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It is unknown whether the impact of high diet quality and physical activity depends on the level of polygenic risk score (PRS) in different ancestries. Our cross-sectional study utilized de-identified data from 1987-2010 for self-reported European Americans (n = 6575) and African Americans (n = 1606). The high-risk PRS increased ASCVD risk by 59% (Risk Ratio (RR) = 1.59; 95% Confidence Interval:1.16-2.17) in the highest tertile for African Americans and by 15% (RR = 1.15; 1.13-1.30) and 18% (RR = 1.18; 1.04-1.35) in the second and highest tertiles compared to the lowest tertile in European Americans. Within the highest PRS tertiles, high physical activity-diet combinations (Dietary Approaches to Stop High Blood Pressure (DASH), Mediterranean, or Southern) reduced ASCVD risks by 9% (RR = 0.91; 0.85-0.96) to 15% (RR = 0.85; 0.80-0.90) in European Americans; and by 13% (RR = 0.87; 0.78-0.97) and 18% (RR = 0.82; 0.72-0.95) for DASH and Mediterranean diets, respectively, in African Americans. Top molecular pathways included fructose metabolism and catabolism linked to obesity, insulin resistance, and type 2 diabetes. Additional molecular pathways for African Americans were Vitamin D linked to depression and aging acceleration and death signaling associated with cancer. Effects of high diet quality and high physical activity can counterbalance the influences of genetically high-risk PRSs on ASCVD risk, especially in African Americans.
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Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Dieta Mediterránea , Humanos , Enfermedades Cardiovasculares/genética , Enfermedades Cardiovasculares/prevención & control , Factores de Riesgo , Patrones Dietéticos , Puntuación de Riesgo Genético , Estudios TransversalesRESUMEN
Background: It is unknown whether the impact of high diet-quality and physical activity (PA) depends on the level of polygenic risk score (PRS) in different ancestries. Objective: Determine the associations and interactions between high-risk PRSs, dietary patterns, and high PA with atherosclerotic cardiovascular disease (ASCVD) in European Americans (EAs) and African Americans (AAs). Another aim determined the molecular pathways of PRS-mapped genes and their relationships with dietary intake. Methods: Cross-sectional analyses utilized de-identified data from 1987-2010 from 7-National Heart, Lung, and Blood Institute Candidate Gene Association Resource studies from the Database of Genotypes and Phenotypes studies for EAs (n=6,575) and AAs (n=1,606). Results: The high-risk PRS increased ASCVD risk by 59% (Risk Ratio=1.59;95% Confidence Interval:1.16-2.17) in the highest tertile for AAs and by 15% (RR=1.15;1.13-1.30) and 18% (RR=1.18;1.04-1.35) in the second and highest tertiles compared to the lowest tertile in EAs. Within the highest PRS tertiles, high PA-diet combinations (Dietary Approaches to Stop High Blood Pressure (DASH), or Mediterranean, or Southern) reduced ASCVD risks by 9% (RR=0.91;0.85-0.96) to 15% (RR=0.85;0.80-0.90) in EAs; and by 13% (RR=0.87;0.78-0.97) and 18% (RR=0.82;0.72-0.95) for the DASH and Mediterranean diets, respectively in AAs. Top molecular pathways included fructose metabolism and catabolism linked to obesity, insulin resistance, and type 2 diabetes in both ancestries. Additional molecular pathways for AAs were Vitamin D linked to depression and aging acceleration; and death signaling associated with cancer. Conclusions: Effects of high diet-quality and high PA can counterbalance the influences of genetically high-risk PRSs on ASCVD risk, especially in AAs.
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BACKGROUND: Carbohydrate and protein dietary proportions have been debated as to whether higher or lower levels are optimal for diabetes metabolic control. OBJECTIVE: The objective of this study was to investigate the associations, interactions, and mediational relationships between a polygenic risk score (PRS), carbohydrate and protein intake, and physical activity level on type 2 diabetes (T2DM) by genetic ancestry, in European Americans and African Americans. A secondary objective examined the biological pathways associated with the PRS-linked genes and their relationships to dietary intake. METHODS: We performed a cross-sectional study in 9,393 participants: 83.3% European Americans and 16.7% African Americans from 7-NHLBI Care studies obtained from the database of Genotypes and Phenotypes. The main outcome was T2DM. Carbohydrate and protein intake derived from food frequency questionnaires were calculated as percent calories. Data were analyzed using multivariable generalized estimation equation models to derive odds ratios (OR) and 95% confidence intervals (CI). Ancestry-specific PRSs were constructed using joint-effects Summary Best Linear Unbiased Estimation in the train dataset and replicated in the test dataset. Mediation analysis was performed using VanderWeele's method. RESULTS: The PRS in the highest tertile was associated with higher risk of T2DM in European Americans (OR = 1.25;CI = 1.03-1.51) and African Americans (OR = 1.54;1.14-2.09). High carbohydrate and low protein intake had lower risks of T2DM when combined with the PRS after adjusting for covariates. In African Americans, high physical activity combined with the high PRS and high protein diet was associated with a 28% lower incidence of T2DM when compared to low physical activity. In mediational models in African Americans, the PRS-T2DM association was mediated by protein intake in the highest tertile by 55%. The top PRS tertile had the highest magnitude of risks with metabolic factors that were significantly associated with T2DM, especially in European Americans. We found metabolic pathways associated with the PRS-linked genes that were related to insulin/IGF and ketogenesis/ketolysis that can be activated by moderate physical activity and intermittent fasting for better T2DM control. CONCLUSIONS: Clinicians may want to consider diets with a higher portion of carbohydrates than protein, especially when the burden of high-risk alleles is great in patients with T2DM. In addition, clinicians and other medical professionals may want to emphasize the addition of physical activity as part of treatment regimen especially for African Americans. Given the metabolic pathways we identified, moderate physical activity and intermittent fasting should be explored. Researchers may want to consider longitudinal or randomized clinical trials to determine the predictive ability of different dietary patterns to inhibit T2DM in the presence of obesity and an elevated PRS.
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Diabetes Mellitus Tipo 2 , Humanos , Estudios Transversales , Factores de Riesgo , Obesidad , Dieta con Restricción de ProteínasRESUMEN
BACKGROUND: Associations have been observed among genetic variants, dietary patterns, and metabolic syndrome (MetS). A gap in knowledge is whether a genetic risk score (GRS) and dietary patterns interact to increase MetS risk among African Americans. We investigated whether MetS risk was influenced by interaction between a GRS and dietary patterns among Whites and African Americans. A secondary aim examined if molecular genetic clusterings differed by racial ancestry. METHODS: We used longitudinal data over 4-visits (1987-1998) that included 10,681 participants aged 45-64y at baseline from the Atherosclerosis Risk in Communities study (8451 Whites and 2230 African Americans). We constructed a simple-count GRS as the linear weighted sum of high-risk alleles (0, 1, 2) from cardiovascular disease polymorphisms from the genome-wide association studies catalog associated with MetS risk. Three dietary patterns were determined by factor analysis of food frequency questionnaire data: Western, healthy, and high-fat dairy. MetS was defined according to the 2016 National Cholesterol Education Program Adult Treatment Panel III criteria but used 2017 American Heart Association/American College of Cardiology criteria for elevated blood pressure. Analyses included generalized linear model risk ratios (RR), 95% confidence intervals (CI), and Bonferroni correction for multiple testing. RESULTS: The Western dietary pattern was associated with higher risk for MetS across increasing GRS tertiles among Whites (p < 0.017). The high-fat dairy pattern was protective against MetS, but its impact was most effective in the lowest GRS tertile in Whites (RR = 0.62; CI: 0.52-0.74) and African Americans (RR = 0.67; CI: 0.49-0.91). Among each racial group within GRS tertiles, the Western dietary pattern was associated with development and cycling of MetS status between visits, and the high-fat dairy pattern with being free from MetS (p < 0.017). The healthy dietary pattern was associated with higher risk of MetS among African Americans which may be explained by higher sucrose intake (p < 0.0001). Fewer genes, but more metabolic pathways for obesity, body fat distribution, and lipid and carbohydrate metabolism were identified in African Americans than Whites. Some polymorphisms were linked to the Western and high-fat dairy patterns. CONCLUSION: The influence of dietary patterns on MetS risk appears to differ by genetic predisposition and racial ancestry.
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Síndrome MetabólicoRESUMEN
BACKGROUND AND AIMS: Despite the proven evidence of high glycemic index (GI) and glycemic load (GL) diets to increase cardiometabolic risks, knowledge about the meta-evidence for carbohydrate quality within world geographic regions is limited. We conducted a meta-analysis to synthesize the evidence of GI/GL studies and carbohydrate quality, gathering additional exposures for carbohydrate, high glycemic carbohydrate, total dietary fiber, and cereal fiber and risks for type 2 diabetes (T2DM), coronary heart disease (CHD), stroke, and mortality, grouped into the US, Europe, and Asia. Secondary aims examined cardiometabolic risks in overweight/obese individuals, by sex, and dose-response dietary variable trends. METHODS AND RESULTS: 40-prospective observational studies from 4-Medline bibliographical databases (Ovid, PubMed, EBSCOhost, CINAHL) were search up to November 2019. Random-effects hazard ratios (HR) and 95% confidence intervals (CI) for highest vs. lowest categories and continuous form combined were reported. Heterogeneity (I2>50%) was frequent in US GI/GL studies due to differing study characteristics. Increased risks ((HRGI,T2DM,US=1.14;CI:1.06,1.21), HRGL,T2DM,US=1.02 (1.01, 1.03)), HRGI,T2DM,Asia=1.25;1.02,1.53), and HRGL,T2DM,Asia=1.37 (1.17, 1.60)) were associated with cardiometabolic diseases. GI/GL in overweight/obese females had the strongest magnitude of risks in US-and Asian studies. Total dietary fiber (HRT2DM,US = 0.92;0.88,0.96) and cereal fiber (HRT2DM,US = 0.83;0.77,0.90) decreased risk of developing T2DM. Among females, we found protective dose-response risks for total dietary fiber (HR5g-total-dietary-fiber,T2DM,US = 0.94;0.92,0.97), but cereal fiber showed better ability to lower T2DM risk (HR5g-cereal-fiber,T2DM,US = 0.67;0.60,0.74). Total dietary-and cereal fibers' dose-response effects were nullified by GL, but not so for cereal fiber with GI. CONCLUSIONS: Overweight/obese females could shift their carbohydrate intake for higher cereal fiber to decrease T2DM risk, but higher GL may cancel-out this effect.
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Glucemia/metabolismo , Enfermedad Coronaria/epidemiología , Diabetes Mellitus Tipo 2/epidemiología , Carbohidratos de la Dieta/administración & dosificación , Índice Glucémico , Carga Glucémica , Accidente Cerebrovascular/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Asia/epidemiología , Biomarcadores/sangre , Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/mortalidad , Enfermedad Coronaria/prevención & control , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/mortalidad , Diabetes Mellitus Tipo 2/prevención & control , Carbohidratos de la Dieta/efectos adversos , Carbohidratos de la Dieta/sangre , Europa (Continente)/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/epidemiología , Estudios Observacionales como Asunto , Pronóstico , Medición de Riesgo , Factores de Riesgo , Factores Sexuales , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/mortalidad , Accidente Cerebrovascular/prevención & control , Estados Unidos/epidemiología , Adulto JovenRESUMEN
Cross-sectional studies indicate that the fat mass and obesity-associated (FTO) rs9939609 gene variant is associated with metabolic syndrome (MetS) primarily in European ancestry. However, the association is not fully elucidated in African Americans.We hypothesized that rs9939609 (AT = moderate-risk carriers or AA = high-risk carriers compared to TT = low-risk carriers) is associated with MetS and its component risk factors over time; and that its association is ancestry-specific. A secondary hypothesis was that higher levels of physical activity can decrease the deleterious effect of rs9939609 at higher body mass index (BMI).Atherosclerosis Risk in Communities study repeated measures data from 4 visits (1987-1998) were obtained from the database of Genotypes and Phenotypes for 10,358 participants (8170 Whites and 2188 African Americans) aged 45 to 64 years at baseline. Guidelines for elevated blood pressure by the American College of Cardiology and American Heart Association Task Force were updated within the MetS criteria. Risk ratios (RR) and 95% confidence intervals from generalized estimating equations assessed population-average risks.MetS was present among 3479 (42.6%) Whites and 1098 (50.2%) African Americans at baseline, and 50.3% Whites and 57% African Americans over 11-years of follow-up. Among MetS component risk factors, high waist circumference was most prevalent among White AT (RRâ=â1.07; 1.06-1.09) and AA (RRâ=â1.12; 1.10-1.14) higher-risk carriers. High triglycerides were elevated among African American AA high-risk carriers (RRâ=â1.11; 1.02-1.21) compared to TT low-risk carriers. Over time, White AT-and AA higher-risk carriers had 1.07 and 1.08-fold increase (Pâ<â.0001) in MetS risk. Physical activity had independent protective effects on MetS among both races (Pâ<â.05). White AA high-risk carriers with normal BMI and low vs high physical activity had higher MetS risk (RRâ=â1.69; 1.25-2.30 and RRâ=â0.68;0.53-0.87, respectively). In rs9939609 × BMI× physical activity interaction, White A-allele high-risk carriers had lower MetS risk (RRâ=â0.68; 0.53-0.87). Among Whites, physical activity can lessen the effect of rs9939609 and high BMI on risk for MetS.
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Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato/genética , Predisposición Genética a la Enfermedad , Síndrome Metabólico/genética , Negro o Afroamericano , Anciano , Índice de Masa Corporal , Bases de Datos Factuales , Femenino , Humanos , Estudios Longitudinales , Masculino , Síndrome Metabólico/etiología , Persona de Mediana Edad , Obesidad , Factores de Riesgo , Estados Unidos , Población BlancaRESUMEN
OBJECTIVE: To determine which anthropometric measures are the strongest discriminators of incident type 2 diabetes (T2DM) among White and Black males and females in a large U.S. cohort. METHODS: We used Atherosclerosis Risk in Communities study data from 12,121 participants aged 45-64 years without diabetes at baseline who were followed for over 11 years. Anthropometric measures included a body shape index (ABSI), body adiposity index (BAI), body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR), waist to height ratio (WHtR), and waist to hip to height ratio (WHHR). All anthropometric measures were repeated at each visit and converted to Z-scores. Hazard ratios and 95% confidence intervals adjusted for age were calculated using repeated measures Cox proportional hazard regression analysis. Akaike Information Criteria was used to select best-fit models. The magnitude of the hazard ratio effect sizes and the Harrell's C-indexes were used to rank the highest associations and discriminators, respectively. RESULTS: There were 1,359 incident diabetes cases. Higher values of all anthropometric measures increased the risk for development of T2DM (p < 0.0001) except ABSI, which was not significant in White and Black males. Statistically significant hazard ratios ranged from 1.26-1.63 for males and 1.15-1.88 for females. In general, the largest hazard ratios were those that corresponded to the highest Harrell's C-Index and lowest Akaike Information Criteria values. Among White and Black males and females, BMI, WC, WHR, and WHtR were comparable in discriminating cases from non-cases of T2DM. ABSI, BAI, and WHHR were inferior discriminators of incident T2DM across all race-gender groups. CONCLUSIONS: BMI, the most commonly used anthropometric measure, and three anthropometric measures that included waist circumference (i.e., WC, WHR, WHtR) were the best anthropometric discriminators of incident T2DM across all race-gender groups in the ARIC cohort.
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Antropometría , Aterosclerosis/epidemiología , Población Negra/estadística & datos numéricos , Diabetes Mellitus Tipo 2/epidemiología , Población Blanca/estadística & datos numéricos , Adulto , Femenino , Humanos , Incidencia , Estudios Longitudinales , Masculino , Factores de RiesgoRESUMEN
BACKGROUND: The aim of the present study was to determine the best anthropometric discriminators of type 2 diabetes mellitus (T2DM) among White and Black males and females in a large US sample. METHODS: We used Atherosclerosis Risk in Communities study baseline data (1987-89) from 15 242 participants (1827 with T2DM) aged 45-65 years. Anthropometric measures included a body shape index (ABSI), body adiposity index (BAI), body mass index, waist circumference (WC), waist: height ratio (WHtR), and waist: hip ratio (WHR). All anthropometric measures were standardized to Z-scores. Using logistic regression, odds ratios for T2DM were adjusted for age, physical activity, and family history of T2DM. The Akaike information criterion and receiver operating characteristic C-statistic were used to select the best-fit models. RESULTS: Body mass index, WC, WHtR, and WHR were comparable discriminators of T2DM among White and Black males, and were superior to ABSI and BAI in predicting T2DM (P < 0.0001). Waist circumference, WHtR, and WHR were the best discriminators among White females, whereas WHR was the best discriminator among Black females. The ABSI was the poorest discriminator of T2DM for all race-gender groups except Black females. Anthropometric values distinguishing T2DM cases from non-cases were lower for Black than White adults. CONCLUSIONS: Anthropometric measures that included WC, either alone or relative to height (WHtR) or hip circumference (WHR), were the strongest discriminators of T2DM across race-gender groups. Body mass index was a comparable discriminator to WC, WHtR, and WHR among males, but not females.
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Antropometría/métodos , Negro o Afroamericano , Diabetes Mellitus Tipo 2/etnología , Población Blanca , Índice de Masa Corporal , Diabetes Mellitus Tipo 2/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estados Unidos , Circunferencia de la Cintura , Relación Cintura-Estatura , Relación Cintura-CaderaRESUMEN
BACKGROUND: The fat mass and obesity-associated (FTO) single nucleotide polymorphisms (SNPs; rs1421085, rs17817449, rs9939609, rs8050136) and macronutrient intake (carbohydrate, protein, fat, total calories) are associated with body mass index (BMI). However, the mechanism for this relationship has not been fully elucidated. OBJECTIVE: This study examined whether macronutrient intake mediates the association between FTO SNPs and BMI. DESIGN: Baseline cross-sectional data from the Atherosclerosis Risk in Communities (ARIC) study of whites (n = 10,176) and African Americans (n = 3641) aged 45 to 64 years were analyzed. RESULTS: In linear regression models with BMI as the dependent variable, FTO SNPs were significantly associated with higher BMI after adjusting for covariates. The addition of energy-adjusted macronutrients attenuated the FTO effect estimates, indicating partial mediation. In whites, ß ranged from 0.40 (95% confidence interval [CI], 0.20, 0.60) for rs17817449 heterozygous carriers to 0.93 (95% CI, 0.64, 122) for rs8050136 homozygous carriers; for African Americans rs17817449 homozygous carriers ß was 0.65 (95% CI, 0.03, 1.27). In models with macronutrient intake as the dependent variable, all FTO SNPs were associated with higher protein intake for homozygous carriers after adjusting for BMI and other covariates. Among whites, ß ranged from 1.44 (95% CI, 0.51, 2.37) for rs8050136 to 1.73 (95% CI, 0.85, 2.61) for rs17817449; among African American rs8050136 homozygous carriers ß was 2.46 (95% CI, 0.77, 4.14). In mediation analysis, in whites only, FTO high-risk alleles were associated with higher BMI partly through their small effects on carbohydrate and protein intake. CONCLUSIONS: These findings suggest that in adults, the relationship between FTO variants and BMI is not primarily through mediation of food intake.
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Índice de Masa Corporal , Ingestión de Energía , Proteínas/genética , Negro o Afroamericano/genética , Anciano , Alelos , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato , Estudios Transversales , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Femenino , Homocigoto , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Proteínas/metabolismo , Encuestas y Cuestionarios , Población Blanca/genéticaRESUMEN
The NASA Study of Cataract in Astronauts (NASCA) was designed to measure the impact of exposure to space radiation on progression rates of cortical, nuclear, and posterior subcapsular cataract in U.S. astronauts who have flown in space and comparison groups of astronauts who had not flown in space, and subjects with a history of military aviation. We present our analyses of 5 years of data with an average of 3.8 exams per subject. All subjects had digital lens images with the Nidek EAS 1000 Lens Imaging System. Because of high variability and skewness of opacity measures, nonparametric methods were used to test for association between rates of opacification and space radiation exposure. First, median regression was used to collapse longitudinal data into robust estimates of progression rates (opacity severity compare to time for each eye of each subject). To quantify and test for a radiation effect, median regression with the dependent variable being the maximum of the two slopes (OD and OS) per subject was then used, adjusting for the confounding variables of age, nutritional, and sun-exposure histories. Median regression showed evidence of an association between the rate of cortical progression in the worse eye with radiation dose and age. The estimated median progression rate from space radiation being 0.25 ± 0.13% lens area/Sv/year (P = 0.062). We found no relationship between radiation exposure and progression of aggregate area of posterior subcapsular cataract or nuclear progression rates. However, longer follow-up may be needed to further understand any impact of space radiation on progression rates for posterior subcapsular cataracts and nuclear cataracts, and to characterize changes to visual acuity.
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Astronautas , Catarata/etiología , Vuelo Espacial , Progresión de la Enfermedad , Relación Dosis-Respuesta en la Radiación , Humanos , Estudios Longitudinales , Efectividad Biológica RelativaRESUMEN
PURPOSE: In this study we examined whether high glycemic index (GI) and glycemic load (GL) diets are associated with increased risk of developing coronary heart disease (CHD) in Whites and African Americans with and without type 2 diabetes. METHODS: Data on 13,051 patients ages 45 to 64 years from the Atherosclerosis Risk in Communities study were analyzed. The ARIC food frequency questionnaire baseline data provided GI and GL indices. A propensity score was created to estimate the effect of a patient's covariates on energy-adjusted GI or GL. During a maximum of 17 years of follow-up, 1683 cases of CHD (371 with diabetes and 1312 without diabetes) were recorded. RESULTS: For every 5-units increase in GI, there was a 1.16-fold (95% confidence interval [95% CI], 1.01-1.33) increased risk of incident CHD in African Americans. For every 30-units increase in GL, there was a 1.11-fold (95% CI, 1.01-1.21) increased risk of incident CHD in Whites. High GL was an especially important CHD risk factor for Whites without diabetes (per 30-units increase; hazard ratio, 1.14; 95% CI, 1.02-1.26). However, these relationships were not seen in individuals with diabetes. CONCLUSIONS: Nutritional advice to reduce the GI and GL in diets of African Americans and Whites subjects (without diabetes) may play a role in reducing CHD risk.
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Negro o Afroamericano/etnología , Enfermedad Coronaria/etnología , Diabetes Mellitus Tipo 2/etnología , Dieta/efectos adversos , Índice Glucémico/etnología , Población Blanca/etnología , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/prevención & control , Diabetes Mellitus Tipo 2/complicaciones , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Medición de Riesgo/métodos , Encuestas y CuestionariosRESUMEN
The NASA Study of Cataract in Astronauts (NASCA) is a 5-year longitudinal study of the effect of space radiation exposure on the severity/progression of nuclear, cortical and posterior subcapsular (PSC) lens opacities. Here we report on baseline data that will be used over the course of the longitudinal study. Participants include 171 consenting astronauts who flew at least one mission in space and a comparison group made up of three components: (a) 53 astronauts who had not flown in space, (b) 95 military aircrew personnel, and (c) 99 non-aircrew ground-based comparison subjects. Continuous measures of nuclear, cortical and PSC lens opacities were derived from Nidek EAS 1000 digitized images. Age, demographics, general health, nutritional intake and solar ocular exposure were measured at baseline. Astronauts who flew at least one mission were matched to comparison subjects using propensity scores based on demographic characteristics and medical history stratified by gender and smoking (ever/never). The cross-sectional data for matched subjects were analyzed by fitting customized non-normal regression models to examine the effect of space radiation on each measure of opacity. The variability and median of cortical cataracts were significantly higher for exposed astronauts than for nonexposed astronauts and comparison subjects with similar ages (P=0.015). Galactic cosmic space radiation (GCR) may be linked to increased PSC area (P=0.056) and the number of PSC centers (P=0.095). Within the astronaut group, PSC size was greater in subjects with higher space radiation doses (P=0.016). No association was found between space radiation and nuclear cataracts. Cross-sectional data analysis revealed a small deleterious effect of space radiation for cortical cataracts and possibly for PSC cataracts. These results suggest increased cataract risks at smaller radiation doses than have been reported previously.