Relationship of normal serum vitamin B12 and folate levels to cognitive test performance in subtypes of geriatric major depression

Selected B vitamins and their possible link to the aetiology of age-related sarcopenia: relevance of UK dietary recommendations

The possible roles of selected B vitamins in the development and progression of sarcopenia are reviewed. Age-related declines in muscle mass and function are associated with huge and increasing costs to healthcare providers. Falls and loss of mobility and independence due to declining muscle mass/function are associated with poor clinical outcomes and their prevention and management are attractive research targets. Nutritional status appears a key modifiable and affordable intervention. There is emerging evidence of sarcopenia being the result not only of diminished anabolic activity but also of declining neurological integrity in older age, which is emerging as an important aspect of the development of age-related decline in muscle mass/function. In this connection, several B vitamins can be viewed as not only cofactors in muscle synthetic processes, but also as neurotrophic agents with involvements in both bioenergetic and trophic pathways. The B vitamins thus selected are examined with respect to their relevance to multiple aspects of neuromuscular function and evidence is considered that requirements, intakes or absorption may be altered in the elderly. In addition, the evidence base for recommended intakes (UK recommended daily allowance) is examined with particular reference to original datasets and their relevance to older individuals. It is possible that inconsistencies in the literature with respect to the nutritional management of sarcopenia may, in part at least, be the result of compromised micronutrient status in some study participants. It is suggested that in order, for example, for intervention with amino acids to be successful, underlying micronutrient deficiencies must first be addressed/eliminated.

Vitamin B12

The biosynthesis of B₁₂, involving up to 30 different enzyme-mediated steps, only occurs in bacteria. Thus, most eukaryotes require an external source of B₁₂, and yet the vitamin appears to have only two functions in eukaryotes: as a cofactor for the enzymes methionine synthase and methylmalonylCoA mutase. These two functions are crucial for normal health in humans, and in particular, the formation of methionine is essential for providing methyl groups for over 100 methylation processes. Interference with the methionine synthase reaction not only depletes the body of methyl groups but also leads to the accumulation of homocysteine, a risk factor for many diseases. The syndrome pernicious anemia, characterized by lack of intrinsic factor, leads to a severe, sometimes fatal form of B₁₂ deficiency. However, there is no sharp cutoff for B₁₂ deficiency; rather, there is a continuous inverse relationship between serum B₁₂ and a variety of undesirable outcomes, including neural tube defects, stroke, and dementia. The brain is particularly vulnerable; in children, inadequate B₁₂ stunts brain and intellectual development. Suboptimal B₁₂ status (serum B₁₂<300pmol/L) is very common, occurring in 30%-60% of the population, in particular in pregnant women and in less-developed countries. Thus, many tens of millions of people in the world may suffer harm from having a poor B₁₂ status. Public health steps are urgently needed to correct this inadequacy.

Dihydrofolate reductase 19-bp deletion polymorphism modifies the association of folate status with memory in a cross-sectional multi-ethnic study of adults

BACKGROUND

Folate status has been positively associated with cognitive function in many studies; however, some studies have observed associations of poor cognitive outcomes with high folate. In search of an explanation, we hypothesized that the association of folate with cognition would be modified by the interaction of high-folate status with a common 19-bp deletion polymorphism in the dihydrofolate reductase (DHFR) gene. To our knowledge, the cognitive effects of this gene have not been studied previously.

OBJECTIVE

We examined the association between cognitive outcomes with the 19-bp deletion DHFR polymorphism, folate status, and their interaction with high or normal plasma folate.

DESIGN

This was a pooled cross-sectional study of the following 2 Boston-based cohorts of community living adults: the Boston Puerto Rican Health Study and the Nutrition, Aging, and Memory in Elders study. Individuals were genotyped for the DHFR 19-bp deletion genotype, and plasma folate status was determined. Cognitive outcomes included the Mini-Mental State Examination, Center for Epidemiologic Studies Depression Scale, and factor scores for the domains of memory, executive function, and attention from a set of cognitive tests.

RESULTS

The prevalence of the homozygous deletion (del/del) genotype was 23%. In a multivariable analysis, high folate status (>17.8 ng/mL) was associated with better memory scores than was normal-folate status (fourth-fifth quintiles compared with first-third quintiles: β ± SE = -0.22 ± 0.06, P < 0.01). Carriers of the DHFR del/del genotype had worse memory scores (β ± SE = -0.24 ± 0.10, P < 0.05) and worse executive scores (β = -0.19, P < 0.05) than did those with the del/ins and ins/ins genotypes. Finally, we observed an interaction such that carriers of the del/del genotype with high folate had significantly worse memory scores than those of both noncarriers with high-folate and del/del carriers with normal-folate (β-interaction = 0.26 ± 0.13, P < 0.05).

CONCLUSIONS

This study identifies a putative gene-nutrient interaction that, if confirmed, would predict that a sizable minority carrying the del/del genotype might not benefit from high-folate status and could see a worsening of memory. An understanding of how genetic variation affects responses to high-folate exposure will help weigh risks and benefits of folate supplementation for individuals and public health.

Folate and unipolar depression

BACKGROUND

Although major depressive disorder (MDD) is a treatable disease, the remission rates associated with antidepressant monotherapy are still far from optimal. Folate is an inexpensive, easily tolerated natural augmenting agent, which has been reported to improve medication treatment outcomes in patients with MDD.

OBJECTIVE

The aim of this study was to review the literature on the clinical utility of folate augmentation for patients with MDD. FOLATE AND DEPRESSION: Patients with depression have consistently been found to have lower levels of serum and red blood cell folate than normal or nondepressed psychiatric patients. Decreased folate levels have been associated with lowered response rates to standard antidepressant pharmacotherapy. Recent studies have shown that augmentation with a folate supplement increases medication response in both treatment-naïve and treatment-resistant depressed patients irrespective of whether there is folate deficiency.

CONCLUSIONS

Depressed patients with both low and normal folate levels may benefit from augmenting a primary antidepressant medication either initially, at the onset of treatment, or later after some degree of treatment resistance has been recognized.

Consensus paper of the WFSBP Task Force on Biological Markers: biological markers in depression

Biological markers for depression are of great interest to aid in elucidating the causes of major depression. We assess currently available biological markers to query their validity for aiding in the diagnosis of major depression. We specifically focus on neurotrophic factors, serotonergic markers, biochemical markers, immunological markers, neuroimaging, neurophysiological findings, and neuropsychological markers. We delineate the most robust biological markers of major depression. These include decreased platelet imipramine binding, decreased 5-HT1A receptor expression, increase of soluble interleukin-2 receptor and interleukin-6 in serum, decreased brain-derived neurotrophic factor in serum, hypocholesterolemia, low blood folate levels, and impaired suppression of the dexamethasone suppression test. To date, however, none of these markers are sufficiently specific to contribute to the diagnosis of major depression. Thus, with regard to new diagnostic manuals such as DSM-V and ICD-11 which are currently assessing whether biological markers may be included in diagnostic criteria, no biological markers for major depression are currently available for inclusion in the diagnostic criteria.

Vitamin status and cognitive function in a long-term care population

BACKGROUND

Ageing can be associated with poor dietary intake, reduced nutrient absorption, and less efficient utilization of nutrients. Loss of memory and related cognitive function are also common among older persons. This study aimed to measure the prevalence of inadequate vitamin status among long-term care patients and determine if an association exists between vitamin status and each of three variables; cognitive function, vitamin supplementation, and medications which alter gastric acid levels.

METHODS

Seventy-five patients in a long-term care hospital in Guelph, Ontario were recruited to a cross-sectional study. 47 were female and the mean age was 80.7 (+/-11.5) years, ranging from 48 to 100 years. Blood was used to measure levels of vitamins B12 (cobalamin), B6 (pyridoxal-5'-phosphate/PLP), erythrocyte folate, vitamin B3 (niacin) and homocysteine (Hcy). The Standardized Mini-Mental State Examination (SMMSE) was administered to measure cognitive function. A list of medications and vitamin supplementation for each patient was provided by the pharmacy.

RESULTS

The prevalence of low vitamin (B12, B6, erythrocyte folate, niacin) or high metabolite (homocysteine) levels among 75 patients were as follows: B12 <148 pmol/L in 5/75 (6.7%); B12 between 148 and 221 pmol/L in 26/75 (34.7%); B6 <or=30 nmol/L in 4/75 (5.3%); erythrocyte folate <370 nmol/L in 1/75 (1.3%); niacin ratio <or=1 in 20/75 (26.7%); homocysteine >13.3 micromol/L in 31/75 (41.3%). There was no significant difference among residents grouped into marked (n = 44), mild (n = 14), or normal (n = 9) cognitive function when evaluating the effect of vitamin status. There were no significant differences in mean B12 and homocysteine levels between users and non-users of drug therapy (Losec, Zantac, or Axid). Compared to vitamin supplement non-users, supplemented residents had significantly higher mean B12 (p < 0.0001) and erythrocyte folate (p < 0.05) concentrations and significantly lower mean homocysteine (p < 0.01) levels; 229.1 versus 423.6 pmol/L for B12, 882.9 versus 1043.6 nmol/L for erythrocyte folate and 14.4 versus 12.0 micromol/L for homocysteine.

CONCLUSION

Given the prevalence data on vitamin status in this sample population, the possible benefits of vitamin supplementation should be considered in clinical intervention studies using these populations of elderly.

Nutritional Contributions to the CNS Pathophysiology of HIV-1 Infection and Implications for Treatment

Nutritional deficiencies are commonplace in patients with human immunodeficiency virus type 1 (HIV-1) infection, and recent research has indicated that nutritional factors may play an important role in the pathogenesis of HIV-1 disease. Although nutritional deficiencies are unlikely to be the primary causative factor in disease progression, they may contribute to cognitive dysfunction, neurologic abnormalities, mood disturbance, and immune dysregulation associated with HIV-1 infection. Furthermore, deficiencies of specific micronutrients have been associated with increased risk of HIV-1-associated mortality. This article will briefly summarize the role of macronutrient deficiency, the interactions of specific micronutrient deficiencies with neuropsychiatric functioning, and the role of these factors in HIV-1 disease progression. Since recent research has shown that normalization of many nutritional deficits and supplementation beyond normal levels are associated with improvements in neuropsychiatric functioning, potential treatment implications will also be discussed.

Cobalamin level is related to self-reported and clinically rated mood and to syndromal depression in bereaved HIV-1(+) and HIV-1(-) homosexual men

OBJECTIVE

An examination of the relationship of plasma cobalamin (vitamin B(12)) level to overall psychological distress, specific mood states, and major depressive disorder was conducted in 159 bereaved men (90 HIV-1(+) and 69 HIV-1(-)).

METHODS

The relationship of a continuous measure of cobalamin level to psychological distress was examined, while controlling for HIV-1 serostatus, life stressors, social support, and coping styles.

RESULTS

Of this sample, 23.9% were either overtly or marginally cobalamin deficient; however, the deficiency rate was not significantly different by HIV-1 serostatus. Cobalamin level was inversely related to self-reported overall distress level and specifically to depression, anxiety, and confusion subscale scores, as well as to clinically rated depressed and anxious mood. Lower plasma cobalamin levels also were associated with the presence of symptoms consistent with major depressive disorder.

CONCLUSION

These findings suggest that cobalamin level may be physiologically related to depressed and anxious mood level, as well as to syndromal depression.

Frequently missed diagnosis in geriatric psychiatry

Older adults are an important segment of the population that has specific health care needs. Their unique biopsychosocial characteristics impact the presentation, evaluation, and management of psychiatric illnesses. This article describes how common psychiatric disorders present in an aging population. Research in this area is relatively new and much more information is still needed. Close attention should be paid to new knowledge as it emerges about this growing population.

Low folate levels in the cognitive decline of elderly patients and the efficacy of folate as a treatment for improving memory deficits

The relevance of low folate levels as determinants of cognitive deficits and the usefulness of folate supplementation in the treatment of cognitive deficits was reviewed from the literature. Over 40 papers and book chapters published in English, French, German, Italian and Spanish were examined. This represents those papers published in the international literature in the last 10 years which were identified by various key words including folate, cognition and aging (or ageing). Among these papers, only 13 articles specifically addressed issues relevant to the criteria adopted for this review. The remaining papers were principally concerned with depression and or with other pathologies of the aged associated with folate deficiency. Although the specific role of low folate levels in the physiopathology of dementia is still under debate, a growing consensus is emerging in the literature where low folate as well as cobalamin levels in aged patients with cognitive deficits are being considered as a sign of functional problems in the absorption and utilization of vitamins, and not merely as a sign of bad eating habits. In studies where folate compounds were evaluated for treatment effects, the results of a majority of investigations indicated that folate treatment was effective in lessening cognitive deficits. Treatment efficacy, however, has not yet been sufficiently demonstrated by these results because there were no controlled studies and the methodology was heterogeneous for the evaluation of cognitive characteristics. An ad hoc double-blind, controlled versus placebo pilot study was undertaken to evaluate the efficacy of folic acid in 30 aged patients with abnormal cognitive decline and folate level below 3 ng/ml to better understand the value of this type of intervention. Our results from this preliminary study demonstrated that patients treated with folic acid for 60 days showed a significant improvement on both memory and attention efficiency when compared with a placebo group. The intensity of memory improvement was positively correlated with initial severity of folate deficiency. On the contrary, the severity of initial cognitive decline was unrelated to the degree of folate deficiency.

Role of homocysteine in age-related vascular and non-vascular diseases

Homocysteine (Hcy) may represent a metabolic link in the pathogenesis of atherosclerotic vascular diseases and old-age dementias. Hyperhomocysteinemia is an independent risk factor for coronary artery disease and peripheral vascular disease, and is also associated with cerebrovascular disease; specifically, the risk of extracranial carotid atherosclerosis significantly increases in relation to Hcy levels. Hcy is a reliable marker of vitamin B12 deficiency, a common condition in the elderly which is known to induce neurological deficits including cognitive impairment; a high prevalence of folate deficiency has been reported in psychogeriatric patients suffering from depression and dementia. Both these vitamins occupy a key position in the remethylation and synthesis of S-adenosylmethionine (SAMe), a major methyl donor in CNS; therefore, deficiencies in either of these vitamins lead to a decrease in SAMe and increase in Hcy, which can be critical in the aging brain. Another pathogenetic mechanism linking high Hcy levels to reduced cognitive performances in the elderly might be represented by excitotoxicity, since hyperhomocysteinemia may lead to an excessive production of homocysteic acid and cysteine sulphinic acid, which act as endogenous agonists of NMDA receptors. Considering the reasonably high prevalence in the general population of a genetic predisposition to a thermolabile form of the enzyme 5,10-methylenetetrahydrofolate reductase (MTHFR), hyperhomocysteinemia can be seen as the result of multiple genetic and environmental factors leading to vascular and/or neurodegenerative disorders where age-related involutive phenomena represent a common pathogenetic ground. Systematic studies in different psychogeriatric conditions monitoring Hcy levels and clinical features before and after vitamin supplementation are therefore highly recommended.

Hyperhomocysteinaemia--a common finding in a psychogeriatric population

Plasma homocysteine concentration is a sensitive marker for cobalamin and folate deficiency. The previously reported high incidence of increased plasma homocysteine in psychogeriatric patients and the association between reduced concentrations of cobalamin, folate and neuropsychiatric symptoms led to the present study on 741 consecutive psychogeriatric patients. The concentrations of plasma homocysteine correlated significantly with blood folate, serum cobalamin and serum creatinine both in demented (n = 295) and in non-demented patients with other psychiatric disorders (n = 215). Plasma homocysteine concentrations were significantly increased in both the demented and the non-demented patients, whereas only the demented patients had lower blood folate and serum creatinine concentrations than 163 control subjects. Almost all of the different diagnostic groups of demented and non-demented patients exhibited significantly increased plasma homocysteine concentrations compared with control subjects. Significantly decreased blood folate concentrations were mainly found in the different diagnosis groups of demented patients. Plasma homocysteine concentrations in both demented and non-demented patients with serum cobalamin and blood folate above the lower 20th percentile of these vitamins in the control subjects were also studied. Despite these vitamin concentrations, both groups of patients still exhibited significantly higher plasma homocysteine concentrations than the control subjects, which may indicate an increased frequency of impaired genetic capacity to metabolize homocysteine in these patients. Patients with either dementia of vascular cause or a history of other occlusive arterial disease had a significantly higher plasma homocysteine concentration than those without a history of vascular disease.

Nocturnal melatonin secretion in multiple sclerosis patients with affective disorders

The pineal gland has been implicated recently in the pathogenesis of multiple sclerosis (MS), a chronic demyelinating disease of CNS. Since nocturnal melatonin secretion is low in some groups of patients with mental depression, we predicted lower melatonin secretion in MS patients with history of affective illness compared to those without psychiatric disorders. To test this hypothesis, we studied single nocturnal plasma melatonin levels and the incidence of pineal calcification (PC) on CT scan in a cohort of 25 MS patients (4 men, 21 women; mean age = 39.4 years, SD = 9.3), 15 of whom had a history of coexisting psychiatric disorders with predominant affective symptomatology. Other factors that may be related to depression such as vitamin B12, folic acid, zinc, magnesium, and homocysteine, were also included in the analysis. Neither any of the metabolic factors surveyed nor the incidence of PC distinguished the psychiatric from the control group. However, the mean melatonin level in the psychiatric patients was significantly lower than in the control group. Since low melatonin secretion in patients with depression may be related to a phase-advance of the circadian oscillator regulating the offset of melatonin secretion, we propose that the depression of MS likewise may reflect the presence of dampened circadian oscillators. Furthermore, since exacerbation of motor symptoms in MS patients may be temporally related to worsening of depression, we propose that circadian phase lability may also underlie the relapsing-remitting course of the disease. Consequently, pharmacological agents such as lithium or bright light therapy, which have been shown to phase-delay circadian rhythms, might be effective in the treatment of affective symptoms in MS as well as preventing motor exacerbation and hastening a remission from an acute attack.