Impairment of homocysteine metabolism in patients with retinal vascular occlusion and non-arteritic ischemic optic neuropathy

Author(s):  
Olaf Stanger ◽  
Martin Weger ◽  
Rima Obeid ◽  
Werner Temmel ◽  
Andreas Meinitzer ◽  
...  

AbstractMild hyperhomocysteinemia is established as an independent risk factor for atherothrombotic disease, including ocular pathologies such as retinal vascular occlusion and non-arteritic ischemic optic neuropathy (NAION). Low intake or low status of B-vitamins explains elevated total homocysteine (tHcy) concentrations only in part. The underlying cause for disturbed homocysteine metabolism requires further insight. We investigated whether the combined determinations of plasma tHcy, methylmalonic acid (MMA) and cystathionine provide more information on the causes of impaired homocysteine metabolism as compared with vitamin B

PLoS ONE ◽  
2017 ◽  
Vol 12 (8) ◽  
pp. e0181766 ◽  
Author(s):  
Josep Callizo ◽  
Nicolas Feltgen ◽  
Antje Ammermann ◽  
Janina Ganser ◽  
Sebastian Bemme ◽  
...  

2020 ◽  
pp. 112067212095759
Author(s):  
Amy Dai ◽  
Lasse Malmqvist ◽  
Simon P Rothenbuehler ◽  
Steffen Hamann

Purpose: To examine optic nerve head (ONH) anatomy in young adults with central retinal vein occlusion (CRVO), branch retinal vein occlusion (BRVO), central retinal artery occlusion (CRAO), branch retinal artery occlusion (BRAO) or nonarteritic anterior ischemic optic neuropathy (NA-AION) in order to look for associated, potentially predisposing anomalies. Methods: Cross-sectional study including 54 patients (ages 16–50 years) diagnosed from 2009 to 2018 with CRVO, BRVO, CRAO, BRAO, or NA-AION. Using Optical Coherence Tomography the presence of optic disc drusen (ODD), prelaminar hyperreflective lines and peripapillary hyperreflective ovoid mass-like structures (PHOMS), and determination of scleral canal size, retinal nerve fiber layer thickness (RNFLT) and macular ganglion cell layer thickness (GCLT) was obtained. Data for retinal vascular occlusion patients were grouped and analyzed together. Results: ODD were found in 13% of all patients, 2% of retinal vascular occlusion patients and 67% of NA-AION patients ( p < 0.0001). Prelaminar hyperreflective lines were found in 35% of all patients, 24% of retinal vascular occlusion patients and 89% of NA-AION patients ( p = 0.0005). PHOMS were found in 20% of all patients, 13% of retinal vascular occlusion patients and 56% of NA-AION patients ( p = 0.012). RNFLT was decreased in ODD patients compared to patients without ODD ( p = 0.01). Scleral canal diameter and GCLT was not correlated with ODD, prelaminar hyperreflective lines or PHOMS. Conclusion: ODD, prelaminar hyperreflective lines and PHOMS were more frequent in NA-AION patients compared to retinal vascular occlusion patients. The prevalence of ODD in retinal vascular occlusion patients was similar to the reported prevalence in the general population.


2003 ◽  
Vol 9 (3) ◽  
pp. 239-245 ◽  
Author(s):  
M Vrethem ◽  
E Mattsson ◽  
H Hebelka ◽  
K Leerbeck ◽  
A Österberg ◽  
...  

Objective: The aim of this study was to evaluate if multiple sclerosis (MS) is associated with vitamin B12 (cobalamin) deficiency. Methods: We measured serum vitamin B12, plasma folate, serum methylmalonic acid (MMA), plasma homocysteine (tHcy) and also cerebrospinal fluid (C SF) MMA and tHcy in 72 patients with MS and 23 controls. Results: The mean plasma tHcy level was significantly increased in MS patients (11.6 mmol/L) compared with controls (7.4 mmol/L) (P =4-0.002). Seven patients showed low serum vitamin B12levels but only one of them had concomitant high plasma tHcy. None of them showed high serum MMA. Plasma or blood folate levels did not differ between MS patients and controls. We found no significant differences in mean values or frequency of pathological tests of serum B12, serum MMA, mean corpuscular volume (MC V), haemoglobin concentration, C SF tHcy or C SF MMA between patients and healthy subjects. There were no correlations between C SF and serum/plasma levels of MMA or tHcy. Serum vitamin B12, serum MMA, plasma tHcy, C SF Hcy or C SF MMA were not correlated to disability status, activity of disease, duration of disease or age. Conclusions:The relevance of the increased mean value of plasma tHcy thus seems uncertain and does not indicate functional vitamin B12 deficiency. We can not, however, exclude the possibility of a genetically induced dysfunction of the homocysteine metabolism relevant for the development of neuroinflammation/degeneration. O ur findings indicate that, regardless of a significant increase in plasma tHcy in MS patients, the MS disease is not generally associated with vitamin B12 deficiency since we did not find any other factors indicating vitamin B12 deficiency. A nalysis of C SF MMA and C SF tHcy, which probably reflects the brain vitamin B12 status better than serum, are not warranted in MS. We conclude that B12 deficiency, in general, is not associated with MS.


2013 ◽  
Vol 109 (5) ◽  
pp. 785-794 ◽  
Author(s):  
Derek Obersby ◽  
David C. Chappell ◽  
Andrew Dunnett ◽  
Amalia A. Tsiami

There is strong evidence indicating that elevated plasma total homocysteine (tHcy) levels are a major independent biomarker and/or a contributor to chronic conditions, such as CVD. A deficiency of vitamin B12can elevate homocysteine. Vegetarians are a group of the population who are potentially at greater risk of vitamin B12deficiency than omnivores. This is the first systematic review and meta-analysis to appraise a range of studies that compared the homocysteine and vitamin B12levels of vegetarians and omnivores. The search methods employed identified 443 entries, from which, by screening using set inclusion and exclusion criteria, six eligible cohort case studies and eleven cross-sectional studies from 1999 to 2010 were revealed, which compared concentrations of plasma tHcy and serum vitamin B12of omnivores, lactovegetarians or lacto-ovovegetarians and vegans. Of the identified seventeen studies (3230 participants), only two studies reported that vegan concentrations of plasma tHcy and serum vitamin B12did not differ from omnivores. The present study confirmed that an inverse relationship exists between plasma tHcy and serum vitamin B12, from which it can be concluded that the usual dietary source of vitamin B12is animal products and those who choose to omit or restrict these products are destined to become vitamin B12deficient. At present, the available supplement, which is usually used for fortification of food, is the unreliable cyanocobalamin. A well-designed study is needed to investigate a reliable and suitable supplement to normalise the elevated plasma tHcy of a high majority of vegetarians. This would fill the gaps in the present nutritional scientific knowledge.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1824-1824
Author(s):  
Ekaterina Mineva ◽  
Maya Sternberg ◽  
Christine M Pfeiffer

Abstract Objectives High blood methylmalonic acid (MMA) and homocysteine (tHcy) and low serum B-12 and holotranscobalamin (holoTC) concentrations indicate vitamin B-12 deficiency. The diagnosis is often contradictory when using any test independently. A mathematical model including all 4 biomarkers, named combined indicator of vitamin B-12 status (cB12), has been proposed. Our goal was to describe cB12 in US adults and estimate the prevalence of low or transitional vitamin B-12 status compared to conventional single biomarkers. Methods We assessed cB12 in persons ≥20 y participating in NHANES from 1999 to 2004 from 3 biomarkers: serum vitamin B-12, MMA, and plasma tHcy. Results The following groups had significantly lower cB12: persons ≥70 y compared with younger age groups, males compared with females, non-Hispanic whites compared with non-Hispanic blacks and Mexican Americans, and non-users of vitamin B-12 containing supplements compared with users. Shorter fasting times and impaired renal function also resulted in lower cB12. There was a strong significant association of cB12 with serum vitamin B-12 (Spearman r = 0.75), MMA (r = −0.70), and tHcy concentrations (r = −0.59). The prevalence of vitamin B-12 deficiency varied with the biomarker and cutoff used: 2.2% and 13% for serum vitamin B-12 &lt; 148 and 148 − 222 pmol/L, respectively; 6.0% for MMA exceeding an age-specific cutoff between 250 and 320 nmol/L; and 8.4% for tHcy &gt; 13 μmol/L. Using the proposed cB12 cutoff of &lt; −0.5, 2.7% of adults had “low or transitional vitamin B-12 status”. Conclusions Based on the new combined indicator using 3 biomarkers a larger portion of US adults had adequate vitamin B-12 status (97%) compared to conventional single biomarkers (between 85% and 94%), likely indicating the higher specificity of cB12. It is unclear whether the availability of holoTC data would change these findings. Funding Sources This work was supported by direct appropriations from US Congress.


2017 ◽  
Vol 141 (1) ◽  
pp. 162-166 ◽  
Author(s):  
Hershel R. Patel ◽  
Curtis E. Margo

Ischemic optic neuropathy (ION) describes a state of hypoxic injury of the optic nerve. Clinically, ION is divided into anterior and posterior forms defined by the presence or absence of optic disc swelling, respectively. It is further classified as arteritic when secondary to vasculitis, and nonarteritic when not. The site of vascular occlusion for anterior ION from giant cell arteritis is the short posterior ciliary arteries, but mechanical vascular obstruction does not play a role in most nonarteritic cases. Histologically, ION is characterized by axon and glial necrosis, edema, and a sparse mononuclear response. Like other ischemic injuries, the morphologic alternations in the nerve are time dependent. A variant of ION called cavernous degeneration (of Schnabel) features large cystic spaces filled with mucin. Several conditions can histologically mimic cavernous degeneration of the optic nerve. The scarcity of cases of ION examined histologically has contributed to an incomplete understanding of its pathogenesis.


2013 ◽  
Vol 154 (45) ◽  
pp. 1773-1780
Author(s):  
Miklós Resch ◽  
Ildikó Süveges ◽  
János Németh

Hypertension affects a significant proportion of the population, however, it is often diagnosed with a delay. The aim of this article is to review the well known and less known eye abnormalities related to hypertension, and place them in the context of population based studies. Hypertension affects various parts of the eye. The originally classified hypertensive retinopathy (retinal microvascular changes) is still relevant, but new features are visible in cases of controlled hypertension. Signs of mild hypertensive retinopathy are more common than expected occurring in nearly 10–15% of the adult non-diabetic population. Hypertensive retinopathy can be an indicator of other hypertensive complications such as neurologic and cardiac complications. Microvascular changes are reversible in well controlled hypertension. Proper treatment of hypertension can reduce the development and progression of diabetic retinopathy and, thus, visual loss due to severe retinal diseases such as retinal vascular occlusion (artery and vein), retinal arteriolar emboli, macroaneurysm, ischemic optic neuropathy and age-related macular degeneration.Orv. Hetil., 154(45), 1773–1780.


2009 ◽  
Vol 79 (56) ◽  
pp. 297-307 ◽  
Author(s):  
Laila Hussein ◽  
Sahar Abdel Aziz ◽  
Salwa Tapouzada ◽  
Boehles

Objective:Cobalamin (B12) deficiency has been reported in infants born to mothers with low cobalamin intake. Early diagnosis of vitamin B12 deficiency in infants is critical for the prevention of neurobehavioral disorders. We investigated the relationship between serum vitamin B12 level in newborns and in their healthy mothers who consumed an omnivorous diet. Anthropometry was studied longitudinally to assess the growth velocity of the infants. Urinary methylmalonic acid (MMA) excretion of 6-month old infants was compared retrospectively as the biomarker correlated with the initial serum vitamin B12 concentrations. Methods: Serum cobalamin and blood hemoglobin were determined in 84 pairs of newborns and their mothers. Urinary MMA excretion was measured in the same subjects during the first 6 months of the post partum period. Results: At birth, median serum cobalamin levels were 152.0 pmol/L in the mothers and 296.6 pmol/L in the newborns. Maternal and neonatal serum cobalamin levels had no effect on growth velocity during the first six months of postnatal life. Serum maternal and neonatal cobalamin levels were inversely associated with urinary MMA excretion. Conclusion: Early diagnosis of vitamin B12 status in neonates and infants is crucial, particularly in nutritionally deprived areas. Biochemical measurement of plasma cobalamin or its metabolic marker MMA is highly recommended. Urinary MMA measurement in cobalamin diagnostics provides an advantage in that blood sampling is not required. A vitamin B12 taskforce should be created to alleviate vitamin deficiency and its negative consequences.


2012 ◽  
Vol 82 (4) ◽  
pp. 260-266 ◽  
Author(s):  
Salah E. Gariballa ◽  
Sarah J. Forster ◽  
Hilary J. Powers

Background: Although a number of studies have reported raised total plasma homocysteine (tHcy) concentrations in free-living older people, there are no data on homocysteine response to a mixed nutrient supplement in older patients. A raised plasma homocysteine concentration in older patients is partly a reflection of their co-morbidity, including impaired renal function, and there is uncertainty about the extent to which dietary interventions can improve plasma tHcy. Aim: To determine the plasma tHcy response to dietary supplements during acute illness. Methods: Two-hundred and thirty-six hospitalized, acutely ill older patients, who were part of a randomized double-blind placebo-controlled trial, were assigned to receive a daily oral nutritional supplement drink containing 1.3 mg of vitamin B2, 1.4 mg of vitamin B6, 1.5 μg of B12, 200 μg of folic acid, or a placebo, for 6 weeks. Outcome measures were plasma tHcy concentration at baseline, 6 weeks, and 6 months. Results: The mean plasma tHcy concentration fell among patients given the supplements (mean difference 4.1 µmol/L [95 % C.I, 0.14 to 8.03), p = 0.043], but tHcy concentration increased between 6 weeks and 6 months, after patients stopped taking the supplements [mean difference -2.0 µmol/L (95 % C.I, -03.9 to -0.18), p = 0.033]. About 46 % of patients in the placebo group and 55 % of patients in the supplement group had hyperhomocysteinemia (>14 µmol/L) at baseline compared with 45 % and 29 % at the end of the treatment period. Conclusions: A mixed nutrient supplement containing physiological amounts of B vitamins significantly reduced plasma tHcy concentrations in older patients recovering from acute illness.


Sign in / Sign up

Export Citation Format

Share Document