BACKGROUND: Our previous study reported that cerebral oxygen extraction fraction (OEF) increased in hemodialysis patients with anemia. The increased OEF suggests that the cerebral vasodilatory capacity might be impaired in these patients. To clarify this issue, we measured the CO2 response in patients with anemia secondary to chronic renal failure (CRF) using positron emission tomography (PET). METHODS: Ten anemic patients with CRF (6 females and 4 males) and 6 age-matched normal controls were studied. The underlying diseases of CRF were glomerulonephritis in 8 patients, systemic lupus erythematosus (SLE) in one patient, and hypertension in one patient; in this cohort, 5 patients were on hemodialysis treatment and the remaining 5 patients were in a pre-hemodialysis state. The cerebral blood flow (CBF) was measured by the O-15 H2O bolus injection method with each patient in a resting state and during 5% CO2 inhalation. The CO2 response was estimated as the percentage change of CBF per 1 mm Hg change of PaCO2. RESULTS: The CO2 response was significantly attenuated in anemic patients with CRF in comparison to the normal controls, and it inversely correlated with the severity of anemia. There was no significant difference in the CO2 response between the hemodialysis and pre-hemodialysis patients. The CO2 response significantly correlated with CBF and the cerebral metabolic rate for oxygen (CMRO2) at rest, however, it did not correlate with OEF and cerebral blood volume (CBV). CONCLUSIONS: The present study revealed the existence of a reduced cerebral vasodilatory capacity in anemic patients with CRF, suggesting that chronic hypoxic brain damage might play a role in the impaired cerebrovascular response to CO2.
BACKGROUND: Our previous study reported that cerebral oxygen extraction fraction (OEF) increased in hemodialysis patients with anemia. The increased OEF suggests that the cerebral vasodilatory capacity might be impaired in these patients. To clarify this issue, we measured the CO2 response in patients with anemia secondary to chronic renal failure (CRF) using positron emission tomography (PET). METHODS: Ten anemicpatients with CRF (6 females and 4 males) and 6 age-matched normal controls were studied. The underlying diseases of CRF were glomerulonephritis in 8 patients, systemic lupus erythematosus (SLE) in one patient, and hypertension in one patient; in this cohort, 5 patients were on hemodialysis treatment and the remaining 5 patients were in a pre-hemodialysis state. The cerebral blood flow (CBF) was measured by the O-15H2O bolus injection method with each patient in a resting state and during 5% CO2 inhalation. The CO2 response was estimated as the percentage change of CBF per 1 mm Hg change of PaCO2. RESULTS: The CO2 response was significantly attenuated in anemicpatients with CRF in comparison to the normal controls, and it inversely correlated with the severity of anemia. There was no significant difference in the CO2 response between the hemodialysis and pre-hemodialysis patients. The CO2 response significantly correlated with CBF and the cerebral metabolic rate for oxygen (CMRO2) at rest, however, it did not correlate with OEF and cerebral blood volume (CBV). CONCLUSIONS: The present study revealed the existence of a reduced cerebral vasodilatory capacity in anemicpatients with CRF, suggesting that chronic hypoxic brain damage might play a role in the impaired cerebrovascular response to CO2.
Authors: Lindsay S Cahill; Lisa M Gazdzinski; Albert Ky Tsui; Yu-Qing Zhou; Sharon Portnoy; Elaine Liu; C David Mazer; Gregory Mt Hare; Andrea Kassner; John G Sled Journal: J Cereb Blood Flow Metab Date: 2016-07-20 Impact factor: 6.200
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Authors: Hesamoddin Jahanian; Thomas Christen; Michael E Moseley; Nicholas M Pajewski; Clinton B Wright; Manjula K Tamura; Greg Zaharchuk Journal: J Cereb Blood Flow Metab Date: 2016-01-01 Impact factor: 6.200
Authors: Charles Gasparovic; Clifford Qualls; Ernest R Greene; Wilmer L Sibbitt; Carlos A Roldan Journal: J Rheumatol Date: 2012-01-15 Impact factor: 4.666
Authors: Sanaz Sedaghat; Meike W Vernooij; Elizabeth Loehrer; Francesco U S Mattace-Raso; Albert Hofman; Aad van der Lugt; Oscar H Franco; Abbas Dehghan; M Arfan Ikram Journal: J Am Soc Nephrol Date: 2015-08-06 Impact factor: 10.121