| 1. |
- Wanby, Pär, et al.
(författare)
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Asymmetric dimethylarginine and total homocysteine in plasma after oral methionine loading
- 2003
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Ingår i: Scandinavian Journal of Clinical & Laboratory Investigation. - : Informa UK Limited. - 1502-7686 .- 0036-5513. ; 63:5, s. 347-353
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Tidskriftsartikel (refereegranskat)abstract
- Background: Elevation of homocysteine (Hcy) and asymmetric dimethylarginine (ADMA) in plasma are believed to be involved in the pathogenesis of cardiovascular disease (CVD). In humans, oral methionine loading results in acute elevation of plasma Hcy. This is associated with impaired NO-dependent vasodilatation, a mechanism that may explain the relationship between elevated Hcy and risk of CVD. ADMA, an endogenous competitive inhibitor of NO-synthase, may be elevated in plasma of patients with CVD. It was proposed that ADMA is synthesized in a methionine-dependent reaction which also forms Hcy. In this study plasma total homocysteine (tHcy) and ADMA concentrations were measured before and after oral methionine loading of human subjects. Methods: Plasma tHcy and ADMA levels were measured in 12 healthy males (age 32-58 years) before and after oral loading with L-methionine (100 mg/kg body weight in orange juice). Results: At noon, 4 h after methionine loading, tHcy and ADMA levels (35.4 +/- 10.9 and 0.80 +/- 0.13 mumol/L, mean +/-SD) were significantly higher than the corresponding values obtained at noon the day before (15.6 +/- 7.4 and 0.63 +/- 0.10 mumol/L, both p < 0.001). Noon values 4 h after methionine loading were also significantly higher than values obtained immediately before the methionine load (13.7 &PLUSMN; 5.9 and 0.66 &PLUSMN; 0.10 μmol/L, both p < 0.001). Reinvestigation of 8 of 12 subjects showed that at 4 and 8 h after compared with levels immediately before methionine loading there was a significant increase in tHcy (28.4 +/- 10.2 and 33.45 +/- 11.1 vs. 10.8 +/- 3.3 mumol/L, both p < 0.001). However, the corresponding ADMA levels did not increase (0.73 &PLUSMN; 0.17 and 0.76 &PLUSMN; 0.22 vs. 0.70 &PLUSMN; 0.10 μmol/L, both not significant). Conclusions: No clear evidence was found to support the supposition that methionine-induced hyperhomocysteinaemia may be accompanied by elevated levels of ADMA, an endogenous competitive NO-synthase inhibitor that may represent an alternative pathogenic mechanism for homocysteine-associated impairment of endothelial NO-dependent functions.
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| 2. |
- Hultberg, Björn, et al.
(författare)
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Poor metabolic control, early age at onset, and marginal folate deficiency are associated with increasing levels of plasma homocysteine in insulin-dependent diabetes mellitus. A five-year follow-up study
- 1997
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Ingår i: Scandinavian Journal of Clinical & Laboratory Investigation. - 1502-7686. ; 57:7, s. 595-600
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Tidskriftsartikel (refereegranskat)abstract
- In a previous study, we showed that diabetic patients exhibited significantly increased concentrations of total plasma homocysteine (tHcy), but not until the onset of nephropathy. It was suggested that the hyperhomocysteinaemia might contribute to the accelerated atherosclerotic process in diabetic patients. In the present study, we have analysed the main determinants of plasma homocysteine (i.e. serum cobalamin, blood folate and serum creatinine), and also some other parameters related to diabetes mellitus, such as medical history, metabolic and renal quantities, on two occasions with a 5-year interval in 50 patients with insulin-dependent diabetes mellitus, in order to further elucidate the relation between plasma tHcy and diabetes mellitus. The result of the present study shows that diabetic patients with the lowest age at onset and with the poorest metabolic control are those most prone to a rapid increase in plasma tHcy concentration. The increment in plasma tHcy concentration in this group of patients may at least partly be explained by a marginal deficiency of blood folate concentrations.
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| 3. |
- Lind, Peter, et al.
(författare)
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Risk of myocardial infarction in relation to plasma levels of homocysteine and inflammation-sensitive proteins: a long-term nested case-control study.
- 2003
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Ingår i: Angiology. - 0003-3197. ; 54:4, s. 401-410
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have found that the homocysteine plasma level is associated with cardiovascular disease. The authors previously described a relationship between concentrations of fibrinogen and other inflammation-sensitive plasma proteins, namely, alpha1-antitrypsin, ceruloplasmin, haptoglobin, and orosomucoid (alpha1-acid glucoprotein) and the incidence of myocardial infarction (MI). Whether levels of these proteins are related to homocysteine has not been clarified. The aim of this study was to investigate whether a supposed relationship between homocysteine in plasma and the occurrence of MI is modified by these inflammation-sensitive proteins. A nested case-control study was designed, comprising 241 cases of MI, with a mean age of 48 years at baseline, and 241 controls matched for age, month of examination, and duration of follow-up. The mean homocysteine concentration did not differ between cases and controls and there was no association between the baseline homocysteine level and the time lapse before the occurrence of the MI. For the cases, there was no correlation between homocysteine and any of the measured proteins, but for the controls, homocysteine was weakly but significantly negatively correlated to haptoglobin and ceruloplasmin and slightly positively correlated to albumin. For the separated groups of cases and controls there was no association between the number of inflammation-sensitive proteins in the top quartiles and homocysteine concentration. In this population-based, prospective cohort study the occurrence of MI had no relationship to homocysteine baseline plasma level. Furthermore, there was no strong association between homocysteine and the concentrations of any of these inflammation-sensitive proteins.
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| 4. |
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| 5. |
- Nilsson, Anna-Karin, et al.
(författare)
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C-reactive protein: vascular risk marker in elderly patients with mental illness.
- 2008
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 26:3, s. 251-256
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There is increasing evidence that vascular disease contributes to cognitive impairment and dementia. Clarification of the role of vascular risk factors in dementia is important because most are modifiable, in contrast to other risk factors such as age and genetics. METHODS: In 428 patients with mental illness we have investigated the relation of vascular disease to diagnoses, and a biochemical parameter, C-reactive protein (CRP), which is associated with inflammation and vascular disease. RESULTS: Patients with vascular disease showed higher CRP levels than patients without vascular disease. Furthermore, patients with Alzheimer's disease showed lower CRP levels than patients with vascular dementia, mild cognitive impairment or depression. There is no obvious reason for this finding, since it could not be attributed to drug treatment. CONCLUSION: The findings indicate that the control of conventional vascular risk factors and therapy could be guided by the level of CRP.
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| 6. |
- Nilsson, Karin, et al.
(författare)
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Association between plasma homocysteine levels and mortality in elderly patients with mental illness.
- 2009
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 27:6, s. 579-583
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/METHOD: Total plasma homocysteine (tHcy) concentration is elevated in elderly patients with mental illness. Plasma tHcy is known to be associated with cardiovascular disease, renal impairment and negative lifestyle factors, and has been shown to predict mortality in human subjects. Epidemiological data on this topic in elderly patients with mental illness are missing. We therefore investigated the association between plasma tHcy levels and mortality in these patients. RESULTS: The group of deceased patients showed higher age, higher plasma tHcy, lower renal function and lower serum folate than patients who were still alive. Only age, plasma tHcy and the presence of vascular disease significantly influenced mortality. CONCLUSION: The association between plasma tHcy level and mortality risk was probably explained in part by the two plasma tHcy determinants age and presence of vascular disease. The determination of plasma tHcy in elderly patients with mental illness may help to identify patients in need of more intensive treatment.
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| 7. |
- Nilsson, Karin, et al.
(författare)
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Elevated plasma homocysteine concentration in elderly patients with mental illness is mainly related to the presence of vascular disease and not the diagnosis
- 2007
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 24:3, s. 162-168
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Tidskriftsartikel (refereegranskat)abstract
- Background: Plasma total homocysteine (tHcy) is often elevated in patients with mental illness. Since patients with mental illness and vascular disease exhibit a higher plasma tHcy concentration than patients without vascular disease, it is possible that elevated plasma tHcy in mental illness is mainly due to concomitant vascular disease. Methods: We have investigated plasma tHcy, cobalamin/folate status, renal function and the presence of vascular disease in patients with vascular dementia (VaD, n = 501), Alzheimer's disease ( AD, n = 300), depression ( n = 259) and in healthy subjects ( n = 144) stratified according to age ( below and above 75 years). Results: Plasma tHcy concentration showed the highest increase in patients with VaD compared to patients with AD or depression. After the exclusion of patients with cobalamin/ folate deficiencies and increased serum creatinine, patients with AD or depression above 75 years with vascular disease showed a similar elevation of plasma tHcy concentration as patients with VaD. Furthermore, patients with AD and depression without vascular disease showed a similar plasma tHcy concentration to healthy subjects. Conclusion: The findings imply that elevated plasma tHcy concentration in elderly patients with mental illness is mainly associated with the presence of vascular disease and is not related to the specific psychogeriatric diagnosis.
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| 8. |
- Nilsson, Karin, et al.
(författare)
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Homocysteine, cystatin C and N-terminal-pro brain natriuretic Peptide. Vascular risk markers in elderly patients with mental illness.
- 2008
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 25:1, s. 88-96
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There is increasing evidence that vascular disease contributes to cognitive impairment and dementia. Clarification of the role of vascular risk factors in dementia is important because most are modifiable, in contrast to other risk factors such as age and genetics. METHODS: In 451 patients with mental illness we have investigated three biochemical markers related to vascular disease, total plasma homocysteine (tHcy), cystatin C, and N-terminal-pro brain natriuretic peptide (NT-proBNP), and their association with vascular disease, diagnoses, and brain imaging findings (CT). RESULTS: Plasma tHcy, serum cystatin C, and serum NT-proBNP showed significantly increased frequencies of elevated levels in patients with vascular disease, in patients with a pathological CT finding indicating cerebrovascular disease, and in patients above 75 years of age. CONCLUSION: It is possible that the control of conventional vascular risk factors and therapy could be guided by the level of plasma tHcy, serum cystatin C, and serum NT-proBNP. Patients with an elevation of any of these three parameters could be selected for a lower target level of risk factors such as blood pressure, hyperlipidemia etc. than conventional target levels.
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| 9. |
- Nilsson, K, et al.
(författare)
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Lack of association between plasma homocysteine and inflammation in psychogeriatric patients
- 2002
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Ingår i: Dementia and Geriatric Cognitive Disorders. - 1420-8008. ; 14:3, s. 151-155
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Tidskriftsartikel (refereegranskat)abstract
- Background/Objectives: In previous studies we observed a high incidence of elevated plasma homocysteine (tHcy) concentrations in psychogeriatric patients. Plasma tHcy is increased in folate deficiency. Folates are sensitive to oxidative stress. Oxidative stress, caused by inflammatory processes, could represent an endogenous reason for folate deficiency, even when the dietary intake of the vitamin is within the recommended range. It has been suggested that oxidative stress rather than insufficient folate intake causes hyperhomocysteinemia in different forms of psychogeriatric diseases. In the present study we investigated the association between plasma tHcy and C-reactive protein (CRP), a sensitive marker for inflammation, in psychogeriatric patients. Methods: Plasma tHcy, its main determinants, and CRP were measured in plasma and serum of 132 psychogeriatric patients (53 males and 79 females, mean age 75 12 years). Results. In the psychogeriatric patients, plasma tHcy was elevated and blood folate and serum creatinine were lower than in control subjects, whereas serum CRP concentrations did not differ significantly. We also subdivided the psychogeriatric patients into different diagnosis groups, yet there were no differences in serum CRP concentrations in these groups compared with age-matched control groups. There was a significant correlation between plasma tHcy and serum CRP (rho = 0.19, p < 0.05). A stepwise multiple regression analysis including serum CRP, age, blood folate, serum cobalamin, serum methylmalonic acid and serum creatinine showed that only blood folate (p < 0.001), age (p < 0.001), serum creatinine (p < 0.001), serum cobalamin (p < 0.001), and serum methylmalonic acid (p < 0.001) independently predicted plasma tHcy concentration. Thus CRP concentration was not an independent predictor of plasma tHcy. Conclusion: The present study did not show any association between inflammatory status and plasma tHcy concentration in psychogeriatric patients.
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| 10. |
- Nilsson, Karin, et al.
(författare)
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Plasma Homocysteine and Cognition in Elderly Patients with Dementia or Other Psychogeriatric Diseases.
- 2010
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 30:3, s. 198-204
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Tidskriftsartikel (refereegranskat)abstract
- Background: Total plasma homocysteine (tHcy) concentration is elevated in elderly patients with mental illness, and patients with vascular disease have higher plasma tHcy concentrations than patients without vascular disease. Increasing evidence indicates that vascular risk factors play a role in the development of cognitive impairment. Method: We have investigated the relation between plasma tHcy, its determinants and cognition, measured as MMSE, in 448 consecutively enrolled patients with dementia or other psychogeriatric diseases. Results: Multiple regression analyses showed that plasma tHcy was related to cognitive function in all patients as well as in demented and non-demented patients. The apparent close relationship between plasma tHcy and cognition was mainly dependent on its determinant age, whereas the other determinants of plasma tHcy exhibited a limited influence on the relation between plasma tHcy and cognition. Plasma tHcy has its own, albeit modest, relationship to cognitive function (predictive value about 5%). Conclusion: Plasma tHcy itself seems to play a minor role in cognitive impairment in patients with dementia or other psychogeriatric diseases. When investigating the relation between plasma tHcy and cognition, it is important to consider the distribution of the main determinants of plasma tHcy and to correct plasma tHcy for these variables.
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