Abstract
Post-prandial hyperlipidaemia (PPH) acutely impairs systemic vascular endothelial function, potentially attributable to a free radical-mediated reduction in vascular nitric oxide (NO) bioavailability (oxidative-nitrosative stress). However, it remains to be determined whether this extends to the cerebrovasculature. To examine this, 38 (19 young (≤ 35 years) and 19 aged (≥ 60 years)) healthy males were recruited. Cerebrovascular function (middle cerebral artery velocity, MCAv) and cerebrovascular reactivity to hypercapnea (CVRCO2Hyper) and hypocapnea (CVRCO2Hypo) were determined via trans-cranial Doppler ultrasound and capnography. Venous blood samples were obtained for the assessment of triglycerides (photometry), glucose (photometry), insulin (radio-immunoassay), ascorbate free radical (A•−, electron paramagnetic resonance spectroscopy) and nitrite (NO2-, ozone-based chemiluminescence) in the fasted state prior to and 4 hours following consumption of a standardised high-fat meal (1,362 kcal; 130g of fat). Circulating triglycerides, glucose and insulin increased in both groups following the high-fat meal ( P < 0.05), with triglycerides increasing by 1.37 + 1.09 mmol/L in the young and 1.54 + 1.00 mmol/L in the aged ( P < 0.05). This resulted in an increased systemic formation of free radicals in the young ( P < 0.05) but not the aged ( P > 0.05) and corresponding reduction in NO2- in both groups ( P < 0.05). While the meal had no effect on MCAv in either age group, CVRCO2Hyper was selectively impaired in the aged ( P < 0.05). These findings indicate that PPH causes acute cerebrovascular dysfunction in the aged subsequent to systemic nitrosative stress.
Original language | English |
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Article number | CS20171406 |
Pages (from-to) | 2807-2812 |
Journal | Clinical Science |
Volume | 131 |
Issue number | 32 |
Early online date | 20 Oct 2017 |
DOIs | |
Publication status | Published - 28 Nov 2017 |
Keywords
- Aging
- Cerebrovascular Function
- High-fat meal
- Hyperlipidaemia
- oxidative stress
- Oxidative-Nitrosative stress