Background
Short-term intake of egg-derived protein hydrolysates, such as NWT-03, suggest improvements in arterial stiffness and metabolic profiles, but well-designed longer-term human intervention trials are lacking. This study examined the longer-term effects of NWT-03 on arterial stiffness and cardiometabolic markers in men and women with metabolic syndrome.

Methods
Seventy-six adults with metabolic syndrome (age 61±10 years; BMI 31.7±4.0 kg/m²) participated in a randomized, controlled, double-blind, cross-over trial with a 27-day intervention (5 g/day NWT-03) or placebo period, separated by two-to-eight weeks of washout. At baseline and after the intervention, measurements were performed in the fasting state and 2-hours following acute intake of the study product. Regional arterial stiffness was assessed by carotid-radial (PWV_c-r) and carotid-femoral pulse wave velocity (PWV_c-f), and wave reflection was determined by the central augmentation index (CAIxHR75). Moreover, a panel of established cardiometabolic risk markers were assessed.

Results
After 27 days consuming NWT-03, no significant changes in PWV_c-r (0.05 m/s; -0.20 to 0.30; P=0.715) or PWV_c-f (-0.19 m/s; -0.48 to 0.11; P=0.216) were observed. Fasting pulse pressure was however reduced by 2 mmHg (95%CI: -4 to 0; P=0.043) following longer-term NWT-03 supplementation, but no differences were observed for other fasting cardiometabolic markers. No effects were observed following acute NWT-03 intake at baseline. However, acute intake of NWT-03 following the intervention significantly lowered CAIxHR75 (-1.3%; -2.6 to -0.1; P=0.037) and diastolic blood pressure (-2 mmHg; -3 to 0; P=0.036), but no differences were observed for markers of lipid and glucose metabolism. 

Conclusion
Longer-term NWT-03 supplementation does not affect arterial stiffness, but may improve fasting blood pressure in adults with metabolic syndrome. The acute intake of NWT-03 after the intervention also improved markers of wave reflection and blood pressure.