Simplifying Alzheimer's Disease Monitoring: A Novel Machine-Learning Approach to Estimate the Clinical Dementia Rating Sum of Box Changes Using the Mini-Mental State Examination and Functional Activities Questionnaire.

Background: Primary outcome measure in the clinical trials of disease modifying therapy (DMT) drugs for Alzheimer's disease (AD) has often been evaluated by Clinical Dementia Rating sum of boxes (CDRSB). However, CDR testing requires specialized training and 30-50 minutes to complete, not being suitable for daily clinical practice. Objective: Herein, we proposed a machine-learning method to estimate CDRSB changes using simpler cognitive/functional batteries (Mini-Mental State Examination [MMSE] and Functional Activities Questionnaire [FAQ]), to replace CDR testing. Methods: Baseline data from 944 ADNI and 171 J-ADNI amyloid-positive participants were used to build machine-learning models predicting annualized CDRSB changes between visits, based on MMSE and FAQ scores. Prediction performance was evaluated with mean absolute error (MAE) and R2 comparing predicted to actual rmDeltaCDRSB/rmDeltayear. We further assessed whether decline in cognitive function surpassing particular thresholds could be identified using the predicted rmDeltaCDRSB/rmDeltayear. RESULTS: The models achieved the minimum required prediction errors (MAE < 1.0) and satisfactory prediction accuracy (R2>0.5) for mild cognitive impairment (MCI) patients for changes in CDRSB over periods of 18 months or longer. Predictions of annualized CDRSB progression>0.5, >1.0, or >1.5 demonstrated a consistent performance (i.e., Matthews correlation coefficient>0.5). These results were largely replicated in the J-ADNI case predictions. CONCLUSIONS: Our method effectively predicted MCI patient deterioration in the CDRSB based solely on MMSE and FAQ scores. It may aid routine practice for disease-modifying therapy drug efficacy evaluation, without necessitating CDR testing at every visit.

Combining plasma Aß and p-tau217 improves detection of brain amyloid in non-demented elderly.

BACKGROUND: Maximizing the efficiency to screen amyloid-positive individuals in asymptomatic and non-demented aged population using blood-based biomarkers is essential for future success of clinical trials in the early stage of Alzheimer's disease (AD). In this study, we elucidate the utility of combination of plasma amyloid-ß (Aß)-related biomarkers and tau phosphorylated at threonine 217 (p-tau217) to predict abnormal Aß-positron emission tomography (PET) in the preclinical and prodromal AD. METHODS: We designed the cross-sectional study including two ethnically distinct cohorts, the Japanese trial-ready cohort for preclinica and prodromal AD (J-TRC) and the Swedish BioFINDER study. J-TRC included 474 non-demented individuals (CDR 0: 331, CDR 0.5: 143). Participants underwent plasma Aß and p-tau217 assessments, and Aß-PET imaging. Findings in J-TRC were replicated in the BioFINDER cohort including 177 participants (cognitively unimpaired: 114, mild cognitive impairment: 63). In both cohorts, plasma Aß(1-42) (Aß42) and Aß(1-40) (Aß40) were measured using immunoprecipitation-MALDI TOF mass spectrometry (Shimadzu), and p-tau217 was measured with an immunoassay on the Meso Scale Discovery platform (Eli Lilly). RESULTS: Aß-PET was abnormal in 81 participants from J-TRC and 71 participants from BioFINDER. Plasma Aß42/Aß40 ratio and p-tau217 individually showed moderate to high accuracies when detecting abnormal Aß-PET scans, which were improved by combining plasma biomarkers and by including age, sex and APOE genotype in the models. In J-TRC, the highest AUCs were observed for the models combining p-tau217/Aß42 ratio, APOE, age, sex in the whole cohort (AUC = 0.936), combining p-tau217, Aß42/Aß40 ratio, APOE, age, sex in the CDR 0 group (AUC = 0.948), and combining p-tau217/Aß42 ratio, APOE, age, sex in the CDR 0.5 group (AUC = 0.955), respectively. Each subgroup results were replicated in BioFINDER, where the highest AUCs were seen for models combining p-tau217, Aß42/40 ratio, APOE, age, sex in cognitively unimpaired (AUC = 0.938), and p-tau217/Aß42 ratio, APOE, age, sex in mild cognitive impairment (AUC = 0.914). CONCLUSIONS: Combination of plasma Aß-related biomarkers and p-tau217 exhibits high performance when predicting Aß-PET positivity. Adding basic clinical information (i.e., age, sex, APOE Îµ genotype) improved the prediction in preclinical AD, but not in prodromal AD. Combination of Aß-related biomarkers and p-tau217 could be highly useful for pre-screening of participants in clinical trials of preclinical and prodromal AD.

Advertisement by medical facilities as an opportunity route of APOE genetic testing in Japan: a website analysis.

The APOE-ε4 allele(s) is a strong risk factor for Alzheimer's disease (AD). A significant point of access for this allele testing is through services provided by medical facilities in Japan, which advertise out-of-insurance APOE testing on their websites. There is a concern that website advertisements for APOE testing may influence the ability for individuals to adequately self-determine whether to undergo APOE testing. We conducted a cross-sectional survey on medical facility websites in Japan advertising APOE genetic testing. We predefined desirable features for advertisement descriptions based on legal regulations and guidelines published by relevant professional societies and evaluated each website according to these features. We identified 220 medical facilities that had posted advertisements on their websites for the provision of APOE genetic testing, of which 85% were small clinics. Contact information, details, and costs of testing were described in most of the websites. Meanwhile, features such as "explaining APOE as a risk gene," "notes on interpreting APOE results," or "explaining examination methods" (e.g., blood sampling) were described to a variable degree depending on individual facilities. "Notes on genetic testing" or "referring to genetic counseling" were hardly referred to, and specialists with appropriate expertise were considered to participate in clinical practice in approximately one-third of these facilities providing APOE testing services. These website evaluation results showed moderate to substantial reliability between independent raters. These results suggest that self-determination of pursuing out-of-insurance APOE testing at some medical facilities in Japan may possibly be influenced in an inappropriate manner, at least in its entry route of taking the test.

Perceptions of older adults and generativity among older citizens in Japan: a descriptive cross-sectional study.

BACKGROUND: As the population ages worldwide, including in Japan, there is a growing expectation for older adults to remain active participants in society. The act of sharing one's experiences and knowledge with younger generations through social engagement not only enriches the lives of older individuals, but also holds significant value for our society. In this study, we examined both positive and negative perceptions of older adults and investigated the correlation between these perceptions and generativity among older citizens. Additionally, we evaluated the impact of life satisfaction on these factors. METHODS: We conducted a survey of 100 older adults in Japan (mean age, 71.68 years) and utilized multiple regression analyses, using positive and negative perceptions of older adults, life satisfaction, and demographic factors as independent variables. The sub-categories of generativity-namely, generative action, concern, and accomplishment-were used as dependent variables. RESULTS: Participants who held a more positive perception of older adults demonstrated a higher level of generative actions and concerns. Additionally, participants who reported higher levels of life satisfaction also exhibited more generative actions, concerns, and accomplishments. Conversely, those who held a more negative perception of older adults were found to have higher levels of generative actions. CONCLUSION: Enhancing positive perceptions of older adults among them can boost the sub-categories of generativity. This study, which was conducted from an exploratory perspective, has several limitations, including a potential sampling bias. A more comprehensive examination of the relationship between perceptions of older adults and generativity is anticipated in future research.

[Survey on the Current Advertising and Sales of Mucuna pruriens in Consumer-to-consumer Internet Trading in Japan].

Mucuna pruriens (MP) is leguminous plant which contains 5% of L-3,4-dihydroxyphenylalanine (levodopa) in its seeds. It may have a potential to be used as an alternative therapy for Parkinson's disease (PD). Meanwhile, there is a concern in terms of public health that MP products can be overused by patients with PD. As an entry for patients with PD to acquire MP products in Japan, they are often purchased via internet auctions or free markets. MP products are not reagrded as 'pharmatheutical' by Japanese law as long as the specific legal requirements on advertisements are met, so that the MP products can be advertised or sold without any permission from the authorities. In this study, we aimed to conduct internet survey as to the complianse status of these legal requirements. Several major internet auction or free market websites in Japan were surveyed in May-June 2023 by the authors, and 1157 MP product pages were examined. We found approximately 30-40% of the MP products were suspected to have potential legal risks in terms of their advertisements in their website descriptions, such as claiming pharmatheutical efficacy or describing pharmatheutical-like dosages. In addition, approximately 30-40% of the MP products also did not refer to cautions not to take MP products excessively because of the levodopa ingredients. Current study suggested the need of careful description of the MP products in the auction or free market websites for the MP products exhibitors or sellers, in order to fullfill legal requirements as well as to prevent MP abuse.

Evaluation of the usefulness of a paper-pencil group cognitive assessment for older adults in the community.

BACKGROUND: As the older population increases, the need for early detection of cognitive decline is also increasing. In this study, we examined whether our paper-pencil type group examination for cognitive assessment (PAPLICA) could detect the effects of years of education and aging. METHODS: PAPLICA was conducted on 829 older people. The inclusion criteria were age 60 years or older and the ability to come to the event site alone. The exclusion criteria were participants with a medical or psychiatric disorder or dementia.One examiner conducted the test on a group of approximately 10-20 people in approximately 25 min. Participants were instructed on tackling the issues projected on the projector, and their answers were recorded in a response booklet. RESULTS: An independent sample t-test was performed for years of education, and ANCOVA was performed for aging. Among the test items included in PAPLICA, the Speed I and Letter fluency tests were unable to detect the effects of aging. Furthermore, the age at which the effect of aging manifests varies depending on the test item. For instance, a decline in scores in the Speed I and Picture ECR Free recall tests was observed in the 70-74 age group; for that of Word DRT, Picture ECR cued recall, and Similarity, in the 75-79 age group; for CFT, in the 80-84 age group, and for CLOX, the decline was observed in the 85 ≤ age group. CONCLUSIONS: PAPLICA, similar to other neuropsychological tests, was able to detect the effects of years of education and aging. Future testing should be conducted on different demographics to identify the differences in patterns of cognitive decline.

Proteomic profile of nuclei containing p62-positive inclusions in a patient with neuronal intranuclear inclusion disease.

Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disease characterized by eosinophilic hyaline intranuclear inclusions in the neurons, glial cells, and other somatic cells. Although CGG repeat expansions in NOTCH2NLC have been identified in most East Asian patients with NIID, the pathophysiology of NIID remains unclear. Ubiquitin- and p62-positive intranuclear inclusions are the pathological hallmark of NIID. Targeted immunostaining studies have identified several other proteins present in these inclusions. However, the global molecular changes within nuclei with these inclusions remained unclear. Herein, we analyzed the proteomic profile of nuclei with p62-positive inclusions in a NIID patient with CGG repeat expansion in NOTCH2NLC to discover candidate proteins involved in the NIID pathophysiology. We used fluorescence-activated cell sorting and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify each protein identified in the nuclei with p62-positive inclusions. The distribution of increased proteins was confirmed via immunofluorescence in autopsy brain samples from three patients with genetically confirmed NIID. Overall, 526 proteins were identified, of which 243 were consistently quantified using MS. A 1.4-fold increase was consistently observed for 20 proteins in nuclei with p62-positive inclusions compared to those without. Fifteen proteins identified with medium or high confidence in the LC-MS/MS analysis were further evaluated. Gene ontology enrichment analysis showed enrichment of several terms, including poly(A) RNA binding, nucleosomal DNA binding, and protein binding. Immunofluorescence studies confirmed that the fluorescent intensities of increased RNA-binding proteins identified by proteomic analysis, namely hnRNP A2/B1, hnRNP A3, and hnRNP C1/C2, were higher in the nuclei with p62-positive inclusions than in those without, which were not confined to the intranuclear inclusions. We identified several increased proteins in nuclei with p62-positive inclusions. Although larger studies are needed to validate our results, these proteomic data may form the basis for understanding the pathophysiology of NIID.

[Successful Thoracic Endovascular Aortic Repair in a Patient with Mid-aortic Syndrome:Report of a Case].

We report a case of thoracic endovascular aortic repair (TEVAR) for mid-aortic syndrome, which is characterized by a segmental narrowing of the aorta, in a 71-year-old man who presented with intermittent claudication. Contrast-enhanced computed tomography (CT) showed segmental stenosis of the descending aorta, for which TEVAR was performed. The ankle-branchial index increased after surgery, and the dorsalis pedis arterial pulses became palpable bilaterally. The patient was discharged on postoperative day 14 without any complication. At present, four years after surgery, he is in good condition with improved renal function, requiring no hospitalization for the treatment of heart failure.

Change in long-term care service usage in Japan following the COVID-19 pandemic: A survey using a nationwide statistical summary in 2018-2021.

AIM: Social restrictions due to the coronavirus disease (COVID-19) pandemic forced many long-term care (LTC) service-users to refrain from using services. We aimed to evaluate the degree of change in the use of LTC services. METHODS: We retrospectively analyzed data from the publicly distributed nationwide statistics summarizing the monthly number of public LTC insurance users in Japan between April 2018 and March 2021. The degree of decline was quantified as a ratio, where the ratio of a certain month to the reference month was divided by the ratio in the previous year. RESULTS: The use of LTC services started to decline in March 2020 and reached its largest decline in May 2020. Thereafter, it recovered but insufficiently, even as of late 2020. The degree of decline was particularly large for services provided in facilities for community-dwelling elderly individuals [Ratio to the previous year = 0.717 (95% CI: 0.645-0.796) in short-stay services, and Ratio = 0.876 (95% CI: 0.802-0.957) in outpatient services], but was non-significant in other types of services, including those provided for elderly individuals living in nursing homes. CONCLUSIONS: Community-dwelling elderly individuals who had used outpatient or short-stay services were especially affected by the COVID-19 pandemic in 2020. This underlines the need for further investigation of the medium- or long-term influence of the decline in service usage on the mental and physical health of the LTC service-users and their caregivers. Geriatr Gerontol Int 2022; 22: 803-809.

Preoperative factors associated with shunt responsiveness in patients with idiopathic normal-pressure hydrocephalus.

OBJECTIVE: We aimed to evaluate a possible association between preoperative factors (disease duration and vascular risk factors) and shunt responsiveness in patients with idiopathic normal-pressure hydrocephalus (iNPH). METHODS: We conducted a retrospective observational study in a high-volume center for iNPH treatment in Japan and reviewed the clinical data of 107 consecutive patients with probable iNPH who underwent shunt surgery between January 1, 2018, and August 31, 2019, and were followed up for at least 12 months after surgery. Preoperatively, these patients underwent the timed up-and-go test (TUG) and Mini-Mental State Examination (MMSE); moreover, follow-up evaluations were performed 12 months postoperatively, at which TUG and MMSE scores were used as metrics for shunt responsiveness assessment. The degree of shunt responsiveness was regressed to several preoperative factors, including preoperative TUG and MMSE scores, vascular risk factors, and duration from iNPH onset to shunt surgery, to evaluate which preoperative factors may be predictive of shunt responsiveness. RESULTS: In multivariate regression analysis, there was no statistically significant association between the presence of preoperative vascular risk factors and the postoperative TUG or MMSE score 12 months after shunt surgery. Meanwhile, preoperative history of ischemic stroke and a longer duration from iNPH onset to surgery were significantly associated with poorer shunt responsiveness in terms of MMSE and TUG scores. CONCLUSIONS: The current study suggested the potential involvement of stroke history and disease duration with the 1-year prognosis of iNPH after shunt surgery, of which validity needs to be corroborated in further studies.

Predicting the CTG Repeat Size from a Single Spirometry Test Performed at Any Time during the Disease Course of Myotonic Dystrophy Type 1.

Objective In myotonic dystrophy type 1 (DM1), the CTG repeat size in the dystrophia myotonica protein kinase gene has been shown to correlate with disease severity and is a potential predictive marker for respiratory decline. However, genetic testing can be challenging in some clinical situations. We developed a simple formula for estimating the CTG repeat size using a single spirometry test in patients with DM1. Methods In this single-center retrospective study, we reviewed 50 consecutive patients with genetically confirmed DM1 whose follow-up visits were at our hospital. The patients were randomly assigned to training and test analysis subsets. By applying a linear mixed model to the longitudinal spirometry results of the training set, we calculated the fixed effects on the annual respiratory decline. Subsequently, we derived a prediction formula to calculate the repeat size that incorporated %vital capacity (%VC) and the patient's age at the time of the spirometry evaluation; the results were validated by the test set. Results A total of 157 spirometry tests were recorded. The fixed effects on the annual %VC decline were =-0.90. The derived formula [repeat size=-16.8× (age+%VC/0.90) +2663] had a moderate predictive performance with a mean coefficient of determination of 0.41. Conclusion The CTG repeat size in patients with DM1 can be potentially predicted using a simple formula based on a single spirometry test conducted at any time over the disease course. It can be useful as a supportive tool for advance care planning when genetic testing is not available.

Pharmacokinetics and tissue distribution of orally administrated imidazole dipeptides in carnosine synthase gene knockout mice.

Imidazole dipeptides (ID) are abundant in skeletal muscle and the brain and have various functions, such as antioxidant, pH-buffering, metal-ion chelation. However, the physiological significance of ID has not been fully elucidated. In this study, we orally administered ID to conventional carnosine synthase gene-deficient mice (Carns-KO mice) to investigate the pharmacokinetics. Carnosine or anserine was administered at a dose of 500 mg (∼2 mmol) per kilogram of mouse body weight, and ID contents in the tissues were measured. No ID were detected in untreated Carns-KO mice. In the ID treatment groups, the ID concentrations in the tissues increased in a time-dependent manner in the gastrocnemius muscle, soleus muscle, and cerebrum after ID administration. Our findings suggest that the Carns-KO mice are a valuable animal model for directly evaluating the effects of dietary ID and for elucidating the physiological functions of oral ID administration.

Automated Evaluation of Conventional Clock-Drawing Test Using Deep Neural Network: Potential as a Mass Screening Tool to Detect Individuals With Cognitive Decline.

Introduction: The Clock-Drawing Test (CDT) is a simple cognitive tool to examine multiple domains of cognition including executive function. We aimed to build a CDT-based deep neural network (DNN) model using data from a large cohort of older adults, to automatically detect cognitive decline, and explore its potential as a mass screening tool. Methods: Over 40,000 CDT images were obtained from the National Health and Aging Trends Study (NHATS) database, which collects the annual surveys of nationally representative community-dwelling older adults in the United States. A convolutional neural network was utilized in deep learning architecture to predict the cognitive status of participants based on drawn clock images. Results: The trained DNN model achieved balanced accuracy of 90.1 ± 0.6% in identifying those with a decline in executive function compared to those without [positive likelihood ratio (PLH) = 16.3 ± 6.8, negative likelihood ratio (NLH) = 0.14 ± 0.03], and 77.2 ± 2.7 % balanced accuracy for identifying those with probable dementia from those without (PLH = 5.1 ± 0.5, NLH = 0.37 ± 0.07). Conclusions: This study demonstrated the feasibility of implementing conventional CDT to be automatically evaluated by DNN with a fair performance in a larger scale than ever, suggesting its potential as a mass screening test for ruling-in or ruling-out those with executive dysfunction or with probable dementia.

Time to onset of drug-induced parkinsonism: Analysis using a large Japanese adverse event self-reporting database.

Whether there are differences in the time to onset of drug-induced parkinsonism (DIP) depending on the type of drugs causing DIP remains uncertain, so that question was investigated here using a large real-world database. Fourteen DIP-related drug categories were defined to perform a disproportionality analysis using a large Japanese pharmacovigilance database containing more than 600,000 self-reported adverse events (AEs) recorded between April 2004 and September 2021 to identify AEs indicating "parkinsonism" in association with the defined drug categories. The time from drug administration to the onset of DIP was comparatively analyzed. Results indicated that the median time to onset was shorter than 1 month in more than half of the cases of DIP; it was shortest with peripheral dopamine antagonists (median: 0.1 weeks), followed by benzodiazepine (median: 0.5 weeks), butyrophenone (median: 0.7 weeks), novel antidepressants (median: 2.5 weeks), atypical antipsychotics (median: 3.3 weeks), other antidepressants (e.g., lithium, median: 3.7 weeks), and benzamide (median: 4.5 weeks). In contrast, anti-dementia drugs, tricyclic antidepressants, and antiepileptic drugs resulted in a relatively longer time to onset (median: 9.9, 17.2, and 28.4 weeks, respectively). In addition, a maximum delay of even longer than 2 years was reported for benzamide (846 weeks), anti-Parkinsonism drugs (382 weeks), phenothiazine (232 weeks), atypical antipsychotics (167 weeks), anti-dementia drugs (161 weeks), and benzodiazepines (120 weeks). The current results suggested that the characteristics of the time to onset of DIP may substantially differ depending on the type of drug causing that DIP. This finding may help when diagnosing patients with parkinsonism.

Suicide Prevention Program with Cooperation from Senior Volunteers, Governments, and Schools: A Study of the Intervention Effects of "Educational Lessons Regarding SOS Output" Focusing on Junior High School Students.

As a suicide countermeasure for young people, implementing "SOS output education" that provides young people with opportunities and approaches to seeking support with community cooperation can be expected to reduce lifelong suicide risk. We implemented an "SOS output education" for junior high school students with cooperation from educators, government staff, and older people working as community volunteers. A total of 188 students were allocated to an intervention group and a waiting group. Outcome assessments were implemented at three points in time: before the program (Time 1), after the program (Time 2), and three months after the program (Time 3). Results showed that the number of people with worries increased in the intervention group compared with the waiting group between Time 1 and Time 2. There was also an increase in people with "reliable adults" between Time 1 and Time 3, and people with "adults who you can talk to at any time" increased between Time 2 and Time 3 in the intervention group. By implementing the SOS output education program with community cooperation, an increase was observed in the intervention group in terms of support-seeking awareness and the number of people with reliable adults and with adults who they can talk to at any time.

Stress cardiomyopathy (Takotsubo syndrome) in patients who received adrenergic agonist drugs: A pharmacovigilance study using the Japanese Adverse Drug Event Report (JADER) database.

INTRODUCTION: Stress cardiomyopathy, or Takotsubo syndrome (TTS), is an acute and reversible syndrome developing in strong association with psychological or physiological stressors. While a surge in the circulating catecholamine level is suspected as one of its pathophysiologies, the contribution of treatment with sympathomimetic drugs to the development of TTS remains uncertain. METHODS: We conducted a disproportionality analysis using the Japanese Adverse Drug Event Report (JADER) database containing more than 500,000 patient cases recorded between April 2004 and March 2019, to detect TTS ('stress cardiomyopathy') as adverse event signals associated with adrenergic agonist drugs usage by calculating reporting odds ratio (ROR). RESULTS: Among 306 TTS cases reported to JADER, we identified 58 TTS cases with exposure to adrenergic agonist drugs, predominantly of women (52/58, 89.7%) and those in the median age-decades of the 70s. After adjusting for age in decades and sex, most of the intravenous catecholamines showed significantly higher reporting (lower 95% ROR > 1) for TTS, including adrenaline, noradrenaline, dobutamine, dopamine, phenylephrine, and ephedrine. In addition, peroral midodrine, transdermal tulobuterol, inhaled salbutamol, and inhaled procaterol also showed significantly higher ROR for TTS. We also identified a small number of TTS cases with Parkinson's disease taking midodrine or droxidopa, but not receiving other adrenergic agonists. CONCLUSION: The current pharmacovigilance study showed significantly higher RORs for TTS following the use of some of the adrenergic drugs, being mostly consistent with the TTS-related adrenergic drugs reported in earlier literature. A potential association of taking midodrine or droxidopa with the development of TTS was also suggested.

Diagnostic Values of Venous Peak Lactate, Lactate-to-pyruvate Ratio, and Fold Increase in Lactate from Baseline in Aerobic Exercise Tests in Patients with Mitochondrial Diseases.

Objective Although aerobic exercise tests on cycle ergometry have long been used for initial assessments of cases of suspected mitochondrial disease, the test parameters in patients with final diagnoses of other diseases via the widely used 15 W for 15 minutes exercise protocol have not been fully characterized. Methods We retrospectively reviewed all patients who underwent the test at our institution. We classified the patients with genetic diagnoses or those who met previously reported clinical criteria as having mitochondrial diseases and those with a final diagnosis of another disease as having other diseases. Results were available from 6 patients with mitochondrial disease and 15 with other diseases. Results During the test, elevated venous peak lactate above the upper normal limit of healthy controls at rest [19.2 mg/dL (2.13 mM)] was observed in 3 patients with mitochondrial diseases (50.0%) and 5 with other diseases (33.3%). In the group of patients with elevated venous peak lactate, a lactate-to-pyruvate ratio of >20 was observed in all 3 patients with mitochondrial disease but in only 1 of the 5 with other diseases. More than a 2-fold increase in venous lactate from baseline was observed in 4 patients with mitochondrial disease (66.7%) and 1 with another disease (6.7%). Conclusion Elevated venous peak lactate levels were observed in patients with final diagnoses of other diseases, even under a low 15-minute workload at 15 W. The lactate-to-pyruvate ratio and increase in lactate level from baseline may add diagnostic value to venous peak lactate levels alone.