Smooth Curve Research Articles

Association between HDL cholesterol with diabetic retinopathy in diabetic patients: a cross-sectional retrospective study

ObjectiveDiabetic patients are often comorbid with dyslipidemia, however, the relationship between high-density lipoprotein cholesterol(HDL-C) and diabetic retinopathy (DR) in the adult diabetic population remains to be fully elucidated.The aim of this study is to evaluate the associations between HDL-C and DR in the United States adults with diabetes.MethodsA total of 1708 participants from the National Health and Nutrition Examination Survey (NHANES) 2005–2008 were enrolled in the present study. Fundus images of all study subjects were captured and evaluated using a digital camera and an ophthalmic digital imaging system, and the diagnosis of DR was made by the severity scale of the Early Treatment Diabetic Retinopathy Study (ETDRS).Roche Diagnostics were used to measure serum HDL-C concentration. The relationship of DR with HDL-C was investigated using multivariable logistic regression. The potential non-line correlation was explored with smooth curve fitting approach.ResultsThe fully-adjusted model showed that HDL-C positively correlated with DR(OR:1.69, 95%CI: 1.25–2.31).However, an inverted U-shaped association between them was observed by applying the smooth curve fitted method. The inflection point of HDL-C(1.99mmol/l) was calculated by utilizing the two-piecewise logistic regression model. In the subgroup analysis, the inverted U-shaped nonlinear correlation between HDL-C and DR was also found in female, Non-Hispanic White, and lower age groups.ConclusionOur study revealed an inverted U-shaped positive relationship between HDL-C and DR.The findings may provide us with a more comprehensive understanding of the association between HDL-C and DR.

Association between serum potassium and Parkinson’s disease in the US (NHANES 2005–2020)

BackgroundEvaluating the correlation between serum potassium and Parkinson’s disease (PD) in US adults.MethodsA cross-sectional study was conducted on 20,495 adults aged 40 years or older using NHANES data from 2005 to 2020. The study utilized one-way logistic regression and multifactorial logistic regression to examine the correlation between serum potassium levels and PD. Additionally, a smoothed curve fitting approach was employed to assess the concentration-response relationship between serum potassium and PD. Stratified analyses were carried out to investigate potential interactions between serum potassium levels and PD with variables such as age, sex, race, marital status, education, BMI, smoking and medical conditions like coronary, stroke, diabetes, hypertension, and hypercholesterolemia.ResultsIn this study, a total of 20,495 participants, comprising 403 PD and 20,092 non-PD individuals, were included. After adjusted for covariates, multivariable logistic regression revealed that high serum potassium level was an independent risk factor for PD (OR:1.86, 95% CI:1.45 ~ 2.39, p < 0.01).The linear association between serum potassium and PD was described using fitted smoothing curves. Age, sex, race, education, marital, BMI, coronary, stroke, diabetes, hypertension and hypercholesterolemia were not significantly correlated with this positive connection, according to subgroup analysis and interaction testing (P for interaction >0.05).ConclusionSerum potassium levels are elevated in patients with Parkinson's disease compared to non-PD patients. Additional prospective studies are required to explore the significance of serum potassium levels in individuals with Parkinson's disease.

An Effective Method for Slicing Triangle Meshes Using a Freeform Curve

Slicing 3D polygonal meshes is a fundamental operation in various applications such as virtual surgery, garment simulation, and game development. Existing methods primarily slice meshes using either a single line or a set of line segments approximating a smooth curve. This paper introduces a novel approach to freely slice a triangle mesh using a freeform curve without discretizing it into line segments. The user draws a stroke on the screen, defining the desired cutting trajectory. Subsequently, a freeform curve approximating this stroke is generated and extended into a ruled surface in the user’s viewing direction. To efficiently compute intersections between the ruled surface and a triangle mesh, the Line–Surface Intersection (LSI) problem is broken down into two subproblems: Plane–Curve Intersection (PCI) followed by Line–Line Intersection (LLI). Intersection points are then connected to form polylines, effectively cutting the mesh into multiple submeshes. To ensure the solidity of the submeshes, cross-sections are generated by trimming the ruled surface along the polylines and merged with the corresponding submeshes. Our method empowers users to slice triangle meshes along arbitrary trajectories encompassing both straight and freely curved paths while preserving efficiency and accuracy. The effectiveness of the proposed approach is demonstrated through experimental results showing various examples of mesh slicing.

Characterizing the relationships between dietary indices, gallstone prevalence and the need for gallbladder surgery in the general US population

BackgroundThe dietary inflammatory index (DII) and composite dietary antioxidant index (CDAI) were developed as tools for use when seeking to assess the potential inflammatory and antioxidant activity of a given diet, respectively. The associations between these indices and gallstone incidence remain largely unexplored.ObjectiveThe present study sought to clarify how both the DII and the CDAI are related to gallstone incidence and age at first gallbladder surgery among adults in the USA.MethodsCross-sectional data from the 2017–2020 cycles of the National Health and Nutrition Examination Survey (NHANES) pertaining to 12,426 individuals were used to conduct the present study. Data from 2 days with 24-h dietary recall were employed when calculating DII and CDAI scores. Relationships between dietary indices and the incidence of gallstones were assessed through logistic regression analyses, while linear regression analyses were employed to characterize how these indices are associated with the age at first gallbladder surgery.ResultsHigher DII scores and lower CDAI scores, which, respectively, denote diets with greater inflammatory potential and reduced antioxidant potential, were found to be associated with higher gallstone incidence even following adjustment for potential confounding factors. Smooth curve fitting suggested that the association between DII and gallstones was nearly linear, whereas that between CDAI and gallstone incidence was nonlinear. Higher DII values were also related to first gallbladder surgery at an earlier age (β = −0.64, 95% CI: −1.26, −0.02).ConclusionThese results emphasize the benefits of anti-inflammatory diets rich in antioxidants, which may help reduce gallstone incidence among adults in the USA. Higher DII scores may also predict the need for gallbladder surgery at a younger age.

Smooth morphing of immersed spherical curves and application to ruled surfaces

In this paper, we realize a rapid, smooth iterative morphing algorithm between two immersed and closed spherical curves of arbitrary turning numbers. By compensating in turning numbers, we linearly interpolate between geodesic curvatures and the side lengths of their accurate spherical polygons approximation. Our algorithm is essentially based on a geometrical closure condition for a flow of spherical polygons involving the variation of both sides and exterior angles. A curvature smoothing flow using discrete geodesic curvature is adopted for smooth curve generation. To demonstrate the good properties of the method, a morphing of spherical curves and ruled surfaces is illustrated.

Association between vitamin B2 intake and prostate-specific antigen in American men: 2003–2010 National Health and Nutrition Examination Survey

BackgroundAccumulating evidence suggests a pivotal role of vitamin B2 in the pathogenesis and progression of prostate cancer (PCa). Vitamin B2 intake has been postulated to modulate the screening rate for PCa by altering the concentration of prostate-specific antigen(PSA). However, the relationship between vitamin B2 and PSA remains indeterminate. Hence, we conducted a comprehensive evaluation of the association between vitamin B2 intake and PSA levels, utilizing data from the National Health and Nutrition Examination Survey (NHANES) database.MethodsFrom a pool of 20,371 participants in the NHANES survey conducted between 2003 and 2010, a cohort of 2,323 participants was selected for the present study. The male participants were classified into four distinct groups based on their levels of vitamin B2 intake. We employed a multiple linear regression model and a non-parametric regression method to investigate the relationship between vitamin B2 and PSA levels.ResultsThe study cohort comprised of 2,323 participants with a mean age of 54.95 years (± 11.73). Our findings revealed a statistically significant inverse correlation between vitamin B2 intake (mg) and PSA levels, with a reduction of 0.13 ng/ml PSA concentration for every unit increase in vitamin B2 intake. Furthermore, we employed a fully adjusted model to construct a smooth curve to explore the possible linear relationship between vitamin B2 intake and PSA concentration.ConclusionsOur study in American men has unveiled a notable inverse association between vitamin B2 intake and PSA levels, potentially posing a challenge for the identification of asymptomatic prostate cancer. Specifically, our findings suggest that individuals with higher vitamin B2 intake may be at a greater risk of being diagnosed with advanced prostate cancer in the future, possibly indicating a detection bias. These results may offer a novel explanation for the observed positive correlation between vitamin B2 intake and prostate cancer.

Investigating the L-Glu-NMDA receptor-H2S-NMDA receptor pathway that regulates gastric function in rats’ nucleus ambiguus

Investigating the L-Glu-NMDA receptor-H2S-NMDA receptor pathway that regulates gastric function in rats’ nucleus ambiguus

The non-linear associations between blood manganese level and sarcopenia in patients undergoing maintenance hemodialysis: A multicenter cross-sectional study

Background & AimsManganese (Mn), a vital element in energy metabolism, is predominantly stored in skeletal muscles and plays a crucial role in muscle function and strength. Patients on maintenance hemodialysis (MHD) often experience muscle wasting due to metabolic disruption and inflammation. This study aimed to explore the relationship between blood Mn levels and sarcopenia in a patient population. MethodsIn this multicenter cross-sectional study, conducted from March 2021 to March 2022, 386 patients on MHD from three medical centers were included. Blood Mn levels were measured using inductively coupled plasma mass spectrometry, and body composition was assessed post-dialysis using bioelectrical impedance analysis. Grip strength was measured using a digital dynamometer. The patients were categorized into groups with and without sarcopenia. Using a generalized additive model to fit a smooth curve, we employed a generalized linear model to identify the optimal inflection point and explore the threshold effect after discovering a segmented relationship. Subsequently, a binary logistic regression analysis was conducted to investigate the relationship between blood manganese levels and the risk of sarcopenia, with adjustments made for potential confounding factors. ResultsA negative correlation was observed between blood Mn levels and sarcopenia-related parameters (Appendicular Skeletal Muscle Mass Index and grip strength) in Spearman’s correlation analysis (both P<0.05). After adjusting for confounding factors, a nonlinear association was identified. When blood Mn was ≤10.6μg/L, the increase in sarcopenia was not statistically significant (P>0.05). Conversely, when blood Mn exceeded 10.6μg/L, each 1μg/L increase raised the risk of sarcopenia by 0.1 times. Considering confounders, multivariate binary logistic regression confirmed an independent association between elevated blood Mn levels and sarcopenia. ConclusionThis study revealed an independent association between elevated blood Mn levels (>10.6μg/L) and sarcopenia in patients undergoing MHD. These findings emphasize the importance of understanding the Mn metabolism in the context of muscle health in this patient population. Further research is warranted to explore the underlying mechanisms and potential interventions for mitigating sarcopenia in patients with elevated blood Mn levels undergoing MHD.

Gaussian maps for singular curves on Enriques surfaces

Gaussian maps for singular curves on Enriques surfaces

A nonlinear relationship between the triglycerides to high-density lipoprotein cholesterol ratio and stroke risk: an analysis based on data from the China Health and Retirement Longitudinal Study

ObjectiveThe connection between triglycerides to high-density lipoprotein cholesterol (TG/HDL-C) ratio and stroke risk is controversial. Our goal was to explore this relationship in individuals aged 45 and older enrolled in the China Health and Retirement Longitudinal Study (CHARLS).MethodsOur analysis encompassed 10,164 participants from the CHARLS cohorts. We applied the Cox proportional-hazards regression model to evaluate the potential correlation between the TG/HDL-C ratio and stroke incidence. Using a cubic spline function and smooth curve fitting within the Cox model allowed us to unearth a possible non-linear pattern in this relationship. We also conducted thorough sensitivity and subgroup analyses to deepen our understanding of the TG/HDL-C ratio’s impact on stroke risk.ResultsAdjusting for various risk factors, we observed a significant link between the TG/HDL-C ratio and increased stroke risk in individuals aged 45 and above (HR: 1.03, 95% CI 1.00–1.05, P = 0.0426). The relationship appeared non-linear, with an inflection at a TG/HDL-C ratio of 1.85. Ratios below this threshold indicated a heightened stroke risk (HR: 1.28, 95% CI 1.06–1.54, P = 0.0089), while ratios above it did not show a significant risk increase (HR: 1.01, 95% CI 0.98–1.04, P = 0.6738). Sensitivity analysis confirmed the robustness of these findings. Notably, non-smokers exhibited a stronger correlation between the TG/HDL-C ratio and stroke risk compared to past and current smokers.ConclusionOur investigation revealed a significant, yet non-linear, association between the TG/HDL-C ratio and the incidence of stroke among individuals aged 45 and above. Specifically, we found that stroke risk increased in correlation with TG/HDL-C ratio below the threshold of 1.85. These insights may guide healthcare providers in advising and developing more effective strategies for stroke prevention in this demographic.

Associations between non-insulin-based insulin resistance indices and heart failure prevalence in overweight/obesity adults without diabetes mellitus: evidence from the NHANES 2001–2018

BackgroundThe triglyceride glucose (TyG) index and triglyceride-to-high-density lipoprotein cholesterol (TG/HDL-C) ratio are recognized as simple non-insulin-based insulin resistance indices. Our study aimed to explore the relationship between these two indicators and heart failure (HF) in overweight or obesity individuals without diabetes.MethodsThis cross-sectional study selected 13,473 participants from the National Health and Nutrition Examination Survey (NHANES) 2001–2018 dataset. Weighted multivariable logistic regression and subgroup analysis were employed to evaluate the relationships between TyG index, TG/HDL-C ratio, and HF prevalence, respectively. Additionally, smooth curve fitting was utilized to analyze the dose–response relationships.ResultsA total of 13,473 obesity or overweight people without diabetes were included in this study through screening, among whom 291 (2.16%) had comorbid HF. The results of multivariable logistic regression suggested that the highest TyG index (OR = 2.4, 95% CI = 1.4–4.2, p = 0.002) and the highest TG/HDL-C ratio (OR = 1.2, 95% CI = 1.1–1.3, p < 0.001) both increased the prevalence of HF, especially in the non-Hispanic population. Dose–response relationships suggested nonlinear relationships between these two indicators and HF.ConclusionOur study demonstrated that elevated TyG index and TG/HDL-C ratio were closely associated with the prevalence of HF, and both exhibited nonlinear relationships with HF prevalence in overweight/obesity adults without diabetes. Based on these findings, additional prospective studies are needed for further validation.

Visual Functions Are Associated with Biomarker Changes in Alzheimer's Disease.

While various biomarkers of Alzheimer's disease (AD) have been associated with general cognitive function, their association to visual-perceptive function across the AD spectrum warrant more attention due to its significant impact on quality of life. Thus, this study explores how AD biomarkers are associated with decline in this cognitive domain. To explore associations between various fluid and imaging biomarkers and visual-based cognitive assessments in participants across the AD spectrum. Data from participants (N = 1,460) in the Alzheimer's Disease Neuroimaging Initiative were analyzed, including fluid and imaging biomarkers. Along with the Mini-Mental State Examination (MMSE), three specific visual-based cognitive tests were investigated: Trail Making Test (TMT) A and TMT B, and the Boston Naming Test (BNT). Locally estimated scatterplot smoothing curves and Pearson correlation coefficients were used to examine associations. MMSE showed the strongest correlations with most biomarkers, followed by TMT-B. The p-tau181/Aβ1-42 ratio, along with the volume of the hippocampus and entorhinal cortex, had the strongest associations among the biomarkers. Several biomarkers are associated with visual processing across the disease spectrum, emphasizing their potential in assessing disease severity and contributing to progression models of visual function and cognition.

Associations between weight-adjusted-waist index and telomere length: Results from NHANES: An observational study.

Previous studies have demonstrated the connection between obesity and telomere length. A recently devised metric for determining obesity, the weight-adjusted-waist index (WWI), offers a distinct advantage in predicting fat and lean mass by depicting weight-independent abdominal adiposity. This article presents the results of the inaugural study on the relationship between WWI and telomere length in adult populations. The cross-sectional investigation analyzed data from 3479 participants from the National Health and Nutrition Examination Survey (NHANES) conducted from 1999 to 2000. To inspect linear and nonlinear correlations, we adopted weighted multiple logistic regression analysis and smooth curve fit, respectively. In addition, threshold effects and subgroup analyses were accomplished. In the fully adapted model, a significant adverse association of WWI with telomere length was detected [β = -0.02, 95% CI: (-0.03, -0.00), P value = 0.01]. The adverse correlation remained consistent across all subcategories. We also discovered an inverted U-shaped curve linking WWI and telomere length, with a conspicuous inflection point of 10.07 cm/√kg. For the first time, our research demonstrated strong links between WWI and telomere length. The inflection point suggests that controlling WWI within an optimum range might be essential for aging and health.

Serum Klotho and insulin resistance: Insights from a cross-sectional analysis.

The prevalence of diabetes has surged globally, posing significant health and economic burdens. Insulin resistance underlies the initiation and development of type 2 diabetes. Klotho is a crucial endogenous antiaging factor, associated with atherosclerotic cardiovascular diseases, cancer, neurological disorders, and renal diseases. It additionally has a function in controlling glucose metabolism and holds promise as a new therapeutic target for diabetes. However, its relationship with insulin resistance remains unclear. This study utilizes the National Health and Nutrition Examination Survey (NHANES) 2007 to 2016 data to investigate the relationship between serum Klotho concentrations and insulin resistance. In this observational study, information from the NHANES spanning 2007 to 2016 was employed. The sample consisted of 6371 participants. Weighted linear regression model and chi-square tests were utilized to assess differences in continuous and categorical variables, respectively, among groups categorized by Klotho quartiles. The relationship between Klotho and HOMA-IR (homeostatic model assessment of insulin resistance) was studied using multiple linear regression. Smooth curve fitting was used to analyze nonlinear relationships and the inflection point was determined through a 2-stage linear regression method. After adjusting for multiple confounding factors, serum Klotho levels were found to be positively correlated with insulin resistance [0.90 (0.68, 1.13)]. This correlation is nonlinear and exhibits a saturation effect, with the inflection point identified at 1.24 pg/µL. When Klotho levels are below 1.24 pg/µL, for every unit increase in Klotho, HOMA-IR increases by 1.30 units. Conversely, when Klotho levels exceed 1.24 pg/µL, there is no correlation between HOMA-IR and Klotho. Subgroup analysis reveals that the relationship between HOMA-IR and Klotho varies depending on diabetes and body mass index (BMI). This positive correlation was most prominent in the obese nondiabetic population. There is a positive correlation between serum Klotho and insulin resistance.

Association between blood chromium and hepatic steatosis assessed by liver ultrasound transient elastography: National Health and Nutrition Examination Survey 2017-2020.

Hepatic steatosis is a significant pathological feature of fatty liver disease (FLD) which is widely spread with no effective treatment available. Previous studies suggest that chromium (Cr) intake reduces lipid deposition in the liver in animals. However, the connection between blood Cr and hepatic steatosis among humans remains inconclusive. Using the data from the National Health and Nutrition Examination Survey (NHANES) 2017-2020, we performed a cross-sectional analysis, including 4,926 participants. The controlled attenuation parameter (CAP) measured by the vibration controlled transient elastography (VCTE) was used to evaluate the degree of liver steatosis. Weighted univariate regression, multivariate linear regression, smooth fitting curves and subgroup analysis were used. In addition, we carried out trend tests, multiple interpolations, and interaction analyses to conduct sensitivity analyses. After adjusting with various covariables, multivariate linear regression analysis demonstrated a significant negative correlation between blood Cr and CAP [β (95% CI) = -5.62 (-11.02, -0.21)]. The negative correlation between blood Cr and CAP was more significant in the males, 50-59 years, overweight, hypercholesterolemia, HDL-C ≥ 65 mg/dL, HbA1c (5.70-6.10 %), HOMA-IR (0.12-2.76), total bilirubin (0.30-0.40 mg/dL), ever alcohol consumption subjects. Of note, the relationships between blood Cr and CAP followed a U-shaped curve in the smokers and non-smokers, with blood Cr thresholds of 0.48, 0.69 μg/L, respectively. There is an independently negative correlation between blood Cr and hepatic steatosis in American. Our study provides clinical researchers with a new insight into the prospective prevention of hepatic steatosis.

Nonlinear relationship between platelet count and 30-day in-hospital mortality in intensive care unit stroke patients: a multicenter retrospective cohort study.

Evidence of the relationship between platelet count and 30-day in-hospital mortality in ICU stroke patients is still scarce. Therefore, the purpose of this study was to explore the relationship between platelet count and 30-day in-hospital mortality among ICU stroke patients. We conducted a multicenter retrospective cohort study using data from 8,029 ICU stroke patients in the US eICU-CRD v2.0 database from 2014 to 2015. Utilizing binary logistic regression, smooth curve fitting, and subgroup analyses, we examined the link between platelet count and 30-day in-hospital mortality. The 30-day in-hospital mortality prevalence was 14.02%, and the mean platelet count of 223 × 109/L. Adjusting for covariates, our findings revealed an inverse association between platelet count and 30-day in-hospital mortality (OR = 0.975, 95% CI: 0.966, 0.984). Subgroup analyses supported the robustness of these results. Moreover, a nonlinear relationship was observed between platelet count and 30-day in-hospital mortality, with the inflection point at 163 × 109/L. On the left side of the inflection point, the effect size (OR) was 0.92 (0.89, 0.95), while on the right side, the relationship was not statistically significant. This study establishes an independent negative association between platelet count and 30-day in-hospital mortality in ICU stroke patients. Furthermore, a nonlinear relationship with a saturation effect was identified, suggesting that maintaining the platelet count around 163 × 109/L can reduce 30-day in-hospital mortality in these patients.

Association between dietary fiber intake and diabetic nephropathy among adult diabetes mellitus in the United States: A cross-sectional study

ObjectiveThere has been some evidence that dietary fiber may be associated with diabetic nephropathy (DN), but the relationship is still unclear. The purpose of this study was to examine the association between dietary fiber intake and DN. MethodsThis cross-sectional study used National Health and Nutrition Examination Survey (NHANES) data collected between 2007 and 2020. Weighted multivariate logistic regression was used to examine the relation between dietary fiber intake and DN. In addition, fitted smoothed curves were used to explore potential non-linear relationships. If non-linearity was observed, inflection points were further calculated by a recursive algorithm. ResultsThe study finally included 5964 subjects ≥20 years of age. The mean age was 60.8 ± 13.4 years with males (52.4 %), and non-Hispanic Whites (62.4 %), and the weighted prevalence of DN was 36.7 %. Dietary fiber was negatively associated with the risk of DN after controlling for all confounding variables (OR = 0.89, 95%CI: 0.80, 0.99). Smoothed curve fit plots of the dose relationship showed that dietary fiber intake was linearly related to DN, whereas males (inflection point of 8.0 g/d) and non-Hispanic Blacks (inflection point of 14.9 g/d) followed a non-linear inverted U-shaped curve relationship. In United States adults aged 20 and older, dietary fiber intake may be associated with a reduced risk of DN. ConclusionAppropriate increases in dietary fiber intake may offer potential benefits for DN. In conclusion, it appears that increasing dietary fiber intake may be one of the most effective strategies for the prevention and management of DN.

Hα Time Delays of Active Galactic Nuclei from the Zwicky Transient Facility Broadband Photometry

In our previous work on broadband photometric reverberation mapping (PRM), we proposed the interpolated cross-correlation function (ICCF)-Cut process to obtain the time lags of the Hα emission line from two broadband lightcurves via subtracting the continuum emission from the line band. Extending the work, we enlarge our sample to the Zwicky Transient Facility (ZTF) database. We adopt two criteria to select 123 type 1 active galactic nuclei (AGNs) with sufficient variability and smooth light curves from 3537 AGNs at z < 0.09 with more than 100 epoch observations in the g and r bands from the ZTF database. We calculate the Hα time lags for 23 of them that have previous spectroscopic reverberation mapping (SRM) results using the ICCF-Cut, Just Another Vehicle for Estimating Lags In Nuclei (JAVELIN), and χ 2 methods. Our obtained Hα time lags are slightly larger than the Hβ time lags, which is consistent with the previous SRM results and the theoretical model of the AGN broad-line region. The comparisons between the SRM and PRM lag distributions and between the subtracted emission line light curves indicate that after selecting AGNs with the two criteria, combining the ICCF-Cut, JAVELIN, and χ 2 methods provides an efficient way to get the reliable Hα lags from the broadband PRM. Such techniques can be used to estimate the black hole masses of a large sample of AGNs in large multiepoch photometric sky surveys such as the Legacy Survey of Space and Time and the survey from the Wide Field Survey Telescope in the near future.

The association between waist-to-height ratio and cognitive function in older adults

ABSTRACT Objectives The waist-to-height ratio (WHtR) is a simple, practical, and effective tool used to assess central obesity. Despite its usefulness, few studies have investigated the association between WHtR and cognitive function among older adults in the United States. This study aims to investigate the associations between WHtR and cognitive function. Methods The study sample comprised adults who participated in the National Health and Nutrition Examination Survey (NHANES) between 2011 and 2014. WHtR was calculated from measured waist circumference and height. Cognitive function was assessed using the digit symbol substitution test. A weighted multiple linear regression analysis was performed to evaluate the association between WHtR and cognitive function, with smooth curve fitting applied to detect non-linearities. Results Our analysis included 1709 participants over the age of 65. After adjusting for potential confounders, WHtR was found to have a negative association with cognitive function (β = −36.91, 95% CI: −54.54 to −19.29, P < 0.001). Subgroup analyzes stratified by sex and race showed that the negative correlation of WHtR with cognitive function remained in both men and women, as well as in non-Hispanic white and other races. Among women, the association between WHtR and cognitive function followed an inverted U-shaped curve, with an inflection point of 0.68. Conclusion This study provides evidence of a negative association between WHtR and cognitive function in older adults. These findings suggest that in advanced age, central obesity may have negative implications for cognitive function.

The association between flavonoids intake and hypertension in U.S. adults: A cross-sectional study from The National Health and Nutrition Examination Survey.

Although in vitro experiments have demonstrated the potential of flavonoid compounds in regulating blood pressure, there is still a lack of evidence from large population studies. We conducted a cross-sectional study using the National Health and Nutrition Examination Survey to investigate the relationship between flavonoid intake levels (natural log transformation) and hypertension events. A total of 15 752 participants aged over 20 years were included, and a weighted multivariable logistic regression analysis was performed to explore the relationship between total flavonoids, five sub types intake, and hypertension events. Smooth curve fitting was used to explore potential nonlinear relationships. Higher total flavonoids intake was associated with a lower risk of hypertension than the lowest group. The adjusted odds ratios (95% CIs) were 0.79 (0.70-0.88) for total flavonoids intake. Elevated total flavonoids intake levels were significantly and linearly associated with a lower risk of hypertension. For each unit increase in the total flavonoids intake level, the adjusted ORs for risk of hypertension decrease by 5% (OR 0.95; 95% CI, 0.92-0.98). In addition, in restricted cubic spline regression, we found that flavan-3-ols, anthocyanidins, and flavonols intake were linearly and negatively related to prevalence of hypertension. Flavones intake showed nonlinear associations with prevalence of hypertension with inflection points of -1.90. Within a certain range, a negative correlation exists between flavonoids intake and hypertension events. This finding provides insights into dietary modifications in the prevention of hypertension.