The Association Between Cognition of Obstructive Sleep Apnea Patients and Urinary AD7c-NTP Level: Investigation and Application.

BACKGROUND: Obstructive sleep apnea (OSA) is a multi-component disorder, which has many comorbidities, including cognitive impairment. Although its potential risk factors were unknown, they could affect the patient's quality of life and long-term prognosis. OBJECTIVE: The purpose of this study was to investigate the application of urinary Alzheimer's disease-associated neurofilament protein (AD7c-NTP) levels in the assessment of cognitive impairment in OSA patients, and to analyze the predictive value of potential high-risk factors on cognitive impairment in OSA patients. METHODS: 138 young and middle-aged adults were recruited and underwent overnight polysomnographic recording, Montreal Cognitive Assessment (MoCA), and urinary AD7c-NTP test. AD7c-NTP and other factors were further applied as biomarkers to develop a cognition risk prediction model. RESULTS: Compared with the control, OSA patients showed significantly lower MoCA scores and higher urinary AD7c-NTP concentrations, while the severe OSA group appeared more significant. The urinary AD7c-NTP level of the OSA cognitive impairment group was higher than that of the non-cognitive impairment group. The results of regression analysis showed that urinary AD7c-NTP level was an independent predictor of cognitive impairment in OSA patients. Based on urinary AD7c-NTP levels and other selected factors, a multimodal prediction model for assessing the risk of cognitive impairment in OSA patients was initially established. CONCLUSION: The increased urinary AD7c-NTP level could be used as a relevant peripheral biomarker of cognitive impairment in OSA patients. A model using urinary AD7c-NTP combined with other factors was developed and could accurately assess the cognition risk of OSA patients.

Urinary AD7c-NTP Evaluates Cognition Impairment and Differentially Diagnoses AD and MCI.

The AD7c-NTP is a promising biomarker for AD diagnosis. However, the exact urinary AD7c-NTP concentration to differentiate AD from the mild cognitive impairment (MCI) remains inconclusive. We enrolled 98 and 90 clinical defined AD and MCI patients, respectively, and access their cognition impairment with Neuropsychiatric Inventory (NPI) and Mental State Examination (MMSE) along with their urinary AD7c-NTP. We demonstrated that urinary AD7c-NTP level in sequence from high to low was AD, MCI, and healthy groups (P < .01), and the AD7c-NTP was positively and negatively correlated with the NPI and MMSE scores, respectively. Additionally, AD7c-NTP well-matched NPI subscale scores, including agitation, depression, and apathy (P < .05). Importantly, the optimal cut-off AD7c-NTP level to distinguish the AD and MCI was .94 ng/mL (sensitivity 85.71% & specificity 73.91%). Conclusively, urinary AD7c-NTP could be used for cognition impairment evaluation and differentiated diagnosis of AD and MCI.

Urinary and faecal metabolic characteristics in APP/PS1 transgenic mouse model of Alzheimer's disease with and without cognitive decline.

Alzheimer's disease (AD) has been considered to be a systematic metabolic disorder, but little information is available about metabolic changes in the urine and feces. In this study, we investigated urinary and faecal metabolic profiles in amyloid precursor protein/presenilin 1 (APP/PS1) mice at 3 and 9 months of age (3 M and 9 M) and age-matched wild-type (WT) mice by using 1H NMR-based metabolomics, and aimed to explore changes in metabolic pathways during amyloid pathology progression and identify potential metabolite biomarkers at earlier stage of AD. The results show that learning and memory abilities were impaired in APP/PS1 mice relative to WT mice at 9 M, but not at 3 M. However, metabolomics analysis demonstrates that AD disrupted metabolic phenotypes in the urine and feces of APP/PS1 mice at both 3 M and 9 M, including amino acid metabolism, microbial metabolism and energy metabolism. In addition, several potential metabolite biomarkers were identified for discriminating AD and WT mice prior to cognitive decline with the AUC values from 0.755 to 0.971, such as taurine, hippurate, urea and methylamine in the urine as well as alanine, leucine and valine in the feces. Therefore, our results not only confirmed AD as a metabolic disorder, but also contributed to the identification of potential biomarkers at earlier stage of AD.

Urinary metabolic phenotyping for Alzheimer's disease.

Finding early disease markers using non-invasive and widely available methods is essential to develop a successful therapy for Alzheimer's Disease. Few studies to date have examined urine, the most readily available biofluid. Here we report the largest study to date using comprehensive metabolic phenotyping platforms (NMR spectroscopy and UHPLC-MS) to probe the urinary metabolome in-depth in people with Alzheimer's Disease and Mild Cognitive Impairment. Feature reduction was performed using metabolomic Quantitative Trait Loci, resulting in the list of metabolites associated with the genetic variants. This approach helps accuracy in identification of disease states and provides a route to a plausible mechanistic link to pathological processes. Using these mQTLs we built a Random Forests model, which not only correctly discriminates between people with Alzheimer's Disease and age-matched controls, but also between individuals with Mild Cognitive Impairment who were later diagnosed with Alzheimer's Disease and those who were not. Further annotation of top-ranking metabolic features nominated by the trained model revealed the involvement of cholesterol-derived metabolites and small-molecules that were linked to Alzheimer's pathology in previous studies.

Elevated Urinary AD7c-NTP Levels in Older Adults with Hypertension and Cognitive Impairment.

BACKGROUND: Hypertension, a common chronic disease, is associated with cognitive impairment. Cognitive impairment, especially Alzheimer's disease (AD), seriously affects older adults' quality of life and aggravates the burden of disease on society and families. Elevated Alzheimer-associated neuronal thread protein (AD7c-NTP) has been observed in the urine of patients with AD and mild cognitive impairment; however, it is not clear whether this protein can be used as a biomarker for cognitive impairment in older hypertensive patients. OBJECTIVE: To explore the value of urinary AD7c-NTP, and the association of urinary AD7c-NTP with cognitive function in older hypertensive patients. METHODS: This was a cross-sectional study. In total, 134 hypertensive patients aged ≥60 years were divided into two groups: Lower Cognitive Function group (LCF group, n = 89) and Normal Control group (NC group, n = 45) based on the Montreal Cognitive Assessment (MoCA). Urinary AD7c-NTP, blood glucose, serum insulin, superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured. RESULTS: Urinary AD7c-NTP level was significantly higher in the LCF group than in the NC group [0.48 (0.21-1.00) versus 0.25 (0.04-0.44) ng/ml, p < 0.001]. The LCF group had lower SOD level [(43.07±23.74) versus (53.12±25.80) U/ml, p = 0.026] and higher homeostasis model assessment of insulin resistance (HOMA-IR) [7.17 (3.74-13.94) versus 6.01 (3.78-7.43), p = 0.033] than the NC group. Urinary AD7c-NTP level was associated with MoCA score and HOMA-IR but not with SOD, MDA, blood glucose, and insulin. CONCLUSION: The level of urinary AD7c-NTP is elevated in older hypertensive patients with lower cognitive function, and insulin resistance may be involved in the process.

Comparison of Urinary Alzheimer-Associated Neural Thread Protein (AD7c-NTP) Levels Between Patients With Amnestic and Nonamnestic Mild Cognitive Impairment.

Urinary Alzheimer-associated neural thread protein (AD7c-NTP) is a potential biomarker of Alzheimer disease (AD) or mild cognitive impairment (MCI). It is still unclear whether the urinary levels of AD7c-NTP are different between patients with amnestic MCI (aMCI) and nonamnestic MCI (naMCI). The present study aimed to explore the differences in urinary levels of AD7c-NTP between patients with aMCI and naMCI. Forty-six patients with MCI were divided into aMCI group (n = 23) and naMCI group (n = 23). The mean level of urinary AD7c-NTP in the aMCI group (32.75 ± 10.0 µg/mL) was significantly higher than that in the naMCI group (25.34 ± 9.0 µg/mL; P = .011). As far as we know, the present study is the first to show that individuals with aMCI have higher levels of urinary AD7c-NTP than those with naMCI, suggesting that urinary AD7c-NTP may be a potential biomarker to help identify patients with aMCI and naMCI.

Oxidative Damage of DNA as Early Marker of Alzheimer's Disease.

Alzheimer's Disease (AD) is the most common cause of dementia, and its characteristic histopathological hallmarks are neurofibrillary tangles and senile plaques. Among involved mechanisms, oxidative stress plays an important role in damaging cell components (e.g., proteins, nucleic acids). In this study, different oxidized products of proteins and DNA were determined in the urine samples from mild cognitive impairment due to AD patients (n = 53) and healthy controls (n = 27) by means of ultra-performance liquid chromatography-tandem mass spectrometry analysis. A multivariate model developed by partial least squares generated a diagnostic model for AD with an AUC-ROC (area under the curve-receiver operating characteristic) of 0.843. From the studied analytes, 8-OHdG (8-hydroxy-2'-deoxyguanosine) and the ratio 8-OHdG/2dG (2'-deoxyguanosine) were able to distinguish between AD and healthy participants, showing statistically significant differences between groups, postulating DNA oxidation as a molecular pathway involved in early AD.

Urinary Alzheimer-Associated Neuronal Thread Protein is not Elevated in Patients with Subjective Cognitive Decline and Patients with Depressive State.

Subjective cognitive decline (SCD) is a risk factor for Alzheimer's disease (AD). Urinary Alzheimer-associated neuronal thread protein (AD7c-NTP) has been identified as a biomarker for AD. It was hypothesized that if urinary AD7c-NTP were also elevated in SCD, as it is in prodromal AD (mild cognitive impairment stage), it could be a convenient and efficient clinical biomarker for the early diagnosis of SCD. SCD is often accompanied by a depressive state (DS), and the impact of DS on urinary AD7c-NTP levels remains unknown. A total of 297 right-handed Chinese Han subjects were recruited, including 98 subjects with SCD, 92 patients with DS, and 107 well-matched cognitively normal controls (NC). The levels of AD7c-NTP in urine samples were measured using an enzyme-linked immunosorbent assay AD7c-NTP kit. Our results demonstrated that urinary AD7c-NTP levels in the SCD group (0.7561±0.5657 ng/mL) were not significantly higher than in either the DS (0.7527±0.5607 ng/mL) or NC (0.7214±0.5077 ng/mL) groups. Furthermore, urinary AD7c-NTP levels were not correlated with Hamilton Depression Rating Scale and Hamilton Anxiety Scale scores, but they were negatively associated with Mini-Mental State Examination scores (r = -0.222, p = 0.033) and Montreal Cognitive Assessment-Basic scores (r = -0.207, p = 0.048). Urinary AD7c-NTP level is not elevated in SCD and is unaffected by DS. Urinary AD7c-NTP may therefore not be a good potential biomarker for SCD and DS, although it may become elevated with more severe cognitive decline.

Associations of Chronic Kidney Disease Markers with Cognitive Function: A 12-Year Follow-Up Study.

BACKGROUND: The role of chronic kidney disease (CKD) as a risk factor for cognitive impairment independent of their shared antecedents remains controversial. OBJECTIVE: To determine whether kidney damage (indicated by albuminuria) or kidney dysfunction (estimated glomerular filtration rate [eGFR] <60 ml/min/1.73 m2) predict future (12-year) cognitive function independently of their shared risk factors. METHODS: We studied 4,128 individuals from the 1999/00 population-based Australian Diabetes, Obesity, and Lifestyle (AusDiab) Study who returned in 2011/12 for follow-up cognitive function testing. Albuminuria was defined by urinary albumin:creatinine≥3.5 (women) or≥2.5 mg/mmol (men). Kidney dysfunction was indicated by eGFR <60 ml/min/1.73 m2. Cognitive function domains assessed included memory (California Verbal Learning Test [CVLT]) and processing speed (Symbol Digit Modalities Test [SDMT]). RESULTS: Baseline albuminuria and kidney dysfunction were identified in 142 (3.4%) and 39 (0.9%) individuals, respectively, with minimal overlap (n = 7). Those with albuminuria demonstrated concurrently reduced 12-year SDMT (p = 0.084) and CVLT scores (p = 0.005) following adjustment for age, sex, and education. However, only CVLT performance remained worse (p = 0.027) following additional adjustment for myocardial infarction, stroke, and related risk factors (hypertension, diabetes, dyslipidemia, smoking, BMI, physical activity, and alcohol intake). Indeed, these collective covariates were responsible for 47% of the effect of albuminuria on SDMT, but only 21% of its effect on CVLT. Kidney dysfunction was not associated with either SDMT or CVLT performance (p > 0.10). CONCLUSIONS: Albuminuria predicted worse memory function at 12 years follow-up, whereas its effect on processing speed was driven largely by differences in cardiovascular risk. Kidney dysfunction based on eGFR predicted neither cognitive domain.

High prevalence of hypohydration in occupations with heat stress-Perspectives for performance in combined cognitive and motor tasks.

PURPOSE: To evaluate the prevalence of dehydration in occupational settings and contextualize findings to effects on performance in cognitively dominated tasks, simple and complex motor tasks during moderate and high heat stress. METHODS: The study included an occupational part with hydration assessed in five industries across Europe with urine samples collected from 139 workers and analyzed for urine specific gravity. In addition, laboratory experiments included eight male participants completing mild-intensity exercise once with full fluid replacement to maintain euhydration, and once with restricted water intake until the dehydration level corresponded to 2% bodyweight deficit. Following familiarization, euhydration and dehydration sessions were completed on separate days in random order (cross-over design) with assessment of simple motor (target pinch), complex motor (visuo-motor tracking), cognitive (math addition) and combined motor-cognitive (math and pinch) performance at baseline, at 1°C (MOD) and 2°C (HYPER) delta increase in body core temperature. RESULTS: The field studies revealed that 70% of all workers had urine specific gravity values ≥1.020 corresponding to the urine specific gravity (1.020±0.001) at the end of the laboratory dehydration session. At this hydration level, HYPER was associated with reductions in simple motor task performance by 4±1%, math task by 4±1%, math and pinch by 9±3% and visuo-motor tracking by 16±4% (all P<0.05 compared to baseline), whereas no significant changes were observed when the heat stress was MOD (P>0.05). In the euhydration session, HYPER reduced complex (tracking) motor performance by 10±3% and simple pinch by 3±1% (both P<0.05, compared to baseline), while performance in the two cognitively dominated tasks were unaffected when dehydration was prevented (P>0.05). CONCLUSION: Dehydration at levels commonly observed across a range of occupational settings with environmental heat stress aggravates the impact of hyperthermia on performance in tasks relying on combinations of cognitive function and motor response accuracy.

Serum Ethanolamine Plasmalogen and Urine Myo-Inositol as Cognitive Decline Markers.

Recent studies have suggested that metabolic disorders, particularly type 2 diabetes mellitus (T2DM), and dementia, including Alzheimer's disease (AD), were linked at the clinical and molecular levels. Brain insulin deficiency and resistance may be key events in AD pathology mechanistically linking AD to T2DM. Ethanolamine plasmalogens (PlsEtns) are abundant in the brain and play essential roles in neuronal function and myelin formation. As such, PlsEtn deficiency may be pathologically relevant in some neurodegenerative disorders such as AD. Decreased brain PlsEtn associated with dementia may reflect serum PlsEtn deficiency. We hypothesized that myo-inositol plays a role in myelin formation through its facilitation of PlsEtn biosynthesis. Excessive urinary myo-inositol (UMI) loss would likely result in PlsEtn deficiency potentially leading to demyelinating diseases such as dementia. Accordingly, measurement of both serum PlsEtn and baseline UMI excretion could improve the detection of cognitive impairment (CI) in a more specific and reliable manner. To verify our hypothesis, we conducted a clinical observational study of memory clinic outpatients (MCO) and cognitively normal elderly (NE) for nearly 4.5years. We demonstrated that serum PlsEtn concentration associated with UMI excretion was useful for predicting advancing dementia in patients with mild CI. Because hyperglycemia and associated insulin resistance might be a leading cause of increased baseline UMI excretion, serum PlsEtn quantitation would be useful in detecting CI among the elderly with hyperglycemia. Our findings suggest that myo-inositol is a novel candidate molecule linking T2DM to AD.

The association between urinary Alzheimer-associated neuronal thread protein and cognitive impairment in late-life depression: a controlled pilot study.

Accumulation of tau protein is associated with both Alzheimer's disease (AD) and late-life depression (LLD). Alzheimer-associated neuronal thread protein (AD7c-NTP), which is closely linked with the tau protein, is elevated in the cerebrospinal fluid and urine of AD patients. This study examined the association between urinary AD7c-NTP and late-life depression with cognitive impairment. One hundred and thirty-eight subjects were recruited into late-life depression with cognitive impairment (LLD-CI, n=52), late-life depression without cognitive impairment (LLD-NCI, n=29), AD (n=27), and healthy control (HC, n=30) groups. The level of urinary AD7c-NTP was measured using the enzyme-linked immunosorbent assay method. The Montreal Cognitive Assessment scale (MoCA), Hamilton Rating Scale for Depression (HRSD) and Hamilton Anxiety Rating Scale (HAMA) were used to assess cognitive functions and depressive and anxiety symptoms in the AD and LLD groups. Urinary levels of AD7c-NTP in the LLD-CI group (1.0±0.7ng/ml) were significantly higher than both the LLD-NCI (0.5±0.3ng/ml) and HC groups (0.5±0.3ng/ml), but lower than in the AD group (1.6±1.7 ng/ml). No significant associations were found in the level of urinary AD7c-NTP in relation to age, gender, education and MoCA in the LLD-CI group. The level of urinary AD7c-NTP appears to be associated with cognitive impairment in late-life depression and may be a potential biomarker for early identification of cognitive impairment in LLD.

Urine AD7c-NTP Predicts Amyloid Deposition and Symptom of Agitation in Patients with Alzheimer's Disease and Mild Cognitive Impairment.

BACKGROUND: Expression of neuronal thread protein (NTP), which is considered to be related to neuritic sprouting and neuronal death, may be elevated in brain tissue, cerebrospinal fluid, and even urine in patients with Alzheimer's disease (AD). OBJECTIVE: In this study, we analyzed the correlation between urine AD-associated NTP (AD7c-NTP) level, and amyloid-ß (Aß) deposition, and clinical symptoms in AD and mild cognitive impairment (MCI). METHODS: Twenty-two patients with mild to moderate AD and 8 subjects with MCI were recruited. Aß deposition was measured with [11C]-labeled Pittsburgh compound B (PiB)-positron emission tomography (PET) in all participants. Urine AD7c-NTP levels were measured using enzyme-linked immunosorbent assay. Mini-Mental State Examination (MMSE) and Neuropsychiatric Inventory (NPI) were used to evaluate cognitive function and behavioral psychological symptoms, respectively. RESULTS: Fourteen (63.6%) of AD patients and 2 (25.0%) of MCI subjects were Aß positive on PiB-PET. There was a significant difference in urine AD7c-NTP level between Aß positive (2.27±2.22 ng/ml) and negative (0.55±0.60 ng/ml) subjects (p = 0.018). Using 1.46 ng/ml as a cut-off value, 68.8% of Aß positive subjects showed elevated urine AD7c-NTP level, and 92.9% of Aß negative subjects showed normal urine AD7c-NTP level. There were no relationships between urine AD7c-NTP level and MMSE and total NPI scores. However, AD7c-NTP level positively correlated with agitation score on NPI. CONCLUSIONS: Urine AD7c-NTP had high specificity and moderate sensitivity in predicting Aß deposition among patients with cognitive impairment. Furthermore, urine AD7c-NTP level strongly correlated with the symptom of agitation.

Urine Metabonomics Reveals Early Biomarkers in Diabetic Cognitive Dysfunction.

Recently, increasing attention has been paid to diabetic encephalopathy, which is a frequent diabetic complication and affects nearly 30% of diabetics. Because cognitive dysfunction from diabetic encephalopathy might develop into irreversible dementia, early diagnosis and detection of this disease is of great significance for its prevention and treatment. This study is to investigate the early specific metabolites biomarkers in urine prior to the onset of diabetic cognitive dysfunction (DCD) by using metabolomics technology. An ultra-high performance liquid-chromatography-quadrupole time-of-flight-mass spectrometry (UPLC-Q/TOF-MS) platform was used to analyze the urine samples from diabetic mice that were associated with mild cognitive impairment (MCI) and nonassociated with MCI in the stage of diabetes (prior to the onset of DCD). We then screened and validated the early biomarkers using OPLS-DA model and support vector machine (SVM) method. Following multivariate statistical and integration analysis, we found that seven metabolites could be accepted as early biomarkers of DCD, and the SVM results showed that the prediction accuracy is as high as 91.66%. The identities of four biomarkers were determined by mass spectrometry. The identified biomarkers were largely involved in nicotinate and nicotinamide metabolism, glutathione metabolism, tryptophan metabolism, and sphingolipid metabolism. The present study first revealed reliable biomarkers for early diagnosis of DCD. It provides new insight and strategy for the early diagnosis and treatment of DCD.

High-Throughput Metabolomics for Discovering Potential Metabolite Biomarkers and Metabolic Mechanism from the APPswe/PS1dE9 Transgenic Model of Alzheimer's Disease.

Alzheimer's disease (AD), a neurodegenerative disorder, is the major form of dementia. As AD is an irreversible disease, it is necessary to focus on earlier intervention. However, the potential biomarkers of preclinical AD are still not clear. In this study, urinary metabolomics based on ultra-high-performance liquid chromatography coupled with quadruple time-of-flight mass spectrometry was performed for delineating the metabolic changes and potential early biomarkers in APPswe/PS1dE9 (APP/PS1) transgenic mice. A total of 24 differentially regulated metabolites were identified when comparing transgenic mice to wild-type mice using multivariate statistical analysis. Among them, 10 metabolites were significantly upregulated and 14 metabolites were downregulated. On the basis of these potential biomarkers, metabolic pathway analysis found that pentose and glucuronate interconversions, glyoxylate and dicarboxylate metabolism, starch and sucrose metabolism, the citrate cycle, tryptophan metabolism, and arginine and proline metabolism were disturbed in APP/PS1 mice. Our study revealed that levels of endogenous metabolites in the urine of APP/PS1 mice changed prior to the emergence of learning and cognitive impairment, which may be associated with abnormal nitric oxide production pathways and metabolic disorders of monoaminergic neurotransmitters. In conclusion, this study showed that metabolomics provides an early indicator of disease occurrence for AD.

Potential fluid biomarkers for pathological brain changes in Alzheimer's disease: Implication for the screening of cognitive frailty.

Cognitive frailty (CF) overlaps with early neuropathological alterations associated with aging­related major neurocognitive disorders, including Alzheimer's disease (AD). Fluid biomarkers for these pathological brain alterations allow for early diagnosis in the preclinical stages of AD, and for objective prognostic assessments in clinical intervention trials. These biomarkers may also be helpful in the screening of CF. The present study reviewed the literature and identified systematic reviews of cohort studies and other authoritative reports. The selection criteria for potentially suitable fluid biomarkers included: i) Frequent use in studies of fluid­derived markers and ii) evidence of novel measurement techniques for fluid­derived markers. The present study focused on studies that assessed these biomarkers in AD, mild cognitive impairment and non­AD demented subjects. At present, widely used fluid biomarkers include cerebrospinal fluid (CSF), total tau, phosphorylated tau and amyloid­ß levels. With the development of novel measurement techniques and improvements in understanding regarding the mechanisms underlying aging­related major neurocognitive disorders, numerous novel biomarkers associated with various aspects of AD neuropathology are being explored. These include specific measurements of Aß oligomer or monomer forms, tau proteins in the peripheral plasma and CSF, and novel markers of synaptic dysfunction, neuronal damage and apoptosis, neuronal activity alteration, neuroinflammation, blood brain barrier dysfunction, oxidative stress, metabolites, mitochondrial function and aberrant lipid metabolism. The proposed panels of fluid biomarkers may be useful in the early diagnosis of AD, prediction of the progression of AD from preclinical stages to the dementia stage, and the differentiation of AD from non­AD dementia. In combination with physical frailty, the present study surmised that these biomarkers may also be used as biomarkers for CF, thus contribute to discovering causes and informing interventions for cognitive impairment in individuals with CF.

The level of Alzheimer-associated neuronal thread protein in urine may be an important biomarker of mild cognitive impairment.

Increased levels of Alzheimer-associated neuronal thread protein (AD7c-NTP) are often detected in urine in the early course of Alzheimer's disease (AD), which makes it a promising biomarker for AD. However, whether the concentration of urinary AD7c-NTP is increased in patients with mild cognitive impairment (MCI) remains unclear. The aim of this study was to explore the value of urinary AD7c-NTP to assist in the diagnosis of cognitive impairment by comparing differences in urinary AD7c-NTP among normal controls, MCI patients and AD patients. One hundred and seventy patients from the Xuan wu Hospital, Capital Medical University were divided into three groups according to their clinical diagnosis: an AD group (n=45), an MCI group (n=60) and a normal group (n=65). The Mini Mental State Examination and the Montreal Cognitive Assessment scale were used to screen for the diagnosis of AD and MCI, and patients met the diagnostic criteria of the National Institute of Neurological Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association. The level of urinary AD7c-NTP was determined using the enzyme-linked immunosorbent assay method. The urinary levels of AD7c-NTP in the AD group (median 2.14 [range 0.49-6.39] ng/ml) and the MCI group (median 1.57 [range 0.4-4.15] ng/ml) were significantly higher than those of the normal group (median 0.53 [range 0.04-2.07] ng/ml). To our knowledge our study is the first to show that the level of urinary AD7c-NTP in MCI patients is higher than in healthy people, which suggests that the level of urinary AD7c-NTP may be an important biomarker for early diagnosis of MCI.

Distinguishing mild cognitive impairment from Alzheimer's disease with acrolein metabolites and creatinine in urine.

BACKGROUND: We previously reported that the level of urinary 3-hydroxypropyl mercapturic acid (3-HPMA)/creatinine (Cre) was reduced following stroke. The aim of this study was to determine whether the level of 3-HPMA/Cre in urine was reduced in subjects with dementia. METHODS: The level of 3-HPMA was measured by LC-MS/MS, and that of amino acid conjugated acrolein (AC-Acro) was by ELISA. The study included 128 elderly subjects divided into 74 non-demented (control), 22 mild cognitive impairment (MCI) and 32 Alzheimer's disease (AD) subjects. RESULTS: The urinary 3-HPMA/Cre and AC-Acro/Cre in MCI plus AD subjects were significantly lower than those in control subjects. In addition, urinary Cre in AD subjects was significantly higher than that in MCI subjects, and 3-HPMA/Cre and AC-Acro/Cre in AD subjects were significantly lower than that in MCI subjects. Among these three markers, the lower 3-HPMA/Cre ratio was most strongly correlated with the decline of MMSE (Mini-Mental State Examination) and the increase in CDRsob (Clinical Dementia Rating Scale Sum of Boxes Scores). Furthermore, reduction in 3-HPMA/Cre in urine was well correlated with increase in Aß40/42 in plasma in demented subjects. CONCLUSION: The results indicate that 3-HPMA/Cre in urine is the most reliable biochemical marker to distinguish AD subjects from MCI subjects among three markers.

Combining serum and urine biomarkers in the early diagnosis of mild cognitive impairment that evolves into Alzheimer's disease in patients with the apolipoprotein E ϵ4 genotype.

Possession of the apolipoprotein E (APOE) ϵ4 genotype is a major predictor of progression to Alzheimer's disease (AD), particularly in patients with mild cognitive impairment (MCI). However, the use of APOE genotyping in the diagnosis of MCI is limited due to its low sensitivity and specificity, which often results in a high false-positive rate. In this study, we found that there was a significant decrease in serum BDNF and notable increase in urine AD7c-NTP in MCI patients who harbored the APOE ϵ4 allele. Both serum BDNF and urine AD7c-NTP had higher positive predictive values and were more sensitive biomarkers of MCI. Additionally, a testing strategy employing serum BDNF and urine AD7c-NTP revealed increases in sensitivity, positive and negative predictive values, and predictive ability compared with the use of either biomarker alone, suggested that combinatorial detection might have great potential for translation to the clinic.

[Diagnostic value of AD7C-NTP for patients with mild cognitive impairment due to Alzheimer's disease].

OBJECTIVE: To explore the diagnostic value of Alzheimer-associated neuronal thread protein (AD7C-NTP) in the assessment of patients with mild cognitive impairment (MCI) due to Alzheimer's disease. METHODS: All subjects were recruited from neurology ward and clinic of our hospital from December 2012 to September 2013. Using enzyme linked immunosorbent assay (ELISA), the cerebrospinal fluid (CSF), serum and urinary levels of AD7C-NTP were tested for 88 elders, including 52 patients with MCI and 36 healthy controls. Statistical analysis was performed with SPSS 18.0. RESULTS: The CSF, serum and urinary levels of AD7C-NTP of two groups were (637 ± 191) and (372 ± 98); (499 ± 139) and (271 ± 105) and (343 ± 99) and (195 ± 76) ng/L respectively. Using receiver operating characteristic (ROC) curve, the optimal CSF cut-off point of AD7C-NTP for the diagnosis of MCI was 436.97 ng/L with a sensitivity of 86.7% and a specificity of 85.0%; the optimal serum cut-off point of AD7C-NTP for the diagnosis of MCI was 367.06 ng/L with a sensitivity of 76.7% and a specificity of 85.0%; the optimal cut-off point of AD7C-NTP in urine for the diagnosis of MCI was 268.57 ng/L with a sensitivity of 83.3% and a specificity of 90.0%. CONCLUSION: Compared with the normal healthy control group, the MCI group has significantly elevated CSF, serum and urine levels of AD7C-NTP. The CSF and urinary levels of AD7C-NTP have high sensitivity and specificity with similar results. And AD7C-NTP may aid the diagnosis of MCI.