteristic of acute coronary syndrome.

Only lutein + zeaxanthin were inversely correlated with IL-6 at baseline (r = -0.366, p < 0.001) and follow-up (r= -0.546, p < 0.001), and only in the patients with stable angina.

Peripheral blood mononuclear cells from the patients with angina were then pre-treated with lutein and incubated with lipopolysaccharide to induce secretion of IL-6 and other cytokines.

Pre-treatment with lutein dose-dependently lowered secretion of IL-6, IL-1b (p < 0.01) and TNF (p < 0.05), and also reduced IL-6, IL-1b and TNF mRNA expression (p < 0.05).

In short, the team showed that immune cells absorb and store lutein, and that greater content of lutein in these cells suppress production of inflammatory molecules. 

 “Future dietary intervention studies are warranted to confirm whether increasing the consumption of lutein has beneficial effects on clinical outcomes in patients with CAD,” the authors wrote.  The authors also note that population-based studies have consistently associated higher plasma lutein levels with decreased carotid artery intima-media thickness, raising the hypothesis that lutein plays a role in early protection against atherosclerosis.

CVD: Risk Factor for Rapid Glaucoma Progression

In this retrospective case-control study (2), university researchers in Australia set out to determine how intraocular and systemic risk factors differ between a cohort of patients with rapidly progressing glaucoma disease and those with non-rapid disease progression.

Those with rapid progression were older, had significantly lower central corneal thickness and baseline intraocular pressures (IOPs), and were more likely to have pseudoexfoliation, disc hemorrhages, changes in ocular medication, and IOP-lowering surgery.

The authors also found a correlation between cardiovascular disease (CVD) and rapid progression. Those with CVD were 2.33 times more likely to develop rapidly progressive glaucoma disease, despite lower mean and baseline IOPs.

“Cardiovascular disease is an important risk factor for rapid glaucoma disease progression irrespective of IOP control”, the study concluded. The authors suggest that clinicians pay careful attention to CVD risk factors in their glaucoma patients.

References

1. Chung RWS, et al. Lutein exerts anti-inflammatory effects in patients with coronary artery disease. Atherosclerosis. 262:87-93, 2017.
2. Wai TC, et al. Risk factors for rapid glaucoma disease progression. Am J Ophthalmol. 180:151-57, 2017.