The frequently low cobalamin levels in dementia usually signify treatable metabolic, neurologic and electrophysiologic abnormalities

Expression of the cobalamin transporters cubam and MRP1 in the canine ileum-Upregulation in chronic inflammatory enteropathy

Chronic inflammatory enteropathy (CIE) in dogs, a spontaneous model of human inflammatory bowel disease (IBD), is associated with a high rate of cobalamin deficiency. The etiology of hypocobalaminemia in human IBD and canine CIE remains unknown, and compromised intestinal uptake of cobalamin resulting from ileal cobalamin receptor deficiency has been proposed as a possible cause. Here, we evaluated the intestinal expression of the cobalamin receptor subunits, amnionless (AMN) and cubilin (CUBN), and the basolateral efflux transporter multi-drug resistance protein 1 (MRP1) in 22 dogs with CIE in comparison to healthy dogs. Epithelial CUBN and AMN levels were quantified by confocal laser scanning microscopy using immunohistochemistry in endoscopic ileal biopsies from dogs with (i) CIE and normocobalaminemia, (ii) CIE and suboptimal serum cobalamin status, (iii) CIE and severe hypocobalaminemia, and (iv) healthy controls. CUBN and MRP1 expression was quantified by RT-qPCR. Receptor expression was evaluated for correlation with clinical patient data. Ileal mucosal protein levels of AMN and CUBN as well as mRNA levels of CUBN and MRP1 were significantly increased in dogs with CIE compared to healthy controls. Ileal cobalamin receptor expression was positively correlated with age, clinical disease activity index (CCECAI) score, and lacteal dilation in the ileum, inversely correlated with serum folate concentrations, but was not associated with serum cobalamin concentrations. Cobalamin receptor downregulation does not appear to be the primary cause of hypocobalaminemia in canine CIE. In dogs of older age with severe clinical signs and/or microscopic intestinal lesions, intestinal cobalamin receptor upregulation is proposed as a mechanism to compensate for CIE-associated hypocobalaminemia. These results support oral supplementation strategies in hypocobalaminemic CIE patients.

Methylmalonic acid analysis using urine filter paper samples to screen for metabolic vitamin B12 deficiency in older adults

Aim: Methylmalonic acid (MMA) analysis in urine represents a noninvasive approach to screening for vitamin B₁₂ deficiency in older adults. A method allowing the analysis of MMA/creatinine in fasting urine collected on filter paper was developed/validated. Method: Dry urine specimens were eluted using a solution containing internal standards, filtrated and analyzed by ultra-performance LC-MS/MS. Results: The method allowed the chromatographic separation of MMA from succinic acid. Dried urine samples were stable for 86 days at room temperature. The MMA/creatinine ratios measured in urine collected on filter paper were highly correlated with values derived from the corresponding liquid specimens. Conclusion: This robust filter paper method might greatly improve the accessibility and cost-effectiveness of vitamin B₁₂ deficiency screening in older adults.

Serum cobalamin concentrations in dogs with leishmaniosis before and during treatment

Hypocobalaminemia in dogs is most commonly associated with gastrointestinal disorders leading to impaired absorption and utilization of cobalamin. The objectives of this study were to compare serum cobalamin concentrations between dogs with leishmaniosis and clinically healthy dogs, and to assess possible alterations of serum cobalamin concentrations in dogs with leishmaniosis at different timepoints during treatment. Fifty-five dogs with leishmaniosis and 129 clinically healthy dogs were prospectively enrolled. Diagnosis of leishmaniosis was based on clinical presentation, positive serology and microscopic detection of Leishmania amastigotes in lymph node aspiration smears. Twenty of the dogs with leishmaniosis were treated with a combination of meglumine antimonate and allopurinol for 28 days and serum cobalamin concentrations were measured in blood samples that were collected before initiation of treatment (timepoint 0) and on days 14 and 28. In order to estimate alterations of serum cobalamin concentrations during treatment, cobalamin concentrations were measured in blood samples from 20 out of 55 dogs with leishmaniosis at all timepoints. Serum cobalamin concentrations were significantly lower in dogs with leishmaniosis before treatment (median: 362 ng/L; IQR: 277-477 ng/L) compared to clinically healthy dogs (median: 470 ng/L; IQR: 367-632 ng/L; P = 0.0035). Serum cobalamin concentrations increased significantly in dogs with leishmaniosis on day 14 of treatment compared to timepoint 0 (P = 0.02). In the present study, serum cobalamin concentrations were significantly lower in dogs with leishmaniosis compared to clinically healthy dogs. In addition, there was an increase in serum cobalamin concentrations during treatment. The clinical significance of hypocobalaminemia in dogs with leishmaniosis remains to be determined.

Involvements of Hyperhomocysteinemia in Neurological Disorders

Homocysteine (HCY), a physiological amino acid formed when proteins break down, leads to a pathological condition called hyperhomocysteinemia (HHCY), when it is over a definite limit. It is well known that an increase in HCY levels in blood, can contribute to arterial damage and several cardiovascular disease, but the knowledge about the relationship between HCY and brain disorders is very poor. Recent studies demonstrated that an alteration in HCY metabolism or a deficiency in folate or vitamin B12 can cause altered methylation and/or redox potentials, that leads to a modification on calcium influx in cells, or into an accumulation in amyloid and/or tau protein involving a cascade of events that culminate in apoptosis, and, in the worst conditions, neuronal death. The present review will thus summarize how much is known about the possible role of HHCY in neurodegenerative disease.

Shifts in B12 opinions in primary health care of Sweden

Aims: The diagnosis and management of vitamin B12 deficiency varies between countries and within countries. The aim of the study was to map current attitudes and values behind clinical decision-making in Swedish primary health care, which has a unique B12 tradition: two patients out of three are treated with oral high-dose cyanocobalamin. Most patients with B12-associated problems are managed in primary health care by general practitioners (GPs). Methods: The study was designed to elucidate possible opinion shifts among GPs during the period 1996- 1998. GPs ( n=499), stratified and randomized, received a questionnaire with 24 statements on B12-associated clinical and laboratory problems, to be evaluated by a visuo-analogue scale. Results: The majority of GPs in primary health care in Sweden accepted homocysteine and methylmalonic acid (MMA) as markers for functional deficiency of vitamin B12. The evaluation of classical markers of B12 deficiency was wary and balanced. There was a consensus of the need for B12 therapy to risk groups such as patients with atrophic gastritis or previous gastric surgery. The answers also appeared to refl ect an improvement of professional knowledge and competence concerning B 12-associated problems among Swedish GPs between 1996 and 1998. Conclusions: The overriding conclusion was that B12-associated opinions of Swedish GPs were stable within the period studied, with marginal improvements of knowledge and competence.

Determining Functional Vitamin B12 Deficiency in the Elderly

BACKGROUND

Elevated concentration of serum total homocysteine usually occurs in vitamin B-12 deficiency. This metabolite can be measured and used for screening functional vitamin B-12 deficiency.

OBJECTIVES

We assessed functional vitamin B12 deficiency in Tehranian elderly admitted to elderly research center, University of Social Welfare and Rehabilitation Sciences.

PATIENTS AND MATERIALS

A cross-sectional study was performed on 232 elderly admitted to elderly research center in Tehran, Iran in 2012. According to other studies, individuals were classified into two groups: high risk of vitamin B-12 deficiency (< 220 pmol/L) and borderline vitamin B-12 (220-258 pmol/L) accompanied by elevated homocysteine (> 15 micmol/L).

RESULTS

Cut-off of 15.0 pmol/L for homocysteine was identified for persons with normal or elevated concentrations. Among persons aged 65-74 and ≥ 75 years, respectively, 56% and 93% were at high risk of vitamin B-12 deficiency.

CONCLUSIONS

The prevalence of B12 deficiency was higher in this study compared to other studies, so more attention and massive efficacious policy should be designed to reduce the deficiency of this vitamin.

Cobalamin deficiency in the elderly: aetiology and management: a study of 125 patients in a geriatric hospital

INTRODUCTION

Cobalamin deficiency is frequent in elderly patients and the main aetiologies are food-cobalamin malabsorption and pernicious anaemia. The aim of our retrospective study was to identify the causes and methods of management of cobalamin deficiency at Nice geriatric university hospital.

METHODS

A retrospective monocentric study was conducted over 14 months at Nice geriatric hospital, which included patients with cobalamin deficiency having received supplementation. The clinical and paraclinical data, etiological diagnosis, treatment and follow-up modalities were analyzed retrospectively.

RESULTS

We studied 125 elderly patients whose median age was 85.5 ± 7 years. The etiological diagnosis was food-cobalamin malabsorption for 72 patients (57.6 %), nutritional cobalamin deficiency for 15 patients (12 %), pernicious anaemia for 12 patients (9.6 %) and there was no etiological diagnosis for 26 patients (20.8 %). Concerning cobalamin therapy, 111 patients (88.8 %) received oral therapy and 14 (11.2 %) intramuscular therapy. Vitamin B12 levels increased significantly after supplementation (p<0.001) but cobalamin administration varied according to the diagnoses (p<0.001) and was less effective in patients with dementia (p=0.04) and food-cobalamin malabsorption.

CONCLUSION

Our study showed the importance of food-cobalamin malabsorption in etiological diagnosis in accordance with the literature, but also the non-negligible share of nutritional cobalamin deficiency. Mainly oral cobalamin supplementation was used in our study with a significant increase in vitamin B12 levels. An oral cobalamin regimen is proposed for elderly patients with cobalamin deficiency but with no severe neurological signs.

Low serum vitamin B12 levels among psychiatric patients admitted in Butabika mental hospital in Uganda

Background

Psychiatric manifestations have been noted in patients with low serum vitamin B₁₂ levels even in the absence of other neurologic and/or haematologic abnormalities. There is no literature on low serum B₁₂ prevalence among Ugandans with psychiatric illnesses. The aim of this study was to establish the prevalence, risk factors, and clinical manifestations of low serum vitamin B₁₂ among psychiatric patients admitted in a Mental Health Hospital in Uganda.

Method

Using a cross sectional descriptive study design, 280 in-patients selected by systematic sampling were studied using a standardized protocol. Low serum vitamin B12 was defined as a level < 240 pg /mL.

Results

We found a prevalence of low serum B₁₂ in 28.6% of the participants. Absent vibration sense which was significantly associated (58.3% Vs. 26.7%: OR = 3.84 (95% C.I. 1.18, 12.49); p-value = 0.025) with low vitamin B₁₂ was observed among 12 participants. Macro-ovalocytes present among 23 participants on peripheral film were significantly associated with low serum levels (73.9% Vs. 26.2%: OR = 7.99 (95% C.I. 3.01, 21.19) p-value < 0.0001). Factors significantly associated with low serum B₁₂ levels included psychiatric diagnosis of schizophrenia (AOR 1.74 (95% C.I. 1.00, 3.02); p-value = 0.049), duration of psychiatric illness > or = 3 years (AOR 2.27 (95% C.I. 1.29, 3.98); p-value = 0.004), and hospitalization < 3 weeks (AOR 4.01 (95% C.I. 1.02, 15.79); p-value = 0.047). Female participants were associated with protection from low serum levels (AOR 0.4 (95% C.I. 0.22, 0.73); p-value = 0.003).

Conclusion

Low serum B₁₂ is common among hospitalized psychiatric patients with the majority having no haematological findings. Associated risk factors included having a psychiatric diagnosis of schizophrenia, a shorter duration of hospitalization and longer duration of psychiatric illness. Female participants were less likely to have low serum vitamin B₁₂ levels. Routine screening for serum vitamin B₁₂ levels should be adopted by all hospitals for admitted psychiatric patients.

Neurologic aspects of cobalamin (B12) deficiency

Optimal functioning of the central and peripheral nervous system is dependent on a constant supply of appropriate nutrients. Particularly important for optimal functioning of the nervous system is cobalamin (vitamin B12). Cobalamin deficiency is particularly common in the elderly and after gastric surgery. Many patients with clinically expressed cobalamin deficiency have intrinsic factor-related malabsorption such as that seen in pernicious anemia. The commonly recognized neurological manifestations of cobalamin deficiency include a myelopathy with or without an associated neuropathy. This review deals with neurological aspects of vitamin B12 deficiency and attempts to highlight recent developments.

Cobalamin in companion animals: diagnostic marker, deficiency states and therapeutic implications

Measurement of the water-soluble vitamin cobalamin has long been of interest as a marker of gastrointestinal disease in companion animals due to the highly localized presence of cobalamin receptors in the ileum. An increasing body of evidence suggests that cobalamin deficiency is an important co-morbidity in many companion animal patients with gastrointestinal and pancreatic disease. Congenital disorders of cobalamin absorption and cellular metabolism are also increasingly recognized in companion animal breeds. The early recognition of these disorders and timely treatment with parenteral cobalamin can be life-saving. In this article, the normal mechanisms of cobalamin absorption, the use of cobalamin as a marker of intestinal disease and data on the prevalence of hypocobalaminemia in a variety of diseases are described. The prognostic impact of and rational therapy for hypocobalaminemia in domestic animals are discussed.

Diagnosis and management of clinical and subclinical cobalamin deficiencies: why controversies persist in the age of sensitive metabolic testing

In the past two decades, sensitive biochemical tests have uncovered cobalamin deficiency much more frequently than ever before. Almost all cases involve mild, biochemical changes without clinical manifestations (subclinical cobalamin deficiency; SCCD), whose health impact is unclear. Because the causes of SCCD are most often unknown, nonmalabsorptive, and seldom documented, controversy and confusion surround the diagnostic criteria and, inevitably, consequences and management of SCCD. To complicate matters, our grasp of the rarer clinical deficiency, usually a serious, progressive medical disease rooted in severe malabsorption, has receded as absorption testing has disappeared. Reexamining the accumulation of assumptions and misperceptions about cobalamin deficiency and distinguishing SCCD from clinical deficiency is long overdue. The biology of cobalamin provides an important starting point: cobalamin stores exceed daily losses so greatly and binding proteins regulate absorption so effectively that deficiency typically achieves clinical expression only after years of severe, relentless malabsorption. Dietary insufficiency, mild, partial malabsorption, and other incomplete, intermittent causes can usually produce only SCCD. Thus, the most fundamental difference between the two deficiencies is the relentlessness of the underlying cause, which determines prognosis and health impact. Inattention to absorptive status has exacerbated the limitations of biochemical testing. All the biochemical tests are highly sensitive but specificity is poor, no diagnostic gold standard exists, and diagnostic cutpoints fluctuate excessively. To limit the adverse diagnostic consequences, the diagnosis of SCCD, whose need for treatment is unclear, should be deferred unless at least two tests are abnormal. Indeed, cobalamin biology indicates that the absorption system, while enhancing cobalamin delivery, also sets a strict upper limit on it, which suggests that cobalamin excess is undesirable. Solving cobalamin deficiency requires balanced assessment of the different imperatives of clinical and public health concerns, better rationalization of diagnostic testing, consistent definitions of normality in relation to SCCD, and rational cutpoint selection.

Vitamin B12 in neurology and ageing; clinical and genetic aspects

The classic neurological and psychiatric features associated with vitamin B12 deficiency have been well described and are the subject of many excellent review articles. The advent of sensitive diagnostic tests, including homocysteine and methylmalonic acid assays, has revealed a surprisingly high prevalence of a more subtle 'subclinical' form of B12 deficiency, particularly within the elderly. This is often associated with cognitive impairment and dementia, including Alzheimer's disease. Metabolic evidence of B12 deficiency is also reported in association with other neurodegenerative disorders including vascular dementia, Parkinson's disease and multiple sclerosis. These conditions are all associated with chronic neuro-inflammation and oxidative stress. It is possible that these clinical associations reflect compromised vitamin B12 metabolism due to such stress. Physicians are also increasingly aware of considerable inter-individual variation in the clinical response to B12 replacement therapy. Further research is needed to determine to what extent this is attributable to genetic determinants of vitamin B12 absorption, distribution and cellular uptake.

A randomised controlled trial investigating the effect of vitamin B12 supplementation on neurological function in healthy older people: the Older People and Enhanced Neurological function (OPEN) study protocol [ISRCTN54195799]

Background

Vitamin B12 deficiency is common in older people and the prevalence increases with age. Vitamin B12 deficiency may present as macrocytic anaemia, subacute combined degeneration of the spinal cord, or as neuropathy, but is often asymptomatic in older people. The diagnosis and indications for treatment are clear for individuals with low plasma levels of vitamin B12 in the setting of megaloblastic anaemia and neuropathy, but the relevance of treatment of vitamin B12 deficiency in the absence of such clinical signs is uncertain.

Methods

The aim of the present study is to assess whether dietary supplementation with crystalline vitamin B12 will improve electrophysiological indices of neurological function in older people who have biochemical evidence of vitamin B12 insufficiency in the absence of anaemia. To test this hypothesis we designed a randomized double-blind placebo-controlled trial involving 200 older people aged 75 years or greater who were randomly allocated to receive either a daily oral tablet containing 1 mg vitamin B12 or a matching placebo tablet. The primary outcome assessed at 12 months is change in electrophysiological indices of peripheral and central neurosensory responses required for mobility and sensory function. We here report the detailed study protocol.

Conclusions

In view of the high prevalence of vitamin B12 deficiency in later life, the present trial could have considerable significance for public health.

Mandatory fortification of the food supply with cobalamin: an idea whose time has not yet come

The success of folic acid fortification has generated consideration of similar fortification with cobalamin for its own sake but more so to mitigate possible neurologic risks from increased folate intake by cobalamin-deficient persons. However, the folate model itself, the success of which was predicted by successful clinical trials and the known favorable facts of high folic acid bioavailability and the infrequency of folate malabsorption, may not apply to cobalamin fortification. Cobalamin bioavailability is more restricted than folic acid and is unfortunately poorest in persons deficient in cobalamin. Moreover, clinical trials to demonstrate actual health benefits of relevant oral doses have not yet been done in persons with mild subclinical deficiency, who are the only practical targets of cobalamin fortification because >94% of persons with clinically overt cobalamin deficiency have severe malabsorption and therefore cannot respond to normal fortification doses. However, it is only in the severely malabsorptive disorders, such as pernicious anemia, not subclinical deficiency, that neurologic deterioration following folic acid therapy has been described to date. It is still unknown whether mild deficiency states, which usually arise from normal absorption or only food-bound cobalamin malabsorption, have real health consequences or how often they progress to overt clinical cobalamin deficiency. Reports of cognitive or other risks in the common subclinical deficiency state, although worrisome, have been inconsistent. Moreover, their observational nature proved neither causative connections nor documented health benefits. Extensive work, especially randomized clinical trials, must be done before mandatory dietary intervention on a national scale can be justified.

Neurologic presentations of nutritional deficiencies

Optimal functioning of the central and peripheral nervous system is dependent on a constant supply of appropriate nutrients. The first section of this review discusses neurologic manifestations related to deficiency of key nutrients such as vitamin B(12), folate, copper, vitamin E, thiamine, and others. The second section addresses neurologic complications related to bariatric surgery. The third sections includes neurologic presentations caused by nutrient deficiencies in the setting of alcoholism. The concluding section addresses neurologic deficiency diseases that have a geographic predilection.

Cognitive and psychiatric effects of vitamin B12 replacement in dementia with low serum B12 levels: a nursing home study

BACKGROUND

The aim of this study is to determine whether B12 replacement would ameliorate cognitive and psychiatric symptoms in elderly subjects with dementia and low serum B12 levels.

METHODS

A test group (n = 28) of nursing home residents with low serum B12 levels (<250 pg/mL) and a matched comparison group (n = 28) with normal serum B12 levels (>300 pg/mL) were evaluated by blinded raters while the test group received intramuscular (IM) B12 replacement therapy. All subjects were assessed at baseline, 8 weeks, and 16 weeks with the Dementia Rating Scale, Brief Psychiatric Rating Scale, and Geriatric Depression Scale.

RESULTS

Although B12 replacement produced significant improvement in hematologic and metabolic parameters, it yielded no significant effect on cognitive or psychiatric variables. A few subjects evidenced notable individual treatment responses; however, these were not statistically more frequent than in the normal B12 group.

CONCLUSIONS

These results suggest that B12 replacement is unlikely to benefit cognitive or psychiatric symptoms in the vast majority of elderly dementia patients with low serum B12 levels.

Efficacy and safety of fortification and supplementation with vitamin B12: biochemical and physiological effects

Long known as an uncommon but serious medical disorder requiring medical management, vitamin B12 deficiency is now seen to be common worldwide, but it is in a quite different form than traditionally envisioned. Most of the newly recognized deficiency is subclinical in nature, its health impact and natural history are uncertain, and its prevalence has been greatly inflated by also including persons with "low-normal" vitamin B12 levels, few of whom are deficient. The spread of folic acid fortification has also introduced concerns about folate's potentially adverse neurologic consequences in persons with undetected vitamin B12 deficiency. Fortification with vitamin B12 may prove more complicated than fortification with folic acid, however, because the bioavailability of vitamin B12 is limited. Bioavailability for those who need the vitamin B12 the most is especially poor, because they often have malabsorption affecting either classical intrinsic factor-mediated absorption or food-vitamin B12 absorption. Moreover, new evidence shows that many elderly persons respond poorly to daily oral doses under 500 microg (1 microg = 0.74 nmol), even if they do not have classical malabsorption, which suggests that proposed fortification with 1 to 10 microg may be ineffective. Those least in need of vitamin B12 usually have normal absorption and are thus at greatest risk for whatever unknown adverse effects of high-dose fortification might emerge, such as the effects of excess accumulation of cyanocobalamin. Studies are needed to define the still unproven health benefits of vitamin B12 fortification, the optimal levels of fortification, the stability of such fortification, interactions with other nutrients, and any possible adverse effects on healthy persons. The answers will permit formulation of appropriately informed decisions about mandatory fortification or (because fortification may prove a poor choice) about targeted supplementation in subpopulations with special needs for additional vitamin B12, such as vegetarians, nursing mothers, and the elderly.

How I treat cobalamin (vitamin B12) deficiency

The challenges in medical management of cobalamin deficiency lie in attention to the unique pathophysiology that underlies cobalamin deficiency, more than in the mechanics of therapy. The central physiologic principles are that clinically important deficiency is more likely to occur (and progress) when intrinsic factor-driven absorption fails than when diet is poor and that most causes take years to produce clinically obvious deficiency. Transient defects have little clinical impact. The key management principle is the importance of follow-up, which also requires knowing how the deficiency arose. The virtues of these principles are not always fully appreciated. Recent developments have made diagnosis and management more difficult by diminishing the ability to determine cobalamin absorption status. Clinicians must also grapple with premature medicalization of isolated, mild biochemical changes that added many asymptomatic cases of still undetermined medical relevance to their caseload, often expanded by inflated cobalamin level criteria. The potential for misattribution of cobalamin-unrelated presentations to nongermane cobalamin and metabolite abnormalities has grown. Pathophysiologically based management requires systematic attention to each of its individual components: correctly diagnosing cobalamin deficiency, reversing it, defining its underlying cause, preventing relapse, managing the underlying disorder and its complications, and educating the patient.

Biomarkers of folate and vitamin B(12) status in cerebrospinal fluid

Folate and vitamin B(12) are essential cofactors for the methionine/homocysteine cycle in the brain. These vitamins mediate the remethylation of homocysteine (Hcy), which affects the production of the universal methyl donor, S-adenosylmethionine (SAM), in the brain among other organs. Additionally, increased plasma concentrations of total Hcy (tHcy) are associated with cerebrovascular disease and can compromise the blood-brain barrier. tHcy concentrations in the brain and cerebrospinal fluid become increased in several psychiatric and neurological disorders. Disturbances in the transmethylation pathway indicated by abnormal SAM, S-adenosylhomocysteine or their ratio have been reported in many neurodegenerative diseases, such as dementia, depression or Parkinson's disease. Cobalamin is essential for neuronal generation and its deficiency can cause degeneration of the nervous system. Available data emphasize that deficiency of folate and vitamin B(12) can lead to elevated concentrations of tHcy and disturbed methylation potential in the brain. Therefore, acquired or inherited disorders in these metabolic pathways are associated with brain abnormalities and severe neurological symptoms that are mostly irreversible, even after providing the missing cofactors. This review discusses the relationship between brain and blood levels of key vitamins and metabolites related to one carbon metabolism.

Comparison of clinical and electrodiagnostic features in B12 deficiency neurological syndromes with and without antiparietal cell antibodies

BACKGROUND AND AIMS

This study was undertaken to compare the clinical and electrodiagnostic (Edx) features in autoimmune and nutritional vitamin B12 deficiency neurological syndromes.

METHODS

Consecutive patients with vitamin B12 deficiency neurological syndromes were evaluated and blood counts, red blood cell indices, serum chemistry, thyroid function, HIV serology, antiparietal cell antibody (APCA), serum B12, bone marrow and spinal MRI assessed. EDx studies included nerve conduction, tibial somatosensory (SEP) and motor evoked potential (MEP) to the tibialis anterior, and visual evoked potential (VEP). The results were compared between APCA positive and negative groups.

RESULTS

57 patients aged 17-80 years (mean 45.3) were studied; 48 were vegetarians. The presenting clinical syndromes were myeloneuropathy in 25, myelopathy in 14, myeloneuroencephalopathy in 13, myeloencephalopathy in four and behavioural abnormality only in one patient. Spinal MRI in 47 patients revealed posterior spinal cord hyperintensity in 21 and cord atrophy in six. Nerve conduction was abnormal in 15%, MEP in 56.6%, SEP in 87.3% and VEP in 63.6% of patients. At 3 months, 31 patients had complete, 11 partial and three poor recovery. APCA was positive in 49% of patients. There was no difference in clinical, MRI or Edx findings or outcome between the APCA positive and negative groups.

CONCLUSION

APCA was positive in 49% of patients with B12 deficiency neurological syndrome but their clinical, MRI and Edx changes were not different from the APCA negative group. Neurological manifestations may be caused by B12 deficiency itself rather than the underlying cause.

Methylmalonic acid and cognitive function in the Medical Research Council Cognitive Function and Ageing Study

BACKGROUND

An elevated blood concentration of homocysteine is an established risk factor for cognitive impairment and dementia, but associations between cognition and methylmalonic acid (MMA), a related metabolic marker of vitamin B-12 deficiency, are less clear.

OBJECTIVE

The aim was to determine the utility of serum MMA and holotranscobalamin as markers of vitamin B-12 status in relation to cognitive function and to investigate their association with discrete cognitive domains.

DESIGN

This was a cross-sectional survey of 84 nondemented elderly participants (aged >69 y) from the Welsh cohort of the Medical Research Council's Cognitive Function and Ageing Study. Cognitive status was determined by Mini-Mental State Examination (MMSE) and the Cognitive Section of the Cambridge Mental Disorders of the Elderly Examination (CAMCOG).

RESULTS

Nearly one-half (43%) of the persons selected had likely metabolically significant vitamin B-12 deficiency. Higher MMA concentrations were associated with lower MMSE scores independent of age and education (P = 0.007). MMA concentration correlated inversely with CAMCOG scores of ideational praxis (P < 0.05) and language comprehension (P < 0.05) and expression (P < 0.01). Serum folate correlated weakly but significantly with language (P < 0.05), remote memory (P < 0.05), and constructional and ideational praxis scores (P < 0.05 and P < 0.01, respectively).

CONCLUSION

The high prevalence of likely metabolically significant vitamin B-12 deficiency in the elderly is associated with lower cognitive function scores and particularly with lower scores of language comprehension and expression.

Diagnosis of megaloblastic anaemias

There are a large number of causes of megaloblastic anaemia. The most frequent are disorders resulting in vitamin B(12) or folate deficiency. The diagnostic process often consists first of establishing the presence of B(12) or folate deficiency and then of determining the cause of deficiency. The blood count, blood film, serum B(12) assay, and red cell and serum folate assays are the primary investigations. Other useful investigations include serum/plasma methylmalonic acid (MMA), plasma total homocysteine (tHCYS) and serum holo-transcobalamin II assays. All currently used tests have limitations regarding specificity or sensitivity or both and the metabolite assays are not widely available. An understanding of these limitations is essential in formulating any diagnostic strategy. The wide use of serum B(12) and metabolite assays has resulted in the increasingly early diagnosis of B(12) deficiency, often in patients without B(12)-related symptoms (subclinical deficiency). Food cobalamin malabsorption is the most frequent cause of a low serum B(12). At least 25% of low serum B(12) levels are not associated with elevated metabolite levels and may not indicate B(12) deficiency. Some of these are caused by partial deficiency of transcobalamine I.

[Neurological manifestations of vitamin B12 deficiency: a retrospective study of 26 cases]

PURPOSE

Neurological symptoms of B12 vitamin deficiency are polymorph. Causes are dominated by Biermer's disease and B12 vitamin non dissociation that is frequent in the elderly.

METHODS

We realized a retrospective study during 11 years. Patients with neurological symptoms associated to megaloblastosis were included. Treatment with B12 vitamin lead to haematological manifestation regression.

RESULTS

26 cases were analyzed. Mean age was 50+/-14.5 years and there were 11 women and 15 men. Neurological signs included combined medullar sclerosis (N = 10), peripheral neuropathy (N = 10), isolated paresthesia (N = 5) and inferior limb pyramidal syndrome (N = 1). Neurological signs revealed vitamin B12 deficiency in 4 cases. Mean haemoglobin rate was 6.2+/-2.6 g/dl, mean MCV was 109+/-56 fl. Eight patients had macrocytic anaemia, nine bi-cytopenia and eight deep pancytopenia. Electromyography (N = 8) confirmed neuropathy and medullar MRI (N = 2) showed antero-posterior cordonal demyelinisation of cervico-dorsal medulla. Causes of B12 vitamin deficiency were Biermer's disease (N = 11), non dissociation of B12 vitamin's syndrome (N = 8) and partial gastrectomy (N = 1). In 6 patients, no aetiology was found. Treatment with parenteral vitamin B12 induced neurological symptoms regression in 14 cases. Patient with neurological disorder had significantly higher platelet count and haemoglobin level as compared with patients without neurological disorder. Reticulocyte crisis was more precocious in patients with neurological disorders.

CONCLUSION

Neurological symptoms in vitamin B12 deficiency are frequent. We insist on isolated forms, inaugural forms and on the interest of medullar MRI for early diagnosis.

Cobalamin (vitamin B12) in subacute combined degeneration and beyond: traditional interpretations and novel theories

Subacute combined degeneration (SCD) is a neuropathy due to cobalamin (Cbl) (vitamin B(12)) deficiency acquired in adult age. Hitherto, the theories advanced to explain the pathogenesis of SCD have postulated a causal relationship between SCD lesions and the impairment of either or both of two Cbl-dependent reactions. We have identified a new experimental model, the totally gastrectomized rat, to reproduce the key morphological features of the disease [spongy vacuolation, intramyelinic and interstitial edema of the white matter of the central nervous system (CNS), and astrogliosis], and found new mechanisms responsible for the pathogenesis of SCD: the neuropathological lesions in TGX rats are not only due to mere vitamin withdrawal but also to the overproduction of the myelinolytic tumor necrosis factor (TNF)-alpha and the reduced synthesis of the two neurotrophic agents, epidermal growth factor (EGF) and interleukin-6. This deregulation of the balance between TNF-alpha and EGF synthesis induced by Cbl deficiency has been verified in the sera of patients with pernicious anemia (but not in those with iron-deficient anemia), and in the cerebrospinal fluid (CSF) of SCD patients. These new functions are not linked to the coenzyme functions of the vitamin, but it is still unknown whether they involve genetic or epigenetic mechanisms. Low Cbl levels have also been repeatedly observed in the sera and/or CSF of patients with Alzheimer's disease or multiple sclerosis, but whether Cbl deficit plays a role in the pathogenesis of these diseases is still unclear.

Prevalence of vitamin B12 deficiency in spinal cord injury11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the author(s) or on any organization with which the author(s) is/are associated

OBJECTIVE

To assess the prevalence of vitamin B(12) deficiency in persons with spinal cord injury (SCI) or disease (SCD).

DESIGN

Cross-sectional study with prospective blood collection and retrospective medical record review.

SETTING

Regional Veterans Affairs SCI service.

PARTICIPANTS

One hundred six adult men with chronic SCI or SCD and without other acute medical or surgical complications; most had SCI or SCD due to trauma or cervical spinal stenosis.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Fasting blood samples were obtained at annual evaluation for serum B(12), folic acid, methylmalonic acid (MMA), and homocysteine. Serum levels were analyzed graphically and associated with patient variables by using statistical tests.

RESULTS

The vitamin B(12) level was subnormal in 5.7% of subjects; of those, all had supranormal MMA levels, all were age 40 to 59, most had complete SCI, and 67% had symptoms suggestive of B(12) deficiency. Low-normal B(12) levels were associated with a high prevalence of supranormal MMA. Subjects with either subnormal B(12) or low normal B(12) with supranormal MMA, both suggestive of vitamin B(12) deficiency, comprised 13.3% of the total group of subjects.

CONCLUSION

Vitamin B(12) deficiency is most common in middle-aged SCI or SCD persons with complete or near-complete spinal cord involvement (ie, American Spinal Injury Association class A-C injuries). Treatment with either parenteral or oral B(12) replacement may optimize health and prevent irreversible neuropsychiatric complications in those with subnormal and low-normal B(12) levels.

News and views on folate and elderly persons

Elderly persons are especially exposed to folate deficiency, where normal/subnormal folate levels do not exclude tissue deficiency. Accompanying diseases, medication, and lifestyle factors may contribute to/cause deficiency. Symptoms of deficiency can be hematological, neurological, or neuropsychiatric, but it is likely that there are also cardiovascular manifestations as well as associations with malignancies. The physician should make an individualized investigation to establish the probable cause. Among the available determinants of the folate/cobalamin state, plasma homocysteine (Hcy) is a swift and sensitive marker and has the strongest connection to cognitive function. The association is generally stronger between Hcy levels and symptoms than between vitamin-related levels and symptoms. The duration as well as the severity of symptoms are of importance in terms of the improvement of neurological and neuropsychiatric symptoms when substitution is performed. The issue of general folate fortification of flour is complex, and there are as many pros and cons as there are countries in which it is considered to be launched. It is important to bear in mind that in our modern society, deficiency of folate/cobalamin--overt or latent--mainly is a problem of the elderly and a challenge to the doctor.

Update on Cobalamin, Folate, and Homocysteine

Three topics affecting cobalamin, folate, and homocysteine that have generated interest, activity, and advances in recent years are discussed. These are: (I) the application of an expanded variety of tools to the diagnosis of cobalamin deficiency, and how these affect and are affected by our current understanding of deficiency; (II) the nature of the interaction between homocysteine and vascular disease, and how the relationship is affected by vitamins; and (III) the improved understanding of relevant genetic disorders and common genetic polymorphisms, and how these interact with environmental influences.

The diagnostic approach to cobalamin deficiency now allows better diagnosis of difficult and atypical cases and more confident rejection of the diagnosis when deficiency does not exist. However, the process has also become a complex and sometimes vexing undertaking. Part of the difficulty derives from the lack of a diagnostic gold standard among the many available tests, part from the overwhelming numerical preponderance of patients with subclinical deficiency (in which isolated biochemical findings exist without clinical signs or symptoms) among the cobalamin deficiency states, and part from the decreased availability of reliable tests to identify the causes of a patient’s cobalamin deficiency and thus a growing deemphasis of that important part of the diagnostic process. In Section I, Dr. Carmel discusses the tests, the diagnostic issues, and possible approaches to the clinical evaluation. It is suggested no single algorithm fits all cases, some of which require more biochemical proof than others, and that differentiating between subclinical and clinical deficiency, despite their overlap, may be a helpful and practical point of departure in the evaluation of patients encountered in clinical practice. The arguments for and against a suggested expansion of the cobalamin reference range are also weighed.

The epidemiologic data suggest that homocysteine elevation is a risk factor for vascular and thrombotic disease. In Section II, Dr. Green notes that the interactions of metabolism and clinical risk are not well understood and a causative relationship remains unproven despite new reports that lowering homocysteine levels may reduce vascular complications. Genetic and acquired influences may interact in important ways that are still being sorted out. The use of vitamins, especially folate, often reduces homocysteine levels but also carries potential disadvantages and even risks. Folate fortification of the diet and supplement use have also markedly reduced the frequency of folate deficiency, and cobalamin deficiency is now the more common deficiency state, especially among the elderly.

Although genetic disorders are rare, they illuminate important metabolic mechanisms and pose diagnostic challenges, especially when clinical presentation occurs later in life. In Section III, Drs. Rosenblatt and Watkins use selected disorders to illustrate the subject. Imerslund-Gräsbeck syndrome, a hereditary disorder of cobalamin absorption at the ileal level, demonstrates genetic heterogeneity. Finnish patients show mutation of the gene for cubilin, the multiligand receptor for intrinsic factor. Surprisingly, Norwegian and other patients have been found recently to have mutations of the AMN (amnionless) gene, mutations that are lethal in mice at the embryonic stage. Two disorders of cobalamin metabolism, cblG and cblE, are now known to arise from mutations of the methionine synthase and methionine synthase reductase genes, respectively. These disorders feature megaloblastic anemia and neurologic manifestations. The folate disorder selected for illustration, methylenetetrahydrofolate reductase (MTHFR) deficiency, paradoxically causes neurological problems but no megaloblastic anemia. This rare deficiency is the most common inborn error of folate metabolism. It is distinct from the very common MTHFR gene polymorphisms, mutations that cause mild to moderate reductions in MTHFR activity but no direct clinical manifestations. The MTHFR polymorphisms, especially the 677C→T mutation, may contribute to vascular and birth defect risks, while reducing the risk of certain malignancies, such as colon cancer. These polymorphisms and those of genes for other enzymes and proteins related to cobalamin, folate, and homocysteine metabolism may be important role players in frequent interactions between genes and the environment.

Psychological interventions for depression in adolescent and adult congenital heart disease

BACKGROUND

Adult and adolescent congenital heart disease is increasing in prevalence as better medical care means more children are surviving to adulthood. People with chromic disease often also experience depression. There are several non-pharmacological treatments that might be effective in treating depression and improving quality of life for adults and young adults with congenital heart disease. The aim of this review was to assess the effects of treatments such as psychotherapy, cognitive behavioural therapies and talking therapies for treating depression in this population.

OBJECTIVES

To assess the effects (both harms and benefits) of psychological interventions for treating depression in young adults and adults with congenital heart disease.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register (CCTR) (on The Cochrane Library issue 4, 2002), MEDLINE (1966 to August 2002), EMBASE (1980 to August 2002), PsycLIT (1887 to August 2002), the Database of Abstracts of Reviews of Effectiveness (DARE) (Issue 4, 2002 of the Cochrane Library), Biological Abstracts (January 1980 to August 2002), and CINAHL (January 1980 to August 2002). Abstracts from national and international cardiology and psychology conferences and dissertation abstracts were also searched.

SELECTION CRITERIA

Randomised controlled trials comparing psychological interventions with no intervention for people over 15 years with depression who have congenital heart disease.

DATA COLLECTION AND ANALYSIS

Two reviewers independently screened titles and abstracts of studies that were potentially relevant to the review. Studies that were clearly ineligible were rejected. Two reviewers independently assessed the abstracts or full papers for inclusion criteria. Further information was sought from the authors where papers contained insufficient information to make a decision about eligibility.

MAIN RESULTS

No randomised controlled trials were identified.

REVIEWER'S CONCLUSIONS

Depression is common in patients with congenital heart disease and can exacerbate the physical consequences of the illness. There are effective pharmacological and non-pharmacological treatments for depression, but we have not been able to identify any trials showing the effectiveness of non-pharmacological treatments. A well designed randomised controlled trial is needed to assess the effects of psychological interventions for depression in congenital heart disease.

Cobalamin supplementation improves cognitive and cerebral function in older, cobalamin-deficient persons

BACKGROUND

Mild cobalamin (Cbl) deficiency is frequently found in older persons and is associated with cognitive and cerebral abnormalities. The effects of Cbl supplementation on these abnormalities are largely unknown.

METHODS

In a single-blind, placebo-controlled intervention study, 16 healthy community-dwelling elderly subjects with low plasma Cbl concentration and no cognitive impairments were studied. Subjects underwent 1 month of treatment with placebo, followed by 5 months of treatment with intramuscular injections of hydroxycobalamin. Before and after measurements of plasma cobalamin, total homocysteine (tHcy), methylmalonic acid (MMA), quantitative electroencephalograph (qEEG), and psychometric tests were taken.

RESULTS

After Cbl supplementation, plasma Cbl concentrations increased, and plasma MMA and tHcy concentrations decreased. The performance on the Verbal Word Learning Test, Verbal Fluency and Similarities improved. qEEG showed more fast activity and less slow activity. Lower plasma tHcy concentrations were related to increased fast activity on qEEG on the one hand and improved performance on the Verbal Word Learning Test and Similarities on the other. Increased fast or decreased slow activity on qEEG was associated with improved performance on the Verbal Word Learning Test, Similarities and Verbal Fluency.

CONCLUSIONS

Electrographic signs of improved cerebral function and improved cognitive function were found after Cbl supplementation in older subjects with low plasma Cbl concentrations who were free of significant cognitive impairment. These improvements were related to a reduction of plasma tHcy concentration.

In what extent anemia coexists with cognitive impairment in elderly: a cross-sectional study in Greece

BACKGROUND

A project aimed at studying the frequency of dementia and depression in the catchment area of the Health Centre of Chrissoupolis (HCCh), Northern Greece, was carried out. This paper reports the association between AD and anemia among the elderly participants in this Greek study.

METHODS

Eligible participants were people 65 years or over who were (a) living in the Elderly People's Home (all 48 subjects included); (b) visiting the Open Center for Elderly People during a 20 workday period (75 subjects) and (c) visiting the HCCh for routine medical care. The Mini Mental State Examination (MMSE) was used in assessing the cognitive capacity of the participants. Blood was drawn for serum hematocrit, vitamin B12 and folate determination.

RESULTS

The prevalence proportions of possible cognitive impairment among anemic and non-anemic males were 55.6% and 34.4%, respectively (X2 = 5.8, d.f. = 1, p = 0.016). The corresponding proportions in females were 47.5% and 40.1 % (X2 = 1.1, d.f. = 1, p = 0.305). Using logistic regression analysis, age-group (>or= 80 yrs), type of Institute, vitamin B12 and anemia had significant independent associations with possible cognitive impairment.

CONCLUSIONS

Anemia is a frequent finding in elderly and it may be a risk factor for dementia, but the extent of the associated deterioration of cognitive impairment or the relation with AD is not known. GPs should be aware of this coexistence and recommend for screening, assaying and treating elderly people.

Vitamin B12 in primary health care and geriatrics--attitudes, knowledge and competence

OBJECTIVES

The objective of the study was to test attitudes, knowledge and competence of Swedish general practitioners and geriatricians concerning B12-associated problems in 1998.

METHODS

Postal questionnaires were sent to a random sample of 485 GPs and a total sample of 613 geriatricians. The response rates were 70% in the GP group and 69% in the geriatrician group. The questionnaire contained 24 statements to be evaluated by a visuo-analogue scale.

RESULTS

There were small numerical differences between the two physician groups. The geriatricians were more aware of risk groups for B12 deficiency. GPs were less categorical concerning low hit rate in the laboratory testing of clinical conclusions. There were statistical differences in both directions for statements on pitfalls in laboratory diagnostics. GPs were somewhat less prone to give risk groups prophylactic B12 therapy.

CONCLUSIONS

GPs and geriatricians appeared to be familiar with the current debate on B12-associated problems, suggesting that health care quality will be unaffected by patient transfer from hospital care to primary health care.

Markers for the functional availability of cobalamin/folate and their association with neuropsychiatric symptoms in the elderly

Cobalamin/folate deficiency is common in elderly subjects and may lead to psychiatric symptoms, but even more often it increases the severity of other organic and non-organic mental diseases. This paper reviews the literature relevant for markers of cobalamin/folate status and their relation to neuropsychiatric symptoms in the elderly. Plasma homocysteine, a marker of cobalamin/folate status, is frequently increased in psychogeriatric patients. Among markers of cobalamin/folate status, plasma homocysteine shows the best association with neuropsychiatric dysfunction.

Nutrition and cognitive impairment in the elderly

As the number of older people is growing rapidly worldwide and the fact that elderly people are also apparently living longer, dementia, the most common cause of cognitive impairment is getting to be a greater public health problem. Nutrition plays a role in the ageing process, but there is still a lack of knowledge about nutrition-related risk factors in cognitive impairment. Research in this area has been intensive during the last decade, and results indicate that subclinical deficiency in essential nutrients (antioxidants such as vitamins C, E and beta-carotene, vitamin B(12), vitamin B(6), folate) and nutrition-related disorders, as hypercholesterolaemia, hypertriacylglycerolaemia, hypertension, and diabetes could be some of the nutrition-related risk factors, which can be present for a long time before cognitive impairment becomes evident. Large-scale clinical trials in high-risk populations are needed to determine whether lowering blood homocysteine levels reduces the risk of cognitive impairment and may delay the clinical onset of dementia and perhaps of Alzheimer's disease. A curative treatment of cognitive impairment, especially Alzheimer's disease, is currently impossible. Actual drug therapy, if started early enough, may slow down the progression of the disease. Longitudinal studies are required in order to establish the possible link of nutrient intake--nutritional status with cognitive impairment, and if it is possible, in fact, to inhibit or delay the onset of dementia.

Homocysteine, vascular dementia and Alzheimer's disease

There is some evidence from recent observational studies that hyperhomocysteinemia is a risk factor for cognitive dysfunction, including Alzheimer's disease and vascular dementia. There are only a few intervention studies, and the results are disappointing for such a frequent disease. Prospective double-blind and placebo-controlled intervention studies are not available. If homocysteine-lowering therapy will be in the running for the prevention and treatment of dementia, we must be able to diagnose the disease at a preclinical stage (i.e. 5 or 10 or 20 years before the disease becomes clinically overt for Alzheimer's disease). At the moment, there are insufficient data to support a vitamin B12, B6 or folate therapy in the prevention or treatment of patients with dementia.

Improvement of cognitive functions after cobalamin/folate supplementation in elderly patients with dementia and elevated plasma homocysteine

OBJECTIVES

To investigate the effect of cobalamin/folate supplementation on cognitive function in elderly patients with dementia.

METHOD

The cobalamin/folate status of the patients was evaluated by measuring plasma homocysteine, serum methylmalonic acid, serum cobalamin and blood folate. Thirty-three patients were studied and repeatedly assessed with the Mini-Mental State Examination (MMSE) and 'A short cognitive performance test for assessing memory and attention' (SKT) during vitamin substitution.

RESULTS

Patients with mild-moderate dementia and elevated plasma homocysteine levels improved clinically with increased test scores after vitamin substitution, while severely demented patients and patients with normal plasma homocysteine levels did not improve clinically.

CONCLUSIONS

Plasma homocysteine may be the best marker for detecting treatable cobalamin/folate deficiency in patients with dementia.

The association between antiulcer medication and initiation of cobalamin replacement in older persons

As chronic use of antiulcer medications might predispose older persons to cobalamin deficiency, we studied participants (> 65 years) in the clinical examination of the Canadian Study of Health and Aging to test the association between the use of an antiulcer medication (histamine-2 blocker or proton pump inhibitor) at baseline with initiation of cobalamin replacement during the 5 year follow-up period. Of 1054 eligible subjects, 125 (11.7%) were taking an antiulcer medication at baseline. At follow-up, 49 (4.6%) had started cobalamin replacement. Antiulcer medication use at baseline was significantly associated with the initiation of cobalamin therapy (odds ratio 2.56, 95% confidence interval 1.30-5.05), even after adjusting for age, gender and institutional residence (odds ratio 2.61, 95% confidence interval 1.31-5.23). There is an independent association between the use of antiulcer medication and initiation of cobalamin therapy. While the relationship is not unambiguously causal, this finding underscores the need for judicious prescribing of antiulcer medications for older persons.

Anemia and aging: an overview of clinical, diagnostic and biological issues

Anemia, usually mild, is one of the more common problems of the aged, especially in men. Although the anemia is often multifactorial, the specific entities can be grouped into three broad categories: (a) anemias due to causes more common in the elderly; (b) anemias without special predilection for the elderly; (c) anemias of unknown cause. The major biological questions concern the third category, which accounts for 14-17% of the anemias, and whether senescence itself contributes to anemia. Current opinion favors a diminished erythropoietic reserve with aging, but the data are inconsistent and the mechanism has not been established. It may be that cytokine modulation of erythropoiesis is abnormal. Some findings in unexplained anemia bear partial resemblance to the changes of anemia of chronic disease, suggesting the possibility that subtle unidentified inflammatory responses of unknown origin may be operative in many elderly people. Of the anemias of known cause that are especially common in the elderly, anemia of chronic disease is an important entity but is sometimes obscured or overlooked and its diagnosis rests on crude tests. Cobalamin deficiency is very common also, although most cases are mild and not accompanied by anemia. Because the basic diagnostic approach to anemia is neither complex nor very invasive and anemia may be a marker of poor prognosis, attribution of anemia to senescence is not advisable until other causes have been ruled out.

Role of homocysteine, cystathionine and methylmalonic acid measurement for diagnosis of vitamin deficiency in high-aged subjects

BACKGROUND

Intracellular B-vitamin and folate deficiency indicated by hyperhomocysteinemia is very frequent in the elderly population. Hyperhomocysteinemia increases the risk of atherothrombotic diseases and neuropsychiatric complications. Our aim was to evaluate the prevalence of increased serum metabolite concentrations in subjects of a higher age, and whether the measurement of metabolite concentrations is more effective in diagnosing B-vitamin deficiency than mere homocysteine.

MATERIALS AND METHODS

Homocysteine (HCY), cystathionine (CYS) and methylmalonic acid (MMA) were investigated in serum together with vitamin B-12, B-6 and folate in 90 high-aged subjects (85-102 years), 92 seniors (65-75 years), and in 50 younger subjects (19-50 years).

RESULTS

Elderly subjects (high-aged and senior) had elevated serum concentrations of metabolites. High-aged subjects had a higher frequency of pathological increases than seniors: HCY 62% vs. 24%; MMA 62% vs. 23%; CYS 81% vs. 36%. Folate and vitamin B-6 concentrations were significantly decreased in both elderly groups; vitamin B-12 was only decreased in high-aged subjects. Utilising vitamin B-6, B-12 and folate for diagnosis of intracellular vitamin deficiency, the rate was 30% in seniors and 55% in high aged subjects. However, utilising the metabolites (HCY, MMA and CYS) for the diagnosis of intracellular vitamin deficiency, there was a distinctly increased rate of 55% in seniors respective to 90% in high-aged subjects. Backward multiple regression analysis revealed that only folate, MMA, creatinine and age were independent variables influencing the HCY concentration. Furthermore, the MMA concentration was significantly and independently influenced by folate, vitamin B-12, HCY and creatinine, and the serum concentration of CYS by vitamin B-12, creatinine and age.

CONCLUSION

The metabolites HCY, MMA and CYS are sensitive indicators diagnosing impaired remethylation of homocysteine to methionine with parallel activation of catabolic pathway. Compared to mere HCY or B-vitamins in serum, the efficiency of diagnosing a disturbed HCY metabolism increases very much in utilising the metabolites HCY, MMA and CYS. For differential diagnosis, parallel measurement of folate and creatinine is recommended. The early and correct diagnosis of B-vitamin deficiency in elderly subjects is of high clinical relevance.

[Anemia caused by vitamin B 12 deficiency in subjects aged over 75 years: new hypotheses. A study of 20 cases]

PURPOSE

New hypotheses have recently been developed on vitamin B12 deficiency and the frequently observed occurrence in the elderly subject of food cobalamin malabsorption, i.e., the non-dissociation of B12 and its carrier protein (ND B12), and the possibility of rectifying this imbalance by oral crystalline B12 supplementation. The aim of this study was therefore to confirm these hypotheses in a series of patients aged over 75 years with anemia due to B12 deficiency.

METHODS

A retrospective study was carried out over a 5-year period on patients aged over 75 years presenting with megaloblastic anemia (hemoglobin [Hb] < 12 g/dL) and vitamin B12/cobalamin deficiency (B12 < 160 pg/mL).

RESULTS

Twenty cases were analyzed. The average age of the patient population was 82.5 +/- 6 years, and the F/M sex ratio was 1:2. Mean Hb levels were 7.9 +/- 2.4 g/dL, mean serum B12 levels were 83 +/- 24 pg/mL, and mean homocysteinemic levels were 35 +/- 27 mumol/L. The diagnosis was as follows: food cobalamin malabsorption/ND B12 (n = 10), Biermer's disease/pernicious anemia (n = 5), malabsorption due to pancreatic insufficiency (n = 1), and low dietary B12 levels (n = 1). Disorders associated with ND B12 were: atrophic gastritis and Helicobacter pylori infection (n = 6), antacid or biguanide intake (n = 3), alcohol abuse (n = 2), or idiopathic syndrome (n = 2). In the patients who were followed up (n = 10), i.m. (n = 5) or oral (n = 5) administration of crystalline B12 resulted in the correction of hematological abnormalities.

CONCLUSION

In the elderly subject, food cobalamin/ND B12 malabsorption appears to be the main cause of B12 deficiency, and is frequently associated with atrophic gastritis. In these cases, administration of oral crystalline B12 may be an efficient means of treating this disorder.

Current concepts in cobalamin deficiency

The application of sensitive metabolic tests, such as the deoxyuridine suppression test and measurement of homocysteine and methylmalonic acid, to cobalamin status has identified the entity of mild, preclinical cobalamin deficiency. This state, common in the elderly, responds to cobalamin therapy. Preclinical deficiency may exist within the nervous system as well, although this requires further study. Nevertheless, it is well to remember that not all low cobalamin levels and not all abnormal metabolite results reflect cobalamin deficiency. Interpretation of metabolic results still requires caution, as do proposals to raise the cut-off point for low cobalamin levels to capture some normal levels that are associated with metabolic abnormality. The recognition of mild, preclinical deficiency has opened up many important issues. These include identifying its causes, what should be done about it, and what the clinical impact of the hyperhomocysteinemia itself is. Although malabsorptive disorders, especially food-cobalamin malabsorption, underlie about half of all cases of preclinical deficiency, no cause can be found in the remainder of these cases; poor dietary intake appears to be uncommon. In addition, unusual states of neurologically symptomatic cobalamin deficiency are being recognized, such as nitrous oxide exposure in patients with unrecognized deficiency and severe deficiency in children of mildly deficient mothers. All of these have broadened and complicated the picture of cobalamin deficiency while providing greater opportunities for prevention.