Yu-Shan Sun

Examining the Association Between Quadriceps Strength and Cognitive Performance in the Elderly.

AbstractEmerging evidences showed impaired muscle strength was prevalent in older adults with mild cognition impairment or dementia. However, little was known about the role of quadriceps strength in the cognition decline among older population. The objective of our study was to investigate the relation between quadriceps strength and cognitive performance. Using data from the National Health and Nutrition Examination Survey (1999–2002), a total of 1799 participants aged ≥60 years were enrolled in the study. Every subject completed a household interview, digit symbol substitution test (DSST), physical performances, and a questionnaire regarding personal health. Estimation of relationship between quadriceps strength and cognition was using multiple linear regression and quartile-based analysis with an extended-model approach for covariates adjustment. In a model adjusted for demographics, chronic diseases, health behaviors, and levels of folate and vitamin B12, the level of quadriceps strength was significantly associated with the scores of DSST. The &bgr; coefficient interpreted as change of DSST scores for each Newton increment in quadriceps strength comparing participants in the highest quartile of quadriceps strength to those in the lowest quartile was 5.003 (95% confidence interval, 2.725–7.281, P < 0.001). The trends of incremental DSST score across increasing quartiles of quadriceps strength were statistically significant (all P for trend <0.001). Higher quadriceps strength was associated with better cognitive performance.

Components of Metabolic Syndrome as Risk Factors for Hearing Threshold Shifts

Background Hearing loss was a common, chronically disabling condition in the general population and had been associated with several inflammatory diseases. Metabolic syndrome, which was associated with insulin resistance and visceral obesity, was considered a chronic inflammatory disease. To date, few attempts had been made to establish a direct relationship between hearing loss and metabolic syndrome. The aim of the present study was to investigate the relationship between metabolic syndrome and hearing loss by analyzing the data in the reports of the National Health and Nutrition Examination Survey 1999–2004. Methods This study included 2100 participants aged ≤ 65 years who enrolled in the National Health and Nutrition Examination Survey (1999–2004). We examined the relationship between the presence of different features of metabolic syndrome in the participants and their pure-tone air-conduction hearing thresholds, including low-frequency and high-frequency thresholds. Results After adjusting for potential confounders, such as age, medical conditions, and smoking status, the participants with more components of metabolic syndrome were found to have higher hearing thresholds than those with fewer components of metabolic syndrome (p < 0.05 for a trend). The low-frequency hearing threshold was associated with individual components of metabolic syndrome, such as abdominal obesity, high blood pressure, elevated triglycerides, and a low level of high-density lipoprotein cholesterol (HDL-C) (p < 0.05 for all parameters). Conclusions The results indicated that the presence of a greater number of components of metabolic syndrome was significantly associated with the hearing threshold in the US adult population. Among the components of metabolic syndrome, the most apparent association was observed between low HDL and hearing loss.

Components of Metabolic Syndrome and the Risk of Disability among the Elderly Population

The direct relationship between metabolic syndrome (MetS) and function disability has not been established. The aim of the present study was to investigate the relationship between MetS and functional disability in the elderly. This retrospective observational study included 1,778 participants aged 60–84 years from the National Health and Nutrition Examination Survey (1999–2002). Impairments in activities of daily living (ADL), instrumental activities of daily living (IADL), leisure and social activities (LSA), lower extremity mobility (LEM), and general physical activities (GPA) were assessed. Additionally, the associations between the features of MetS and disability were evaluated. MetS was associated with a high prevalence of functional dependence in ADL, IADL, LSA, LEM, and GPA. After adjusting for potential confounders, a high number of MetS components was found to be associated with increased disability (P = 0.002). Additionally, associations were observed between MetS components, including abdominal obesity and high triglycerides levels, and functional dependence in ADL, IADL, LSA, LEM, and GPA (all, P < 0.05). A linear increase in disability might be associated with the number of MetS components in an elderly population. Additionally, MetS abnormalities, particularly abdominal obesity and high triglycerides levels, might be highly predictive of functional dependence in the elderly.

All-cause mortality risk in elderly individuals with disabilities: a retrospective observational study

Objectives Disability is considered an important issue that affects the elderly population. This study aimed to explore the relationship between disability and all-cause mortality in US elderly individuals. Design Retrospective and longitudinal designs. Setting Data from the National Health and Nutrition Examination Survey (NHANES 1999–2002) conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention. Participants A total of 1834 participants in the age range 60–84 years from NHANES 1999–2002. Main outcome measures We acquired five major domains of disability (activities of daily living (ADL), general physical activities (GPA), instrumental ADL (IADL), lower extremity mobility (LEM) and leisure and social activities (LSA)) through self-reporting. We applied an extended-model approach with Cox (proportional hazards) regression analysis to investigate the relationship between different features of disability and all-cause mortality risk in the study population. Results During a mean follow-up of 5.7 years, 77 deaths occurred. An increased risk of all-cause mortality was identified in elderly individuals with disability after adjustment for potential confounders (HR 2.23; 95% CI 1.29 to 3.85; p=0.004). Participants with more than one domain of disability were associated with a higher risk of mortality (ptrend=0.047). Adjusted HRs and 95% CIs for each domain of disability were 2.53 (1.49 to 4.31), 1.99 (0.93 to 4.29), 1.74 (0.72 to 4.16), 1.57 (0.76 to 3.27) and 1.52 (0.93 to 2.48) for LEM, LSA, ADL, IADL and GPA, respectively. Conclusions The results of this study support an increased association between disability and all-cause mortality in the elderly in the USA. Disability in LEM may be a good predictor of high risk of all-cause mortality in elderly subjects.

Association between fluid intake and kidney function, and survival outcomes analysis: a nationwide population-based study

Objectives Fluid intake, one of the most common daily activities, has not been well studied in chronic kidney disease (CKD) populations, and clinical outcomes are rarely addressed. The aim of this nationwide study is to explore the influence of daily fluid intake on cardiovascular and all-cause mortality and its association with renal function. Design Observational cohort study. Participants In all, 2182 participants aged more than 20 years participated in the Third National Health and Nutrition Examination Survey (1988–1994). Main outcome measures Survival outcomes in patients with or without CKD, using multiple variable adjusted Cox proportional hazard models. Results In a longitudinal survey with a median follow-up length of 15.4 years, 1080 participants died and 473 cardiovascular deaths were recorded. For all-cause mortality in the CKD group, individuals in the highest quartile of fluid intake (≧3.576 L/day) had better survival outcomes than those in the lowest quartile of fluid intake (≤2.147 L/day) (p=0.029) after adjustment of several pertinent variables. Conclusions Although the interpretation of this observational study was limited by the failure to identify the compositions of ingested fluids, adequate hydration may offer some advantages in patients with CKD. However, the underlying pathophysiological mechanisms of the responses of normal and injured kidneys to chronic changes in fluid consumption warrant further investigation.

The association of uric acid with the risk of metabolic syndrome, arterial hypertension or diabetes in young subjects- An observational study

BACKGROUND A growing number of studies are available to shed some light on the association between uric acid (UA) and cardiovascular diseases. However, there have been few studies to support a causal link between UA, metabolic syndrome (MetS), diabetes mellitus (DM) and hypertension (HTN) in young subjects. METHODS From the Health Examination Registration System of Taiwanese military service during the period 2013-2015, there were 46,561 eligible participants who were 20years old or older in our study. Different analytical steps of analysis were performed to examine the association between UA and cardiometabolic risk using logistic regression, receiver operating characteristic (ROC) curve analysis and Cox regression. RESULTS For total population, serum UA had significant associations with the presence of MetS (OR=2.08, 95% CI=1.51-2.87), DM (OR=2.59, 95% CI=1.09-6.19) and HTN (OR=1.49, 95% CI=1.07-2.07) in the cross-sectional analysis. According to the cut-off values of UA calculating by the ROC curve analysis in each sex/age subgroup, the association between UA and incident adverse outcomes were analyzed in a longitudinal study. In male, higher UA significantly increased the risks for developing MetS in 30-40years (HR=1.12, 95% CI=1.01-1.25), DM in <30years (HR=2.75, 95% CI=1.38-5.45) and HTN in all subgroups (HR=1.17, 95% CI=1.01-1.37; HR=1.65, 95% CI=1.08-2.53; HR=1.72, 95% CI=1.22-2.43). In females, a higher UA was significantly associated with an increased risk of incident MetS in >40years (HR=2.99, 95% CI=1.34-6.64), HTN in >40years (HR=2.58, 95% CI=1.02-6.55), and no increased risk of DM. CONCLUSIONS Our study concluded that serum UA is an important predictor for the risk of incident MetS, DM, and HTN in adults, especially in male population.

Calf Circumference as a Novel Tool for Risk of Disability of the Elderly Population

Disability became increasingly common with age, and crude rates of disability were rising around the globe. The aim of this study was to investigate the association between calf circumference (CC) and disability in the U.S. elderly population. From the 1999–2006 National Health and Nutrition Examination Survey, a total of 4,245 participants with an age range of 60–84 years were included. Disability was defined as the total number of difficulties within the following 5 major domains of disability, such as activities of daily living (ADL), instrumental ADL, general physical activities, lower extremity mobility, and leisure and social activities. The association between CC and disability was investigated through the regression model adjusted for multiple covariates. According to the fully adjusted model regarding disability, the β coefficients for each quartile of increasing CC were −0.041 for quartile 2 (P = 0.096), −0.060 for quartile 3 (P = 0.027), and −0.073 for quartile 4 (P = 0.026) respectively, compared with lowest quartile. There was a negative association between CC and disability among the elderly population. Calf circumference may be a novel risk assessment for disability of elderly people.

Serum Uric Acid Relation for Hearing Threshold Shift.

Objectives The effects of serum uric acid (UA) level on a variety of diseases were found from experimental and observational studies via oxidative stress and anti-oxidants. However, research on the association of UA and hearing thresholds is relatively sparse. We investigated this issue in the U.S. general population to evaluate the relationship of serum UA levels and pure tone threshold of hearing. Methods Forty four thousand eighty four eligible participants aged 20 to 69 years who have serum UA data and received Audiometry Examination Component were enrolled from the National Health and Nutrition Examination Survey 1999–2004. Hearing thresholds (dB) as a pure tone average at low frequencies (0.5, 1, 2 kHz) and at high frequencies (3, 4, 6, and 8 kHz) were computed. Multivariate linear regression models and tertile-based analysis with an extended-model approach for covariates adjustment were used to assess the correlation between serum UA level and hearing thresholds. Results In the adjusted mode of tertile-based analysis, the regression coefficients elucidated as the change of log-transformed mean hearing thresholds upon comparing participants in the highest tertile of serum UA to those in the lowest tertile were –0.067 (P=0.023) in high frequency and –0.058 (P=0.054) in low frequency. After adjusting for multiple pertinent covariates, inverse association between tertiles of serum UA and hearing thresholds remained essentially unchanged. The negative trends between serum UA and hearing thresholds were statistically significant (P for trends <0.05) in tertile-based multiple linear regressions. Conclusion Individuals with elevated UA levels independently were found to be inversely associated with hearing thresholds for pure tone audiometry in a nationally representative sample of U.S. adults.

Role of Educational Status in Explaining the Association between Body Mass Index and Cognitive Function

Abstract Preserving physical and cognitive function becomes an important issue as people age. A growing number of studies have found that the correlation between body mass index (BMI) and cognitive function changes in different age groups. It is obvious that higher educational status is linked to higher cognitive function in terms of numerous risk factors that influence cognitive function. This study aimed to investigate the interplay between obesity and cognitive function categorized by different educational status. This study included 5021 participants aged 20 to 59 years who completed 3 neurocognitive function tests, including a simple reaction time test (SRTT), a symbol digit substitution test (SDST), and a serial digit learning test (SDLT) as reported in the National Health and Nutrition Examination Survey (NHANES) III database. The associations between neurocognitive function and BMI were analyzed using multivariate linear regression while controlling for confounders. After adjusting for pertinent covariates in mode 3, the &bgr; coefficients in the female participants with more than 12 years of education (interpreted as change of 3 neurocognitive function tests for each increment in BMI) comparing obesity groups to those with normal BMI were 16.2 (P < 0.001 for SRTT), 0.14 (P < 0.05 for SDST), and 0.9 (P < 0.05 for SDLT). Male participants with more than 12 years of education and female participants with fewer than 12 years of education demonstrated increased impairment as their BMI increased. However, this association was not significant after adjustments. Obese individuals had worse neurocognitive function than those of normal weight or overweight, especially in women with a high educational level.

Examining the association between serum lactic dehydrogenase and all-cause mortality in patients with metabolic syndrome: a retrospective observational study.

Objectives Emerging evidence indicates that elevated serum lactic dehydrogenase (LDH) levels are associated with increased cardiovascular mortality, but the mechanisms for this relationship remain uncertain. Since metabolic syndrome (MetS) is correlated with a higher risk of cardiovascular complications, we investigated the joint association between serum LDH levels and all-cause mortality in the US general population with MetS. Design Retrospective study. Setting The USA. Participants A retrospective observational study of 3872 adults with MetS and 7516 adults without MetS in the National Health and Nutrition Examination Survey III was performed. Main outcome measures Participants with and without MetS were both divided into 3 groups according to their serum LDH level. Multivariable Cox regression analyses and Kaplan-Meier survival probabilities were used to jointly relate all-cause, cardiovascular and cancer mortality risk to different serum LDH levels. Results For all-cause mortality in participants with MetS, multivariable adjusted HRs were 1.006 (95% CI 0.837 to 1.210; p=0.947) for serum LDH of 149–176 U/L compared with 65–149 U/L, and 1.273 (95% CI 1.049 to 1.547; p=0.015) for serum LDH of 176–668 U/L compared with 65–149 U/L. Conclusions Results support a positive association between higher level of serum LDH and mortality from all causes in individuals with MetS.