Relationship between vitamin B12 and sensory and motor peripheral nerve function in older adults

Vitamin B12 deficiency in dialysis patients: risk factors, diagnosis, complications, and treatment: A comprehensive review

Vitamin B12 deficiency is a significant concern among patients with end-stage renal disease undergoing dialysis. However, there hasn't been extensive research conducted on this particular patient group. The reported incidence rates vary widely, ranging from 20% to 90%, reflecting the complexity of its diagnosis. Dialysis patients often face multiple nutritional deficiencies, including a lack of essential vitamins, due to factors such as dietary restrictions, impaired absorption, and nutrient loss during dialysis. Diagnosing vitamin B12 deficiency in these patients is challenging, and addressing it is crucial to prevent complications and improve their overall quality of life. This review paper delves into the available body of evidence on vitamin B12 deficiency in dialysis patients, examining the contributing risk factors, diagnostic challenges, potential complications, and available treatment options. It provides a well-rounded perspective on the topic, making it a valuable resource for researchers, healthcare practitioners, and policymakers interested in addressing the nutritional needs of dialysis patients.

A 12-Week Ballroom Dance Training Improves Physical Fitness Performance More Than Walking Training in Older Women, Regardless of Vitamin B12 or D Adequacy

AIM

This study aimed to compare the effects of Ballroom Dancing (BD) versus Walking Training (WT) on the physical fitness performance in physically independent older women with adequate or inadequate levels of vitamins B12 and D.

METHODS

Forty-three sedentary women aged 68.5 ± 6.5 years, were allocated to the BD (n = 23) or WT (n = 20) groups. They took part in a 12-week intervention, performed 3 times a week, for about 50 minutes with moderate effort intensity. Data were collected through Short Physical Performance Battery (SPPB), 6 minutes Walk Test (6MWT), Hand Grip Test (HGT), Isokinetic tests for lower limbs and blood tests to detect serum levels of vitamins B12 and D.

RESULTS

The BD group performed better after the intervention in relation to the WT in the Sit and Stand Test (SST) (BD pre = 3.1 score vs post = 3.8 score; WT pre = 2.8 score vs post = 3.4 score; P = .02) and in the Peak Torque 180° extension (PKTOQ 180° extension) (BD pre = 56.7 Nm vs post = 61.2 Nm, WT pre = 56.7 Nm vs post = 56.1; P < .01).

CONCLUSION

A time effect was observed in all other variables, with the exception of HGT. Both interventions improved physical fitness performance, regardless of the adequacy of vitamins B12 and D, but the older women from BD obtained significant improvements in more variables than the WT.

The Role of Cobalamin in Multiple Sclerosis: An Update

Multiple sclerosis (MS) is a neurodegenerative condition that results in axonal and permanent damage to the central nervous system, necessitating healing owing to autoimmune reactions and persistent neuroinflammation. Antioxidant and anti-inflammatory drugs are essential for the management of oxidative stress and neuroinflammation. Additionally, multivitamin supplementation, particularly vitamin B12 (cobalamin), may be beneficial for neuronal protection. Although there is no documented connection between vitamin B12 deficiency and MS, researchers have explored its potential as a metabolic cause. This review highlights the therapeutic benefits of cobalamin (Cbl) in patients with MS.

Diagnosis, Treatment and Long-Term Management of Vitamin B12 Deficiency in Adults: A Delphi Expert Consensus

Background/Objectives: Vitamin B12 deficiency can cause variable symptoms, which may be irreversible if not diagnosed and treated in a timely manner. We aimed to develop a widely accepted expert consensus to guide the practice of diagnosing and treating B12 deficiency. Methods: We conducted a scoping review of the literature published in PubMed since January 2003. Data were used to design a two-round Delphi survey to study the level of consensus among 42 experts. Results: The panelists agreed on the need for educational and organizational changes in the current medical practices for diagnosing and treating B12 deficiency. Recognition of clinical symptoms should receive the highest priority in establishing the diagnosis. There is agreement that the serum B12 concentration is useful as a screening marker and methylmalonic acid or homocysteine can support the diagnosis. Patient lifestyle, disease history, and medications can provide clues to the cause of B12 deficiency. Regardless of the cause of the deficiency, initial treatment with parenteral B12 was regarded as the first choice for patients with acute and severe manifestations of B12 deficiency. The use of high-dose oral B12 at different frequencies may be considered for long-term treatment. Prophylactic B12 supplementation should be considered for specific high-risk groups. Conclusions: There is a consensus that clinical symptoms need to receive more attention in establishing the diagnosis of B12 deficiency. B12 laboratory markers can support the diagnosis. The severity of clinical symptoms, the causes of B12 deficiency, and the treatment goals govern decisions regarding the route and dose of B12 therapy.

Insulinoma with peripheral neuropathy: a case report

BACKGROUND

Insulinomas are rare neuroendocrine tumors that typically present with hypoglycemic crises. Peripheral neuropathy is an uncommon complication of insulinoma. Most clinicians expect peripheral neuropathy symptoms to reverse completely after the insulin-secreting tumor is resected, but this may be a misassumption.

CASE REPORT

We report a case of a 16-year-old Brazilian boy with clonic muscle spasms of the lower limbs for almost one year. Disabling paraparesis and confusional episodes had progressively set in as well. There were no sensorial abnormalities in the lower limbs, upper limbs or cranial nerves. An electromyography revealed a motor neuropathy of the lower limbs. The diagnosis of insulinoma was established as serum insulin and C-peptide concentrations were inappropriately normal during spontaneous episodes of hypoglycemia. Following a normal abdominal magnetic resonance scan, the imaging work-up continued with an endoscopic ultrasound, which localized the tumor at the pancreatic body-tail transition. Once localized, a prompt surgical removal (enucleation) of the tumor was undertaken, leading to an immediate and complete resolution of hypoglycemia. The time length between the onset of symptoms and tumor resection was 15 months. After surgery, the symptoms of peripheral neuropathy of the lower limbs showed a slow and only partial improvement. At a two-year follow-up after surgery, although being able to lead a normal and productive life, the patient still reported symptoms of reduced muscular strength in the lower limbs and a new electroneuromyography analysis showed chronic denervation and reinnervation in the legs' muscles-indicating chronic neuropathic injury.

CONCLUSION

The events of this case reinforce the importance of an agile diagnostic work-up and spry definitive treatment for patients with this uncommon disease, enabling the cure of neuroglycopenia before permanent bothersome complications ensue.

Association of women-specific health factors in the severity of Parkinson's disease

Parkinson's disease (PD) is an age-related neurological disorder known for the observational differences in its risk, progression, and severity between men and women. While estrogen has been considered to be a protective factor in the development of PD, there is little known about the role that fluctuations in hormones and immune responses from sex-specific health experiences have in the disease's development and severity. We sought to identify women-specific health experiences associated with PD severity, after adjusting for known PD factors, by developing and distributing a women-specific questionnaire across the United States and creating multivariable models for PD severity. We created a questionnaire that addresses women's specific experiences and their PD clinical history and deployed it through The Parkinson's Foundation: PD Generation. To determine the association between women-specific health factors and PD severity, we constructed multivariable logistic regression models based on the MDS-UPDRS scale and the participants' questionnaire responses, genetics, and clinical data. For our initial launch in November 2021, we had 304 complete responses from PD GENEration. Univariate and multivariate logistic modeling found significant associations between major depressive disorder, perinatal depression, natural childbirth, LRRK2 genotype, B12 deficiency, total hysterectomy, and increased PD severity. This study is a nationally available questionnaire for women's health and PD. It shifts the paradigm in understanding PD etiology and acknowledging how sex-specific experiences may contribute to PD severity. In addition, the work in this study sets the foundation for future research to investigate the factors behind sex differences in PD.

Association between vitamin B12 status and heart rate variability in patients with ischemic stroke

Autonomic dysfunction is common in patients with ischemic stroke. An ischemic stroke may induce abnormalities in autonomic tone, resulting in poor heart rate regulation and an increased risk of severe cardiac arrest and sudden death. Heart rate variability (HRV) is a reliable index for evaluating autonomic dysfunction. Vitamin B12 deficiency is frequent among older adults and is a known risk factor for ischemic stroke. As vitamin B12 deficiency affects the peripheral nerves and the central nervous system, it can lead to autonomic dysfunction. However, no study has been published on the correlation between HRV and vitamin B12 status in patients with ischemic stroke. This study aimed to investigate the relationship between HRV and vitamin B12 status and to determine whether the serum vitamin B12 level can be a predictor of HRV parameters. This retrospective study enrolled patients with ischemic stroke between January 2015 and December 2022. The patients underwent serum vitamin B12 level measurements and 24-h Holter monitoring. Pearson correlation analysis was used to investigate the correlation between serum vitamin B12 levels and HRV parameters. The impact of serum vitamin B12 status on HRV parameters was determined using multiple linear regression analysis. A total of 87 patients with ischemic stroke were included in this study. HRV parameters were significantly correlated with serum vitamin B12 status in the frequency domain. In multiple linear regression analysis, the serum vitamin B12 status was a significant predictor of HRV parameters. HRV parameters may be correlated with serum vitamin B12 status in patients with ischemic stroke. Therefore, the serum vitamin B12 status may be a significant predictor of autonomic dysfunction. Our results may provide objective evidence for the impact of serum vitamin B12 status on autonomic dysfunction in patients with ischemic stroke.

Electrophysiological profile of serum vitamin B12 levels, correlation with serum methylmalonic acid levels, and determination of subclinical peripheral nerve involvement

Background/Aim: Vitamin B12 is essential for normal neural conduction in peripheral nerves. This study aimed to investigate the electrophysiological profile for varying degrees of serum B12 levels and to determine whether a correlation existed between electrophysiological profiles and serum methylmalonic acid (MMA) levels. Also, determination of subclinical peripheral nerve involvement with cold administration was planned in serum B12 levels. Methods: A total of 101 (63 females, 38 males) subjects with known serum vitamin B12 levels were selected randomly from the neurology outpatient clinic for this study. The subjects were divided into three groups based on the serum total Vitamin B12 levels: (1) B12 deficiency (<126 pg/mL), (2) low B12 (126-250 pg/mL), and (3) normal B12 (250–500 pg/mL). Serum MMA and nerve conduction studies (NCS) were assessed and compared between the three groups. After the cooling procedure was applied to the ulnar and sural nerves, NCS was repeated. Results: There were 13 subjects in the B12 deficiency group, 44 subjects in the low B12 group, and 44 subjects in the normal group. We found that ulnar sensory nerve action potential amplitudes were significantly decreased (P = 0.009), ulnar F latency (P = 0.003; P < 0.001)) was prolonged, and peroneal combined muscle action potential amplitudes decreased (P = 0.026) in the B12 deficiency when compared with the low and normal B12 groups. Sural nerve amplitude and conduction velocities were found to be significantly abnormal after the cold application in all groups (P < 0.001). The increase in sural nerve sensory nerve amplitude potentials (SNAP) amplitudes was higher in the B12 deficiency group than in the other groups. Mean serum MMA levels were high in all groups. A correlation of nerve conduction study (NCS) changes with serum vitamin B12 and MMA was not observed in the groups after cold application. Conclusion: Vitamin B12 deficiency may cause subclinical sensorial and motor axonal nerve conduction changes. Nerve conduction changes may not always reach pathological values based on electrophysiological studies but may be detected after cooling administration even in the normal serum B12 levels. A correlation between serum MMA and vitamin B12 levels was found. Therefore, serum levels of vitamin B12, which is important for nerve conduction, should be carefully evaluated in clinical practice.

Associations of Lower Extremity Peripheral Nerve Impairment and Risk of Dementia in Black and White Older Adults

BACKGROUND AND OBJECTIVES

Peripheral nerve impairments and dementia are common among older adults and share risk factors. However, few studies have examined whether peripheral nerve function and dementia are associated. We evaluated whether lower extremity peripheral nerve impairments were associated with higher incidence of dementia and whether associations differed by comorbidity subgroups (diabetes, low vitamin B12, and APOE ε4 allele carriers).

METHODS

We studied Black and White Health, Aging, and Body Composition Study participants 70 to 79 years of age and without dementia at enrollment. Lower extremity sensory and motor peripheral nerve function was measured at year 4 (the analytic baseline of this study). Sensory nerve impairments were measured with monofilament (1.4 g, 10 g) and vibration threshold of the toe. Monofilament insensitivity was defined as unable to detect monofilament (3 of 4 touches), and vibration detection impairment was defined as >130 μm. Fibular motor impairments were defined as <1 mV compound motor action potential (CMAP) amplitude and slow nerve conduction velocity <40 m/s. Incident dementia over the following 11 years was determined from medical records, cognitive scores, and medications. Cox proportional hazard models adjusted for demographics and health conditions assessed associations of nerve impairments with incident dementia.

RESULTS

Among 2,174 participants (52% women, 35% Black), 45% could not detect monofilament 1.4 g, 9% could not detect monofilament 10 g, 6% could not feel vibration, 10% had low CMAP amplitude, and 24% had slow conduction velocity. Monofilament 10 g (hazard ratio [HR] 1.35, 95% CI 0.99-1.84) and vibration detection insensitivity (HR 1.73, 95% CI 1.24-2.40) were associated/borderline associated with a higher risk of dementia after covariate adjustment. Estimates were elevated but not significant for monofilament 1.4 g, CMAP amplitude, and conduction velocity (p > 0.05). Increasing number of peripheral nerve impairments was associated with higher risk of dementia in a graded fashion; for ≥3 impairments, the HR was 2.37 (95% CI 1.29-4.38). In subgroup analyses, effect estimates were generally higher among those with diabetes, low vitamin B12, and APOE ε4 allele except for vibration detection.

DISCUSSION

Peripheral nerve impairments, especially sensory, were associated with a higher risk of dementia even after adjustment for age and other health factors. These associations may represent a shared susceptibility to nervous system degeneration.

Neuropsychiatric manifestations in vitamin B12 deficiency

Vitamin B12 deficiency can have distressing neuropsychiatric symptoms. It can have an etiological role in clinical presentations like depression, anxiety, psychosis, dementia, and delirium, requiring screening of at-risk populations. Few mechanisms that underlie the neuropsychiatric manifestations of B12 deficiency include alteration in one-carbon metabolism, genetic vulnerability, and alteration in folate metabolism. Maintaining a high serum B12 level in elderly can be protective against Alzheimer's disease (AD). In an established AD, its deficiency is associated with higher cognitive decline and risk for delirium. The other mental changes associated with B12 deficiency include apathy, agitation, impaired concentration, insomnia, persecutory delusions, auditory and visual hallucinations, and disorganized thought-process. Besides serum vitamin B12, plasma methylmalonic acid (MMA) and homocysteine helps in diagnosis. The chapter focuses on early recognition and effective treatment of these neuropsychiatric manifestations of vitamin B12 deficiency.

The cross-sectional association of cognition with diabetic peripheral and autonomic neuropathy-The GRADE study

BACKGROUND

Studies examining whether measures of cognition are related to the presence of diabetic peripheral neuropathy (DPN) and/or cardiovascular autonomic neuropathy (CAN) are lacking, as are data regarding factors potentially explaining such associations.

METHODS

Participants were from the Glycemia Reduction Approaches in Diabetes Study (GRADE) that examined 5047 middle-aged people with type 2 diabetes of <10 years of known duration. Verbal learning and immediate and delayed recall (memory) were assessed with the Spanish English Verbal Learning Test; frontal executive function and processing speed with the Digit Symbol Substitution Test; and ability to concentrate and organize data with word and animal fluency tests. DPN was assessed with the Michigan Neuropathy Screening Instrument and CAN by indices of heart rate variability (standard deviation of normal beat to beat variation [SDNN] and root mean square of successive differences [RMSSD]).

RESULTS

DPN was significantly inversely related to measures of immediate recall and processing speed. The percent of cognitive variation explained by DPN was small. Tests of CAN had an inconsistent or absent association with measures of cognition. Higher waist circumference and urine albumin creatinine (UACR) levels were the strongest correlates in the relationship between DPN and cognitive impairment.

CONCLUSION

DPN, but not CAN, was cross-sectionally associated with lower performance in measures of cognition in people with type 2 diabetes of <10 years of known duration. Greater waist circumference and UACR were important variables in this association. The mechanisms underlying the cross-sectional association of DPN with cognitive impairment are unknown. Clinicaltrials.gov: NCT01794143.

Association between neuropathy and B-vitamins: A systematic review and meta-analysis

BACKGROUND

Peripheral neuropathy (PN) is common in patients with diseases that are in turn associated with deficiency of the B-vitamins, and vitamin treatment has shown mixed results.

METHODS

This systematic review and meta-analysis studied the association between PN/pain and B-vitamin biomarkers and investigated whether vitamin treatment can ameliorate the symptoms. PubMed and Web of Science were searched according to the study protocol.

RESULTS

A total of 46 observational and seven interventional studies were identified and included in the data synthesis. The presence of PN was associated with lowered B12 levels (pooled estimate [95% CIs] = 1.51 [1.23-1.84], n = 34, Cochran Q Test I²  = 43.3%, p = 0.003) and elevated methylmalonic acid (2.53 [1.39-4.60], n = 9, I²  = 63.8%, p = 0.005) and homocysteine (3.48 [2.01-6.04], n = 15, I²  = 70.6%, p < 0.001). B12 treatment (vs. the comparators) showed a non-significant association with symptom improvement (1.36 (0.66-2.79), n = 4, I²  = 28.9%). Treatment with B1 was associated with a significant improvement in symptoms (5.34 [1.87-15.19], n = 3, I²  = 64.6%, p = 0.059). Analysis of seven trials combined showed a non-significant higher odds ratio for improvement under treatment with the B-vitamins (2.58 [0.98-6.79], I²  = 80.0%, p < 0.001).

CONCLUSIONS

PN is associated with lowered plasma vitamin B12 and elevated methylmalonic acid and homocysteine. Overall, interventional studies have suggested that B-vitamins could improve symptoms of PN. Available trials have limitations and generally did not investigate vitamin status prior to treatment. Well-designed studies, especially in non-diabetes PN, are needed. This meta-analysis is registered at PROSPERO (ID: CRD42020144917).

Efficacy and Safety of the Combination of Superoxide Dismutase, Alpha Lipoic Acid, Vitamin B12, and Carnitine for 12 Months in Patients with Diabetic Neuropathy

Aim: To investigate the efficacy of Superoxide Dismutase, Alpha Lipoic Acid, Acetyl L-Carnitine, and Vitamin B12 (B12) in one tablet in Diabetic Neuropathy (DN). Patients–methods: In this prospective, double-blind, placebo-controlled study, 85 patients with Diabetes Mellitus Type 2 (DMT2) were randomly assigned, either to receive the combination of four elements (active group, n = 43), or placebo (n = 42) for 12 months. We used the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE), measured the vibration perception threshold (BIO), and Cardiovascular Autonomic Reflex Tests (CARTs). Nerve function was assessed by DPN Check [sural nerve conduction velocity (SNCV) and amplitude (SNAP)]. Pain (PS) and quality of life (QL) questionnaires were administered. Results: At follow-up, BIO, MNSIQ, QL, PAIN, and SNCV, SNAP, and B12 levels had significantly improved inactive group (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.027, p = 0.031, and p < 0.001 respectively), whereas the inplacebo group MCR (mean circular resultant) and PAIN deteriorated (p < 0.001, p < 0.001). The changes in MNSIQ, QL, SNCV, BIO, and PAIN differed significantly between groups (p < 0.001, p < 0.001, p = 0.031, p < 0.001, and p < 0.001 respectively). Conclusions: The combination of the four elements in one tablet for 12 months in patients with DMT2 improved all indices of peripheral neuropathy, including SNAP and SNCV, pain, and Quality of Life perception, except CARTs and MNSIE.

Role of Functional Biomarkers to Identify Early Vitamin B12 Deficiency in Patients with Sleeve Gastrectomy: A Cross-Sectional Study

Background and objectives: Although laparoscopic sleeve gastrectomy (LSG) is effective for obesity management, postoperative vitamin B12 (B12) deficiency is of major concern. In this cross-sectional study, we assessed the levels of B12 and its related functional biomarkers, namely, total homocysteine (tHcy), methylmalonic acid (MMA), folate, methylcitric acid (MCA), and hemoglobin (Hb), in one-year postoperative LSG patients and matched controls. Materials and Methods: Plasma B12, tHcy, MMA, folate, and MCA were measured in matched controls (n = 66) and patients (n = 71) using validated liquid chromatography-tandem mass spectrometry techniques and protocols in the United Arab Emirates (UAE). Results: The median B12 concentration in patients (177 pmol/L) was significantly lower (p < 0.001) than in the controls (334.7 pmol/L). The tHcy and MMA levels were significantly increased (p < 0.001 and p = 0.011, respectively) and folate levels were significantly decreased (p = 0.001) in the LSG patients compared to the controls. Interestingly, no significant difference in MCA levels were observed between the two groups. The levels of tHcy and MMA were concomitantly increased with the decreased folate levels in postoperative LSG patients when compared with the controls. The Hb levels were significantly lower in males and females in the patient group compared with those in the control group, respectively (p = 0.005 and p = 0.043). Conclusions: This is the first report of serum levels of B12 and its functional biomarkers in postoperative LSG patients among a local population from the UAE. Our findings revealed significant alterations of the B12 biomarkers, total B12, MMA, and tHcy in one-year postoperative LSG patients.

Vitamin D deficiency increases severity of paclitaxel-induced peripheral neuropathy

PURPOSE

Approximately 25% of patients receiving weekly paclitaxel for breast cancer require treatment disruptions to avoid severe, irreversible peripheral neuropathy (PN). Vitamin insufficiencies are PN risk factors in many diseases, but their relevance to chemotherapy-induced PN is unknown.

METHODS

We investigated whether baseline insufficiency of vitamin D, vitamin B12, folate, or homocysteine increased PN in patients with breast cancer receiving weekly paclitaxel in a retrospective analysis of a prospective observational study. Patient-reported PN was collected at baseline and during treatment on the Quality of Life Questionnaire Chemotherapy-Induced Peripheral Neuropathy (CIPN20). The primary analysis tested associations between vitamin deficiency and the maximum increase from baseline in the CIPN20 sensory subscale (ΔCIPN8). Secondary analyses tested for association with PN-induced treatment disruptions and adjusted associations for treatment and clinical variables.

RESULTS

25-hydroxy-vitamin D was the only nutrient with sufficient deficiency (< 20 ng/mL) for analysis (15/37 = 41%). Vitamin D-deficient patients had a greater mean PN increase than non-deficient patients (ΔCIPN8 ± SD, 36 ± 23 vs. 16 ± 16, p = 0.003) and a non-significant, approximately threefold increase in risk of treatment disruption (OR 2.98, 95% CI [0.72, 12.34], p = 0.16). In multivariable models adjusted for clinical and treatment variables, baseline vitamin D level was inversely associated with PN (β = - 0.04, p = 0.02).

CONCLUSION

Pre-treatment vitamin D deficiency was associated with PN in women receiving weekly paclitaxel for breast cancer. Vitamin D deficiency may be an easily detected PN risk factor that could be resolved prior to treatment to prevent PN, avoid treatment disruptions, and improve treatment outcomes.

Chronic kidney disease and peripheral nerve function in the Health, Aging and Body Composition Study

BACKGROUND

Chronic kidney disease (CKD) is associated with poor mobility. Peripheral nerve function alterations play a significant role in low mobility. We tested the hypothesis that early CKD is associated with altered sensory, motor and autonomic nerve function.

METHODS

Participants in the Health, Aging and Body Composition cohort who had kidney function measures in Year 3 (1999-2000) and nerve function measurements at Year 4 (2000-01) were analyzed (n = 2290). Sensory (vibration threshold, monofilament insensitivity to light and standard touch), motor [compound motor action potentials (CMAPs), nerve conduction velocities (NCVs)] and autonomic (heart rate response and recovery after a 400-m walk test) nerve function as well as participant characteristics were compared across cystatin C- and creatinine-based estimated glomerular filtration rate categorized as ≤60 (CKD) or >60 mL/min/1.73 m2 (non-CKD). The association between CKD and nerve function was examined with logistic regression adjusted for covariates.

RESULTS

Participants with CKD (n = 476) were older (77 ± 3 versus 75 ± 3 years; P < 0.05) and had a higher prevalence of diabetes (20.6% versus 13.1%; P < 0.001). CKD was associated with higher odds for vibration detection threshold {odds ratio [OR] 1.7 [95% confidence interval (CI) 1.1-2.7]} and light touch insensitivity [OR 1.4 (95% CI 1.1-1.7)]. CMAPs and NCVs were not significantly different between CKD and non-CKD patients. In adjusted analyses, participants with CKD had higher odds of an abnormal heart rate response [OR 1.6 (95% CI 1.1-2.2)] and poor heart rate recovery [OR 1.5 (95% CI 1.1-2.0)].

CONCLUSIONS

CKD is associated with changes in sensory and autonomic nerve function, even after adjustment for demographics and comorbidities, including diabetes. Longitudinal studies in CKD are needed to determine the contribution of nerve impairments to clinically important outcomes.

Homocysteine as a potential predictive factor for high major adverse cardiovascular events risk in female patients with premature acute coronary syndrome

We aimed to investigate the correlation of homocysteine (Hcy) level with clinical characteristics, and explore its predictive value for major adverse cardiovascular events (MACE) risk in female patients with premature acute coronary syndrome (ACS).The serum Hcy level was detected from 1299 female patients with premature ACS. According to the tertile of Hcy level, patients were divided into 3 groups: lowest tertile group (≤9.1 μmol/L), middle tertile group (9.2-11.6 μmol/L) and highest tertile group (>11.6 μmol/L). MACE incidence was recorded and MACE-free survival was caculated with the median follow-up duration of 28.3 months.Increased Hcy correlated with older age (P < .001), higher creatinine level (P < .001), and enhanced uric acid level (P = .001), while reduced fasting glucose concentration (P < .001). MACE incidence was 10.7% and it was highest in highest tertile group (22.1%), followed by middle tertile group (7.7%) and lowest tertile group (2.4%) (P < .001). Receiver operating characteristic curve showed that Hcy distinguished MACE patients from non-MACE patients with the area under the curve of 0.789 (95% CI: 0.742-0.835). Kaplan-Meier curves revealed that MACE-free survival was shortest in Hcy highest tertile group, followed by middle tertile group and lowest tertile group (P < .001). Multivariate Cox analyses further showed that higher Hcy level was an independent predictive factor for poor MACE-free survival (middle tertile vs lowest tertile (P = .001, HR: 3.615, 95% CI: 1.661-7.864); highest tertile vs lowest tertile (P < .001, HR: 11.023, 95% CI: 5.356-22.684)).Hcy serves as a potential predictive factor for increased MACE risk in female patients with premature ACS.

A randomized, open labeled study comparing the serum levels of cobalamin after three doses of 500 mcg vs. a single dose methylcobalamin of 1500 mcg in patients with peripheral neuropathy

Background

Vitamin B12 deficiency has been associated with peripheral neuropathy, loss of sensation in the peripheral nerves, and weakness in the lower extremities. Methylcobalamin is the most effective analogue of vitamin B12 used to treat or prevent the complications associated with vitamin B12 deficiency. The current study aimed to compare the serum cobalamin levels after administration of two different regimes of methylcobalamin in peripheral neuropathy patients.

Methods

The present study was a prospective, randomized, comparative study. The study consisted of two parallel groups, group A (methylcobalamin 500 µg injection intramuscularly three times a week) and group B (methylcobalamin 1500 µg injection intramuscularly once a week). A control group of healthy volunteers was also included.

Results

A total of 24 patients (12 in each group) were included in the study. Five healthy volunteers were also included as a control in each group. At the end of treatment, serum cobalamin levels were significantly (P = 0.028) higher in group A (1892.08 ± 234.50) as compared with group B (1438.5 ± 460.32). The serum cobalamin levels in Group A healthy volunteers were also two times higher than that of group B (P = 0.056). Both the LANSS scale and DN4 questionnaire reported similar results at end of treatment.

Conclusions

The 500 µg methylcobalamin thrice weekly regime is more effective in increasing the serum cobalamin levels as compared to the 1500 µg methylcobalamin once weekly regime.

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.

AGING, DIABETES, AND FALLS

KEY POINTS Falls are a major health issue for older adults, leading to adverse events and even death. Older persons with type 2 diabetes are at increased risk of falling compared to healthy adults of a similar age. Over 400 factors are associated with falls risk, making identification and targeting of key factors to prevent falls problematic. However, the major risk factors include hypertension, diabetes, pain, and polypharmacy. In addition to age and polypharmacy, diabetes-related loss of strength, sensory perception, and balance secondary to peripheral neuropathy along with decline in cognitive function lead to increased risk of falling. Designing specific interventions to target strength and balance training, reducing polypharmacy to improve cognitive function, relaxation of diabetes management to avoid hypoglycemia and hypotension, and relief of pain will produce the greatest benefit for reducing falls in older persons with diabetes. Abbreviation: DPN = diabetic polyneuropathy.

Vitamin B12 deficiency

Vitamin B₁₂ (B12; also known as cobalamin) is a B vitamin that has an important role in cellular metabolism, especially in DNA synthesis, methylation and mitochondrial metabolism. Clinical B12 deficiency with classic haematological and neurological manifestations is relatively uncommon. However, subclinical deficiency affects between 2.5% and 26% of the general population depending on the definition used, although the clinical relevance is unclear. B12 deficiency can affect individuals at all ages, but most particularly elderly individuals. Infants, children, adolescents and women of reproductive age are also at high risk of deficiency in populations where dietary intake of B12-containing animal-derived foods is restricted. Deficiency is caused by either inadequate intake, inadequate bioavailability or malabsorption. Disruption of B12 transport in the blood, or impaired cellular uptake or metabolism causes an intracellular deficiency. Diagnostic biomarkers for B12 status include decreased levels of circulating total B12 and transcobalamin-bound B12, and abnormally increased levels of homocysteine and methylmalonic acid. However, the exact cut-offs to classify clinical and subclinical deficiency remain debated. Management depends on B12 supplementation, either via high-dose oral routes or via parenteral administration. This Primer describes the current knowledge surrounding B12 deficiency, and highlights improvements in diagnostic methods as well as shifting concepts about the prevalence, causes and manifestations of B12 deficiency.

Long-term Metformin Therapy and Monitoring for Vitamin B12 Deficiency Among Older Veterans

OBJECTIVE

To examine the association between long-term metformin therapy and serum vitamin B12 monitoring.

DESIGN

Retrospective cohort study.

SETTING

A single Veterans Affairs Medical Center (VAMC), 2002-2012.

PARTICIPANTS

Veterans 50 years or older with either type 2 diabetes and long-term metformin therapy (n = 3,687) or without diabetes and no prescription for metformin (n = 13,258).

MEASUREMENTS

We determined diabetes status from outpatient visits, and defined long-term metformin therapy as a prescription ≥500 mg/d for at least six consecutive months. We estimated the proportion of participants who received a serum B12 test and used multivariable logistic regression, stratified by age, to evaluate the association between metformin use and serum B12 testing.

RESULTS

Only 37% of older adults with diabetes receiving metformin were tested for vitamin B12 status after long-term metformin prescription. The mean B12 concentration was significantly lower in the metformin-exposed group (439.2 pg/dL) compared to those without diabetes (522.4 pg/dL) (P = .0015). About 7% of persons with diabetes receiving metformin were vitamin B12 deficient (<170 pg/dL) compared to 3% of persons without diabetes or metformin use (P = .0001). Depending on their age, metformin users were two to three times more likely not to receive vitamin B12 testing compared to those without metformin exposure, after adjusting for sex, race and ethnicity, body mass index, and number of years treated at the VAMC.

CONCLUSION

Long-term metformin therapy is significantly associated with lower serum vitamin B12 concentration, yet those at risk are often not monitored for B12 deficiency. Because metformin is first line therapy for type 2 diabetes, clinical decision support should be considered to promote serum B12 monitoring among long-term metformin users for timely identification of the potential need for B12 replacement.

Relationship between sensorimotor peripheral nerve function and indicators of cardiovascular autonomic function in older adults from the Health, Aging and Body Composition Study

BACKGROUND

Age-related peripheral nervous system (PNS) impairments are highly prevalent in older adults. Although sensorimotor and cardiovascular autonomic function have been shown to be related in persons with diabetes, the nature of the relationship in general community-dwelling older adult populations is unknown.

METHODS

Health, Aging and Body Composition participants (n=2399, age=76.5±2.9years, 52% women, 38% black) underwent peripheral nerve testing at the 2000/01 clinic visit. Nerve conduction amplitude and velocity were measured at the peroneal motor nerve. Sensory nerve function was assessed with vibration detection threshold and monofilament (1.4-g/10-g) testing at the big toe. Symptoms of lower-extremity peripheral neuropathy were collected by self-report. Cardiovascular autonomic function indicators included postural hypotension, resting heart rate (HR), as well as HR response to and recovery from submaximal exercise testing (400m walk). Multivariable modeling adjusted for demographic/lifestyle factors, medication use and comorbid conditions.

RESULTS

In fully adjusted models, poor motor nerve conduction velocity (<40m/s) was associated with greater odds of postural hypotension, (OR=1.6, 95% CI: 1.0-2.5), while poor motor amplitude (<1mV) was associated with 2.3beats/min (p=0.003) higher resting HR. No associations were observed between sensory nerve function or symptoms of peripheral neuropathy and indicators of cardiovascular autonomic function.

CONCLUSIONS

Motor nerve function and indicators of cardiovascular autonomic function remained significantly related even after considering many potentially shared risk factors. Future studies should investigate common underlying processes for developing multiple PNS impairments in older adults.

Serum Vitamin B12, Homocysteine and Methylmalonic Acid Levels in Patients With Parenchymal Neuro-Behçet's Syndrome

Objectives

This study aims to investigate the role of serum levels of vitamin B12 (VitB12), homocysteine (Hcy), and methylmalonic acid (MMA) in the development of parenchymal neuro-Behçet's syndrome (NBS) and to compare them with healthy controls and Behçet's syndrome (BS) patients without NBS.

Patients and methods

Serum VitB12, Hcy, and MMA were measured using enzyme-linked immunosorbent assay in 64 patients (36 males, 28 females; mean age 36±8.3 years; range 20 to 56 years) who met the criteria of the International Study Group for Behçet's Disease and 30 matched healthy controls (17 males, 13 females; mean age 35.76±9.6 years; range 20 to 50 years). The study participants were grouped as BS patients with NBS, BS patients without NBS, and healthy controls.

Results

There was no significant difference between the groups regarding serum VitB12, Hcy, and MMA levels (p>0.05). Serum VitB12 levels were below the lower limit and serum Hcy levels were above the upper limit in all participants. MMA levels were normal in all participants. There was no correlation between the serum levels of VitB12, Hcy, and MMA and disease activity (p>0.05).

Conclusion

The results of this study suggest that there is no significant association between VitB12 deficiency and parenchymal NBS. Further studies are needed to investigate the underlying mechanisms of the variable effects of VitB12 deficiency on different clinical manifestations of BS.

Vitamin B12 and Homocysteine Associations with Gait Speed in Older Adults: The Baltimore Longitudinal Study of Aging

OBJECTIVES

This study aimed to assess the independent associations of serum levels of vitamin B12 and plasma concentrations of homocysteine with gait speed decline.

DESIGN, SETTING, PARTICIPANTS

This study utilized longitudinal analysis of participants 50 years or older from The Baltimore Longitudinal Study of Aging, N=774.

MEASUREMENTS

Gait speed (m/s) was assessed using the 6-meter usual pace test. Vitamin B12 and homocysteine concentrations were collected using standard clinical protocols. Linear mixed effects regression was stratified by baseline age category (50-69, 70-79, and ≥80 years old).

RESULTS

Mean follow-up time for the total study sample was 5.4 ± 2.0 years. No association between vitamin B12 and gait speed decline over the follow-up time for any age group was found. Elevated homocysteine concentrations were associated with decline in gait speed after adjustment for covariates (50-69: β= -0.005, p=.057; 70-79: β= -0.013, p<.001, ≥80: β= -0.007, p=.054).

CONCLUSION

Homocysteine and vitamin B12 are inversely related, yet only homocysteine was associated with gait speed decline in this population of healthy older adults. Given these results, future research should be directed towards investigating the relationship in populations with greater variation in vitamin B12 concentrations and other mechanisms influencing homocysteine concentrations.

Vincristine-induced peripheral neuropathy in pediatric cancer patients

Vincristine is a chemotherapeutic agent that is a component of many combination regimens for a variety of malignancies, including several common pediatric tumors. Vincristine treatment is limited by a progressive sensorimotor peripheral neuropathy. Vincristine-induced peripheral neuropathy (VIPN) is particularly challenging to detect and monitor in pediatric patients, in whom the side effect can diminish long term quality of life. This review summarizes the current state of knowledge regarding VIPN, focusing on its description, assessment, prediction, prevention, and treatment. Significant progress has been made in our knowledge about VIPN incidence and progression, and tools have been developed that enable clinicians to reliably measure VIPN in pediatric patients. Despite these successes, little progress has been made in identifying clinically useful predictors of VIPN or in developing effective approaches for VIPN prevention or treatment in either pediatric or adult patients. Further research is needed to predict, prevent, and treat VIPN to maximize therapeutic benefit and avoid unnecessary toxicity from vincristine treatment.

Vitamin B-12 status and neurologic function in older people: a cross-sectional analysis of baseline trial data from the Older People and Enhanced Neurological Function (OPEN) study

BACKGROUND

Aging is associated with a progressive decline in vitamin B-12 status. Overt vitamin B-12 deficiency causes neurologic disturbances in peripheral and central motor and sensory systems, but the public health impact for neurologic disease of moderately low vitamin B-12 status in older people is unclear. Evidence from observational studies is limited by heterogeneity in the definition of vitamin B-12 status and imprecise measures of nerve function.

OBJECTIVE

We aimed to determine whether vitamin B-12 status is associated with electrophysiologic indexes of peripheral or central neurologic function in asymptomatic older people with moderately low vitamin B-12 status.

DESIGN

We used a cross-sectional analysis of baseline data from the Older People and Enhanced Neurological Function study conducted in Southeast England. This trial investigated the effectiveness of vitamin B-12 supplementation on electrophysiologic indexes of neurologic function in asymptomatic older people (mean age: 80 y) with moderately low vitamin B-12 status (serum vitamin B-12 concentrations ≥107 and <210 pmol/L without anemia, n = 201). Vitamin B-12 status was assessed with the use of total vitamin B-12, holotranscobalamin, and a composite indicator of vitamin B-12 status (cB-12). Electrophysiologic measures of sensory and motor components of peripheral and central nerve function were assessed in all participants by a single observer.

RESULTS

In multivariate models, there was no evidence of an association of vitamin B-12, holotranscobalamin, or cB-12 with any nerve conduction outcome. There was also no evidence of an association of vitamin B-12 status with clinical markers of neurologic function.

CONCLUSION

This secondary analysis of high-quality trial data did not show any association of any measure of vitamin B-12 status with either peripheral or central neurologic function or any clinical markers of neurologic function in older people with moderately low vitamin B-12 status. The results of this study are unlikely to be generalizable to a less healthy older population with more severe vitamin B-12 deficiency. This trial was registered at www.controlled-trials.com as ISRCTN54195799.

Oral manifestations in vitamin B12 deficiency patients with or without history of gastrectomy

BACKGROUND

The purpose of this study was to compare clinical features of vitamin B12 deficiency patients with a history of gastrectomy to those without a history of gastrectomy.

METHODS

Twenty-two patients with vitamin B12 deficiency were included. Patients' chief complaints, oral manifestations, blood examination results, and past medical histories were reviewed.

RESULTS

Eleven patients had a history of gastrectomy and 11 did not. The chief complaint was glossodynia in all patients. No significant differences were observed between the two groups regarding age, sex, symptom duration, or plasma vitamin B12 level. Erythema and depapillation of the tongue were the most common findings, however less common among patients without a history of gastrectomy. Two patients with a history of gastrectomy and 5 patients without a history of gastrectomy had normal oral mucosa. Patients with a history of gastrectomy were more anemic. Oral symptoms of the majority of patients responded to antifungals and vitamin B12 replacement. The suggested etiologies for vitamin B12 deficiency in the patients without a history of gastrectomy were gastritis, medications, diet, autoimmunity, and early gastric cancer.

CONCLUSIONS

Vitamin B12 deficiency and its associated etiological factors should be considered in patients with glossodynia, even those whose oral mucosa appears normal and who lack a history of gastrectomy.

The peripheral nerve involvement in Parkinson Disease: A multifaceted phenomenon

In the last decade the possible relationship between Parkinson's disease (PD) and peripheral neuropathy (PN) has received increasing attention. Given that PN is quite common in Parkinson's disease, much controversy has arisen on whether it is part of the neurogenerative process itself - actually one of the possible causes - or a complication of levodopa administration. In this article we will discuss the different hypotheses, as well as our perspective on these open issues.

[Cyanocobalamin-containing lubricant for topical therapy of LASIK-associated dry eye]

AIM

to study the effect of topical treatment with Artelac Balance, a cyanocobalamin-containing lubricant, in patients with post-LASIK corneal neuropathy and LASIK-associated dry eye.

MATERIAL AND METHODS

Patients scheduled for LASIK were enrolled. Inclusion criteria were contact lens wear for 5 years or longer and more than 6 diopters of myopia. The patients were divided into 3 groups. Group 1 was prescribed the cyanocobalamin-containing topical lubricant for 3 months before and 1 month after surgery, group 2 - the same cyanocobalamin-containing lubricant, but only for the first month after surgery, and group 3 received a standard preservative-free lubricant for the first month after surgery. Tear osmolarity and production as well as corneal sensitivity were assessed 90±10 days before and 30±3 days after surgery. The percentage of patients with dry eye symptoms and those who required prolonged use of lubricants were also estimated at day 30±3.

RESULTS

Preoperatively, there were no statistically significant differences in demographic characteristics, tear osmolarity, tear production, or corneal sensitivity between the three study groups. At day 30±3 after surgery, tear production and corneal sensitivity were both significantly higher in group 1 than in group 3 (16.8 mm vs. 13.2 mm, p=0.003 and 37.7±3.1 mm vs. 32.4±2.2 mm, p=0.023, respectively). As to the percentage of patients with dry eye symptoms and those who required prolonged use of lubricants, it was lower in group 1 than in group 3 (51.3% vs. 76.3%, p=0.03 and 38.5% vs. 63.2%, p=0.03, respectively). Between the groups 2 and 3, none of the studied parameters differed significantly.

CONCLUSION

Combined pre- and postoperative use of Artelac Balance, a cyanocobalamin-containing lubricant, has been proved effective in restoring corneal sensitivity and reducing dry eye symptoms in patients at high risk for developing LASIK-associated dry eye.

Sensorimotor Peripheral Nerve Function and the Longitudinal Relationship With Endurance Walking in the Health, Aging and Body Composition Study

OBJECTIVES

To determine whether lower extremity sensorimotor peripheral nerve deficits are associated with reduced walking endurance in older adults.

DESIGN

Prospective cohort study with 6 years of follow-up.

SETTING

Two university research clinics.

PARTICIPANTS

Community-dwelling older adults enrolled in the Health, Aging and Body Composition Study from the 2000-2001 annual clinical examination (N=2393; mean age ± SD, 76.5±2.9y; 48.2% men; 38.2% black) and a subset with longitudinal data (n=1178).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Participants underwent peripheral nerve function examination in 2000-2001, including peroneal motor nerve conduction amplitude and velocity, vibration perception threshold, and monofilament testing. Symptoms of lower extremity peripheral neuropathy included numbness or tingling and sudden stabbing, burning, pain, or aches in the feet or legs. The Long Distance Corridor Walk (LDCW) (400 m) was administered in 2000-2001 and every 2 years afterward for 6 years to assess endurance walking performance over time.

RESULTS

In separate, fully adjusted linear mixed models, poor vibration threshold (>130 μm), 10-g and 1.4-g monofilament insensitivity were each associated with a slower 400-m walk completion time (16.0 s, 14.4s, and 6.9 s slower, respectively; P<.05 for each). Poor motor amplitude (<1 mV), poor vibration perception threshold, and 10-g monofilament insensitivity were related to greater slowing per year (4.7, 4.2, and 3.8 additional seconds per year, respectively; P<.05), although poor motor amplitude was not associated with initial completion time.

CONCLUSIONS

Poorer sensorimotor peripheral nerve function is related to slower endurance walking and greater slowing longitudinally. Interventions to reduce the burden of sensorimotor peripheral nerve function impairments should be considered to help older adults maintain walking endurance-a critical component for remaining independent in the community.

VITAMIN B12 LEVELS IN PATIENTS WITH TYPE 2 DIABETES MELLITUS ON METFORMIN

BACKGROUND

Due to the clinical benefits of metformin, its associated side effects such as vitamin B12 deficiency are usually overlooked and rarely investigated.

OBJECTIVE

This study was carried out to determine the serum level of vitamin B12 in Nigerian patients with type 2 diabetes mellitus (T2DM) on metformin.

METHODS

Serum vitamin B12 level was determined using high performance liquid chromatography (HPLC) in 81 T2DM patients who have been on metformin for 5 years or more. Vitamin B12 deficiency was defined as serum concentration of <200 pg/dl, borderline deficiency as 200 - 300 pg/dl and >300 pg/dl as normal. Differences in vitamin B12 levels between different groups were assessed using Mann Whitney U test and P<0.05 was considered as statistically significant.

RESULTS

Vitamin B12 deficiency and borderline deficiency were recorded in 8.6% and 26.0% of the patients respectively. Vitamin B12 level was significantly lower in patients who have been on metformin for ≥10 years compared with patients with <10 years history of metformin use. Similarly, patients who were on metformin at a dose of >1000 mg/day had significantly lower vitamin B12 level when compared with patients on ≤1000 mg/day.

CONCLUSION

Low serum vitamin B12 level is associated with longer duration and higher dose of metformin use. Therefore, routine determination of vitamin B12 level in patients with T2DM on high dose of metformin and those with prolonged use of metformin might help in identifying patients that would benefit from vitamin B12 supplements.

Effects of vitamin B-12 supplementation on neurologic and cognitive function in older people: a randomized controlled trial

BACKGROUND

Moderate vitamin B-12 deficiency is relatively common in older people. However, there is little robust evidence on the effect of vitamin B-12 supplementation on neurologic and cognitive outcomes in later life.

OBJECTIVE

We investigated whether vitamin B-12 supplementation benefits neurologic and cognitive function in moderately vitamin B-12-deficient older people.

DESIGN

We conducted a double-blind, randomized, placebo-controlled trial in 7 general practices in South East England, United Kingdom. Study participants were aged ≥75 y and had moderate vitamin B-12 deficiency (serum vitamin B-12 concentrations: 107-210 pmol/L) in the absence of anemia and received 1 mg crystalline vitamin B-12 or a matching placebo as a daily oral tablet for 12 mo. Peripheral motor and sensory nerve conduction, central motor conduction, a clinical neurologic examination, and cognitive function were assessed before and after treatment.

RESULTS

A total of 201 participants were enrolled in the trial, and 191 subjects provided outcome data. Compared with baseline, allocation to vitamin B-12 was associated with a 177% increase in serum concentration of vitamin B-12 (641 compared with 231 pmol/L), a 331% increase in serum holotranscobalamin (240 compared with 56 pmol/L), and 17% lower serum homocysteine (14.2 compared with 17.1 μmol/L). In intention-to-treat analysis of covariance models, with adjustment for baseline neurologic function, there was no evidence of an effect of supplementation on the primary outcome of the posterior tibial compound muscle action potential amplitude at 12 mo (mean difference: -0.2 mV; 95% CI: -0.8, 0.3 mV). There was also no evidence of an effect on any secondary peripheral nerve or central motor function outcome, or on cognitive function or clinical examination.

CONCLUSION

Results of the trial do not support the hypothesis that the correction of moderate vitamin B-12 deficiency, in the absence of anemia and of neurologic and cognitive signs or symptoms, has beneficial effects on neurologic or cognitive function in later life. This trial was registered at www.isrctn.com as ISRCTN54195799.

Neurological complications after supracondylar femoral osteotomy in cerebral palsy

BACKGROUND

Knee flexion contracture in children with cerebral palsy (CP) is very common and functional impairment leads to a crouch gait. Correction of the knee flexion contracture and improvement of the gait pattern by supracondylar femoral extension osteotomy seems to be a more effective method than distal hamstring procedures in long-standing severe crouch. Only a small number of publications reported the neurological complications of this surgical technique. This study was planned to identify the risk factors leading to neurological complications after supracondylar femoral extension osteotomy in patients with CP.

METHODS

Supracondylar femoral osteotomies performed for a primary diagnosis of CP with rigid knee flexion deformity of 10 to 30 degrees were included in the study. Supracondylar femoral extension osteotomy was performed in 28 patients (total: 48 cases). Neurological complication was not detected in 43 cases (group 1) and detected in 5 cases (group 2). Previous surgical operation, concomitant operations on the same extremity, application of a brace or long leg cast after operation, preoperative and postoperative popliteal angle, amount of correction, radiologic correction, tourniquet time, level of malnutrition, and emotional state were reviewed.

RESULTS

There were 18 boys and 10 girls. The mean age was 12±4 years in group 1 and 13±1 years in group 2. Except 6 patients, all patients had concomitant operations (38 cases in group 1 and 4 cases in group 2). Postoperatively, long leg cast was used in 38 cases and brace in 10 cases. In group 1 mean correction was 23±3.8 degrees and in group 2 it was 19±5.7 degrees.

CONCLUSIONS

Correlation was not found between the incidence of neurological complications and amount of correction and deformity. After supracondylar femoral extension osteotomy, all patients must be suspected of neurological complication, and measures taken to alleviate the stretch at once if nerve palsy is diagnosed.

LEVEL OF EVIDENCE

Level IV.

Is there an association of vitamin B12 status with neurological function in older people? A systematic review

Low vitamin B12 status is common in older people; however, its public health significance in terms of neurological manifestations remains unclear. The present systematic review evaluated the association of vitamin B12 status with neurological function and clinically relevant neurological outcomes in adults aged 50+ years. A systematic search of nine bibliographic databases (up to March 2013) identified twelve published articles describing two longitudinal and ten cross-sectional analyses. The included study populations ranged in size (n 28-2287) and mean/median age (range 65-81 years). Studies reported various neurological outcomes: nerve function; clinically measured signs and symptoms of nerve function; self-reported neurological symptoms. Studies were assessed for risk of bias, and results were synthesised qualitatively. Among the general population groups of older people, one longitudinal study reported no association, and four of seven cross-sectional studies reported limited evidence of an association of vitamin B12 status with some, but not all, neurological outcomes. Among groups with clinical and/or biochemical evidence of low vitamin B12 status, one longitudinal study reported an association of vitamin B12 status with some, but not all, neurological outcomes and three cross-sectional analyses reported no association. Overall, there is limited evidence from observational studies to suggest an association of vitamin B12 status with neurological function in older people. The heterogeneity and quality of the evidence base preclude more definitive conclusions, and further high-quality research is needed to better inform understanding of public health significance in terms of neurological function of vitamin B12 status in older people.

Vitamin B12 and folate levels in healthy Swiss senior citizens: a prospective study evaluating reference intervals and decision limits

BACKGROUND

The vitamin B12 and folate status in nonanaemic healthy older persons needs attention the more so as decrease in levels may be anticipated from reduced haematinic provision and/or impaired intestinal uptake.

METHODS

A total of 1143 subjectively healthy Swiss midlands participants (637 females and 506 males), ≥60 years of age were included in this study. Levels of vitamin B12, holotranscobalamin (holoTC), methylmalonic acid (MMA), homocysteine (Hcy), serum folate, red blood cell (RBC) folate were measured. Further, Fedosov's wellness score was determined. Associations of age, gender, and cystatin C/creatinine-based estimated kidney function, with the investigated parameters were assessed. Reference intervals were calculated. Further, ROC analysis was done to assess accuracy of the individual parameters in recognizing a deficient vitamin B12 status. Finally, decision limits for sensitive, specific and optimal recognition of vitamin B12 status with individual parameters were derived.

RESULTS

Three age groups: 60-69, 70-79 and ≥ 80 had median B12 (pmol/L) levels of 237, 228 and 231 respectively (p = 0.22), holoTC (pmol/L) of 52, 546 and 52 (p = 0.60) but Hcy (μmol/L) 12, 15 and 16 (p < 0.001), MMA (nmol/L) 207, 221 and 244 (p < 0.001). Hcy and MMA (both p < 0.001), but not holoTC (p = 0.12) and vitamin B12 (p = 0.44) were found to be affected by kidney function. In a linear regression model Fedosov's wellness score was independently associated with kidney function (p < 0.001) but not with age. Total serum folate and red blood cell (RBC) folate drift apart with increasing age: whereas the former decreases (p = 0.01) RBC folate remains in the same bandwidth across all age groups (p = 0.12) A common reference interval combining age and gender strata can be obtained for vitamin B12 and holoTC, whereas a more differentiated approach seems warranted for serum folate and RBC folate.

CONCLUSION

Whereas the vitamin B12 and holoTC levels remain steady after 60 years of age, we observed a significant increment in MMA levels accompanied by increments in Hcy; this is better explained by age-related reduced kidney function than by vitamin B12 insufficiency. Total serum folate levels but not RBC folate levels decreased with progressing age.

Pathways in the diagnosis and management of diabetic polyneuropathy

Distal symmetric polyneuropathy (DSPN), the most common form of diabetic neuropathy, has a complex pathophysiology and can be a major source of physical and psychologic disability. The management of DSPN can be frustrating for both patient and physician. This article provides a general overview of typical patient pathways in DSPN, and highlights variations in diagnosis, management, and referral patterns among different providers. DSPN is managed in several settings by primary care physicians (PCPs), specialists, and nurse practitioners. The initial clinical management of the patient is often dependent on the presenting complaint, the referral pattern of the provider, level of comfort of the PCP in managing diabetic complications, and geographic access to specialists. The primary treatment of DSPN focuses mainly on glycemic control and adjustment of modifiable risk factors, but other causes of neuropathy should also be investigated. Several pharmacologic agents are recommended by treatment guidelines, and as DSPN typically exists with comorbid conditions, a multimodal therapeutic approach should be considered. Barriers to effective management include failure to recognize DSPN, and misdiagnosis. Patient education also remains important. Referral patterns vary widely according to geographic location, access to services, provider preferences, and comfort in managing complex aspects of the disease. The variability in patient pathways affects patient education, satisfaction, and outcomes. Standardized screening tools, a multidisciplinary team approach, and treatment algorithms for diabetic neuropathy should improve future care. To improve patient outcomes, DSPN needs to be diagnosed sooner and interventions made before significant nerve damage occurs.

[Vitamin B12 deficiency in the elderly]

The prevalence of vitamin B12 deficiency increases with age. Patients with dementia and spouses of patients with dementia are at special risk for the development of vitamin B12 deficiency. In a normal diet this vitamin is present only in animal source foods; therefore, vegans frequently develop vitamin B12 deficiency if not using supplements or foods fortified with cobalamin. Apart from dementia, most of these manifestations are completely reversible under correct therapy; therefore it is crucial to identify and to treat even atypical presentations of vitamin B12 deficiency as early as possible. This article deals with the physiology and pathophysiology of vitamin B12 metabolism. A practice-oriented algorithm which also considers health economic aspects for a rational laboratory diagnosis of vitamin B12 deficiency is presented. In cases with severe neurological symptoms, therapy should be parenteral, especially initially. For parenteral treatment, hydroxocobalamin is the drug of choice.

Polyglandular Syndrome Type III and Severe Peripheral Neuropathy: An Unusual Association

Introduction

Polyglandular syndrome is characterized by the association of autoimmune, organ-specific, endocrine and non-endocrine diseases.

Objective

To present a case of polyglandular syndrome type III (b) accompanied by pernicious anemia and autoimmune thyroiditis.

Method

Report the clinical case of a young patient that developed progressive and disabling peripheral neuropathy framework, triggered by vitamin B12 deficiency.

Discussion

It was proven that atrophic gastritis with positive intrinsic anti-factor was responsible for the framework of pernicious anemia, which in turn dangerously reduced the serum levels of vitamin B12, leading to myelopathy. There was a progressive neurological improvement after parenteral cyanocobalamin replacement, keeping the patient at ambulatory, under maintenance therapy.

Conclusion

The importance of suspecting on polyglandular syndrome in the presence of autoimmune frameworks is important, especially those involving diabetes, thyroiditis, atrophic gastritis, pernicious anemia, vitiligo, among others.

Sensory and motor peripheral nerve function and incident mobility disability

OBJECTIVES

To assess the relationship between sensorimotor nerve function and incident mobility disability over 10 years.

DESIGN

Prospective cohort study with longitudinal analysis.

SETTING

Two U.S. clinical sites.

PARTICIPANTS

Population-based sample of community-dwelling older adults with no mobility disability at 2000/01 examination (N = 2,148 [Corrected]; mean age ± SD 76.5 ± 2.9, body mass index 27.1 ± 4.6; 50.2% female, 36.6% black, 10.7% with diabetes mellitus).

MEASUREMENTS

Motor nerve conduction amplitude (poor <1 mV) and velocity (poor <40 m/s) were measured on the deep peroneal nerve. Sensory nerve function was measured using 10- and 1.4-g monofilaments and vibration detection threshold at the toe. Lower extremity symptoms included numbness or tingling and aching or burning pain. Incident mobility disability assessed semiannually over 8.5 years (interquartile range 4.5-9.6 years) was defined as two consecutive self-reports of a lot of difficulty or inability to walk one-quarter of a mile or climb 10 steps.

RESULTS

Nerve impairments were detected in 55% of participants, and 30% developed mobility disability. Worse motor amplitude (HR = 1.29 per SD, 95% CI = 1.16-1.44), vibration detection threshold (HR = 1.13 per SD, 95% CI = 1.04-1.23), symptoms (HR = 1.65, 95% CI = 1.26-2.17), two motor impairments (HR = 2.10, 95% CI = 1.43-3.09), two sensory impairments (HR = 1.91, 95% CI = 1.37-2.68), and three or more nerve impairments (HR = 2.33, 95% CI = 1.54-3.53) predicted incident mobility disability after adjustment. Quadriceps strength mediated relationships between certain nerve impairments and mobility disability, although most remained significant.

CONCLUSION

Poor sensorimotor nerve function independently predicted mobility disability. Future work should investigate modifiable risk factors and interventions such as strength training for preventing disability and improving function in older adults with poor nerve function.