ABSTRACT
INTRODUCTION: Retinal vascular network changes may reflect the integrity of the cerebral microcirculation, and may be associated with cognitive impairment. METHODS: Associations of retinal vascular measures with cognitive function and MRI biomarkers were examined amongst Multi-Ethnic Study of Atherosclerosis (MESA) participants in North Carolina who had gradable retinal photographs at Exams 2 (2002 to 2004, n = 313) and 5 (2010 to 2012, n = 306), and detailed cognitive testing and MRI at Exam 6 (2016 to 2018). RESULTS: After adjustment for covariates and multiple comparisons, greater arteriolar fractal dimension (FD) at Exam 2 was associated with less isotropic free water of gray matter regions (ß = -0.0005, SE = 0.0024, p = 0.01) at Exam 6, while greater arteriolar FD at Exam 5 was associated with greater gray matter cortical volume (in mm3 , ß = 5458, SE = 20.17, p = 0.04) at Exam 6. CONCLUSION: Greater arteriolar FD, reflecting greater complexity of the branching pattern of the retinal arteries, is associated with MRI biomarkers indicative of less neuroinflammation and neurodegeneration.
Subject(s)
Atherosclerosis , Fractals , Humans , Retinal Vessels/diagnostic imaging , Atherosclerosis/diagnostic imaging , Neuroimaging , Biomarkers , CognitionABSTRACT
BACKGROUND: Age-related declines in cognitive function may begin in midlife. PURPOSE: To determine whether blood-based biomarkers of inflammation, metabolic dysregulation and neurotoxins are associated with risk of cognitive decline and impairment. METHODS: Baseline blood samples from the longitudinal Beaver Dam Offspring Study (2005-2008) were assayed for markers of inflammation, metabolic dysregulation, and environmental neurotoxins. Cognitive function was measured at baseline, 5-year (2010-2013) and 10-year (2015-2017) examinations. Participants without cognitive impairment at baseline and with cognitive data from at least one follow-up were included. Cox proportional hazards models were used to evaluate associations between baseline blood biomarkers and the 10-year cumulative incidence of cognitive impairment. Poisson models were used to estimate the relative risk (RR) of 5-year decline in cognitive function by baseline blood biomarkers. Models were adjusted for age, sex, education, and cardiovascular related risk factors. RESULTS: Participants (N = 2421) were a mean age of 49 years and 55% were women. Soluble vascular cell adhesion molecule-1 (sVCAM-1Tertile(T)3 vs T1-2 hazard ratio (HR) = 1.72, 95% confidence interval (CI) = 1.05,2.82) and hemoglobin A1C (HR = 1.75, 95% CI = 1.18,2.59, per 1% in women) were associated with the 10-year cumulative incidence of cognitive impairment. sVCAM-1 (RRT3 vs T1-2 = 1.45, 95% CI = 1.06,1.99) and white blood cell count (RR = 1.10, 95% CI = 1.02,1.19, per 103/µL) were associated with 5-year cognitive decline. CONCLUSIONS: Biomarkers related to inflammation and metabolic dysregulation were associated with an increased risk of developing cognitive decline and impairment. These results extend previous research in cognitive aging to early markers of cognitive decline in midlife, a time when intervention methods may be more efficacious.
Subject(s)
Cognitive Dysfunction , Neurotoxins , Humans , Female , Middle Aged , Male , Inflammation/epidemiology , Longitudinal Studies , Cognitive Dysfunction/epidemiology , Biomarkers , Risk FactorsABSTRACT
PURPOSE: Inflammation is associated with diabetic retinopathy development and progression, and previous studies have demonstrated that omega-3 polyunsaturated fatty acids have anti-inflammatory properties. Therefore, the goal of this study was to determine if omega-3 polyunsaturated fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are associated with decreased risk and severity of retinopathy in individuals with type 2 diabetes. METHODS: In a combined population of 1,356 individuals with type 2 diabetes from the Multi-Ethnic Study of Atherosclerosis and Genetics of Latino Diabetic Retinopathy cohorts, odds ratios using logistic regression were determined to assess the association between polyunsaturated fatty acids and retinopathy. RESULTS: In 1,356 participants with type 2 diabetes, individuals in the fourth quartile of DHA were 17% less likely to have retinopathy compared with the first quartile ( P = 0.009, CI: 0.72-0.95). Secondary analysis revealed 38% lower severity of retinopathy in individuals in the fourth quartile compared with the first quartile of DHA ( P = 0.006; CI: 0.44-0.87) and EPA + DHA ( P = 0.004; CI: 0.44-0.85). No significant associations were observed between EPA and retinopathy. CONCLUSION: DHA is inversely associated with the presence and severity of diabetic retinopathy. Increased intake of dietary sources of DHA may provide some protection against retinopathy in individuals with type 2 diabetes and warrants more research as a preventative option.
Subject(s)
Diabetes Mellitus, Type 2 , Diabetic Retinopathy , Fatty Acids, Omega-3 , Humans , Diabetes Mellitus, Type 2/complications , Diabetic Retinopathy/diagnosis , Eicosapentaenoic Acid , Docosahexaenoic Acids , Fatty Acids, UnsaturatedABSTRACT
Cerebral microvascular dysfunction may contribute to depression via disruption of brain structures involved in mood regulation, but evidence is limited. The retina allows for visualization of a microvascular bed that shares similarities with the cerebral microvasculature. We investigated the associations between baseline retinal arteriolar and venular calibers (central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE), respectively) and incident depressive symptoms in the Multi-Ethnic Study of Atherosclerosis (MESA). We used longitudinal data on 4,366 participants (mean age = 63.2 years; 48.5% women, 28.4% Black) without baseline depressive symptoms. Depressive symptoms, defined as Center for Epidemiologic Studies Depression Scale score ≥16 and/or use of antidepressant medication, were determined between 2002 and 2004 (baseline; MESA visit 2) and at 3 follow-up examinations conducted every 1.5-2 years thereafter. Fundus photography was performed at baseline. After a mean follow-up period of 6.1 years, 21.9% (n = 958) had incident depressive symptoms. After adjustment for sociodemographic, lifestyle, and cardiovascular factors, a 1-standard-deviation larger baseline CRVE was associated with a higher risk of depressive symptoms (hazard ratio = 1.10, 95% confidence interval: 1.02, 1.17), and a 1-standard-deviation larger baseline CRAE was not statistically significantly associated with incident depressive symptoms (hazard ratio = 1.04, 95% confidence interval: 0.97, 1.11). In this study, larger baseline CRVE, but not CRAE, was associated with a higher incidence of depressive symptoms.
Subject(s)
Atherosclerosis , Depression , Atherosclerosis/etiology , Depression/epidemiology , Female , Humans , Male , Middle Aged , Retina , Retinal Vessels , Risk FactorsABSTRACT
PURPOSE: To examine the association between omega-3 polyunsaturated fatty acids, docosahexaenoic acid, and eicosapentaenoic acid and age-related macular degeneration (AMD) in the Multi-Ethnic Study of Atherosclerosis cohort. METHODS: Multi-Ethnic Study of Atherosclerosis is a multicenter, prospective cohort study designed to identify risk factors for cardiovascular disease in four ethnic groups. Six thousand eight hundred and fourteen participants of White, African American, Hispanic/Latino, and Chinese descent, aged 45-84 years, were recruited, with those found to have cardiovascular disease excluded. Our study population included all Multi-Ethnic Study of Atherosclerosis participants with baseline polyunsaturated fatty acid measurements and retinal photography at Examination 5 (n = 3,772). Fundus photographs were assessed for AMD using a standard grading protocol. Relative risk regression (log link) determined associations between polyunsaturated fatty acid levels and AMD. RESULTS: There was a significant association between increasing docosahexaenoic acid levels and increasing docosahexaenoic acid + eicosapentaenoic acid levels with reduced risk for early AMD (n = 214 participants with early AMD, of which n = 99 (46.3%) are non-White). Eicosapentaenoic acid levels alone were not significantly associated with AMD. CONCLUSION: Our analysis suggests increasing levels of docosahexaenoic acid are associated with reduced risk for early AMD in a multiethnic cohort. This represents the first racially diverse study demonstrating an association between omega-3 polyunsaturated fatty acids and AMD risk.
Subject(s)
Atherosclerosis , Fatty Acids, Omega-3 , Macular Degeneration , Docosahexaenoic Acids , Eicosapentaenoic Acid , Ethnicity , Humans , Macular Degeneration/diagnosis , Macular Degeneration/epidemiology , Prospective Studies , Risk FactorsABSTRACT
AIM: To determine whether metformin's effects on carotid artery intima-media thickness (cIMT) in type 1 diabetes differ according to smoking status. METHODS: Regression model effect estimates for the effect of metformin versus placebo (double-blind) on carotid IMT were calculated as a subgroup analysis of the REMOVAL trial. RESULTS: In 428 randomized participants (227 never-smokers, 201 ever-smokers), averaged mean carotid IMT progression (per year) was reduced by metformin versus placebo in never-smokers (-0.012 mm, 95% CI -0.021 to -0.002; p = .0137) but not in ever-smokers (0.003 mm, 95% CI -0.008 to 0.014; p = .5767); and similarly in non-current smokers (-0.008 mm, 95% CI -0.015 to -0.00001; p = .0497) but not in current smokers (0.013 mm, 95% CI -0.007 to 0.032; p = .1887). Three-way interaction terms (treatment*time*smoking status) were significant for never versus ever smoking (p = .0373, prespecified) and non-current versus current smoking (p = .0496, exploratory). Averaged maximal carotid IMT progression (per year) was reduced by metformin versus placebo in never-smokers (-0.020 mm, 95% CI -0.034 to -0.006; p = .0067) but not in ever-smokers (-0.006 mm, 95% CI -0.020 to 0.008; p = .4067), although this analysis was not supported by a significant three-way interaction term. CONCLUSIONS: This subgroup analysis of the REMOVAL trial provides additional support for a potentially wider role of adjunct metformin therapy in cardiovascular risk management in type 1 diabetes, particularly for individuals who have never smoked cigarettes.
Subject(s)
Diabetes Mellitus, Type 1 , Metformin , Carotid Arteries , Carotid Intima-Media Thickness , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 1/drug therapy , Double-Blind Method , Humans , Metformin/therapeutic use , Risk Factors , Smokers , SmokingABSTRACT
SIGNIFICANCE: The macular ganglion cell-inner plexiform layer (mGCIPL) may serve as a quick and easily obtained measure of generalized neurodegeneration. Investigating factors associated with this thickness could help to understand neurodegenerative processes. PURPOSE: This study aimed to characterize and identify associated factors of the mGCIPL thickness in a Beaver Dam Offspring Study cohort of middle-aged U.S. adults. METHODS: Baseline examinations occurred from 2005 to 2008, with follow-up examinations every 5 years. Included participants had baseline data and measured mGCIPL at 10-year follow-up (N = 1848). The mGCIPL was measured using the Cirrus 5000 HD-OCT Macular Cube Scan. Associations between mean mGCIPL thickness and thin mGCIPL, defined as 1 standard deviation (SD) below the population mean, and baseline risk factors were investigated using generalized estimating equations. RESULTS: Participants (mean [SD] baseline age, 48.9 [9.3] years; 54.4% women) had mean (SD) mGCIPL thicknesses of 78.4 (8.1) µm in the right eye and 78.1 (8.5) µm in the left (correlation coefficient = 0.76). In multivariable models, age (-1.07 µm per 5 years; 95% confidence interval [CI], -1.28 to -0.86 µm), high alcohol consumption (-1.44 µm; 95% CI, -2.72 to -0.16 µm), higher interleukin 6 levels (50% increase in level: -0.23 µm; 95% CI, -0.45 to 0.00 µm), myopia (-2.55 µm; 95% CI, -3.17 to -1.94 µm), and glaucoma (-1.74 µm; 95% CI, -2.77 to -0.70 µm) were associated with thinner mGCIPL. Age (per 5 years: odds ratio [OR], 1.38; 95% CI, 1.24 to 1.53), diabetes (OR, 1.89, 95% CI, 1.09 to 3.27), myopia (OR, 2.11; 95% CI, 1.63 to 2.73), and increasing and long-term high C-reactive protein (ORs, 1.46 [95% CI, 1.01 to 2.11] and 1.74 [95% CI, 1.14 to 2.65], respectively) were associated with increased odds of thin mGCIPL. CONCLUSIONS: Factors associated cross-sectionally with mGCIPL thickness, older age, high alcohol consumption, inflammation, diabetes, myopia, and glaucoma may be important to neural retina structure and health and neuronal health system-wide.
Subject(s)
Nerve Fibers/pathology , Retinal Ganglion Cells/pathology , Adult , Aged , Aged, 80 and over , Aging/physiology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Organ Size , Risk Factors , Tomography, Optical Coherence , Young AdultABSTRACT
PURPOSE: The relationships of retinal drusen, retinal pigmentary abnormalities, and macular degeneration to age and sex were studied in 4926 people between the ages of 43 and 86 years who participated in the Beaver Dam Eye Study. METHODS: The presence and severity of various characteristics of drusen and other lesions typical of age-related maculopathy were determined by grading stereoscopic color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System. RESULTS: One or more drusen were present in the macular area of at least 1 eye in 95.5% of the population. People 75 years of age or older had significantly higher frequencies (P < 0.01) of the following characteristics than people 43 to 54 years of age: larger sized drusen (>125 /µm, 24.0% versus 1.9%), soft indistinct drusen (23.0% versus 2.1%), retinal pigment abnormalities (26.6% versus 7.3%), exudative macular degeneration (5.2% versus 0.1%), and geographic atrophy (2.0% versus 0%). CONCLUSION: These data indicate signs of age-related maculopathy are common in people 75 years of age or older and may pose a substantial public health problem.
Subject(s)
Macular Degeneration/epidemiology , Adult , Age Distribution , Aged , Aged, 80 and over , Disease Progression , Female , Geographic Atrophy/diagnosis , Geographic Atrophy/epidemiology , Humans , Incidence , Macula Lutea/pathology , Macular Degeneration/diagnosis , Male , Middle Aged , Photography , Prevalence , Retinal Drusen/diagnosis , Retinal Drusen/epidemiology , Retinal Pigment Epithelium/pathology , Risk Factors , Wisconsin/epidemiologyABSTRACT
BACKGROUND: Relationships between brain-derived neurotrophic factor (BDNF), insulin-like growth factor (IGF-1), aldosterone, and cognition in aging were evaluated in the population-based Epidemiology of Hearing Loss Study (1993 to present). METHODS: Beginning in 1998 to 2000, cognitive impairment was assessed by report of physician diagnoses and the Mini-Mental State Examination. In 2009 to 2010 and 2013 to 2016, information was collected on diagnosis of mild cognitive impairment/dementia. Decline in cognitive function was assessed by principal component analysis from additional tests administered during 2009 to 2010 and 2013 to 2016. BDNF, IGF-1, and aldosterone were measured in serum collected in 1998 to 2000. RESULTS: There were 1970 participants (mean age=66.9 y; 59.1% female) without cognitive impairment at baseline. Among women, low BDNF was associated with 16-year incident cognitive impairment [hazard ratio=1.76; 95% confidence interval (CI)=1.04, 2.98]. Among men, increasing IGF-1 was associated with decreased risk [per SD: relative risk (RR)=0.57; 95% CI=0.35, 0.92], whereas increasing aldosterone levels were associated with increased risk (per SD: RR=1.28; 95% CI=1.01, 1.62) for 5-year incident mild cognitive impairment/dementia. Overall, low BDNF was associated with increased risk (RR=1.52; 95% CI=1.02, 2.26) for 5-year cognitive decline. CONCLUSION: Low levels of serum BDNF and IGF-1 were associated with poorer cognition during aging. There may be differential biomarker effects by sex.
Subject(s)
Aging/physiology , Biomarkers/blood , Cognition/physiology , Cognitive Dysfunction/diagnosis , Protective Factors , Aged , Aldosterone/analysis , Aldosterone/blood , Brain-Derived Neurotrophic Factor/analysis , Brain-Derived Neurotrophic Factor/blood , Female , Humans , Insulin-Like Growth Factor I/analysis , Longitudinal Studies , Male , Neuropsychological Tests/statistics & numerical data , Prospective Studies , United StatesABSTRACT
PURPOSE: To examine the relationship between serum oxidized low-density lipoprotein (ox-LDL) cholesterol and the incidence of age-related macular degeneration (AMD) over a 25-year period in a sample of persons from the population-based Beaver Dam Eye Study (BDES). DESIGN: Observational prospective cohort study. PARTICIPANTS: A total of 4972 people from the BDES (aged 43-84 years and living in Beaver Dam, Wisconsin in 1988) seen during at least 1 of 6 examination phases at approximately 5-year intervals between 1988 and 2016. METHODS: A 50% random sample of participants (N = 2468) was selected for ox-LDL measurements. Stored frozen specimens from every examination phase were processed using an enzyme-linked immunosorbent assay from a single batch. All available intervals were included for a person, resulting in 6586 person-visits. MAIN OUTCOME MEASURES: Age-related macular degeneration was assessed using the Wisconsin Age-related Maculopathy Grading System, and severity was defined using a 5-step severity scale. The severity of the worse eye at each examination was used for analyses. A multi-state Markov (MSM) model was fit to simultaneously assess the ox-LDL relationship to all AMD transitions, including incidence of any AMD, incidence of late AMD, and worsening and improvement of AMD over the 25 years of the study. RESULTS: The mean (standard deviation) level of ox-LDL was 75.3 (23.1) U/L at the baseline examination. When adjusting for age, sex, ARMS2 and CFH risk alleles, and examination phase, the ox-LDL at the beginning of a period was not statistically significantly associated with the incidence of any AMD (hazard ratio per 10 U/L ox-LDL was 1.03, 95% confidence interval 0.98,1.09). Furthermore, ox-LDL was not associated with worsening anywhere along the AMD severity scale, nor with incidence of late AMD. The lack of relationships of ox-LDL to the incidence of any AMD or worsening of AMD remained after adjustment for history of statin use, smoking status, body mass index, and history of cardiovascular disease (data not shown). CONCLUSIONS: Our findings do not provide evidence for statistically significant relationships between ox-LDL and AMD disease development or worsening of AMD.
Subject(s)
Lipoproteins, LDL/blood , Macular Degeneration/epidemiology , Visual Acuity , Adult , Aged , Aged, 80 and over , Biomarkers/blood , Enzyme-Linked Immunosorbent Assay , Female , Follow-Up Studies , Humans , Incidence , Macular Degeneration/blood , Macular Degeneration/diagnosis , Male , Middle Aged , Oxidation-Reduction , Prognosis , Prospective Studies , Retinal Pigment Epithelium/pathology , Time Factors , United States/epidemiologyABSTRACT
Refractive errors, myopia, and hyperopia are common visual disorders greatly affecting older individuals. Refraction is determined by genetic factors but only a small percentage of its variation has been explained. We performed a genetic association analysis with three ocular phenotypes: spherical equivalent (a continous measure of refraction), axial length, and corneal curvature in 1,871 European-Americans from the Beaver Dam Eye Study. Individuals were genotyped on the Illumina exome array and imputed to the Haplotype Reference Consortium reference panel. After increasing the number of analyzed variants in targeted protein-coding regions 10-fold via imputation, we confirmed associations for two previously known loci with corneal curvature (chr4q12, rs2114039; g.55092626T > C, ß = -0.03 (95% confidence interval [CI]): -0.06, -0.01, P value = 0.01) and spherical equivalent (chr15q14, rs634990; g.35006073T > C, ß = -0.27, 95% CI: -0.45, -0.09, P value = 3.79 × 10-3 ). Despite increased single nucleotide polymorphism (SNP) density, we did not detect any novel significant variants after correction for multiple comparisons. In summary, we confirmed two previous loci associated with corneal curvature and spherical equivalent in a European-American population highlighting the potential biological role of those regions in these traits.
Subject(s)
Chromosomes, Human, Pair 15/genetics , Chromosomes, Human, Pair 4/genetics , Exome Sequencing/methods , Polymorphism, Single Nucleotide , Refractive Errors/genetics , White People/genetics , Aged , Aged, 80 and over , Chromosome Mapping , Female , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Male , Middle Aged , Phenotype , United States/ethnologyABSTRACT
AIMS/HYPOTHESIS: The aim of this study was to identify genetic variants associated with beta cell function in type 1 diabetes, as measured by serum C-peptide levels, through meta-genome-wide association studies (meta-GWAS). METHODS: We performed a meta-GWAS to combine the results from five studies in type 1 diabetes with cross-sectionally measured stimulated, fasting or random C-peptide levels, including 3479 European participants. The p values across studies were combined, taking into account sample size and direction of effect. We also performed separate meta-GWAS for stimulated (n = 1303), fasting (n = 2019) and random (n = 1497) C-peptide levels. RESULTS: In the meta-GWAS for stimulated/fasting/random C-peptide levels, a SNP on chromosome 1, rs559047 (Chr1:238753916, T>A, minor allele frequency [MAF] 0.24-0.26), was associated with C-peptide (p = 4.13 × 10-8), meeting the genome-wide significance threshold (p < 5 × 10-8). In the same meta-GWAS, a locus in the MHC region (rs9260151) was close to the genome-wide significance threshold (Chr6:29911030, C>T, MAF 0.07-0.10, p = 8.43 × 10-8). In the stimulated C-peptide meta-GWAS, rs61211515 (Chr6:30100975, T/-, MAF 0.17-0.19) in the MHC region was associated with stimulated C-peptide (ß [SE] = - 0.39 [0.07], p = 9.72 × 10-8). rs61211515 was also associated with the rate of stimulated C-peptide decline over time in a subset of individuals (n = 258) with annual repeated measures for up to 6 years (p = 0.02). In the meta-GWAS of random C-peptide, another MHC region, SNP rs3135002 (Chr6:32668439, C>A, MAF 0.02-0.06), was associated with C-peptide (p = 3.49 × 10-8). Conditional analyses suggested that the three identified variants in the MHC region were independent of each other. rs9260151 and rs3135002 have been associated with type 1 diabetes, whereas rs559047 and rs61211515 have not been associated with a risk of developing type 1 diabetes. CONCLUSIONS/INTERPRETATION: We identified a locus on chromosome 1 and multiple variants in the MHC region, at least some of which were distinct from type 1 diabetes risk loci, that were associated with C-peptide, suggesting partly non-overlapping mechanisms for the development and progression of type 1 diabetes. These associations need to be validated in independent populations. Further investigations could provide insights into mechanisms of beta cell loss and opportunities to preserve beta cell function.
Subject(s)
C-Peptide/blood , Chromosomes, Human, Pair 1/genetics , Diabetes Mellitus, Type 1/genetics , Genome-Wide Association Study , Histocompatibility Antigens Class I/genetics , Adolescent , Adult , Alleles , Cross-Sectional Studies , Diabetes Mellitus, Type 1/blood , Female , Gene Frequency , Genetic Predisposition to Disease , Genotype , Humans , Insulin-Secreting Cells/metabolism , Male , Polymorphism, Single Nucleotide , Young AdultABSTRACT
PURPOSE: To examine the relationships of retinal vessel geometric characteristics (RVGCs) to the incidence and progression of diabetic retinopathy (DR). DESIGN: Observational, prospective cohort study. PARTICIPANTS: Nine hundred ninety-six persons with type 1 diabetes mellitus (T1DM) and 1370 persons with type 2 diabetes mellitus (T2DM) seen at a baseline examination who were eligible for follow-up examinations at subsequent 5-year intervals. A total of 3846 person-interval data from these follow-up examinations are the basis for the analyses. METHODS: Diabetic retinopathy and macular edema were assessed by grading of 30° stereoscopic color fundus photographs. Retinal vessel geometric characteristics were assessed using the Singapore I Vessel Assessment program from a digitized copy of 1 of the field 1 fundus photographs obtained at baseline and follow-up. MAIN OUTCOME MEASURES: The 5-year incidence of any DR, progression of DR, and incidence of proliferative diabetic retinopathy (PDR) and clinically significant macular edema (CSME) in right eyes. RESULTS: Incident DR occurred in 45%, progression in 32%, PDR in 10%, and CSME in 5%. While adjusting for glycated hemoglobin, duration of diabetes, and other factors, retinal arteriolar simple tortuosity was associated significantly with the incidence of any DR (odds ratio [OR], 1.17; 95% confidence interval [CI], 1.01-1.35). Retinal venular branching angle was associated significantly with progression of DR (OR, 1.18; 95% CI, 1.03-1.36), retinal venular curvature tortuosity was associated significantly with the incidence of PDR (OR, 1.15; 95% CI, 1.01-1.30), and retinal venular branching angle (OR, 1.41; 95% CI, 1.10-1.82) was associated significantly with the incidence of CSME. There were no significant associations of other RVGCs with any of the DR outcomes in the full multivariate model. Inclusion of all possible RVGCs did not improve the predictive value of the models that already included retinal vessel diameter and baseline DR severity level. CONCLUSIONS: Retinal vessel geometric characteristics of the retinal venules were associated with progression of DR; however, most of the RVGCs measured from digitized fundus photographs added little to the assessment of risk of incidence and progression of DR when other risk factors were considered in T1DM and T2DM.
Subject(s)
Diabetic Retinopathy/diagnosis , Diabetic Retinopathy/epidemiology , Retinal Vessels/pathology , Adult , Aged , Arterial Pressure/physiology , Diabetes Mellitus, Type 1/complications , Diabetes Mellitus, Type 2/complications , Diabetic Retinopathy/physiopathology , Disease Progression , Female , Follow-Up Studies , Glycated Hemoglobin/metabolism , Humans , Incidence , Macular Edema/diagnosis , Macular Edema/epidemiology , Macular Edema/physiopathology , Male , Middle Aged , Photography , Prospective Studies , Retinal Vessels/diagnostic imaging , Risk FactorsABSTRACT
The conditional lifetime expectancy function (LEF) is the expected lifetime of a subject given survival past a certain time point and the values of a set of explanatory variables. This function is attractive to researchers because it summarizes the entire residual life distribution and has an easy interpretation compared with the popularly used hazard function. In this paper, we propose a general framework of backward multiple imputation for estimating the conditional LEF and the variance of the estimator in the right-censoring setting. Simulation studies are conducted to investigate the empirical properties of the proposed estimator and the corresponding variance estimator. We demonstrate the method on the Beaver Dam Eye Study data, where the expected human lifetime is modeled with smoothing-spline ANOVA given the covariates information including sex, lifestyle factors, and disease variables.
Subject(s)
Life Expectancy , Longevity/physiology , Models, Biological , Analysis of Variance , Body Mass Index , Humans , Sex Factors , Smoking , Social ClassABSTRACT
OBJECTIVES: The Dichotic Digits test (DDT) has been widely used to assess central auditory processing but there is limited information on observed DDT performance in a general population. The purpose of the study was to determine factors related to DDT performance in a large cohort spanning the adult age range. DESIGN: The study was cross-sectional and subjects were participants in the Epidemiology of Hearing Loss Study (EHLS), a population-based investigation of age-related hearing loss, or the Beaver Dam Offspring Study (BOSS), a study of aging in the adult offspring of the EHLS members. Subjects seen during the 4th EHLS (2008 to 2010) or the 2nd BOSS (2010 to 2013) examination were included (N = 3655 participants [1391 EHLS, 2264 BOSS]; mean age = 61.1 years, range = 21 to 100 years). The free and right ear-directed recall DDTs were administered using 25 sets of triple-digit pairs with a 70 dB HL presentation level. Pure-tone audiometric testing was conducted and the pure-tone threshold average (PTA) at 0.5, 1, 2, and 4 kHz was categorized using the worse ear: no loss = PTA ≤ 25 dB HL; mild loss = 25 < PTA ≤ 40 dB HL; moderate or marked loss = PTA > 40 dB HL. Cognitive impairment was defined as a Mini-Mental State Examination score < 24 (maximum = 30) or a self- or proxy-reported history of dementia or Alzheimer's disease. Demographic information was self-reported. General linear models were fit and multiple linear regression was performed. RESULTS: The mean total free recall DDT score was 76.7% (range = 21.3 to 100%). Less than 10% of the participants had a total free recall score below 60% correct. The mean right ear-directed recall score was 98.4% with 69% of the participants scoring 100% and another 15.5% scoring 98.7% (1 incorrect digit). In multivariable modeling of the total free recall scores, the predicted mean free recall score was 1 percentage point lower for every 5-year increase in age, 2.3 percentage points lower in males than females, 8.7 percentage points lower in participants with less than a high school degree than in those with college degrees, 6.8 percentage points lower in participants with a moderate or marked hearing loss compared with no hearing loss, and 8.3 percentage points lower in participants with cognitive impairment compared with those without cognitive impairment. These 5 factors were independently and significantly related to performance and accounted for 22.7% of the total variability in free recall scores. CONCLUSIONS: Substantial variation in the total free recall DDT scores but very little variation in the right ear-directed recall DDT scores was observed. Age, sex, education, hearing loss severity, and cognitive impairment were found to be significantly related to DDT scores but explained less than 25% of the total variability in total free recall scores. The right ear-directed recall DDT by itself may not be of benefit in assessing central auditory processing in a general population because of its limited variability but further evaluation of factors potentially related to free recall DDT variability may prove useful.
Subject(s)
Auditory Perception , Dichotic Listening Tests , Adult , Aged , Aged, 80 and over , Aging/physiology , Audiometry, Pure-Tone , Cohort Studies , Cross-Sectional Studies , Epidemiologic Studies , Female , Hearing Disorders/diagnosis , Hearing Disorders/epidemiology , Humans , Linear Models , Male , Middle Aged , Young AdultABSTRACT
PURPOSE: To determine the incidence and determinants of developing abnormalities on the 12-lead electrocardiogram (ECG) in persons with type 1 diabetes. METHODS: We evaluated the distribution of ECG abnormalities and risk factors for developing new abnormalities in 266 (mean age = 44 years ± 9.0; 50 % female) people with type 1 diabetes from the Wisconsin Epidemiologic Study of Diabetic Retinopathy. This analysis included participants with complete ECG data from study visit 5 (2000-2001) and follow-up ECGs from study visit 7 (2012-2014). ECG abnormalities were classified as major and minor according to Minnesota Code Classification. RESULTS: At baseline, 94 (35 %) participants had at least one ECG abnormality, including 13 major ECG abnormalities. At follow-up, 117 (44 %) participants developed at least one new ECG abnormality, including 35 new major ECG abnormalities. In a multivariable logistic regression model, older age (per 5-year increase: OR = 1.31, 95 % CI = 1.08, 1.60) was associated with the development of at least one new ECG abnormality, while serum HDL cholesterol (per 10-unit increase: OR = 0.98, 95 % CI = 0.96, 1.00) was protective against developing new ECG abnormalities. CONCLUSIONS: The development of new ECG abnormalities is common in type 1 diabetes. Older age and HDL cholesterol are independent risk factors for developing new ECG abnormalities. Further research is needed to determine whether routine ECG screening is indicated in people with type 1 diabetes to identify those with underlying subclinical coronary heart disease.
Subject(s)
Cardiovascular Diseases/epidemiology , Diabetes Mellitus, Type 1/physiopathology , Diabetic Retinopathy/epidemiology , Adult , Cardiovascular Diseases/diagnosis , Cohort Studies , Diabetic Retinopathy/diagnosis , Electrocardiography , Epidemiologic Studies , Female , Humans , Incidence , Male , Middle Aged , Predictive Value of Tests , Risk Factors , Wisconsin/epidemiologyABSTRACT
PURPOSE: Ocular refraction is measured in spherical equivalent as the power of the external lens required to focus images on the retina. Myopia (nearsightedness) and hyperopia (farsightedness) are the most common refractive errors, and the leading causes of visual impairment and blindness in the world. The goal of this study is to identify rare and low-frequency variants that influence spherical equivalent. METHODS: We conducted variant-level and gene-level quantitative trait association analyses for mean spherical equivalent, using data from 1,560 individuals in the Beaver Dam Eye Study. Genotyping was conducted using the Illumina exome array. We analyzed 34,976 single nucleotide variants and 11,571 autosomal genes across the genome, using single-variant tests as well as gene-based tests. RESULTS: Spherical equivalent was significantly associated with five genes in gene-based analysis: PTCHD2 at 1p36.22 (p = 3.6 × 10(-7)), CRISP3 at 6p12.3 (p = 4.3 × 10(-6)), NAP1L4 at 11p15.5 (p = 3.6 × 10(-6)), FSCB at 14q21.2 (p = 1.5 × 10(-7)), and AP3B2 at 15q25.2 (p = 1.6 × 10(-7)). The variant-based tests identified evidence suggestive of association with two novel variants in linkage disequilibrium (pairwise r(2) = 0.80) in the TCTE1 gene region at 6p21.1 (rs2297336, minor allele frequency (MAF) = 14.1%, ß = -0.62 p = 3.7 × 10(-6); rs324146, MAF = 16.9%, ß = -0.55, p = 1.4 × 10(-5)). In addition to these novel findings, we successfully replicated a previously reported association with rs634990 near GJD2 at 15q14 (MAF = 47%, ß = -0.29, p=1.8 × 10(-3)). We also found evidence of association with spherical equivalent on 2q37.1 in PRSS56 at rs1550094 (MAF = 31%, ß = -0.33, p = 1.7 × 10(-3)), a region previously associated with myopia. CONCLUSIONS: We identified several novel candidate genes that may play a role in the control of spherical equivalent. However, further studies are needed to replicate these findings. In addition, our results contribute to the increasing evidence that variation in the GJD2 and PRSS56 genes influence the development of refractive errors. Identifying that variation in these genes is associated with spherical equivalent may provide further insight into the etiology of myopia and consequent vision loss.
Subject(s)
Adaptor Protein Complex 3/genetics , Adaptor Protein Complex beta Subunits/genetics , Calcium-Binding Proteins/genetics , Membrane Proteins/genetics , Myopia/genetics , Nuclear Proteins/genetics , Polymorphism, Single Nucleotide , Salivary Proteins and Peptides/genetics , Seminal Plasma Proteins/genetics , Adult , Aged , Aged, 80 and over , Exome/genetics , Eye Proteins/genetics , Female , Genetic Predisposition to Disease , Genome-Wide Association Study , Genotyping Techniques , Humans , Linkage Disequilibrium , Male , Middle Aged , PhenotypeABSTRACT
PURPOSE: To describe the incidence of age-related macular degeneration (AMD) and associated risk factors in 4 racial/ethnic groups (white, black, Hispanic, and Chinese) residing in the United States. DESIGN: Prospective cohort study. PARTICIPANTS: A total of 3811 participants, aged 46 to 86 years, from the Multi-Ethnic Study of Atherosclerosis (MESA) cohort, with retinal data collected twice, on average, 8 years apart. METHODS: Fundus images, taken using a digital camera through dark-adapted pupils using a standard protocol and the same equipment at both study visits, were graded centrally for early and late AMD on the basis of drusen size, type and area, increased retinal pigment, retinal pigment epithelial depigmentation, neovascular lesions, and geographic atrophy using the modified Wisconsin Age-Related Maculopathy Grading System. Demographic, clinical, and laboratory measures were included in multivariable regression models to determine their impact on the variation in AMD incidence among racial/ethnic groups. MAIN OUTCOME MEASURES: Incident early and late AMD. RESULTS: The overall 8-year age- and sex-standardized incidence of early and late AMD were 4.1% and 2.3%, respectively, with incidence of early and late AMD highest in whites (5.3% and 4.1%, respectively), intermediate in Chinese (4.5% and 2.2%, respectively) and Hispanics (3.3% and 0.8%, respectively), and lowest in blacks (1.6% and 0.4%, respectively). By adjusting for age and sex, blacks had a 70% lower risk of developing early AMD than whites, and this decreased only slightly to a 67% lower risk after multivariable adjustment. By adjusting for age, sex, and race/ethnicity, hyperopia was associated with early AMD (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.04-2.20), as was astigmatism (OR, 1.47; 95% CI, 1.00-2.16), but not myopia (P = 0.29). Age, race/ethnicity, current smoking, hyperopia, and AMD-susceptibility genotypes Complement Factor H (CFH) RS1061170 and Age Related Maculopathy Susceptibility 2 (ARMS2) RS3793917 were independently associated with incident early AMD in multivariable models for the combined sample. However, the only statistically significant factor consistently associated with incident early AMD across the 4 racial/ethnic groups was increasing age. Risk factors for late AMD were not assessed because of its low incidence, particularly across racial/ethnic groups. CONCLUSIONS: Variation in the incidence of early AMD exists among racial/ethnic groups in the United States and is not explained by the clinical, genetic, and environmental factors included in this study.
Subject(s)
Atherosclerosis/ethnology , Ethnicity/statistics & numerical data , Geographic Atrophy/ethnology , Wet Macular Degeneration/ethnology , Aged , Aged, 80 and over , Cohort Studies , Complement Factor H/genetics , Female , Geographic Atrophy/diagnosis , Geographic Atrophy/genetics , Humans , Incidence , Male , Middle Aged , Prospective Studies , Proteins/genetics , Risk Factors , Surveys and Questionnaires , United States/epidemiology , Wet Macular Degeneration/diagnosis , Wet Macular Degeneration/geneticsABSTRACT
BACKGROUND: Vitamin D status has been hypothesized to protect against development of diabetic retinopathy via its anti-inflammatory and anti-angiogenic properties. Additionally, in vitro and in vivo studies suggest vitamin D favorably influences blood pressure and blood glucose control, strong risk factors for diabetic retinopathy. We examined the association between vitamin D status and prevalent diabetic retinopathy in participants with diabetes from a population-based cohort. METHODS: Among participants in the Atherosclerosis Risk in Communities (ARIC) study with diabetes at visit 3 (1993-1995), 1339 (906 Caucasians, 433 African Americans) had serum 25-hydroxyvitamin (25[OH]D) concentrations assessed at visit 2 (1989-1992) and nonmydriatic retinal photographs taken at visit 3. Dietary intake of vitamin D was assessed at visit 1 (1987-1989). Logistic regression was used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) for diabetic retinopathy by categories of season-adjusted 25(OH)D (<30 [referent], 30-<50, 50-<75 and ≥75 nmol/L), by quartile of vitamin D intake (IU/day), and use of vitamin D or fish oil supplements (yes/no). P for trend was estimated using continuous 25(OH)D or vitamin D intake. ORs were adjusted for race, and duration of diabetes. We further adjusted for HBA1c and hypertension to examine if 25(OH)D influenced diabetic retinopathy via its effects on either glycemic control or blood pressure. RESULTS: ORs (95 % CIs) for retinopathy, adjusted for race and duration, were 0.77 (0.45-1.32), 0.64 (0.37-1.10), and 0.39 (0.20-0.75), p for trend = 0.001, for participants with 25(OH)D of 30-<50, 50-<75, and ≥75 nmol/L, respectively. Further adjustment for hypertension minimally influenced results (data not show), but adjustment for HBA1c attenuated the OR among those with 25(OH)D ≥75 (0.47 [0.23-0.96], p for trend = 0.030). No statistically significant association was observed between vitamin D intake from foods or supplements and retinopathy. CONCLUSIONS: 25(OH)D concentrations ≥75 nmol/L were associated with lower odds of any retinopathy assessed 3 years later. We speculate this may be due in part to vitamin D's influence on blood glucose control.
Subject(s)
Black or African American , Diabetic Retinopathy/prevention & control , Dietary Supplements , Vitamin D Deficiency/prevention & control , Vitamin D/analogs & derivatives , White People , Aged , Biomarkers/blood , Cross-Sectional Studies , Diabetic Retinopathy/diagnosis , Diabetic Retinopathy/ethnology , Female , Humans , Logistic Models , Male , Middle Aged , Multivariate Analysis , Odds Ratio , Prevalence , Prospective Studies , Protective Factors , Risk Factors , Time Factors , United States/epidemiology , Vitamin D/blood , Vitamin D Deficiency/blood , Vitamin D Deficiency/diagnosis , Vitamin D Deficiency/ethnologyABSTRACT
Nonsteroidal anti-inflammatory drugs (NSAIDs) may prevent dementia, but previous studies have yielded conflicting results. This study estimated the association of prior NSAID use with incident cognitive impairment in the population-based Epidemiology of Hearing Loss Study (EHLS, n=2422 without cognitive impairment in 1998-2000). Prospectively collected medication data from 1988-1990, 1993-1995, and 1998-2000 were used to categorize NSAID use history at the cognitive baseline (1998-2000). Aspirin use and nonaspirin NSAID use were separately examined. Cox regression models were used to estimate the associations between NSAID use history at baseline and incident cognitive impairment in 2003-2005 or 2009-2010. Logistic regression analyses were used to estimate associations with a second outcome, mild cognitive impairment/dementia, available in 2009-2010. Participants using aspirin at baseline but not 5 years prior were more likely to develop cognitive impairment (adjusted hazard ratio=1.77; 95% confidence interval=1.11, 2.82; model 2), with nonsignificant associations for longer term use. Nonaspirin NSAID use was not associated with incident cognitive impairment or mild cognitive impairment/dementia odds. These results provided no evidence to support a potential protective effect of NSAIDs against dementia.