HIGH VITAMIN B12 LEVELS AND IN-HOSPITAL MORTALITY

Vitamin B12 measurements across neurodegenerative disorders

Background

Vitamin B12 deficiency causes a number of neurological features including cognitive and psychiatric disturbances, gait instability, neuropathy, and autonomic dysfunction. Clinical recognition of B12 deficiency in neurodegenerative disorders is more challenging because it causes defects that overlap with expected disease progression. We sought to determine whether B12 levels at the time of diagnosis in patients with Parkinson’s disease (PD) differed from those in patients with other neurodegenerative disorders.

Methods

We performed a cross-sectional analysis of B12 levels obtained around the time of diagnosis in patients with PD, Multiple System Atrophy (MSA), Dementia with Lewy Bodies (DLB), Alzheimer’s disease (AD), Progressive Supranuclear Palsy (PSP), Frontotemporal Dementia (FTD), or Mild Cognitive Impairment (MCI). We also evaluated the rate of B12 decline in PD, AD, and MCI.

Results

In multivariable analysis adjusted for age, sex, and B12 supplementation, we found that B12 levels were significantly lower at time of diagnosis in patients with PD than in patients with PSP, FTD, and DLB. In PD, AD, and MCI, the rate of B12 decline ranged from − 17 to − 47 pg/ml/year, much greater than that reported for the elderly population.

Conclusions

Further studies are needed to determine whether comorbid B12 deficiency affects progression of these disorders.

Association of vitamin D and vitamin B12 with cognitive impairment in elderly aged 80 years or older: a cross-sectional study

BACKGROUND

The present study aimed to assess the association of vitamin D and vitamin B₁₂ with cognitive impairment in elderly people.

METHODS

The data were obtained from a cross-sectional study that included individuals aged 80 years or older living in the urban and rural areas of the cities of Siderópolis and Treviso in the state of Santa Catarina, Brazil. In total, 165 elderly people were included in the analysis. The outcome of cognitive decline was assessed by the Mini-Mental State Examination. Vitamin D and vitamin B₁₂ levels were measured from blood samples. The socio-demographic, anthropometric and health variables used in the analysis were collected from a questionnaire. Crude and adjusted analyses of the relationship between vitamins D and B₁₂ and cognitive decline were performed using a Poisson regression model.

RESULTS

The prevalence of cognitive decline was 35.2%. In the adjusted model, individuals who had vitamin D levels >19 ng mL^-1 showed a lower prevalence of cognitive decline (prevalence ratio = 0.59; 95% confidence interval = 0.39-0.87). Those participants who had vitamin B₁₂ levels of ≥496 pg mL^-1 had a higher prevalence of cognitive decline (prevalence ratio = 1.90; 95% confidence interval = 1.08-3.36).

CONCLUSIONS

The present study showed that individuals aged ≥80 years who had vitamin D levels of ≤18 ng mL^-1 had a higher prevalence of cognitive decline even after adjustment for potential confounders. In addition, the study demonstrated that vitamin B₁₂ levels of ≥496 pg mL^-1 in this population were also a risk factor for cognitive decline. A cross-sectional analysis does not enable the inference of a cause-effect relationship and additional studies are needed to understand these relationships.

Elevated Plasma Vitamin B12 Concentrations Are Independent Predictors of In-Hospital Mortality in Adult Patients at Nutritional Risk

Background: Elevated plasma vitamin B12 concentrations were identified as predictors of mortality in patients with oncologic, hepatic and renal diseases, and in elderly and critically ill medical patients. The association between vitamin B12 concentrations and in-hospital mortality in adult patients at nutritional risk has not been assessed. Methods: In this five-year prospective study, we investigated whether high vitamin B12 concentrations (>1000 pg/mL) are associated with in-hospital mortality in 1373 not-bed-ridden adult patients at nutritional risk (Nutrition Risk Index <97.5), admitted to medical and surgical departments. Results: Three hundred and ninety-six (28.8%) patients presented vitamin B12 > 1000 pg/mL. Two hundred and four patients died in the hospital (14.9%). The adjusted odds ratio of in-hospital mortality in patients with high vitamin B12 was 2.20 (95% CI, 1.56–3.08; p < 0.001); it was independent of age, gender, body mass index, six-month previous unintentional weight loss, admission ward, presence of malignancy, renal function, C-reactive protein and prealbumin. Patients with high vitamin B12 also had a longer length of stay (LOS) than those with normal concentrations (median 25 days, (IQR 15–41) versus 23 days (IQR 14–36); p = 0.014), and elevated vitamin B12 was an independent predictor of LOS (p = 0.027). Conclusions: An independent association between elevated vitamin B12 concentrations, mortality and LOS was found in our sample of hospitalized adult patients at nutritional risk. Although the underlying mechanisms are still unknown and any cause-effect relation cannot be inferred, clinicians should be aware of the potential negative impact of high vitamin B12 concentrations in hospitalized patients at nutritional risk and avoid inappropriate vitamin supplementation.

Elevated plasma vitamin B12 levels and cancer prognosis: A population-based cohort study

BACKGROUND

Elevated plasma vitamin B12 levels (cobalamin, Cbl) are associated with increased short-term cancer risk among patients referred for this laboratory measurement. We aimed to assess prognosis in cancer patients with elevated plasma Cbl.

METHODS

We conducted a population-based cohort study using data from Danish medical registries during 1998-2014. The study included 25,017 patients with a cancer diagnosis and Cbl levels of 200-600 pmol/L (reference/normal range), 601-800 pmol/L and >800 pmol/L measured up to one year prior to diagnosis, and a comparison cohort of 61,988 cancer patients without a plasma Cbl measurement. Patients treated with Cbl were excluded. Survival probability was assessed using Kaplan-Meier curves. Mortality risk ratios (MRR) were computed using Cox proportional hazard regression, adjusted for age, sex, calendar year, cancer stage and comorbidity, scored using the Charlson comorbidity index.

RESULTS

Survival probabilities were lower among patients with elevated Cbl levels than among patients with normal levels and among members of the comparison cohort [(1-year survival,%) Cbl: 200-600 pmol/L: 69.3%; 601-800 pmol/L: 49.6%; >800 pmol/L: 35.8%; comparison cohort: 72.6%]. Thirty-day mortality was elevated for patients with Cbl levels of 601-800 pmol/L or >800 pmol/L, compared to patients with levels of 200-600 pmol/L [(MRR (95% confidence interval): 601-800 pmol/L vs. 200-600 pmol/L: 1.9 (1.6-2.2); >800 pmol/L vs. 200-600 pmol/L: 2.7 (2.4-3.1)]. This association remained robust for 31-90-day and 91-365-day mortality, showing similar dose-response patterns.

CONCLUSION

Cancer patients with elevated Cbl levels had higher mortality than those with normal Cbl levels. These findings may have clinical significance for assessing the prognosis of cancer patients.

High vitamin B12 levels are not associated with increased mortality risk for ICU patients after adjusting for liver function: a cohort study

BACKGROUND AND AIMS

Recent research has suggested that high vitamin B12 levels may be associated with increased mortality after ICU admission. However, it is known that impaired liver function may lead to elevated B12 since B12 is metabolized through the liver, and therefore high B12 levels may serve as a proxy for poor liver function. The aim of this study is to assess the impact that liver function and liver disease have on the relationship between high vitamin B12 levels and mortality in the ICU.

METHODS

We performed an observational cohort study using ICU data that were collected from patients admitted to four ICU types (medical, surgical, cardiac care and cardiac surgery recovery) in one large urban hospital from 2001 to 2008. We analyzed the medical records of 1,684 adult patients (age ≥ 18 years) who had vitamin B12 and liver function measurements up to 14 days prior to ICU admission or within 24 hours after admission.

RESULTS

While we found an association between high B12 and mortality when we did not control for any potential confounders, after we adjusted for liver function and liver disease, no significant association existed between B12 and mortality using multivariable logistic regression (30-day mortality: OR=1.18, 95% CI 0.81 to 1.72, p=0.3890; 90-day mortality: OR=1.20, 95% CI 0.84 to 1.71, p=0.3077).

CONCLUSIONS

Elevated B12 levels are not a significant predictor of mortality after ICU admission when liver function is controlled for, and may instead be a proxy for poor liver function.

Symptomatic venous thromboembolism in elderly patients following major orthopedic surgery of the lower limb is associated with elevated vitamin B12 serum levels

BACKGROUND

Elevated vitamin B12 serum levels are associated with systemic inflammation and mortality. Since venous thromboembolism (VTE) is associated with systemic inflammation and mortality as well, we have hypothesized that it is also associated with elevated vitamin B12 serum levels in elderly patients following major orthopedic surgery of the lower limb.

METHODS

This is a retrospective study. Medical charts of consecutive elderly (≥65 years) patients admitted for rehabilitation following major orthopedic surgery of the lower limb during 2007-2009 were reviewed. The study group included symptomatic VTE patients. The control group included patients in whom VTE was excluded. Demographics, co-morbidities, VTE risk factors, vitamin B12 serum levels, and 1-year mortality were studied.

RESULTS

The cohort included 197 elderly patients (median age: 82 years): 140 (71.1%) women and 57 (28.9%) men. Overall, 20 (10.2%) patients had VTE (study group) and in 177 (89.8%) patients VTE was excluded (control group). Vitamin B12 serum levels were higher in the study group compared with the control group (median: 634 vs. 409 pg/dL, p=0.024). The incidence of elevated vitamin B12 serum levels (≥500 pg/dL) was higher in the study group compared with the control group (odds ratio 3.1, p=0.031). Elevated vitamin B12 serum levels were associated with VTE (odds ratio 5.3, p=0.011) and with 1-year mortality (odds ratio 6.6, p=0.015) independent of demographics, co-morbidities, and VTE risk factors.

CONCLUSIONS

Symptomatic VTE is associated with elevated vitamin B12 serum levels in elderly patients following major orthopedic surgery of the lower limb.