The serum vitamin B12 concentration in the general population

Gender- and age-related differences in homocysteine concentration: a cross-sectional study of the general population of China

The primary goals of this study were to evaluate the gender- and age-related differences in homocysteine concentration in the general population of China and possible influencing factors. A total of 7872 subjects, divided into male and female groups, participated in this retrospective study. The average homocysteine level, prevalence of hyperhomocysteinemia, and independent factors affecting homocysteine concentration were analyzed. The homocysteine level was significantly higher in males than in females in each age range (aged 20–30, aged 30–40, aged 40–50, aged 50–60, aged 60–80, aged over 80) (P < 0.0001), and the trend did not abate with age. The homocysteine concentration first decreased and then increased, being lowest at 30–50 years of age and significantly increased after 50 years of age. Factors associated with homocysteine concentration in males were smoking status (current smokers versus ex-smokers: β: 0.112), estimated glomerular filtration rate (β =  − 0.192), blood urea nitrogen (β =  − 0.14), diastolic blood pressure (β =  − 0.113), free triiodothyronine (β =  − 0.091), serum potassium (β =  − 0.107) and cystatin C (β = 0.173). In females, independent factors associated with homocysteine concentration were cystatin C (β = 0.319), albumin (β = 0.227), free thyroxine (β = 0.179), age (β = 0.148), free triiodothyronine (β =  − 0.217) and serum potassium (β =  − 0.153). The homocysteine level was significantly higher in males than in females and increased markedly after 50 years of age in both groups. The independent factors associated with increased homocysteine concentration differed between males and females.

Relative reference values for clinical chemical and haematological quantities in 'healthy' elderly people

A search of the literature revealed a paucity of data on reference values for clinical chemical and haematological quantities in reasonably 'healthy' ambulant persons above 65 years of age. On the basis of 90 papers, concerning 37 different types of quantities, the median values for men and for women at 30, 50, 65, and 80 years are calculated relative to the value in men at 30 years. This transformation reduces influences of analytical and demographic factors that have caused considerable systematic differences in the original data. The reference distribution is described as regards symmetry and the change in dispersion with age. The results are given in a table and show four types of changes with age: no significant variation, a fall, an increase or a maximum somewhere between 30 and 80 years; the type of change often depends on sex.

Serum vitamin B12 levels in the aged

In an attempt to throw light on the question of age-related variations in the normal blood content of cobalamin and on the frequency of deficiencies of antimegaloblastic nutriments in the elderly, 273 geriatric patients have been investigated. Low serum vitamin B12 values were found in one third of these patients, due to latent pernicious anaemia in five and malabsorption in seven cases, and probably caused by nutritional deficiency of folate or cobalamin in 78 cases. In that part of the series with apparently normal vitamin B12 levels, the mean value (379+/-14 pg/ml) was lower than the mean (456+/-20 pg/ml) for a younger control group. However, this cannot be taken as a sign of a physiological lowering of the cobalamin values with age, as nutritional deficiencies could not be ruled out in this part of the series. It is concluded that serum vitamin B12 assays should be performed rather liberally in the aged. Patients with nutritional deficiency of cobalamin or folate should be treated, even if frank megaloblastic anaemia is not present.

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 and folate deficiency in the elderly

Elderly persons are more likely to have low values for serum and erythrocyte folate, and for serum cobalamin. Many of those with low vitamin levels have biochemical abnormalities consistent with true deficiency, including increased formiminoglutamic acid excretion, abnormal marrow deoxyuridine suppression, and raised serum levels of methylmalonic acid and homocysteine. Therapy with the appropriate vitamin reverses the biochemical defect. Despite this, the clinical consequences for most elderly persons are remarkably few. True megaloblastic anaemia is rare, and the small number of therapeutic trials to date have not improved the levels of haemoglobin in the treated subjects, although the mean corpuscular volume has decreased significantly. There has been recent concern that these low blood vitamin levels might be important causes of nervous system damage, but studies specifically of the elderly have not demonstrated overall improvements in neurological function following therapy. Vascular damage from high blood homocysteine levels secondary to cobalamin or folate deficiency remains a potential hazard. Dietary insufficiency, malabsorption of protein-bound vitamin B12 secondary to atrophic gastritis, and defective absorption of folyl polyglutamates seem the likeliest possible causes. Pernicious anaemia, although a common cause of severe megaloblastic anaemia in the elderly, is an infrequent cause for the low cobalamin levels in population studies. Although the benefits are uncertain, the balance of the evidence suggests that one should treat elderly persons with low values of cobalamin or folate. Crystalline vitamin B12 and folic acid are absorbed normally and are therefore suitable for replacement therapy, provided that pernicious anaemia is excluded.

Cobalamin levels are not reduced in Alzheimer's disease: results from a population-based study

OBJECTIVE

To determine whether there is a relationship between serum cobalamin levels, normal aging, and Alzheimer's Disease (AD).

DESIGN

Cross-sectional survey.

SETTING

A district (Kungsholmen) in Stockholm, Sweden.

PARTICIPANTS

Population-based cohort of 545 subjects aged more than 74 years. The sample was selected on the basis of evidence of cognitive impairment from all inhabitants in an area of Stockholm (2368 individuals), both living at home or in institutions.

MEASUREMENTS

Serum cobalamin levels and diagnostic evaluation for a diagnosis of dementia and type of dementia.

RESULTS

The serum cobalamin levels in non-demented individuals decreased 5.5 pmol/L with an increase of 1 year of age (regression coefficient = -5.53; P < 0.0001). However, the regression coefficient was 0.21 (P = 0.91) in demented people and 2.57 (P = 0.32) in AD subjects. There was no difference between serum cobalamin levels in demented, AD, and non-demented subjects, except for the oldest ages where demented people and AD sufferers showed higher values. AD patients still living in their own homes had significantly lower cobalamin concentrations compared with institutionalized AD sufferers. The prevalence rate of cobalamin deficiency was 15.5% (95% CI = 11.5-19.5) in normal aging and 18.1% (95% CI = 10.3-25.9) in AD.

CONCLUSIONS

These data suggest that serum cobalamin levels decrease in normal aging, but not in dementia or AD. A lower cobalamin concentration observed in AD sufferers still living in their own homes compared with institutionalized persons with AD seemed to be related to but not fully explained by eating habits. Patients with AD living in their own homes are at risk of developing cobalamin deficiency, and monitoring of serum cobalamin concentrations might be useful in this group.

Vitamin B12 in CSF: reduced CSF/serum B12 ratio in demented men

Vitamin B12 concentrations were determined in serum and cerebrospinal fluid (CSF) of 32 controls and 102 patients with dementia. The dementias were classified as Alzheimer's disease (AD), senile dementia of Alzheimer type (SDAT) and multi-infarct dementia (MID). A substantial number of patients (n = 42) could not be assigned to any of these diagnostic groups, as their dementias were of non-AD/SDAT and non-MID types. They were instead assigned to a group called non ultra descriptum (NUD). CSF B12 correlated significantly with serum B12. There were no statistically significant differences in serum B12 levels between the groups. Although with considerable overlap, CSF B12 concentrations and CSF/serum B12 ratios were significantly lower in the NUD group than in the control group. The NUD group had significantly lower CSF/serum B12 ratios than the group of patients with AD/SDAT. There was significant male predominance in the group of demented patients that had low CSF/serum B12 ratios outside the bivariate reference region. CSF and serum B12 levels appear insufficient as measures of the true brain vitamin B12 status. It may be a more dynamic approach to use the CSF/serum B12 ratio as an indication of transport function across the blood brain barrier, and possibly also across the CSF brain cell barrier.

Serum cobalamins in the elderly: a longitudinal study of a representative population sample from age 70 to 81

In a representative population sample (n = 973) born 1901-1902 and examined at the ages of 70, 75, 79, and 81, the change in serum cobalamins with increasing age was studied by trend analysis using values obtained in single individuals at all four examinations. In subsamples without definable disorders, the mean annual decline was: among men 3.4 pmol/l (p less than 0.05), among women 3.2 pmol/l (n.s.). The decline was possibly more pronounced among individuals with low and intermediate concentrations. The health-related lower reference limits (the 2.5 percentile values of subsamples without definable disorders) did not differ significantly between sexes and age groups, but low concentrations or ongoing cobalamin medication became more common with advancing age. The results indicate a slight fall in serum cobalamins between age 70 and 81 but do not call for age-related lower reference limits.

Prevalence of intrinsic factor antibodies and vitamin B12 malabsorption in older patients admitted to a rehabilitation hospital

It is possible that the commonly measured serum level of vitamin B12 may miss some cases when used to detect vitamin B12 malabsorption and deficiency in older persons. Serum levels of vitamin B12 and intrinsic factor antibody (IFAB) were determined on 250 consecutive patients over the age of 70 admitted to a rehabilitation hospital. Patients with abnormal results on either test were given the standard Schilling test when possible. Eight patients had documented B12 malabsorption. Of these, five had a low serum B12 level alone and one had a low serum B12 level and a positive IFAB level; however, two patients had positive IFAB and normal serum B12 levels. Serum IFAB level may serve as a useful adjunct to serum B12 level in detecting vitamin B12 malabsorption in older patients.

Pernicious anemia in the demented patient without anemia or macrocytosis. A case for early recognition

It is well known that the neurologic manifestations of vitamin B12 deficiency can occur in the absence of anemia. The authors recently observed two elderly patients who presented to a chronic care institution with the diagnosis of dementia, and in both individuals low serum B12 levels were found in conjunction with abnormal Schilling tests. In neither of these two patients was there anemia or macrocytosis. After receiving parenteral B12 injections there was improvement noted in cognitive functions as well as in activities of daily living. The authors are reporting these patients to alert clinicians to the fact that pernicious anemia in the elderly can first present with low serum B12 levels and neurologic abnormalities in the absence of anemia or macrocytosis.

Influence of age and stomach function on serum vitamin B12 concentration

Serum vitamin B12 (B12), maximal gastric acid output (MAO), and B12 absorption were determined in 82 subjects, age 32 to 85 years, who had normal absorption of radiocyanocobalamin. In 46 of the patients the gastric intrinsic factor (IF) was also measured. Serum B12 concentration and MAO varied widely in all age groups from abnormally low to definitely normal. The mean values for serum B12 and MAO, however, declined very similarly with advancing age owing to an increased incidence of low values for these two measurerment in the aged. There was no significant fall in the mean B12 absorption or IF secretion as a function of old age. Achlorhydric and hypochlorhydric patients invariably had lower mean serum B12 concentrations than those with adequate MAO. Conversely, patients with normal MAO all had normal serum B12 levels. Serum B12 concentration, although correlating with both MAO and IF secretion, showed a closer relationship to the former than to the latter. These findings suggest that the stomach, aside from producing the IF, plays an important role in maintaining a normal serum B12 concentration.

A sex difference in the leucocyte count

In a study of a group of 325 blood donors between the ages of 18 and 65 years, the total leucocyte and polymorph counts of the females aged 50 to 65 years were found to be significantly lower than those of the corresponding group of male donors. In the whole series of female donors, there were significantly lower total leucocyte and lymphocyte counts with increasing age and a less significant (P [unk] 0.1) fall in the polymorph count. No age variation in the male counts was found. Analysis of large numbers of leucocyte counts performed on hospital patients has confirmed the sex difference in the total leucocyte count found in the blood donors. The factors responsible for the differences are discussed.