Serum Klotho Levels Research Articles

The relationship between klotho, testosterone, and sexual health parameters among US adult men.

Klotho is a pleotropic hormone involved in a multitude of biological processes necessary for healthy aging, and affords protection from adverse events such as cardiovascular disease, inflammation, and various cancers. Emerging evidence suggests that klotho is also an important component of biochemical pathways that regulate hormone balance, which may include those pathways governing testosterone production and men's sexual health, though data are limited and results are mixed. Using a cohort of 767 men from the NHANES 2015-2016 survey cycle, we set out to quantify the association between serum klotho levels and serum testosterone levels, as well as clinical markers of men's sexual health (e.g., testosterone:estrogen ratio, bioavailable testosterone, and free testosterone). Multivariable linear and logistic regression models while controlling for potential confounders were constructed to quantify the relationship between serum klotho and testosterone, as well as between serum klotho and odds of low testosterone (serum testosterone < 300ng/dL). A positive association was observed between serum klotho and testosterone (β = 0.18, p = 0.04). Serum klotho levels were also stratified into quartiles, and we observed statisticallysignificant increases in testosterone for increasing quartile level of klotho using the first quartile as the reference group (β = 90.51, p = 0.001, β = 106.93, p = 0.002, β = 95.33, p = 0.03 for quartiles 2, 3, and 4, respectively). The average testosterone values by quartiles of klotho were 306.9ng/dL, 390ng/dL, 409.3ng/dL, and 436.6ng/dL, respectively. We modeled important proxies for sexual health including bioavailable and free testosterone, the testosterone:estradiol ratio, and C-reactive protein. Men in the second quartile of klotho had a significantly lower odds of an abnormal testosterone:estradiol ratio compared to the first quartile [OR = 0.18, 95% CI = (0.03, 0.98)].We observed null associations between continuous serum klotho and odds of low testosterone [OR = 1.0, 95% CI = (1.0, 1.0)], and when stratified by quartile, we observed a significant decrease in the odds of low testosterone for individuals in the second quartile of klotho compared to the first quartile [OR = 0.21, 95% CI = (0.05, 0.91)]. In addition, C-reactive protein was inversely associated with testosterone in men (β = - 4.65, p = 0.001), and inversely associated with quartiles of klotho (β = - 2.28, p = 0.04, β = - 2.22, p = 0.04, β = - 2.28, p = 0.03, for quartiles 2, 3, and 4, respectively). Our findings support previous studies suggesting a role for klotho in testosterone levels and sexual function among men. Future studies are warranted to corroborate these findings, determine clinical significance, and elucidate potential mechanisms underlying these associations.

A prospective study of the association between serum klotho and mortality among adults with rheumatoid arthritis in the USA

BackgroundWhile it is known that klotho has negative regulatory effects in a variety of diseases such as metabolic disorders and kidney disease, the specific role of klotho in rheumatoid arthritis (RA) and its effect on mortality are unclear. This study investigated the association between serum klotho levels and mortality in patients with RA.MethodsThis study included 841 adults with RA from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2016 to extract the concentrations of serum klotho. The association between klotho and RA was determined using Cox regression, Kaplan–Meier (KM) curves, and restricted cubic spline (RCS) models.ResultsA total of 841 patients with RA were included in this study, who were divided into four groups based on the quartiles of serum klotho levels (Q1, Q2, Q3, and Q4). Cox regression analysis with adjustment for covariates revealed that high levels of klotho lowered the risk of both all-cause and cardiovascular mortality compared to the Q1 group. The KM curve analysis suggested that this effect was more pronounced for all-cause mortality. The RCS-fitted Cox regression model indicated a U-shaped correlation between serum klotho levels and RA mortality. The risk of all-cause mortality increased with decreasing serum klotho levels below a threshold of 838.81 pg/mL. Subgroup analysis revealed that the protective effect of klotho was more pronounced in patients with the following characteristics: male, white ethnicity, age ≥ 60 years, body mass index < 25 kg/m2, estimated glomerular filtration rate ≥ 60 mL/ (min × 1.73 m2), and 25-hydroxyvitamin D level ≥ 50 nmol/L.ConclusionSerum klotho levels had a U-shaped correlation with all-cause mortality in patients with RA, indicating that maintain a certain level of serum klotho could prevent premature death.

Role of klotho on antidepressant and antisuicidal effects of low-dose ketamine infusion among patients with treatment-resistant depression and suicidal ideation

ObjectivePrevious studies have found an association between klotho, an anti-aging hormone, and major depressive disorder. However, whether low-dose ketamine infusion alters klotho levels among patients with treatment-resistant depression (TRD) remains unknown. MethodsIn total, 48 patients with TRD and strong suicidal ideation were randomly assigned to a single 0.5 mg/kg ketamine or 0.045 mg/kg midazolam regimen and were subjected to a 2-week follow-up. Depressive and suicidal symptoms were assessed before the infusion and during the follow-up. The serum levels of klotho were assessed at baseline and 3 days postinfusion. ResultsA generalized linear model with adjustment of baseline klotho levels showed that, despite the fact that ketamine did not significantly increase levels of klotho, patients in the ketamine group had higher levels of klotho at Day 3 postinfusion than patients in the midazolam group (p = 0.043). However, we found no association between changes in klotho levels and changes in depressive and suicidal symptoms (all p > 0.05). Higher klotho levels at baseline were associated with poorer antidepressant effect of low-dose ketamine during postinfusion follow-up. DiscussionKlotho may play a role in the antidepressant effect of low-dose ketamine. Additional molecular studies are necessary to elucidate the neuromechanisms of TRD, ketamine, and klotho.

Association between Serum Klotho and Physical Frailty in Middle-Aged and Older Adults: Finding From the National Health and Nutrition Examination Survey.

To date, no consensus has been reached regarding the role of klotho in the development of frailty. This study aimed to examine the relationship between serum klotho and physical frailty and to explore potential age, sex, and racial/ethnic differences, using a large, nationally representative sample of middle-aged and older adults in the United States. Cross-sectional study. Participants were 7107 adults aged 45years or older from the 2007-2008, 2009-2010, 2011-2012, 2013-2014, and 2015-2016 cycles of the National Health and Nutrition Examination Survey (NHANES), a large data set including a series of cross-sectional nationally representative samples in the United States. We assessed the frailty status using the Physical Frailty Phenotype (PFP) and the Frailty Index (FI). Five criteria were used in the PFP, and 34 health items were included to construct the FI as a proportion of accumulated deficits. We used multinomial and binary logistic regression models to examine the association between serum klotho and frailty, adjusted for several covariates. Participants with a higher serum klotho level (>785.5 pg/mL) had a lower prevalence of frailty, defined by either the PFP or the FI, than those with a lower level (≤785.5 pg/mL). After adjustment for all covariates, the higher serum klotho level was associated with a 26% (95% CI 2%-45%) and 17% (95% CI 1%-30%) lower odds of frailty vs robustness when using the PFP and FI, respectively. In the PFP, the association was significantly stronger among participants aged <60years than those aged ≥60years (odds ratio: 0.60 vs 0.85; Pinteraction= .03). No effect modification by race/ethnicity on the association was found. Higher serum klotho level relates to lower odds of physical frailty among middle-aged and older adults. Our findings suggest that klotho might be a potential biomarker of frailty, specifically in the middle-aged population. Future research should further investigate the mechanisms underlying this association to determine if lower levels of klotho may serve as a novel risk factor for physical frailty.

An evaluation of both serum Klotho/FGF-23 and apelin-13 for detection of diabetic nephropathy.

The aim of our study is to evaluate whether serum Klotho/FGF-23 and apelin-13 can be used as new biomarkers for detection of development of nephropathy. In this cross-sectional study, 88 type 2 diabetes mellitus (T2DM) patients and 38 healthy controls were included. The mean duration of T2DM was 11.4 ± 9.7years. T2DM individuals were categorized into two groups as group 1 with e-GFR < 60mL/min/1.73 m2 and group 2 with e-GFR > 60mL/min/1.73 m2. They were also divided into two groups according to their 24h urine albumin levels, classifying them as follows: normoalbuminuria if less than 30mg/day and albuminuria if more than 30mg/day. Mean serum Klotho levels in the T2DM group were observed to be significantly higher than in the control group. Serum apelin-13 levels were observed to be significantly lower in the T2DM group compared to the control group (p < 0.001). In the diabetic group, apelin-13 levels were positively correlated with age, waist circumference, and albuminuria while they were negatively correlated with e-GFR. Apelin-13 levels were seen to be significantly higher in group 1 (p < 0.001). Apelin-13 levels were found to be significantly higher in individuals with diabetic nephropathy than in those without diabetic nephropathy. In the diabetic group, a significant relationship was detected between apelin-13 levels and albumin excretion. Based on these findings, we consider that serum Klotho and apelin-13 levels may have a protective effect on diabetic nephropathy and can additionally be used as a biomarker to predict diabetic nephropathy.

The Association between Dietary Fiber Intake and Serum Klotho Levels in Americans: A Cross-Sectional Study from the National Health and Nutrition Examination Survey.

Klotho is an aging-related marker closely associated with a number of diseases. A growing body of evidence suggests that dietary factors and lifestyle habits can impact serum Klotho levels. The effect of dietary fiber, a key component of a healthy diet, on the body's serum Klotho levels has not been fully elucidated. The aim of this study was to explore the relationship between dietary fiber intake and serum Klotho levels in people aged 40-79 years in the United States. A total of 11,282 participants were included in this study, all from the National Health and Nutrition Examination Survey from 2007 to 2016. Dietary fiber intake was assessed by uniformly trained interviewers using the 24 h dietary recall method. Serum Klotho was quantified using commercially available ELISA kits manufactured by IBL International, Japan. The relationship between dietary fiber intake and serum Klotho levels was analyzed using a multiple linear regression model. Subsequently, the non-linear dose-response relationship between the two was further explored using a restricted cubic spline (RCS) model. After adjusting for potential confounders, serum Klotho levels increased by 1.9% (95% confidence interval [CI]: 0.8%, 3.0%) for each interquartile range increase in dietary fiber intake in all participants. Considering dietary fiber intake as a categorical variable, serum Klotho levels were found to be 4.7% higher in participants in the highest quartile of dietary fiber intake than in those in the lowest quartile (95% CI: 1.8%, 7.6%). RCS plots depicted a non-linear positive correlation between dietary fiber intake and serum Klotho levels. Subgroup analysis revealed that the relationship between dietary fiber intake and serum Klotho levels was more pronounced in older (percentage change: 7.0%; 95% CI: 2.5%, 11.7%) and overweight and obese participants (percentage change: 4.9%; 95% CI: 1.5%, 8.4%). The results of this study showed that dietary fiber intake was significantly associated with serum Klotho levels in participants. This finding is yet to be further confirmed by prospective studies.

Klotho reduces the risk of osteoporosis in postmenopausal women: a cross-sectional study of the National Health and Nutrition Examination Survey (NHANES)

BackgroundOsteoporosis (OP) is one of the diseases that endanger the health of the elderly population. Klotho protein is a hormone with anti-aging effects. A few studies have discussed the relationship between Klotho and OP. However, there is still a lack of research on larger populations. This study aims to evaluate the association between OP and Klotho in American postmenopausal women.MethodsThis is a retrospective study. We searched the National Health and Nutrition Examination Survey (NHANES) database and collected data of 3 survey cycles, finally involving 871 postmenopausal women over 50 years old in the present study. All participants took dual-energy X-ray absorptiometry examination and serum Klotho testing at the time of investigation. After adjusting the possible confounding variables, a multivariate regression model was employed to estimate the relationship between OP and Klotho proteins. Besides, the P for trend and restricted cubic spline (RCS) were applied to examine the threshold effect and calculate the inflection point.ResultsFactors influencing the occurrence of OP included age, ethnicity, body mass index and Klotho levels. Multivariate regression analysis indicated that the serum Klotho concentration was lower in OP patients than that in participants without OP (OR[log2Klotho] = 0.568, P = 0.027). The C-index of the prediction model built was 0.765, indicating good prediction performance. After adjusting the above-mentioned four variables, P values for trend showed significant differences between groups. RCSs revealed that when the Klotho concentration reached 824.09 pg/ml, the risk of OP decreased drastically.ConclusionBased on the analysis of the data collected from the NHANES database, we propose a correlation between Klotho and postmenopausal OP. A higher serum Klotho level is related to a lower incidence of OP. The findings of the present study can provide guidance for research on diagnosis and risk assessment of OP.

Analysis of the association between serum antiaging humoral factor klotho and cardiovascular disease potential risk factor apolipoprotein B in general population.

Cardiovascular disease (CVD) is a prevalent health issue, and various risk factors contribute to its development, including blood lipids, blood pressure, diabetes, smoking, and alcohol consumption. Apolipoprotein B (ApoB) is related to CVD. ApoB is present on the surface of low-density lipoprotein (LDL), and its cellular recognition and LDL uptake are mainly achieved through recognition. It plays a crucial role in the diagnosis and treatment of CVD. This study aims to investigate the relationship between Klotho and ApoB in the general population of the United States as the correlation between serum Klotho and apoB is currently unknown. These findings could potentially guide the development of future treatments for CVD. This study utilized data from the National Health and Nutrition Examination Survey (NHANES) collected between 2007 and 2016. A linear regression model and smooth curve fitting were conducted to analyze the relationship between serum Klotho and apoB. The results indicate a negative correlation between serum Klotho concentration and apoB concentration (β = -71.7; 95% confidence interval [CI]: -120.8, -22.6; P = .005). After adjusting for confounding variables, the negative correlation between apoB concentration and serum Klotho concentration became more significant (β = -91.8; 95% CI: -151.3, -32.2; P = .004). When apoB concentration was converted from a continuous variable to a categorical variable (tertiles: T1 <0.8 g/L; T2: ≥0.8 g/L to <1.0 g/L; T3: ≥1.0 g/L), the serum klotho level of participants in the highest tertile (≥1.0 g/L) was -44.8 pg/mL (95% CI: -86.3, -3.2; P = .040) lower than that in the lowest tertile (<0.8 g/L). The smooth curve fitting diagram revealed differences in the relationship between serum Klotho concentration and apoB among individuals with different CVD risk factors. This study demonstrates a significant negative correlation between serum Klotho concentration and apoB concentration, even after controlling for confounding factors. The findings suggest that serum Klotho and apoB may be involved in the development of CVD, and targeting these factors could be a potential approach for CVD prevention and treatment.

#2598 KLOTHO DEFICIENCY INDUCES REGULATORY T CELLS IN MURINE LUPUS NEPHRITIS

Abstract Background and Aims Recent studies demonstrate that klotho deficiency participate in various chronic kidney disease. However, it has not been fully assessed the influence of klotho in autoimmune kidney diseases. On the one hand, klotho is known to binds transforming growth factor β (TGFβ) receptor to antagonize its pathophysiological actions including renal fibrosis. On the other hand, TGFβ is required to generate and maintain regulatory T cells with inducing FOXP3, an important cell population for immunological tolerance. Method NZBWF1 mice were used as a model of lupus nephritis. NZBWF1 mice were housed separately in metabolic cage, and divided into two groups (n=10 for each): one group was treated with daily subcutaneous injection of klotho protein (20 µg/kg/day), and the other received vehicle alone. Systolic blood pressure was measured by tail-cuff method. Glomerular filtration rate was assessed using FITC-inulin. Four weeks later, the animals were killed to harvest the spleen and kidneys for analyses. Results Klotho supplementation suppressed blood pressure, 8-epi-prostaglandin F2a excretion and renal angiotensin II levels (p&amp;lt;0.05 for all) without changes in albuminuria and glomerular filtration rate in NZBWF1 mice. Exogenous klotho protein supplementation increased serum klotho levels, urine klotho excretion, and endogenous renal expression of klotho in NZBWF1 mice (p&amp;lt;0.05 for all). Surprisingly, anti-double strand DNA antibody was slightly elevated in klotho-treated NZBWF1 mice (p&amp;lt;0.05). Glomerular pathology and interstitial cell infiltration were similar between 2 groups. The spleen tended to be greater in klotho-treated group, but statistical significance was not attained. In consistent, CD8+FOXP3+ T cells were unaltered between 2 groups. However, klotho supplementation reduced CD4+FOXP3+ T cells in spleen of NZBWF1 mice (p&amp;lt;0.05). Conclusion The present data indicated that klotho protein supplementation suppressed renal renin-angiotensin system, ameliorating blood pressure and oxidative stress. Our results suggest that klotho supplementation worsened auto-antibody, possibly by inhibiting TGFβ with resultant deterioration in regulatory T cells. The present findings implicate that although klotho may not suite for the management of autoimmune kidney diseases, such as lupus and ANCA-related nephritis, klotho supplementation for dialysis patients could mitigate against the defect in cellular immunity and susceptibility to infections including tuberculosis and COVID-19.

Klotho inversely relates with carotid intima- media thickness in atherosclerotic patients with normal renal function (eGFR ≥60 mL/min/1.73m2): a proof-of-concept study.

Klotho protein is predominantly expressed in the kidneys and has also been detected in vascular tissue and peripheral blood circulating cells to a lesser extent. Carotid artery intima-media thickness (CIMT) burden, a marker of subclinical atherosclerosis, has been associated with reductions in circulating Klotho levels in chronic kidney disease patients, who show reduced levels of this protein at all stages of the disease. However, the contribution of serum Klotho and its expression levels in peripheral blood circulating cells and in the carotid artery wall on the CIMT in the absence of kidney impairment has not yet been evaluated. We conducted a single-center study in 35 atherosclerotic patients with preserved kidney function (eGFR≥60 mL/min/1.73m2) subjected to elective carotid surgery. Serum levels of Klotho and cytokines TNFa, IL6 and IL10 were determined by ELISA and transcripts encoding for Klotho (KL), TNF, IL6 and IL10 from vascular segments were measured by qRT-PCR. Klotho protein expression in the intima-media and adventitia areas was analyzed using immunohistochemistry. APatients with higher values of CIMT showed reduced Klotho levels in serum (430.8 [357.7-592.9] vs. 667.8 [632.5-712.9] pg/mL; p<0.001), mRNA expression in blood circulating cells and carotid artery wall (2.92 [2.06-4.8] vs. 3.69 [2.42-7.13] log.a.u., p=0.015; 0.41 [0.16-0.59] vs. 0.79 [0.37-1.4] log.a.u., p=0.013, respectively) and immunoreactivity in the intimal-medial area of the carotids (4.23 [4.15-4.27] vs. 4.49 [4.28-4.63] log µm2 p=0.008). CIMT was inversely related with Klotho levels in serum (r= -0.717, p<0.001), blood mRNA expression (r=-0.426, p=0.011), and with carotid artery mRNA and immunoreactivity levels (r= -0.45, p=0.07; r= -0.455, p= 0.006, respectively). Multivariate analysis showed that serum Klotho, together with the gene expression levels of tumor necrosis factor TNFa in blood circulating cells, were independent determinants of CIMT values (adjusted R2 = 0.593, p<0.001). The results of this study in subjects with eGFR≥60mL/min/1.73m2 show that patients with carotid artery atherosclerosis and higher values of CIMT present reduced soluble Klotho levels, as well as decreased KL mRNA expression in peripheral blood circulating cells and Klotho protein levels in the intima-media of the carotid artery wall.

Association between Serum Klotho and Kidney Stones in US Middle-Aged and Older Individuals with Diabetes Mellitus: Results from 2007 to 2016 National Health and Nutrition Survey

Introduction: Kidney stones (KSs) are associated with hematuria and renal failure and pose a significant clinical and public health concern. Diabetes is associated with a higher risk of KSs. In addition, α-Klotho (Klotho), as a novel antiaging protein, is associated with kidney disease, diabetes, and complications and may participate in the pathological mechanism of KSs. However, studies that used large population-based database research are limited. Therefore, this study aimed to investigate whether or not KS prevalence is associated with serum Klotho levels in diabetic adults in the USA. Methods: This nationally representative cross-sectional study used data on diabetic adults in the USA aged 40–79 years from the National Health and Nutrition Examination Survey 2007–2016 cycles. Multivariate logistic regression models were used to calculate the association between Klotho and KS. Restricted cubic splines were used to further test for linearity and explore the shape of the dose-response association. Moreover, we performed stratified and interaction analyses to see if the relationship was stable in different subgroups. Results: Among the 3,537 diabetic patients included in this study (mean age of 61.4 years, consisting of 51.3% males), 543 participants (15.4%) suffered from KS. In the fully adjusted model, Klotho was negatively associated with KS (OR = 0.72; 95% CI: 0.54–0.96; p = 0.027). A negative relationship was observed between the occurrence of KS and Klotho (nonlinear: p = 0.560). Some differences in the association between Klotho and KS were found in stratified analyses; however, these differences lacked statistical significance. Conclusions: Serum Klotho was negatively associated with the incidence of KS; when ln-transformed Klotho concentration increased by 1 unit, the risk of KS was 28% lower.

Association between perfluoroalkyl and polyfluoroalkyl internal exposure and serum α-Klotho levels in middle-old aged participants.

Exposure to perfluoroalkyl and polyfluoroalkyl substances causes oxidative stress, which is strongly associated with adverse health effects. Klotho protein plays an anti-aging role via antioxidation activity. We investigated the levels of serum α-Klotho and PFAS exposure in adults who participated in the National Health and Nutrition Examination Survey from 2013 to 2016. A nationally representative subsample of 1,499 adults aged 40-79 years was analyzed for the associations of serum α-Klotho levels with serum PFAS exposures by correlation analysis and multiple general linear models. Of note, the potential confounding factors including age and gender were adjusted. Quantile-based g-computation models were used to assess the effects of mixed PFAS exposure on serum α-Klotho levels. The weighted geometric mean of serum α-Klotho was 791.38 pg/mL for the subjects during 2013-2016. After adjusting for potential confounders, serum Klotho levels showed a statistically significant downward trend with increasing quartiles of PFOA and PFNA. Multivariate adjusted general linear regression analysis showed that increased exposure to PFNA was substantially associated with lower serum levels of α-Klotho, and each 1-unit increase in PFNA concentration was accompanied by a 20.23 pg/mL decrease in α-Klotho level; while no significant association was observed between other PFAS exposures and serum α-Klotho levels. It was negatively correlated between α-Klotho and Q4 for PFNA relative to the lowest quartile (Q1) of exposure (P = 0.025). It was found that the strongest negative correlation between PFNA exposure and serum α-Klotho levels was in the middle-aged (40-59 years) female participants. Furthermore, the mixture of the four PFAS substances showed an overall inverse association with serum α-Klotho concentrations, with PFNA being the major contributor. Taken together, in a representative sample of the U.S. middle-aged and elderly populations, serum concentrations of PFAS, especially PFNA, have been negatively associated with serum levels of α-Klotho, which is strongly associated with cognition and aging. It was important to note that the majority of associations were limited to middle-aged women. It will be meaningful to clarify the causal relationship and the pathogenic mechanisms of PFAS exposure and α-Klotho levels, which is helpful to aging and aging-related diseases.

The role of Klotho and FGF23 in cardiovascular outcomes of diabetic patients with chronic limb threatening ischemia: a prospective study

Cardiovascular complications after lower extremity revascularization (LER) are common in diabetic patients with peripheral arterial disease (PAD) and chronic limb threatening ischemia (CLTI). The Klotho-fibroblast growth factor 23 (FGF23) axis is associated with endothelial injury and cardiovascular risk. We aimed to analyze the relationship between Klotho and FGF23 serum levels and the incidence of major adverse cardiovascular events (MACE) and major adverse limb events (MALE) after LER in diabetic patients with PAD and CLTI. Baseline levels of Klotho and FGF23, and their association with subsequent incidence of MACE and MALE were analyzed in a prospective, non-randomized study in a population of diabetic patients with PAD and CLTI requiring LER. A total of 220 patients were followed for 12 months after LER. Sixty-three MACE and 122 MALE were recorded during follow-up period. Baseline lower Klotho serum levels (295.3 ± 151.3 pg/mL vs. 446.4 ± 171.7 pg/mL, p < 0.01), whereas increased serum levels FGF23 (75.0 ± 11.8 pg/mL vs. 53.2 ± 15.4 pg/mL, p < 0.01) were significantly associated with the development of MACE. Receiver operating characteristic (ROC) analysis confirmed the predictive power of Klotho and FGF23 baseline levels. Furthermore, decreased Klotho levels were associated with the occurrence of MALE after LER (329.1 ± 136.8 pg/mL vs 495.4 ± 183.9 pg/mL, p < 0.01). We found that Klotho and FGF23 baseline levels are a potential biomarker for increased cardiovascular risk after LER in diabetic patients with PAD and CLTI.

Effects of Multiwall Carbon Nanotubes on Premature Kidney Aging: Biochemical and Histological Analysis.

Carbon nanotubes (CNTs) have gained much attention due to their superb properties, which make them promising options for the reinforcing composite materials with desirable mechanical properties. However, little is known about the linkage between lung exposure to nanomaterials and kidney disease. In this study, we compared the effects on the kidneys and aging for two different types of multiwall carbon nanotubes (MWCNTs): pristine MWCNTs (PMWCNTs) and acid-treated MWCNTs (TMWCNTs), with TMWCNTs being the preferred form for use as a composite material due to its superior dispersion properties. We used tracheal instillation and maximum tolerated dose (MTD) for both types of CNTs. MTD was determined as a 10% weight loss dose in a 3-month subchronic study, and the appropriate dosage for 1-year exposure was 0.1 mg/mouse. Serum and kidney samples were analyzed using ELISA, Western blot, and immunohistochemistry after 6 months and 1 year of treatment. PMWCNT-administered mice showed the activation of pathways for inflammation, apoptosis, and insufficient autophagy, as well as decreased serum Klotho levels and increased serum levels of DKK-1, FGF-23, and sclerostin, while TMWCNTs did not. Our study suggests that lung exposure to PMWCNTs can induce premature kidney aging and highlights a possible toxic effect of using MWCNTs on the kidneys in the industrial field, further highlighting that dispersibility can affect the toxicity of the nanotubes.

The Effects of a Six-Week Aerobic Exercise on Serum Levels of Klotho, IL-10, IL-1, and Oxidative Stress in Sedentary Young Women

Objectives: Insufficient physical activity is considered one of the leading causes of premature death worldwide. This study, therefore, aimed to investigate the effects of six weeks of moderate-intensity aerobic exercise on serum levels of Klotho, interleukin 10 (IL-10), IL-1, and oxidative stress in young women with a sedentary lifestyle. Materials and Methods: The present study was a semi-experimental study with a control group. Out of all volunteers, 20 young women eligible to participate in the study were selected and divided into the two groups (n=10) of experimental (i.e., six weeks of moderate-intensity aerobic exercise) and control (i.e., no exercise). Members of the experimental group performed an aerobic exercise program including running on a treadmill with an intensity of 55%-70% of their maximum heart rates (220-age). The running plan started with 50% of their maximum heart rates and reached 70% at the end of the six-week exercise program (three sessions per week). Paired t-test and independent t-test were conducted to examine intra-group and inter-group differences. All statistical procedures were performed using the SPSS version26 statistical package (P≤0.05). Results: At the beginning of the study, no significant difference was observed between the groups in terms of the markers. Six-week aerobic training increased Klotho (mean: 540, lower: 141.5, upper: 938.4) and IL-10 (mean: 0.43, lower: -1.56 upper: -0.47) in experimental group in comparison to control group (P=0.001). Six-week aerobic training decreased IL-1 (mean: 0.78, lower: -1.16 upper: -0.39) and H2O2 (mean: 0.41, lower: -0.96, upper: 0.12) in experimental group in comparison to control group (P=0.001). Conclusions: In sum, six-week moderate-intensity aerobic exercise program increased Klotho and IL-10 levels and decreased IL-1 and oxidative stress levels in young women with a sedentary lifestyle. According to these results, the decrease in oxidative stress and IL-1 levels due to exercise caused an increase in Klotho, and an increase in Klotho level, in turn, increased IL-10.

Association between serum manganese and serum klotho in a 40-80-year-old American population from NHANES 2011-2016.

Objectives: Manganese is one of the essential trace elements that are required by the human body. Klotho protein is a classic anti-aging marker. The association between the levels of serum manganese and serum klotho in individuals between the ages of 40-80 in the United States remains unclear. Methods: Data for this cross-sectional study was obtained from the National Health and Nutrition Examination Survey (NHANES 2011-2016) in the United States. We performed multiple linear regression analyses to investigate the association between the levels of serum manganese and serum klotho. Furthermore, we performed a fitted smoothing curve according to a restricted cubic spline (RCS). Stratification and subgroup analyses were performed for further verification of the results. Results: Weighted multivariate linear regression analysis showed that serum manganese levels were independently and positively associated with serum klotho levels (β = 6.30, 95% confidence interval: 3.30-9.40). Kruskal-Wallis test showed that participants with higher manganese quartiles had higher serum klotho levels (Q1: 808.54 ± 256.39pg/mL; Q2: 854.56 ± 266.13pg/mL; Q3: 865.13 ± 300.60pg/mL; and Q4: 871.72 ± 338.85pg/mL, p < 0.001). The RCS curve indicated that the association between the levels of serum manganese and serum klotho was non-linear. Furthermore, a significantly positive association was found between serum manganese and serum klotho levels in the majority of subgroups. Conclusion: A non-linear and positive association was found between the levels of serum manganese and serum klotho in individuals aged 40-80 in the United States according to the NHANES (2011-2016).

Individual nutrients and serum klotho levels in adults aged 40-79 years.

Several dietary factors (including adherence to the Mediterranean diet or higher nut intake) seem to positively affect circulating antiaging Klotho protein levels; yet, a description of possible relationships between individual nutrients and Klotho activity has not been evaluated. We analyzed the association of dietary intake of individual macro- and micronutrients and nonnutritive food components with circulating Klotho levels in a sample of 40- to 79-year-old US adults. Data from the 2015-2016 National Health and Nutrition Examination Survey were analyzed. Nutrient/food component intakes were calculated in relation to total energy intake using the nutrient density method, and available pristine serum samples were analyzed for serum Klotho concentrations. The final study sample consisted of 2637 participants (mean age 59.0 ± 10.7 years; 52% women). Higher Klotho concentrations were found with higher intake of carbohydrates (p < .001), total sugars (p < .001), dietary fibers (p < .001), vitamin D (p=.05), total folates (p=.015), and copper (p=.018). The results of the regression analysis with a crude model showed significant associations among five nutrients/food components (carbohydrates, alcohol, total sugars, dietary fibers, and niacin) and soluble Klotho levels across the sample. After adjusting the models for age and gender, the nutrient/food component-Klotho association remained significant for carbohydrates, total sugars, and alcohol (p < .05). Dietary exposure to individual nutrients and nonnutritive food components appears to be associated with Klotho activity; however, additional research is needed to investigate the relationship between cause and effect in diet composition-Klotho interplay.

Association of α-klotho levels with serum copper and cadmium levels in schizophrenia

IntroductionSchizophrenia is associated with harmful health effects such as oxidative stress from heavy metal exposure. We considered the relationship between genes and heavy metals in association with oxidative stress and then investigated the association between serum α- klotho and copper and cadmium exposure among schizophrenia patients in western India.ObjectivesTo investigated the association between serum α- klotho and copper and cadmium exposure among schizophrenia patients in western India.Methods100 individuals participated out of which 50 were diagnosed with schizophrenia, severity was assessed by using PANSS score and 50 were taken as controls using General health questionnaire. Serum Klotho levels were estimated using ELISA. Serum Cadmium (Cd) and Serum Copper (Cu) was estimated using Atomic Absorption Spectrophotometry.ResultsThe mean ± SD levels of Serum Cd, Serum Cu and serum Klotho were 1.05 ± 0.55 μg/dl, 135.5 ± 51.25 μg/ml and 62.9 ± 35.1 ng/ml respectively in the patients and 0.23 ± 0.17 μg/dl, 147.9 ± 25.42 μg/ml and 78.6 ± 34.6 ng/ml respectively in controls. The differences in Serum Cd, Serum Cu levels and Klotho levels among the study group were highly significant (p &lt;0.05).ConclusionsBoth Cu and Cd levels were significantly raised in schizophrenic patients compared with controls. Serum klotho levels showed a statistically significant decreasing trend with increasing cadmium levels. These results suggest that cadmium levels may be associated with the serum klotho levels which may be associated with decreased cognition in schizophrenia.Disclosure of InterestNone Declared

Lactoferrin alleviates cyclophosphamide induced-nephropathy through suppressing the orchestration between Wnt4/β-catenin and ERK1/2/NF-κB signaling and modulating klotho and Nrf2/HO-1 pathway

AimsCyclophosphamide is an alkylating agent with vast arrays of therapeutic activity. Currently, its medical use is limited due to its numerous adverse events, including nephrotoxicity. This study aimed to follow the molecular mechanisms behind the potential renoprotective action of lactoferrin (LF) against cyclophosphamide (CP)-induced renal injury. Materials and methodsFor fulfillment of our aim, Spragw-Dwaly rats were orally administrated LF (300 mg/kg) for seven consecutive days, followed by a single intraperitoneal injection of CP (150 mg/kg). Key findingsTreatment of CP-injured rats with LF significantly reduced the elevated creatinine and blood urea nitrogen (BUN), markedly upregulated Nrf2/HO-1 signaling with consequent increase in renal total antioxidant capacity (TAC) and decrease in renal malondialdehyde (MDA) level. Furthermore, LF treatment significantly reduced the elevated renal p-ERK1/2 expression, tumor necrosis factor-α (TNFα), interleukin-6 (IL-6), nuclear factor-kappa B (NF-κB) levels in CP-treated animals. Interestingly, LF treatment downregulated Wnt4/β-catenin signaling and increased both renal klotho gene expression and serum klotho level. Furthermore, LF treatment reduced apoptosis in kidney tissue via suppressing GSK-3β expression and modulating caspase-3 and Bcl2 levels. Histopathological examination of kidney tissue confirmed the protective effect of LF against CP-induced renal injury. SignificanceThe present findings document the renoprotective effect of LF against CP-induced nephropathy, which may be mediated via suppressing ERK1/2/ NF-κB and Wnt4/β-catenin trajectories and enhancing klotho expression and Nrf2/HO-1 signaling.

P514 Serum levels of Klotho in inflammatory bowel disease: an exploratory study

Abstract Background Alpha klotho (α-Klotho) is an anti-aging protein recognized as a humoral factor with anti-oxidant and anti-inflammatory effects, showing a bidirectional relationship with inflammation, a main pathophysiologic factor in atherosclerosis. A decrease in Klotho has been associated to cardiovascular disease (CVD), but no previous studies have investigated the relationship between inflammatory bowel disease (IBD), a risk factor for CVD, and Klotho levels. Therefore, we assessed if the serum levels of Klotho differ between patients with IBD and controls, and how this protein is related to the clinical and laboratory characteristics of the disease, subclinical atherosclerosis and metabolic risk factors. Methods Cross-sectional multicentric study that included 251 individuals: 191 IBD patients and 60 healthy controls was conducted. Serum Klotho levels were determined by commercial ELISA immunoassay (IBL International GmbH Laboratories). In the IBD patients disease activity was evaluated using CDAI for Crohn’s disease, partial Mayo (pMayo) for ulcerative colitis, specific laboratory parameters, determination of the Systematic Coronary Risk Evaluation (SCORE), and the presence of subclinical atherosclerosis was assessed using carotid ultrasound for identifying carotid plaque and measurement of carotid intima-media thickness. Results Serum Klotho levels were significantly higher in the IBD group: 734.31 pg/ml vs. 484.17 pg/ml (p&amp;lt;0.001) compared with controls. In the IBD group, no significant differences in the serum Klotho levels were found between the type of IBD (p=0.911), time from diagnosis (p=0.126), disease activity: CDAI (p=0.277), pMayo (p=0.916), type of treatment (0.76), the presence of plaque (p=0.101) or the intima media thickness (p=0.429). However, a significant inverse correlation between serum Klotho and the SCORE was observed in IBD patients: r = -0.176 (p= 0.014) (figure 1) Conclusion Patients with IBD had higher Klotho levels than healthy controls, with an inverse and significant relationship with the SCORE in the IBD patients. Further studies are necessary to clarify the role of Klotho in IBD.