The glycocalyx lines all endothelial cells and has been shown to play an important role in vascular homeostasis. Novel technology allow the glycocalyx to be measured non-invasively in the sublingual microcirculation, and reduction in glycocalyx has been shown in diabetes, coronary artery disease, stroke, sepsis, and ischaemia. We hypothesize that the glycocalyx is reduced in obesity and in the metabolic syndrome, and correlates with elevated inflammatory markers (highly sensitive CRP (hsCRP), tumour necrosis factor alpha (TNF-a), interleukin 6 (IL6)) and markers of endothelial activation (hyaluronan, syndecan-1, vascular cell adhesion molecule (VCAM).
A cross-sectional study was conducted recruiting four groups of volunteers: 1) Healthy non obese, 2) Obese without metabolic syndrome, 3) Obese with metabolic syndrome, 4) Weight loss post bariatric surgery. The glycocalyx was measured using video microscopy (Glycocheck), measurements of obesity (BMI, waist to hip ratio, body fat percentage) recorded and blood and urine samples collected.
107 participants were recruited. The glycocalyx measurements were lowest in the obese with metabolic syndrome group but this was not statistically significant. Highly sensitive CRP and interleukin-6 were significantly higher in the obese with metabolic syndrome group compared with the control group and the post bariatric surgery weight loss group. BMI strongly positively correlated with hsCRP (Pearsons coefficient 0.63, p<0.05).
This is the first study to our knowledge to investigate the glycocalyx in obesity and metabolic syndrome. Our findings suggest glycocalyx thickness may be reduced in obesity, especially with metabolic syndrome. Markers of inflammation were highest in the obese group with metabolic syndrome and lowest in the control group and post bariatric surgery group, suggesting that weight loss reduces inflammation. Future studies with a larger sample size and repeated measurements pre and post bariatric surgery would be useful to further assess the effect of weight loss on the glycocalyx.