Life course body mass index and risk and prognosis of amyotrophic lateral sclerosis: results from the ALS registry Swabia

Skeletal muscle dysfunction in amyotrophic lateral sclerosis: a mitochondrial perspective and therapeutic approaches

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neuromuscular disease that results in the loss of motor neurons and severe skeletal muscle atrophy. The etiology of ALS is linked to skeletal muscle, which can activate a retrograde signaling cascade that destroys motor neurons. This is why satellite cells and mitochondria play a crucial role in the health and performance of skeletal muscles. This review presents current knowledge on the involvement of mitochondrial dysfunction, skeletal muscle atrophy, muscle satellite cells, and neuromuscular junction (NMJ) in ALS. It also discusses current therapeutic strategies, including exercise, drugs, stem cells, gene therapy, and the prospective use of mitochondrial transplantation as a viable therapeutic strategy.

Lifestyle and medical conditions in relation to ALS risk and progression-an introduction to the Swedish ALSrisc Study

BACKGROUND

This study was an introduction to the Swedish ALSrisc Study and explored the association of lifestyle and medical conditions, with risk and progression of amyotrophic lateral sclerosis (ALS).

METHODS

We included 265 newly diagnosed ALS patients during 2016-2022 in Stockholm and 207 ALS-free siblings and partners of the patients as controls. Information on body mass index (BMI), smoking, and history of head injuries, diabetes mellitus, hypercholesterolemia, and hypertension was obtained through the Euro-MOTOR questionnaire at recruitment. Patients were followed from diagnosis until death, invasive ventilation, or November 30, 2022.

RESULTS

Higher BMI at recruitment was associated with lower risk for ALS (OR 0.89, 95%CI 0.83-0.95), especially among those diagnosed after 65 years. One unit increase in the average BMI during the 3 decades before diagnosis was associated with a lower risk for ALS (OR 0.94, 95%CI 0.89-0.99). Diabetes was associated with lower risk of ALS (OR 0.38, 95%CI 0.16-0.90), while hypercholesterolemia was associated with higher risk of ALS (OR 2.10, 95%CI 1.13-3.90). Higher BMI at diagnosis was associated with lower risk of death (HR 0.91, 95%CI 0.84-0.98), while the highest level of smoking exposure (in pack-years) (HR 1.90, 95%CI 1.20-3.00), hypercholesterolemia (HR 1.84, 95%CI 1.06-3.19), and hypertension (HR 1.76, 95%CI 1.03-3.01) were associated with higher risk of death, following ALS diagnosis.

CONCLUSIONS

Higher BMI and diabetes were associated with lower risk of ALS. Higher BMI was associated with lower risk of death, whereas smoking (especially in high pack-years), hypercholesterolemia, and hypertension were associated with higher risk of death after ALS diagnosis.

C9orf72 controls hepatic lipid metabolism by regulating SREBP1 transport

Sterol regulatory element binding transcription factors (SREBPs) play a crucial role in lipid homeostasis. They are processed and transported to the nucleus via COPII, where they induce the expression of lipogenic genes. COPII maintains the homeostasis of organelles and plays an essential role in the protein secretion pathways in eukaryotes. The formation of COPII begins at endoplasmic reticulum exit sites (ERES), and is regulated by SEC16A, which provides a platform for the assembly of COPII. However, there have been few studies on the changes in SEC16A protein levels. The repetitive expansion of the hexanucleotide sequence GGGGCC within the chromosome 9 open reading frame 72 (C9orf72) gene is a prevalent factor in the development of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Here, we found that the absence of C9orf72 leads to a decrease in SEC16A protein levels, resulting in reduced localization of the guanine nucleotide exchange factor SEC12 at the ERES. Consequently, the small GTP binding protein SAR1 is unable to bind the endoplasmic reticulum normally, impairing the assembly of COPII. Ultimately, the disruption of SREBPs transport decreases de novo lipogenesis. These results suggest that C9orf72 acts as a novel role in regulating lipid homeostasis and may serve as a potential therapeutic target for obesity.

Non-motor symptoms in patients with amyotrophic lateral sclerosis: current state and future directions

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive degeneration of both upper and lower motor neurons. A defining histopathological feature in approximately 97% of all ALS cases is the accumulation of phosphorylated trans-activation response (TAR) DNA-binding protein 43 protein (pTDP-43) aggregates in the cytoplasm of neurons and glial cells within the central nervous system. Traditionally, it was believed that the accumulation of TDP-43 aggregates and subsequent neurodegeneration primarily occurs in motor neurons. However, contemporary evidence suggests that as the disease progresses, other systems and brain regions are also affected. Despite this, there has been a limited number of clinical studies assessing the non-motor symptoms in ALS patients. These studies often employ various outcome measures, resulting in a wide range of reported frequencies of non-motor symptoms in ALS patients. The importance of assessing the non-motor symptoms reflects in a fact that they have a significant impact on patients' quality of life, yet they frequently go underdiagnosed and unreported during clinical evaluations. This review aims to provide an up-to-date overview of the current knowledge concerning non-motor symptoms in ALS. Furthermore, we address their diagnosis and treatment in everyday clinical practice.

Alterations to metabolic hormones in amyotrophic lateral sclerosis and frontotemporal dementia postmortem human tissue

Metabolic changes are observed in patients with both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Although regulation of metabolic processes in the CNS is predominantly carried out within the hypothalamus, extra-hypothalamic CNS areas contain metabolic hormone receptors, including those for leptin (LEPR), insulin (INSR), and neuropeptide Y (NPY), indicating that they may play a role in biological processes underlying pathogenic disease processes. The status of these hormones within regions vulnerable in ALS/FTD is not well described. This study sought to determine whether the expression of these hormones and their receptors is altered in pathology-rich regions in cases of human FTD (superior frontal gyrus and insular cortex) and ALS (primary motor cortex and lumbar spinal cord) with TDP-43 pathology compared to matched healthy controls. LEPR mRNA was increased within the superior frontal gyrus of FTD cases and within primary motor cortex and lumbar spinal cord of ALS cases; INSR mRNA was increased in superior frontal gyrus and insular cortex of FTD cases. NPY protein was decreased in primary motor cortex and lumbar spinal cord of ALS cases. Our results demonstrate that metabolic hormones undergo complex alterations in ALS and FTD and suggest that these hormones could play critical roles in the pathogenesis of these diseases.

Mis-localization of endogenous TDP-43 leads to ALS-like early-stage metabolic dysfunction and progressive motor deficits

BACKGROUND

The key pathological signature of ALS/ FTLD is the mis-localization of endogenous TDP-43 from the nucleus to the cytoplasm. However, TDP-43 gain of function in the cytoplasm is still poorly understood since TDP-43 animal models recapitulating mis-localization of endogenous TDP-43 from the nucleus to the cytoplasm are missing.

METHODS

CRISPR/Cas9 technology was used to generate a zebrafish line (called CytoTDP), that mis-locates endogenous TDP-43 from the nucleus to the cytoplasm. Phenotypic characterization of motor neurons and the neuromuscular junction was performed by immunostaining, microglia were immunohistochemically localized by whole-mount tissue clearing and muscle ultrastructure was analyzed by scanning electron microscopy. Behavior was investigated by video tracking and quantitative analysis of swimming parameters. RNA sequencing was used to identify mis-regulated pathways with validation by molecular analysis.

RESULTS

CytoTDP fish have early larval phenotypes resembling clinical features of ALS such as progressive motor defects, neurodegeneration and muscle atrophy. Taking advantage of zebrafish's embryonic development that solely relys on yolk usage until 5 days post fertilization, we demonstrated that microglia proliferation and activation in the hypothalamus is independent from food intake. By comparing CytoTDP to a previously generated TDP-43 knockout line, transcriptomic analyses revealed that mis-localization of endogenous TDP-43, rather than TDP-43 nuclear loss of function, leads to early onset metabolic dysfunction.

CONCLUSIONS

The new TDP-43 model mimics the ALS/FTLD hallmark of progressive motor dysfunction. Our results suggest that functional deficits of the hypothalamus, the metabolic regulatory center, might be the primary cause of weight loss in ALS patients. Cytoplasmic gain of function of endogenous TDP-43 leads to metabolic dysfunction in vivo that are reminiscent of early ALS clinical non-motor metabolic alterations. Thus, the CytoTDP zebrafish model offers a unique opportunity to identify mis-regulated targets for therapeutic intervention early in disease progression.

Time from amyotrophic lateral sclerosis symptom onset to key disease milestones: analysis of data from a multinational cross-sectional survey

OBJECTIVE

To determine the average time from Amyotrophic Lateral Sclerosis (ALS) symptom onset to 11 pre-defined milestones, overall and according to ALS progression rate and geographic location.

METHODS

Data were drawn from the Adelphi Real World ALS Disease-Specific ProgrammeTM, a point-in-time survey of neurologists caring for people living with ALS (pALS) conducted in France, Germany, Italy, Spain, the United Kingdom and the United States from 2020-2021. ALS progression rate was calculated using time since symptom onset and ALS Functional Rating Scale Revised score.

RESULTS

Survey results were available for N = 1003 pALS (progression rate for N = 867). Mean time from symptom onset was 3.8 months to first consultation, 8.0 months to diagnosis, 16.2 months to employment change (part-time/sick leave/retirement/unemployment), 17.5 months to use of a walking aid, 18.5 months to first occurrence of caregiver support, 22.8 months to use of a wheelchair, 24.6 months to use of a communication aid, 27.3 months to use of a respiratory aid, 28.6 months to use of gastrostomy feeding, 29.7 months to use of eye gaze technology and 30.3 months to entering a care facility. Multivariate analysis indicated significant effects of fast (versus slow) progression rate on time to reach all 11 milestones, as well as US (versus European) location, age, body mass index and bulbar onset (versus other) on time to reach milestones.

CONCLUSIONS

pALS rapidly reached clinical and disease-related milestones within 30 months from symptom onset. Milestones were reached significantly faster by pALS with fast versus slow progression. Geographic differences were observed.

Prognostic value of geriatric nutritional risk index in patients with amyotrophic lateral sclerosis

BACKGROUND

The geriatric nutritional risk index (GNRI) is a prognostic indicator for several diseases, meanwhile, nutrition and inflammation play important roles in the disease progression of amyotrophic lateral sclerosis (ALS). However, the association between the GNRI and ALS remains unknown.

METHODS

443 patients diagnosed with ALS were divided into two groups based on the GNRI levels. Associations between GNRI and survival time were analyzed using Kaplan-Meier curves and compared by the log-rank test. Univariate and multivariate analyses were used to assess their prognostic values for survival time. Spearman correlation analysis was used to evaluate the correlation coefficients between GNRI and other clinical variables.

RESULTS

No significant differences were found in diagnostic delay between the two groups. The onset age and disease progression rate (DPR) were significantly lower in high GNRI group while forced vital capacity (FVC), revised version of the ALS functional rating scale (ALSFRS-R), serum albumin and body mass index (BMI) were significantly lower in low GNRI group. Lower GNRI levels were linked with shorter ALS patients' survival time by Kaplan-Meier curves. The univariate and multivariate analysis identified the onset age, gender, onset site, diagnostic delay, DRP and GNRI as predictors of survival time in patients with ALS.

CONCLUSION

Nutritional status was closely corelated with ALS progression. The GNRI may be used as a potential prognostic indictor for ALS patients.

Higher Glycemic Index and Glycemic Load Diet Is Associated with Slower Disease Progression in Amyotrophic Lateral Sclerosis

OBJECTIVE

High-caloric diets may slow the progression of amyotrophic lateral sclerosis; however, key macronutrients have not been identified. We examined whether dietary macronutrients are associated with the rate of progression and length of survival among the prospective cohort study participants.

METHODS

Participants with a confirmed diagnosis of sporadic amyotrophic lateral sclerosis enrolled in the Multicenter Cohort Study of Oxidative Stress were included (n = 304). We evaluated baseline macronutrient intake assessed by food frequency questionnaire in relation to change in revised amyotrophic lateral sclerosis functional rating scale total-score, and tracheostomy-free survival using linear regression and Cox proportional hazard models. Baseline age, sex, disease duration, diagnostic certainty, body mass index, bulbar onset, revised amyotrophic lateral sclerosis functional rating scale total-score, and forced vital capacity were included as covariates.

RESULTS

Baseline higher glycemic index and load were associated with less decline of revised amyotrophic lateral sclerosis functional rating scale total score at 3-month follow-up (β = -0.13, 95% CI -0.2, -0.01, p = 0.03) and (β = -0.01, 95% CI -0.03, -0.0007, p = 0.04), respectively. Glycemic index second-quartile, third-quartile, and fourth-quartile groups were associated with less decline at 3 months by 1.9 (95% CI -3.3, -0.5, p = 0.008), 2.0 (95% CI -3.3, -0.6, p = 0.006), and 1.6 (95% CI -3.0, -0.2, p = 0.03) points compared with the first-quartile group; the glycemic load fourth-quartile group had 1.4 points less decline compared with the first-quartile group (95% CI -2.8, 0.1, p = 0.07). Higher glycemic index was associated with a trend toward longer tracheostomy-free survival (HR 0.97, 95% CI 0.93, 1.00, p = 0.07).

INTERPRETATION

Higher dietary glycemic index and load are associated with slower disease progression in amyotrophic lateral sclerosis. ANN NEUROL 2024;95:217-229.

Mitochondria: A Promising Convergent Target for the Treatment of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by the progressive loss of motor neurons, for which current treatment options are limited. Recent studies have shed light on the role of mitochondria in ALS pathogenesis, making them an attractive therapeutic intervention target. This review contains a very comprehensive critical description of the involvement of mitochondria and mitochondria-mediated mechanisms in ALS. The review covers several key areas related to mitochondria in ALS, including impaired mitochondrial function, mitochondrial bioenergetics, reactive oxygen species, metabolic processes and energy metabolism, mitochondrial dynamics, turnover, autophagy and mitophagy, impaired mitochondrial transport, and apoptosis. This review also highlights preclinical and clinical studies that have investigated various mitochondria-targeted therapies for ALS treatment. These include strategies to improve mitochondrial function, such as the use of dichloroacetate, ketogenic and high-fat diets, acetyl-carnitine, and mitochondria-targeted antioxidants. Additionally, antiapoptotic agents, like the mPTP-targeting agents minocycline and rasagiline, are discussed. The paper aims to contribute to the identification of effective mitochondria-targeted therapies for ALS treatment by synthesizing the current understanding of the role of mitochondria in ALS pathogenesis and reviewing potential convergent therapeutic interventions. The complex interplay between mitochondria and the pathogenic mechanisms of ALS holds promise for the development of novel treatment strategies to combat this devastating disease.

Effect of body mass index on survival after spinal cord injury

Introduction

Increased mortality after acute and chronic spinal cord injury (SCI) remains a challenge and mandates a better understanding of the factors contributing to survival in these patients. This study investigated whether body mass index (BMI) measured after acute traumatic SCI is associated with a change in mortality.

Methods

A prospective longitudinal cohort study was conducted with 742 patients who were admitted to the Acute Spine Unit of the Vancouver General Hospital between 2004 and 2016 with a traumatic SCI. An investigation of the association between BMI on admission and long-term mortality was conducted using classification and regression tree (CART) and generalized additive models (spline curves) from acute care up to 7.7 years after SCI (chronic phase). Multivariable models were adjusted for (i) demographic factors (e.g., age, sex, and Charlson Comorbidity Index) and (ii) injury characteristics (e.g., neurological level and severity and Injury Severity Score).

Results

After the exclusion of incomplete datasets (n = 602), 643 patients were analyzed, of whom 102 (18.5%) died during a period up to 7.7 years after SCI. CART identified three distinct mortality risk groups: (i) BMI: > 30.5 kg/m2, (ii) 17.5-30.5 kg/m2, and (iii) < 17.5 kg/m2. Mortality was lowest in the high BMI group (BMI > 30.5 kg/m2), followed by the middle-weight group (17.5-30.5 kg/m2), and was highest in the underweight group (BMI < 17.5 kg/m2). High BMI had a mild protective effect against mortality after SCI (hazard ratio 0.28, 95% CI: 0.09-0.88, p = 0.029), concordant with a modest "obesity paradox". Moreover, being underweight at admission was a significant risk factor for mortality up to 7.7 years after SCI (hazard ratio 5.5, 95% CI: 2.34-13.17, p < 0.001).

Discussion

Mortality risk (1 month to 7.7 years after SCI) was associated with differences in BMI at admission. Further research is needed to better understand the underlying mechanisms. Given an established association of BMI with metabolic determinants, these results may suggest unknown neuro-metabolic pathways that are crucial for patient survival.

Association Between Fat Depletion and Prognosis of Amyotrophic Lateral Sclerosis: CT-Based Body Composition Analysis

OBJECTIVE

The purpose of this study was to present the results of our investigation of the prognostic value of adipopenia and sarcopenia in patients with amyotrophic lateral sclerosis (ALS).

METHODS

Consecutive patients with ALS with abdominal computed tomography (CT) were retrospectively identified at a single tertiary hospital between January 2010 and July 2021. Deep learning-based volumetric CT body composition analysis software was used to obtain abdominal waist fat volume, fat attenuation, and skeletal muscle area at the L3 level, then normalized to the fat volume index (FVI) and skeletal muscle index (SMI). Adipopenia and sarcopenia were defined as the sex-specific lowest quartile and SMI reference values, respectively. The associations of CT-derived body composition parameters with clinical variables, such as body mass index (BMI) and creatinine, were evaluated by Pearson correlation analyses, and associations with survival were assessed using the multivariable Cox regression analysis.

RESULTS

Eighty subjects (40 men, 65.5 ± 9.4 years of age) were investigated (median interval between disease onset and CT examination = 25 months). The mean BMI at the CT examination was 20.3 ± 4.3 kg/m2 . The BMI showed a positive correlation with both FVI (R = 0.70, p < 0.001) and SMI (R = 0.63, p < 0.001), and the serum creatinine level was associated with SMI (R = 0.68, p < 0.001). After adjusting for sex, age, King's stage, BMI, creatinine, progression rate, and sarcopenia, adipopenia was associated with shorter survival (hazard ratio [HR] = 5.94, 95% confidence interval [CI] = 1.01, 35.0, p = 0.049). In a subgroup analysis for subjects with nutritional failure (stage 4a), the HR of adipopenia was 15.1 (95% CI = 2.45, 93.4, p = 0.003).

INTERPRETATION

Deep learning-based CT-derived adipopenia in patients with ALS is an independent poor prognostic factor for survival. ANN NEUROL 2023;94:1116-1125.

Interaction of sex and onset site on the disease trajectory of amyotrophic lateral sclerosis

BACKGROUND

Studies showed the impact of sex and onset site (spinal or bulbar) on disease onset and survival in ALS. However, they mainly result from cross-sectional or survival analysis, and the interaction of sex and onset site on the different proxies of disease trajectory has not been fully investigated.

METHODS

We selected all patients with repeated observations in the PRO-ACT database. We divided them into four groups depending on their sex and onset site. We estimated a multivariate disease progression model, named ALS Course Map, to investigate the combined temporal changes of the four sub-scores of the revised ALS functional rating scale (ALSFRSr), the forced vital capacity (FVC), and the body mass index (BMI). We then compared the progression rate, the estimated age at onset, and the relative progression of the outcomes across each group.

RESULTS

We included 1438 patients from the PRO-ACT database. They were 51% men with spinal onset, 12% men with bulbar onset, 26% women with spinal onset, and 11% women with bulbar onset. We showed a significant influence of both sex and onset site on the ALSFRSr progression. The BMI decreased 8.9 months earlier (95% CI [3.9, 13.8]) in women than men, after correction for the onset site. Among patients with bulbar onset, FVC was impaired 2.6 months earlier (95% CI [0.6, 4.6]) in women.

CONCLUSION

Using a multivariable disease modelling approach, we showed that sex and onset site are important drivers of the progression of motor function, BMI, and FVC decline.

Cystatin C based estimation of chronic kidney disease and amyotrophic lateral sclerosis in the ALS registry Swabia: associated risk and prognostic value

Kidney function as part of metabolic changes could be associated with amyotrophic lateral-sclerosis (ALS). We investigated the associations between estimated chronic kidney disease (CKD), based on the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) cystatin C equation, and the risk at onset and prognostic value of CKD for ALS. Between October 2010 and June 2014, 362 ALS cases (59.4% men, mean age 65.7 years) and 681 controls (59.5% men, means age 66.3 years) were included in a population-based case-control study based on the ALS registry Swabia in Southern Germany. All ALS cases were followed-up (median 89.7 months), 317 died. Serum samples were measured for cystatin C to estimate the glomerular filtration rate (eGFR) according to the CKD-EPI equation. Information on covariates were assessed by an interview-based standardized questionnaire. Conditional logistic regression models were applied to calculate odds ratios (OR) for risk of ALS associated with eGFR/CKD stages. Time-to-death associated with renal parameters at baseline was assessed in ALS cases only. ALS cases were characterized by lower body mass index, slightly lower smoking prevalence, more intense occupational work and lower education than controls. Median serum cystatin-C based eGFR concentrations were lower in ALS cases than in controls (54.0 vs. 59.5 mL/min pro 1.73 m2). The prevalence of CKD stage ≥ 3 was slightly higher in ALS cases than in controls (14.1 vs. 11.0%). In the adjusted models, CKD stage 2 (OR 1.82, 95% CI 1.32, 2.52) and stage 3 (OR 2.34, 95% CI 1.38, 3.96) were associated with increased ALS risk. In this cohort of ALS cases, eGFR and CKD stage ≥ 3 (HR 0.94; 95% CI 0.64, 1.38) were not associated with prognosis. In this case-control study, higher CKD stages were associated with increased ALS risk, while in the prospective cohort of ALS cases, no indication of an association of CysC-based CKD on mortality was seen. In addition, our work strengthens the importance to evaluate renal function using a marker independent of muscle mass in ALS patients.

Neutrophils Are Associated with Higher Risk of Incident Amyotrophic Lateral Sclerosis in a BMI- and Age-Dependent Manner

OBJECTIVE

Peripheral immune markers have been associated with the progression and prognosis of amyotrophic lateral sclerosis (ALS). However, whether dysregulation of peripheral immunity is a risk factor for ALS or a consequence of motor neuron degeneration has not yet been clarified. We aimed to identify longitudinal associations between prediagnostic peripheral immunity and the risk of incident ALS.

METHODS

A total of 345,000 individuals from the UK Biobank between 2006 and 2010 were included at the baseline. The counts of peripheral immune markers (neutrophils, lymphocytes, monocytes, platelets, and CRP) and its derived metrics (neutrophil-to-lymphocyte ratio [NLR], platelet-to-lymphocyte ratio [PLR], lymphocyte-to-monocyte ratio [LMR], and systemic immune-inflammation index [SII]) were analyzed in relation to the following incident ALS by Cox proportional hazard models. Subgroup and interaction analyses were performed to explore the covariates of these relationships further.

RESULTS

After adjusting for all covariates, the multivariate analysis showed that high neutrophil counts and their derived metrics (NLR and SII) were associated with an increased risk of ALS incidence (per SD increment hazard ratio [HR] = 1.15, 95% confidence interval [CI] = 1.02-1.29 for neutrophils; HR = 1.15, 95% CI = 1.03-1.28 for NLR; and HR = 1.17, 95% CI = 1.05-1.30 for SII). Subgroup and interaction analyses revealed that body mass index (BMI) and age had specific effects on this association. In participants with BMI ≥ 25 or age < 65 years, higher neutrophil counts, and their metrics increased the risk of incident ALS; however, in participants with BMI < 25 or age ≥ 65 years, neutrophils had no effect on incident ALS.

INTERPRETATION

Our study provides evidence that increased neutrophil levels and neutrophil-derived metrics (NLR and SII) are associated with an increased risk of developing ALS. ANN NEUROL 2023;94:942-954.

Nutritional and metabolic factors in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a complex neurodegenerative disease that is classically thought to impact the motor system. Over the past 20 years, research has started to consider the contribution of non-motor symptoms and features of the disease, and how they might affect ALS prognosis. Of the non-motor features of the disease, nutritional status (for example, malnutrition) and metabolic balance (for example, weight loss and hypermetabolism) have been consistently shown to contribute to more rapid disease progression and/or earlier death. Several complex cellular changes observed in ALS, including mitochondrial dysfunction, are also starting to be shown to contribute to bioenergetic failure. The resulting energy depletion in high energy demanding neurons makes them sensitive to apoptosis. Given that nutritional and metabolic stressors at the whole-body and cellular level can impact the capacity to maintain optimal function, these factors present avenues through which we can identify novel targets for treatment in ALS. Several clinical trials are now underway evaluating the effectiveness of modifying energy balance in ALS, making this article timely in reviewing the evidence base for metabolic and nutritional interventions.

The Effect of Skeletal Muscle-Specific Creatine Treatment on ALS NMJ Integrity and Function

Although skeletal muscle (hSKM) has been proven to be actively involved in Amyotrophic Lateral Sclerosis (ALS) neuromuscular junction (NMJ) dysfunction, it is rarely considered as a pharmacological target in preclinical drug discovery. This project investigated how improving ALS hSKM viability and function effects NMJ integrity. Phenotypic ALS NMJ human-on-a-chip models developed from patient-derived induced pluripotent stem cells (iPSCs) were used to study the effect of hSKM-specific creatine treatment on clinically relevant functional ALS NMJ parameters, such as NMJ numbers, fidelity, stability, and fatigue index. Results indicated comparatively enhanced NMJ numbers, fidelity, and stability, as well as reduced fatigue index, across all hSKM-specific creatine-treated systems. Immunocytochemical analysis of the NMJs also revealed improved post-synaptic nicotinic Acetylcholine receptor (AChR) clustering and cluster size in systems supplemented with creatine relative to the un-dosed control. This work strongly suggests hSKM as a therapeutic target in ALS drug discovery. It also demonstrates the need to consider all tissues involved in multi-systemic diseases, such as ALS, in drug discovery efforts. Finally, this work further establishes the BioMEMs NMJ platform as an effective means of performing mutation-specific drug screening, which is a step towards personalized medicine for rare diseases.

Primary care blood tests show lipid profile changes in pre-symptomatic amyotrophic lateral sclerosis

Multiple sources of evidence suggest that changes in metabolism may precede the onset of motor symptoms in amyotrophic lateral sclerosis. This study aimed to seek evidence for alterations in the levels of blood indices collected routinely in the primary care setting prior to the onset of motor symptoms in amyotrophic lateral sclerosis. Premorbid data, measured as part of routine health screening, for total cholesterol, high-density and low-density lipoprotein cholesterol, triglyceride, glycated haemoglobin A1c and creatinine were collected retrospectively from (i) a cohort of amyotrophic lateral sclerosis patients attending a specialist clinic (n = 143) and (ii) from primary care-linked data within UK Biobank. Data were fitted using linear mixed effects models with linear b-splines to identify inflection points, controlling for age and sex. In specialist amyotrophic lateral sclerosis clinic cases, models indicated decreasing levels of total and low-density lipoprotein cholesterol prior to an inflection point in the years before symptom onset (total cholesterol 3.25 years, low-density lipoprotein cholesterol 1.25 years), after which they stabilized or rose. A similar pattern was observed in amyotrophic lateral sclerosis cases within UK Biobank, occurring several years prior to diagnosis (total cholesterol 7 years, low-density lipoprotein cholesterol 7.25 years), differing significantly from matched controls. High-density lipoprotein cholesterol followed a similar pattern but was less robust to sensitivity analyses. Levels of triglyceride remained stable throughout. Glycated haemoglobin temporal profiles were not consistent between the clinic and biobank cohorts. Creatinine level trajectories prior to amyotrophic lateral sclerosis did not differ significantly from controls but decreased significantly in the symptomatic period after an inflection point of 0.25 years after symptom onset (clinic cohort) or 0.5 years before diagnosis (UK Biobank). These data provide further evidence for a pre-symptomatic period of dynamic metabolic change in amyotrophic lateral sclerosis, consistently associated with alterations in blood cholesterols. Such changes may ultimately contribute to biomarkers applicable to population screening and for pathways guiding the targeting of preventative therapy.

Evidence of Metabolic Dysfunction in Amyotrophic Lateral Sclerosis (ALS) Patients and Animal Models

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that affects motor neurons, leading to muscle weakness, paralysis, and eventual death. Research from the past few decades has appreciated that ALS is not only a disease of the motor neurons but also a disease that involves systemic metabolic dysfunction. This review will examine the foundational research of understanding metabolic dysfunction in ALS and provide an overview of past and current studies in ALS patients and animal models, spanning from full systems to various metabolic organs. While ALS-affected muscle tissue exhibits elevated energy demand and a fuel preference switch from glycolysis to fatty acid oxidation, adipose tissue in ALS undergoes increased lipolysis. Dysfunctions in the liver and pancreas contribute to impaired glucose homeostasis and insulin secretion. The central nervous system (CNS) displays abnormal glucose regulation, mitochondrial dysfunction, and increased oxidative stress. Importantly, the hypothalamus, a brain region that controls whole-body metabolism, undergoes atrophy associated with pathological aggregates of TDP-43. This review will also cover past and present treatment options that target metabolic dysfunction in ALS and provide insights into the future of metabolism research in ALS.

Loss of hypothalamic MCH decreases food intake in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is associated with impaired energy metabolism, including weight loss and decreased appetite which are negatively correlated with survival. Neural mechanisms underlying metabolic impairment in ALS remain unknown. ALS patients and presymptomatic gene carriers have early hypothalamic atrophy. The lateral hypothalamic area (LHA) controls metabolic homeostasis through the secretion of neuropeptides such as orexin/hypocretin and melanin-concentrating hormone (MCH). Here, we show loss of MCH-positive neurons in three mouse models of ALS based on SOD1 or FUS mutations. Supplementation with MCH (1.2 µg/d) through continuous intracerebroventricular delivery led to weight gain in male mutant Sod1^G86R mice. MCH supplementation increased food intake, rescued expression of the key appetite-related neuropeptide AgRP (agouti-related protein) and modified respiratory exchange ratio, suggesting increased carbohydrate usage during the inactive phase. Importantly, we document pTDP-43 pathology and neurodegeneration in the LHA of sporadic ALS patients. Neuronal cell loss was associated with pTDP-43-positive inclusions and signs of neurodegeneration in MCH-positive neurons. These results suggest that hypothalamic MCH is lost in ALS and contributes to the metabolic changes, including weight loss and decreased appetite.

Metabolic alterations precede neurofilament changes in presymptomatic ALS gene carriers

BACKGROUND

The emergence of potentially effective new therapies for genetic forms of amyotrophic lateral sclerosis (ALS) necessitates the identification of biomarkers to facilitate early treatment, prior to the onset of motor symptoms. Here, we sought to investigate whether metabolic alterations are detectable in presymptomatic ALS gene mutation carriers, and whether such alterations precede neurofilament light chain (NfL) changes in serum.

METHODS

Between 02/2014 and 11/2021, we prospectively studied 60 presymptomatic ALS gene mutation carriers (40% male, age 48.7 ± 14.9; 28 C9orf72, 22 SOD1, 10 other) compared to 73 individuals from the same families (47% male, age 47.4 ± 12.9) without pathogenic mutations as controls. Bioimpedance analysis (BIA) and indirect calorimetry were performed, and Body Mass Index (BMI), Fat Mass (FM), Body Fat Percentage, Body Water (BW), Lean Body Mass (LBM), Extracellular Mass (ECM), Body Cell Mass (BCM), ECM/BCM ratio, Cells Percentage, Phase Angle, Resting Metabolic Rate (RMR), Metabolic Ratio (MR), and NfL were measured. Participants and evaluators were blinded regarding gene carrier status.

FINDINGS

Presymptomatic ALS gene carriers showed reduced LBM (p = 0.02), BCM (p = 0.004), Cells Percentage (p = 0.04), BW (p = 0.02), Phase Angle (p = 0.04), and increased ECM/BCM ratio (p = 0.04), consistently indicating a loss of metabolically active body cells. While in C9orf72 mutation carriers all tissue masses were reduced, only metabolically active tissue was affected in SOD1 mutation carriers. Unexpectedly, RMR (p = 0.009) and MR (p = 0.01) were lower in presymptomatic ALS gene carriers compared to non-carriers. NfL serum levels were similar in mutation carriers and non-carriers (p = 0.60).

INTERPRETATION

The observed metabolic phenomena might reflect reduced physical activity and/or preemptive, insufficient compensatory mechanisms to prepare for the later hypermetabolic state. As pre-symptomatic biomarkers we propose ECM/BCM ratio and Phase Angle for SOD1, and a 4-compartment affection in BIA for C9orf72 mutation carriers.

FUNDING

This work was an investigator-initiated trial. On the German side, there was no institutional or industrial funding. On the Swedish side, this work was supported by grants from the Swedish Brain Foundation (grants nr. 2013-0279, 2016-0303, 2018-0310, 2020-0353), the Swedish Research Council (grants nr. 2012-3167, 2017-03100), the Knut and Alice Wallenberg Foundation (grants nr. 2012.0091, 2014.0305, 2020.0232), the Ulla-Carin Lindquist Foundation, Umeå University (223-2808-12, 223-1881-13, 2.1.12-1605-14) and the Västerbotten County Council (grants nr 56103-7002829), King Gustaf V:s and Queen Victoria's Freemason's Foundation.

Differenzialdiagnose der Amyotrophen Lateralsklerose in der klinischen Praxis

Die Diagnose der Amyotrophen Lateralsklerose (ALS) beruht vorwiegend auf klinischen Kriterien und kann aufgrund des heterogenen Erscheinungsbildes gerade in frühen Krankheitsstadien mitunter schwierig sein. Wegweisend sind der Nachweis einer kombinierten Pathologie des oberen und unteren Motoneurons, der fokale Onset, das Ausbreitungsmuster (Spreading), das typische Verteilungsmuster der Paresen, das Vorhandensein oder Fehlen nicht-motorischer Zusatzsymptome sowie Art und Geschwindigkeit der Krankheitsprogredienz. Dieser Review stellt Charakteristika der ALS sowohl im Hinblick auf die klinische Untersuchung als auch apparativer Zusatzdiagnostik in Abgrenzung zu den wichtigsten Differenzialdiagnosen in Form von Einschlusskörperchenmyositis, Chronisch Inflammatorischer Demyelinisierender Polyneuropathie (CIDP), Mulifokaler Motorischer Neuropathie (MMN), adulter Form der Spinalen Muskelatrophie (SMA), Kennedy-Syndrom und Hereditärer Spastischer Paralyse (HSP) dar.

Association of blood lipids with onset and prognosis of amyotrophic lateral sclerosis: results from the ALS Swabia registry

BACKGROUND

To date, the role of blood lipid levels and their association with the onset and prognosis of ALS is controversial. We explored these associations in a large, population-based case-control study.

METHODS

Between October 2010 and June 2014, 336 ALS patients (mean age 65.7 ± 10.7; 57.7% male) and 487 sex- and age-matched controls from the same geographic region were recruited within the ALS registry in Southwest Germany. Triglycerides and cholesterol (high-density lipoprotein (HDL), low-density lipoprotein (LDL), total) were measured. The ALS cohort was followed up for vital status. Conditional logistic regression models were applied to calculate odds ratio (OR) for risk of ALS associated with serum lipid concentrations. In ALS patients only, survival models were used to appraise the prognostic value.

RESULTS

High concentration of total cholesterol (OR 1.60, 95% confidence interval (CI) 1.03-2.49, top vs. bottom quartile), but not HDL, LDL, LDL-HDL ratio, or triglycerides, was positively associated with the risk of ALS. During the median follow-up time of 88.9 months, 291 deaths occurred among 336 ALS patients. In the adjusted survival analysis, higher HDL (HR 1.72, 95% CI 1.19-2.50) and LDL cholesterol levels (HR 1.58, 95% CI 1.11-2.26) were associated with higher mortality in ALS patients. In contrast, higher triglyceride levels were associated with lower mortality (HR 0.68, 95% CI 0.48-0.96).

CONCLUSION

The results highlight the importance to distinguish cholesterol from triglycerides when considering the prognostic role of lipid metabolism in ALS. It further strengthens the rationale for a triglyceride-rich diet, while the negative impact of cholesterol must be further explored.

Mutation-specific metabolic profiles in presymptomatic amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

Growing evidence shows that ALS patients feature a disturbed energy metabolism. However, these features have rarely been investigated in the presymptomatic stage.

METHODS

A total of 60 presymptomatic ALS mutation carriers and 70 age- and gender-matched controls (non-mutation carriers from the same families) were recruited. All subjects underwent assessments of their metabolic profiles under fasting conditions at enrollment, including body mass index (BMI), blood pressure and serum levels of blood glucose, total cholesterol, triglycerides, high-density lipoprotein (HDL) and low-density lipoprotein.

RESULTS

All mutations combined, no differences between presymptomatic ALS gene carriers and controls were found. From a cardiovascular point of view, presymptomatic chromosome 9 open reading frame 72 (C9ORF72) gene carriers showed lower cardiovascular risk profiles compared to healthy controls, including lower BMI (median 22.9, interquartile range [IQR] 20.6-26.1 kg/m² vs. 24.9, IQR 22.7-30.5 kg/m² ; p = 0.007), lower systolic blood pressure (120, IQR 110-130 mmHg vs. 128, IQR 120-140 mmHg; p = 0.02), lower fasting serum glucose (89.0, IQR 85.0-97.0 mg/dl vs. 96.0, IQR 89.3-102.0 mg/dl; p = 0.005) and higher HDL (1.6, IQR 1.3-1.8 mmol/l vs. 1.2, IQR 1.0-1.4 mmol/l; p = 0.04). However, presymptomatic superoxide dismutase 1 (SOD1) gene mutation carriers showed higher cardiovascular risk profiles compared to healthy controls, including higher BMI (28.0, IQR 26.1-31.5 kg/m² vs. 24.9, IQR 22.7-30.5 kg/m² ; p = 0.02), higher fasting serum glucose (100.0, IQR 94.0-117.0 mg/dl vs. 96.0, IQR 89.3-102.0 mg/dl; p = 0.04) and lower HDL (1.2, IQR 1.0-1.4 mmol/l vs. 1.4, IQR 1.2-1.7 mmol/l; p = 0.01). These features were most prominent in patients carrying SOD1 gene mutations associated with slow disease progression.

CONCLUSIONS

This study identified distinct metabolic profiles in presymptomatic ALS gene carriers, which might be associated with disease progression in the symptomatic phase.

Potential Applications for Growth Hormone Secretagogues Treatment of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) arises from neuronal death due to complex interactions of genetic, molecular, and environmental factors. Currently, only two drugs, riluzole and edaravone, have been approved to slow the progression of this disease. However, ghrelin and other ligands of the GHS-R1a receptor have demonstrated interesting neuroprotective activities that could be exploited in this pathology. Ghrelin, a 28-amino acid hormone, primarily synthesized and secreted by oxyntic cells in the stomach wall, binds to the pituitary GHS-R1a and stimulates GH secretion; in addition, ghrelin is endowed with multiple extra endocrine bioactivities. Native ghrelin requires esterification with octanoic acid for binding to the GHS-R1a receptor; however, this esterified form is very labile and represents less than 10% of circulating ghrelin. A large number of synthetic compounds, the growth hormone secretagogues (GHS) encompassing short peptides, peptoids, and non-peptidic moieties, are capable of mimicking several biological activities of ghrelin, including stimulation of GH release, appetite, and elevation of blood IGF-I levels. GHS have demonstrated neuroprotective and anticonvulsant effects in experimental models of pathologies both in vitro and in vivo. To illustrate, some GHS, currently under evaluation by regulatory agencies for the treatment of human cachexia, have a good safety profile and are safe for human use. Collectively, evidence suggests that ghrelin and cognate GHS may constitute potential therapies for ALS.

Risk factors of amyotrophic lateral sclerosis: a global meta-summary

Background

The etiology of amyotrophic lateral sclerosis (ALS) remains largely unknown. This study aimed to summarize the relationship between ALS and its genetic and non-genetic risk factors.

Method

A search of relevant literature from PubMed, Embase, and Cochrane Database from inception to December 2022 was performed. Random-effects or fixed-effects models were performed by Stata MP 15.0 to pool multivariate or adjusted ratios (OR). PROSPERO registration number: CRD42022301549.

Results

230 eligible studies were included, of which 67 involved 22 non-genetic factors, and 163 involved genetic factors. Four aspects of non-genetic factors, including lifestyle, environmental and occupational exposures, pre-existing diseases/comorbidity and medical exposures, and others, were analyzed. Exposure to heavy metals (OR = 1.79), pesticides (OR = 1.46), solvents (OR = 1.37), previous head trauma (OR = 1.37), military service (OR = 1.29), stroke (OR = 1.26), magnetic field (OR = 1.22) and hypertension (OR = 1.04) are significant risk factors, but use of antidiabetics (OR = 0.52), high BMI (OR = 0.60 for obese and overweight vs. normal and underweight), living in urban (OR = 0.70), diabetes mellitus (OR = 0.83), and kidney disease (OR = 0.84) decrease the risk for ALS. In addition, eight common ALS-related genes were evaluated, the mutation frequencies of these genes were ranked from highest to lowest as SOD1 (2.2%), C9orf72 (2.1%), ATXN2 (1.7%), FUS (1.7%), TARDBP (0.8%), VCP (0.6%), UBQLN2(0.6%) and SQSTM1 (0.6%) in all the ALS patients.

Conclusions

Our findings suggested that effective intervention for risk exposure and timely modification of lifestyle might prevent the occurrence of ALS. Genetic mutations are important risk factors for ALS and it is essential to detect genetic mutations correctly and scientifically.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=301549, identifier: CRD42022301549.

Correlation of weight and body composition with disease progression rate in patients with amyotrophic lateral sclerosis

This study aims to observe the nutritional status of Chinese patients with amyotrophic lateral sclerosis (ALS), further investigating its effect on disease progression. One hundred consecutive newly diagnosed ALS patients and fifty controls were included. Weight and body composition were measured by bioelectrical impedance analysis at baseline and follow-ups. The revised ALS functional rating scale (ALSFRS-R) was used to calculate the rate of disease progression. Patients with ALS had a significantly lower BMI than controls, while no significant difference was found in body composition. Weight loss occurred in 66 (66%) and 52 (67.5%) patients at diagnosis and follow-up, respectively. Patients with significant weight loss (≥ 5%) at diagnosis had significantly lower BMI, fat mass (FM), and FM in limbs and trunk than those without. Fat-free mass (FFM), FM, and FM in limbs were significantly decreased along with weight loss at follow-up (p < 0.01). Patients with lower visceral fat index, lower proportion of FM, and higher proportion of muscle mass at baseline progressed rapidly during follow-ups (p < 0.05). Multivariate linear regression showed that FFM and weight at follow-up were independently correlated with disease progression rate at follow-up (p < 0.05). Weight loss is a common feature in ALS patients, along with muscle and fat wasting during the disease course. Body composition may serve as a prognostic factor and provide guidance for nutritional management in ALS patients.

Altered Bioenergetics and Metabolic Homeostasis in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that primarily affects motor neurons and causes muscle atrophy, paralysis, and death. While a great deal of progress has been made in deciphering the underlying pathogenic mechanisms, no effective treatments for the disease are currently available. This is mainly due to the high degree of complexity and heterogeneity that characterizes the disease. Over the last few decades of research, alterations to bioenergetic and metabolic homeostasis have emerged as a common denominator across many different forms of ALS. These alterations are found at the cellular level (e.g., mitochondrial dysfunction and impaired expression of monocarboxylate transporters) and at the systemic level (e.g., low BMI and hypermetabolism) and tend to be associated with survival or disease outcomes in patients. Furthermore, an increasing amount of preclinical evidence and some promising clinical evidence suggests that targeting energy metabolism could be an effective therapeutic strategy. This review examines the evidence both for and against these ALS-associated metabolic alterations and highlights potential avenues for therapeutic intervention.

Body fat compartment determination by encoder-decoder convolutional neural network: application to amyotrophic lateral sclerosis

The objective of this study was to automate the discrimination and quantification of human abdominal body fat compartments into subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) from T1-weighted MRI using encoder-decoder convolutional neural networks (CNN) and to apply the algorithm to a diseased patient sample, i.e., patients with amyotrophic lateral sclerosis (ALS). One-hundred-and-fifty-five participants (74 patients with ALS and 81 healthy controls) were split in training (50%), validation (6%), and test (44%) data. SAT and VAT volumes were determined by a novel automated CNN-based algorithm of U-Net like architecture in comparison with an established protocol with semi-automatic assessment as the reference. The dice coefficients between the CNN predicted masks and the reference segmentation were 0.87 ± 0.04 for SAT and 0.64 ± 0.17 for VAT in the control group and 0.87 ± 0.08 for SAT and 0.68 ± 0.15 for VAT in the ALS group. The significantly increased VAT/SAT ratio in the ALS group in comparison to controls confirmed the previous results. In summary, the CNN approach using CNN of U-Net architecture for automated segmentation of abdominal adipose tissue substantially facilitates data processing and offers the opportunity to automatically discriminate abdominal SAT and VAT compartments. Within the research field of neurodegenerative disorders with body composition alterations like ALS, the unbiased analysis of body fat components might pave the way for these parameters as a potential biological marker or a secondary read-out for clinical trials.

Pharyngeal electrical stimulation in amyotrophic lateral sclerosis: a pilot study

Background:

Patients with amyotrophic lateral sclerosis (ALS) suffer from dysphagia that increases the risk for aspiration, pneumonia and weight loss. Pharyngeal electrical stimulation (PES) is a therapeutic technique that applies electric stimuli to the patient’s pharynx in order to improve swallowing based on the principle of cortical plasticity and reorganization. Previous studies have demonstrated positive effects in patients with various neurological diseases.

Objective:

This study was initiated to investigate the effect of PES on swallowing function in patients with ALS.

Methods:

In all, 20 ALS patients with severe dysphagia [characterized by a Penetration Aspiration Scale (PAS) of at least 4 in thin liquid] were randomized to receive either PES for 10 min at 3 consecutive days in addition to Standard Logopaedic Therapy (SLT) or SLT alone. Swallowing function was evaluated by Fiberoptic Endoscopic Evaluation of Swallowing (FEES) at five timepoints: at baseline, 1 day, 4 days, 3 weeks and 3 months after treatment. Primary endpoint was the severity of penetrations or aspirations as classified by PAS. Secondary endpoints were adverse events, dysphagia-related quality of life, Swallowing Quality of Life (SWAL-QOL), Dysphagia Severity Rating Scale (DSRS), residues, leaking, ALS Functional Rating Scale Revised (ALSFRS-R), and the performance in Clinical Evaluation of Swallowing (CES). The trial is registered under the name of ‘Pharyngeal Electrical Stimulation in Amyotrophic Lateral Sclerosis’ with ClinialTrials.gov, number NCT03481348 (https://clinicaltrials.gov/ct2/show/NCT03481348).

Results:

Both groups combined showed a significant improvement (p = 0.003) of median Total-PAS from 3.6 [interquartile range (IQR) = 2.9–5.0] at baseline to 2.3 (IQR = 1.8–4.0) 1 day after treatment. During subsequent study visits, PAS increased again but remained below baseline. PES and control group did not differ significantly 1 day after intervention (p = 0.32). Similar effects were found in the majority of secondary endpoints.

Interpretation:

The findings suggest that PES may not provide an additional positive effect on swallowing function in ALS. SLT seems to yield at least short-term positive effects on swallowing function and swallowing-specific life quality in ALS.

Registration: ClinialTrials.gov: NCT03481348

The hypometabolic state: a good predictor of a better prognosis in amyotrophic lateral sclerosis

BACKGROUND

Malnutrition and weight loss are negative prognostic factors for survival in patients with amyotrophic lateral sclerosis (ALS). However, energy expenditure at rest (REE) is still not included in clinical practice, and no data are available concerning hypometabolic state in ALS.

OBJECTIVE

To evaluate in a referral cohort of patients with ALS the prevalence of hypometabolic state as compared with normometabolic and hypermetabolic states, and to correlate it with clinical phenotype, rate of progression and survival.

DESIGN

We conducted a retrospective study examining REE measured by indirect calorimetry in patients with ALS referred to Milan, Limoges and Tours referral centres between January 2011 and December 2017. Hypometabolism and hypermetabolism states were defined when REE difference between measured and predictive values was ≤-10% and ≥10%, respectively. We evaluated the relationship between these metabolic alterations and measures of body composition, clinical characteristics and survival.

RESULTS

Eight hundred forty-seven patients with ALS were recruited. The median age at onset was 63.79 years (IQR 55.00-71.17). The male/female ratio was 1.26 (M/F: 472/375). Ten per cent of patients with ALS were hypometabolic whereas 40% were hypermetabolic. Hypometabolism was significantly associated with later need for gastrostomy, non-invasive ventilation and tracheostomy placement. Furthermore, hypometabolic patients with ALS significantly outlived normometabolic (HR=1.901 (95% CI 1.080 to 3.345), p=0.0259) and hypermetabolic (HR=2.138 (95% CI 1.154 to 3.958), p=0.0157) patients.

CONCLUSION

Hypometabolism in ALS is not uncommon and is associated with slower disease progression and better survival than normometabolic and hypermetabolic subjects. Indirect calorimetry should be performed at least at time of diagnosis because alterations in metabolism are correlated with prognosis.

Life Course of Physical Activity and Risk and Prognosis of Amyotrophic Lateral Sclerosis in a German ALS Registry

BACKGROUND AND OBJECTIVES

Whether physical activity (PA) is a risk factor for amyotrophic lateral sclerosis (ALS) is controversial because data on lifelong PA are rare. The main objective of this study is to provide insight into PA as a potential risk factor for ALS, reporting data on cumulative PA, leisure-time PA, and occupational PA. This study also aims to gather evidence on the role of PA as a prognostic factor in disease course.

METHODS

Lifetime PA values collected by questionnaires addressing work and leisure time were quantified into metabolic equivalents (METs). A population-based case-control study embedded in the ALS Registry Swabia served to calculate the odds ratio (OR) of ALS by PA in different time intervals and prognosis.

RESULTS

In ALS cases (393 cases, 791 age- and sex-matched controls), we observed reduced total PA at interview and up to 5 years before interview compared to controls. Total PA was not associated with ALS risk 5 to 55 years before interview. Heavy occupational work intensity was associated with increased ALS risk (OR 1.97, 95% confidence interval 1.34, 2.89). Total PA levels were associated with survival in a nonlinear manner: inactive patients and highest activity levels (25 MET-h/wk) revealed the worst survival time of 15.4 and 19.3 months, respectively. Best median survival with 29.8 months was seen at 10.5 MET-h/wk after adjustment for other prognostic factors.

DISCUSSION

Lifetime combined PA decreased sharply several years before disease onset compared to controls. The risk of developing ALS was not associated with former total PA levels 5 to 55 years before interview in contrast to occupational PA, probably reflecting work-associated exposures. We found a strong nonlinear association of current and prediagnostic PA level and survival in ALS cases with the best survival with moderate PA. PA intensity may be a disease-modifying factor with an unfavorable outcome in sedentary and hyperactive behavior.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that PA was not associated with the development of ALS.

A system-wide mislocalization of RNA-binding proteins in motor neurons is a new feature of ALS

Amyotrophic lateral sclerosis (ALS) is a motor neuron disease characterized by progressive degeneration of motor neurons. Mislocalization of TAR DNA-binding protein 43 (TDP-43) is an early event in the formation of cytoplasmic TDP-43-positive inclusions in motor neurons and a hallmark of ALS. However, the underlying mechanism and the pathogenic impact of this mislocalization are relatively unexplored. We previously reported that abnormal AMPK activation mediates TDP-43 mislocalization in motor neurons of humans and mice with ALS. In the present study, we hypothesized that other nuclear proteins are mislocalized in the cytoplasm of motor neurons due to the AMPK-mediated phosphorylation of importin-α1 and subsequently contribute to neuronal degeneration in ALS. To test this hypothesis, we analyzed motor neurons of sporadic ALS patients and found that when AMPK is activated, importin-α1 is abnormally located in the nucleus. Multiple integrative molecular and cellular approaches (including proteomics, immunoprecipitation/western blot analysis, immunohistological evaluations and gradient analysis of preribosomal complexes) were employed to demonstrate that numerous RNA binding proteins are mislocalized in a rodent motor neuron cell line (NSC34) and human motor neurons derived from iPSCs during AMPK activation. We used comparative proteomic analysis of importin-α1 complexes that were immunoprecipitated with a phosphorylation-deficient mutant of importin-α1 (importin-α1-S105A) and a phosphomimetic mutant of importin-α1 (importin-α1-S105D) to identify 194 proteins that have stronger affinity for the unphosphorylated form than the phosphorylated form of importin-α1. Furthermore, GO and STRING analyses suggested that RNA processing and protein translation is the major machinery affected by abnormalities in the AMPK-importin-α1 axis. Consistently, the expression of importin-α1-S105D alters the assembly of preribosomal complexes and increases cell apoptosis. Collectively, we propose that by impairing importin-α1-mediated nuclear import, abnormal AMPK activation in motor neurons alters the cellular distribution of many RNA-binding proteins, which pathogenically affect multiple cellular machineries in motor neurons and contribute to ALS pathogenesis.

Dysregulation of energy homeostasis in amyotrophic lateral sclerosis

PURPOSE OF REVIEW

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease targeting upper and lower motor neurons, inexorably leading to an early death. Defects in energy metabolism have been associated with ALS, including weight loss, increased energy expenditure, decreased body fat mass and increased use of lipid nutrients at the expense of carbohydrates. We review here recent findings on impaired energy metabolism in ALS, and its clinical importance.

RECENT FINDINGS

Hypothalamic atrophy, as well as alterations in hypothalamic peptides controlling energy metabolism, have been associated with metabolic derangements. Recent studies showed that mutations causing familial ALS impact various metabolic pathways, in particular mitochondrial function, and lipid and carbohydrate metabolism, which could underlie these metabolic defects in patients. Importantly, slowing weight loss, through high caloric diets, is a promising therapeutic strategy, and early clinical trials indicated that it might improve survival in at least a subset of patients. More research is needed to improve these therapeutic strategies, define pharmacological options, and refine the population of ALS patients that would benefit from these approaches.

SUMMARY

Dysfunctional energy homeostasis is a major feature of ALS clinical picture and emerges as a potential therapeutic target.

Skeletal Muscle Metabolism: Origin or Prognostic Factor for Amyotrophic Lateral Sclerosis (ALS) Development?

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive and selective loss of motor neurons, amyotrophy and skeletal muscle paralysis usually leading to death due to respiratory failure. While generally considered an intrinsic motor neuron disease, data obtained in recent years, including our own, suggest that motor neuron protection is not sufficient to counter the disease. The dismantling of the neuromuscular junction is closely linked to chronic energy deficit found throughout the body. Metabolic (hypermetabolism and dyslipidemia) and mitochondrial alterations described in patients and murine models of ALS are associated with the development and progression of disease pathology and they appear long before motor neurons die. It is clear that these metabolic changes participate in the pathology of the disease. In this review, we summarize these changes seen throughout the course of the disease, and the subsequent impact of glucose–fatty acid oxidation imbalance on disease progression. We also highlight studies that show that correcting this loss of metabolic flexibility should now be considered a major goal for the treatment of ALS.

Metabolic Dysfunction in Spinal Muscular Atrophy

Spinal muscular atrophy (SMA) is an autosomal recessive genetic disorder leading to paralysis, muscle atrophy, and death. Significant advances in antisense oligonucleotide treatment and gene therapy have made it possible for SMA patients to benefit from improvements in many aspects of the once devastating natural history of the disease. How the depletion of survival motor neuron (SMN) protein, the product of the gene implicated in the disease, leads to the consequent pathogenic changes remains unresolved. Over the past few years, evidence toward a potential contribution of gastrointestinal, metabolic, and endocrine defects to disease phenotype has surfaced. These findings ranged from disrupted body composition, gastrointestinal tract, fatty acid, glucose, amino acid, and hormonal regulation. Together, these changes could have a meaningful clinical impact on disease traits. However, it is currently unclear whether these findings are secondary to widespread denervation or unique to the SMA phenotype. This review provides an in-depth account of metabolism-related research available to date, with a discussion of unique features compared to other motor neuron and related disorders.

Disruption of orbitofrontal-hypothalamic projections in a murine ALS model and in human patients

Background

Increased catabolism has recently been recognized as a clinical manifestation of amyotrophic lateral sclerosis (ALS). The hypothalamic systems have been shown to be involved in the metabolic dysfunction in ALS, but the exact extent of hypothalamic circuit alterations in ALS is yet to be determined. Here we explored the integrity of large-scale cortico-hypothalamic circuits involved in energy homeostasis in murine models and in ALS patients.

Methods

The rAAV2-based large-scale projection mapping and image analysis pipeline based on Wholebrain and Ilastik software suites were used to identify and quantify projections from the forebrain to the lateral hypothalamus in the SOD1(G93A) ALS mouse model (hypermetabolic) and the Fus^ΔNLS ALS mouse model (normo-metabolic). 3 T diffusion tensor imaging (DTI)-magnetic resonance imaging (MRI) was performed on 83 ALS and 65 control cases to investigate cortical projections to the lateral hypothalamus (LHA) in ALS.

Results

Symptomatic SOD1(G93A) mice displayed an expansion of projections from agranular insula, ventrolateral orbitofrontal and secondary motor cortex to the LHA. These findings were reproduced in an independent cohort by using a different analytic approach. In contrast, in the Fus^ΔNLS ALS mouse model hypothalamic inputs from insula and orbitofrontal cortex were maintained while the projections from motor cortex were lost. The DTI-MRI data confirmed the disruption of the orbitofrontal-hypothalamic tract in ALS patients.

Conclusion

This study provides converging murine and human data demonstrating the selective structural disruption of hypothalamic inputs in ALS as a promising factor contributing to the origin of the hypermetabolic phenotype.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40035-021-00241-6.

The correlation of the serum level of L-carnitine with disease severity in patients with Amyotrophic lateral sclerosis

BACKGROUND

The relationship between reserve of L-carnitine and severity in patients with Amyotrophic lateral sclerosis (ALS) is not studied sufficiently. We decided to measure the serum levels of L-carnitine in patients and the relationship with ALS severity.

METHOD

This cross-sectional study evaluated the serum levels of L-carnitine in 30 patients with ALS (total-case) divided into two groups included 15 patients in the Oral-Fed (OF) group and 15 patients in the Enteral-Fed (EF) group, compared with 15 healthy people matched in age and sex in the control group. We measured the body mass index (BMI), daily intake of L-carnitine, amyotrophic lateral sclerosis functional rating scale (ALSFRS), and serum L-carnitine level in all participants and compared among groups.

RESULTS

Serum L-carnitine (p < 0.001) and BMI (p = 0.03) were significantly lower in the total-case group compared to the control group. Alternatively, the serum level of L-carnitine (p = 0.001), ALSFRS (p < 0.001), BMI (p = 0.007), and dietary L-carnitine intake (p = 0.002) were significantly higher in OF group compared with EF. Higher serum L-carnitine levels were associated with a higher score of ALSFRS (β = 0.46, P = 0.01) in the total-case group.

CONCLUSION

Our study's results showed that serum levels of L-carnitine were lower in patients with ALS in comparison to healthy people. Also, the lower serum level of L-carnitine was associated with the higher severity of the disease.

Associations between lifestyle and amyotrophic lateral sclerosis stratified by C9orf72 genotype: a longitudinal, population-based, case-control study

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is considered to be caused by both genetic and environmental factors. The causal cascade is, however, not known. We aimed to assess lifestyle during the presymptomatic phase of ALS, stratified by C9orf72 mutation, and examine evidence supporting causality of lifestyle factors.

METHODS

This study was a longitudinal, population-based, case-control study that used data from the Prospective ALS study the Netherlands. We included patients with a C9orf72 mutation (C9+ group), patients without a C9orf72 mutation (C9- group), and controls. Patients fulfilled the revised El Escorial criteria and were recruited through neurologists and rehabilitation physicians in the Netherlands as well as the Dutch Neuromuscular Patient Association and ALS Centrum website. 1322 population-based controls, matched for age and sex, were enrolled via the patients' general practitioners. Blood relatives or spouses of patients were not eligible as controls. We studied the relationship between ALS risk and smoking, alcohol, physical activity, body-mass index (BMI), and energy intake by the use of structured questionnaires. Smoking, physical activity, and BMI were longitudinally assessed up to 50 years before onset (defined as the period before onset of muscle weakness or bulbar symptoms for cases, or age at completing the questionnaire for controls). We calculated posterior probabilities (P(θ|x)) for causal effects of smoking, alcohol, and BMI, using Bayesian instrumental variable analyses.

FINDINGS

Between Jan 1, 2006 and Jan 27, 2016, we included 143 patients in the C9+ group, 1322 patients in the C9- group, and 1322 controls. Compared with controls, cigarette pack-years (C9+ group mean difference from control 3·15, 95% CI 0·36 to 5·93, p=0·027; C9- group 3·20, 2·02 to 4·39, p<0·0001) and daily energy intake at symptom onset (C9+ group 712 kJ, 95% CI 212 to 1213, p=0·0053; C9- group 497, 295 to 700, p<0·0001) were higher in the C9+ and C9- groups, whereas current BMI (C9+ group -2·01 kg/m², 95% CI -2·73 to -1·29, p<0·0001; C9- group -1·35, -1·64 to -1·06, p<0·0001) and lifetime alcohol consumption (C9+ group -5388 units, 95% CI -9113 to -1663, p=0·0046; C9- group -2185, -3748 to -622, p=0·0062) were lower in the C9+ and C9- groups. Median BMI during the presymptomatic phase for the C9+ group was lower (-0·69 kg/m², 95% CI -1·24 to -0·13, p=0·015) and physical activity was similar (-348 metabolic equivalent of task [MET], 95% CI -966 to 270, p=0·27) to controls, whereas both the median BMI during the presymptomatic phase (0·27 kg/m², 95% CI 0·04 to 0·50, p=0·022) and physical activity (585 MET, 291 to 878, p=0·0001) were higher in the C9- group than controls. Longitudinal analyses showed more cigarette pack-years in the C9- (starting 47 years pre-onset) and C9+ (starting 24 years pre-onset) groups, and higher physical activity over time in the C9- group (starting >30 years pre-onset). BMI of the C9+ group increased more slowly and was significantly lower (starting at 36 years pre-onset) than in controls, whereas the BMI of the C9- group was higher than controls (23-49 years pre-onset, becoming lower 10 years pre-onset). Instrumental variable analyses supported causal effects of alcohol consumption (P(θ|x)=0·9347) and smoking (P(θ|x)=0·9859) on ALS in the C9- group. We found evidence supporting a causal effect of increased BMI at younger age (mean 33·8 years, SD 11·7) in the C9- group (P[θ|x]=0·9272), but not at older ages.

INTERPRETATION

Lifestyle during the presymptomatic phase differs between patients with ALS and controls decades before onset, depends on C9- status, and is probably part of the presymptomatic causal cascade. Identification of modifiable disease-causing lifestyle factors offers opportunities to lower risk of developing neurodegenerative disease.

FUNDING

Netherlands ALS Foundation.

Fat mass loss correlates with faster disease progression in amyotrophic lateral sclerosis patients: Exploring the utility of dual-energy x-ray absorptiometry in a prospective study

Background/objective

Weight loss is a predictor of shorter survival in amyotrophic lateral sclerosis (ALS). We performed serial measures of body composition using Dual-energy X-ray Absorptiometry (DEXA) in ALS patients to explore its utility as a biomarker of disease progression.

Methods

DEXA data were obtained from participants with ALS (enrollment, at 6- and 12- months follow ups) and Parkinson’s disease (enrollment and at 4-month follow up) as a comparator group. Body mass index, total lean mass index, appendicular lean mass index, total fat mass index, and percentage body fat at enrollment were compared between the ALS and PD cohorts and age-matched normative data obtained from the National Health and Nutrition Examination Survey database. Estimated monthly changes of body composition measures in the ALS cohort were compared to those of the PD cohort and were correlated with disease progression measured by the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R).

Results

The ALS cohort (N = 20) had lower baseline total and appendicular lean mass indices compared to the PD cohort (N = 20) and general population. Loss in total and appendicular lean masses were found to be significantly associated with follow-up time. Low baseline percentage body fat (r = 0.72, p = 0.04), loss of percentage body fat (r = 0.81, p = 0.01), and total fat mass index (r = 0.73, p = 0.04) during follow up correlated significantly with monthly decline of ALSFRS-R scores in ALS cohort who had 2 or more follow-ups (N = 8).

Conclusion

Measurement of body composition with DEXA might serve as a biomarker for rapid disease progression in ALS.

Pathophysiology and Treatment of Non-motor Dysfunction in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis is a progressive and fatal neurodegenerative disease typically presenting with bulbar or limb weakness. There is increasing evidence that amyotrophic lateral sclerosis is a multisystem disease with early and frequent impacts on cognition, behaviour, sleep, pain and fatigue. Dysfunction of normal physiological and metabolic processes also appears common. Evidence from pre-symptomatic studies and large epidemiological cohorts examining risk factors for the future development of amyotrophic lateral sclerosis have reported a high prevalence of changes in behaviour and mental health before the emergence of motor weakness. This suggests that changes beyond the motor system are underway at an early stage with dysfunction across brain networks regulating a variety of cognitive, behavioural and other homeostatic processes. The full impact of non-motor dysfunction continues to be established but there is now sufficient evidence that the presence of non-motor symptoms impacts overall survival in amyotrophic lateral sclerosis, and with up to 80% reporting non-motor symptoms, there is an urgent need to develop more robust therapeutic approaches. This review provides a contemporary overview of the pathobiology of non-motor dysfunction, offering readers a practical approach with regard to assessment and management. We review the current evidence for pharmacological and non-pharmacological treatment of non-motor dysfunction in amyotrophic lateral sclerosis and highlight the need to further integrate non-motor dysfunction as an important outcome measure for future clinical trial design.

Loss of appetite in patients with amyotrophic lateral sclerosis is associated with weight loss and anxiety/depression

Weight loss is common in patients with Amyotrophic lateral sclerosis (ALS), and associated with disease progression. Loss of appetite has been shown to be a contributor to weight loss in patients with amyotrophic lateral sclerosis (ALS). However, the reason of loss of appetite is not clear. The Council on Nutrition appetite questionnaire (CNAQ) and the simplified nutritional appetite questionnaire (SNAQ) are short and simple appetite assessment tools, which were using in ALS patients. In our study, the CNAQ and SNAQ were translated into Chinese, and their reliability and validity were tested. The Chinese version of the CNAQ (CNAQ-C) presented more appropriate reliability and validity than the SNAQ. Among the 94 ALS patients, 50 patients (53.2%) had loss of appetite, and we found that anxiety and/or depression contributed to the loss of appetite in the ALS patients. We reconfirmed that loss of appetite was associated with greater weight loss but not with clinical features of ALS. The loss of appetite caused by emotional problems in ALS patients should be taken seriously, and early intervention should be implemented to reduce weight loss.

Skeletal Muscle in ALS: An Unappreciated Therapeutic Opportunity?

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the selective degeneration of upper and lower motor neurons and by the progressive weakness and paralysis of voluntary muscles. Despite intense research efforts and numerous clinical trials, it is still an incurable disease. ALS had long been considered a pure motor neuron disease; however, recent studies have shown that motor neuron protection is not sufficient to prevent the course of the disease since the dismantlement of neuromuscular junctions occurs before motor neuron degeneration. Skeletal muscle alterations have been described in the early stages of the disease, and they seem to be mainly involved in the "dying back" phenomenon of motor neurons and metabolic dysfunctions. In recent years, skeletal muscles have been considered crucial not only for the etiology of ALS but also for its treatment. Here, we review clinical and preclinical studies that targeted skeletal muscles and discuss the different approaches, including pharmacological interventions, supplements or diets, genetic modifications, and training programs.

Early weight instability is associated with cognitive decline and poor survival in amyotrophic lateral sclerosis

OBJECTIVE

Our aim was to measure the monthly rate of weight loss during 6 months prior to a diagnosis of amyotrophic lateral sclerosis (ALS) and to explore the effect on prognosis.

METHODS

We enrolled 522 patients free from eating difficulties and with short diagnostic delay between June 2014 to June 2019. The calculating formula for the monthly rate of weight loss=[(weight at baseline-weight at diagnosis)/(weight at baseline*100 %)]/time interval. We employed logistic regression analysis to reveal any association between weight loss and cognitive dysfunction. Survival analysis was performed using the Kaplan-Meier curves and Cox proportional hazard models.

RESULTS

Weight loss was observed in 272 patients (52.1 %). Patients with severe weight loss had an older age of onset, a lower ALS Functional Rating Scale-Revised score, a faster disease progression rate, and higher frequencies of executive dysfunction and cognitive decline. The monthly rate of weight loss was associated with executive dysfunction and cognitive decline after adjusting for the emotional state. The stratified monthly rate of weight loss was strongly and independently related to ALS survival after adjusting for confounding factors (HR = 1.473, P trend<0.001). Each upper ladder of the rate of weight loss was correlated with worse survival and a 47.3 % (95 % CI: 25.0-73.6 %) increased risk of mortality.

CONCLUSIONS

Weight loss is very common in patients with ALS and is associated with poor survival. It is also associated with executive dysfunction and cognitive decline. An important mechanism of weight loss in the early stage of this disease may be hypermetabolism.

Shared genetic links between amyotrophic lateral sclerosis and obesity-related traits: a genome-wide association study

Epidemiological and clinical studies have suggested comorbidities between amyotrophic lateral sclerosis (ALS) and obesity-related traits. However, little is known about their shared genetic architecture. To examine whether genetic enrichment exists between ALS and obesity-related traits and to identify shared risk loci, we analyzed summary statistics from genome-wide association studies using the conditional false discovery rate statistical framework, and further conducted functional enrichment analysis. Robust genetic enrichment was observed for ALS conditional on body mass index, body fat percentage, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and type 2 diabetes. Nine shared genetic loci were identified, among which 6 were replicated in a second ALS cohort, including C9orf72, G2E3, SCFD1, ATXN3, CLCN3 and GGNBP2. We further identified GGNBP2 as a novel ALS risk gene, by integrating summary data-based Mendelian randomization analysis. Functional enrichment analysis indicated that the shared risk genes were involved in 2 pathways, namely membrane trafficking and vesicle-mediated transport. These results provide a better understanding for the pleiotropy of ALS and have implications for future therapeutic trials.

Ghrelin as a treatment for amyotrophic lateral sclerosis

Ghrelin is a gut hormone best known for its role in regulating appetite and stimulating the secretion of the anabolic hormone growth hormone (GH). However, there is considerable evidence to show wider-ranging biological actions of ghrelin that favour improvements in cellular and systemic metabolism, as well as neuroprotection. Activation of these ghrelin-mediated pathways may alleviate pathogenic processes that are assumed to contribute to accelerated progression of disease in patients with neurodegenerative disease. Here, we provide a brief overview on the history of discoveries that led to the identification of ghrelin. Focussing on the neurodegenerative disease amyotrophic lateral sclerosis (ALS), we also present an overview of emerging evidence that suggests that ghrelin and ghrelin mimetics may serve as potential therapies for the treatment of ALS. Given that ALS is a highly heterogeneous disease, where multiple disease mechanisms contribute to variability in disease onset and rate of disease progression, we speculate that the wide-ranging biological actions of ghrelin might offer therapeutic benefit through modulating multiple disease-relevant processes observed in ALS. Expanding on the well-known actions of ghrelin in regulating food intake and GH secretion, we consider the potential of ghrelin-mediated pathways in improving body weight regulation, metabolism and the anabolic and neuroprotective actions of GH and insulin-like growth factor-1 (IGF-1). This is of clinical significance because loss of body weight, impairments in systemic and cellular metabolism, and reductions in IGF-1 are associated with faster disease progression and worse disease outcome in patients with ALS.

Hypothalamus and weight loss in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating progressive neurodegenerative disorder. While initially pathophysiology was thought to be restricted to motor deficits, it is increasingly recognized that patients develop prominent changes in weight and eating behavior that result from and mediate the underlying neurodegenerative process. These changes include alterations in metabolism, lipid levels, and insulin resistance. Emerging research suggests that these alterations may be mediated through changes in the hypothalamic function, with atrophy of the hypothalamus shown in both ALS patients and also presymptomatic genetic at-risk patients. This chapter reviews the evidence for hypothalamic involvement in ALS, including melanocortin pathways and potential treatment targets.

Cardiovascular comorbidities in amyotrophic lateral sclerosis

BACKGROUND

The role of cardiovascular risk factors in amyotrophic lateral sclerosis (ALS) is controversial. A favourable profile has been found in ALS patients, but previous studies have not specifically considered the profile in different disease phenotypes.

METHODS

Demographic data, smoking habits, lifetime exercise, and medical history including diabetes mellitus, arterial hypertension, hypercholesterolemia, hypertriglyceridemia, stroke, and cardiac events, were analysed in ALS patients and in controls with other neurological disorders, utilising a standardized questionnaire applied by the same neurologist. In ALS patients the results were analysed according to their different phenotypes. Univariate analyses and multinomial logistic models were applied to estimate the odds ratios (ORs) and confidence intervals (CIs) for covariates, to test potential modifiers and their effects.

RESULTS

500 consecutively assessed adult ALS patients (mean age 65.6, 47% women, and 136 bulbar-onset) and 327 age and gender-matched controls were studied. Patients with spinal-onset ALS took more exercise (p = 0.012), reported less hypertension (p = 0.002) and had fewer cardiac events (p = 0.012). Multinomial regression analysis showed that men without hypertension have a higher risk of having spinal-onset ALS (p < 0.001) while female with hypertension have a higher risk of having bulbar-onset ALS (p = 0.033).

CONCLUSIONS

Risk-factors in ALS can be influenced by gender and phenotype. This study suggests that men with spinal ALS are healthier, exercise more and have lower rate of hypertension, but females with bulbar-onset ALS are more prone to hypertension. The complex interplay between exercise, diet and comorbidities with ALS phenotype requires further investigation.