Blue Mountains Eye Study Cohort Research Articles

Changes in Added Sugar Intake and Body Weight in a Cohort of Older Australians: A Secondary Analysis of the Blue Mountains Eye Study.

Background: The evidence regarding the association between added sugar (AS) intake and obesity remains inconsistent. The aim of this study was to investigate the association between changes in the percentage of energy intake from AS (EAS%) and changes in body weight in a cohort study of older Australians during 15 years of follow-up. In addition, associations were assessed according to whether EAS% intake was provided from beverage or non-beverage sources.Methods: Data were analyzed from the participants of the Blue Mountains Eye Study Cohort. Dietary data were collected at baseline (1992–94) and three five-yearly intervals using a 145-item food frequency questionnaire. Participants' body weight was measured at each time point. Five-yearly changes in EAS% intake and body weight were calculated (n = 1,713 at baseline). A generalized estimating equation (GEE) model was used to examine the relationship between the overall five-yearly changes in EAS% intake and body weight, adjusted for dietary and lifestyle variables.Results: In each time interval, the EAS% intake decreased by ~5% in the lowest quartile (Q1) and increased by ~5% in the highest quartile (Q4). The mean (SD) body weight change in Q1 and Q4 were 1.24 (8.10) kg and 1.57 (7.50) kg (first time interval), 0.08 (6.86) kg and −0.19 (5.63) kg (second time interval), and −1.22 (5.16) kg and −0.37 (5.47) kg (third time interval), respectively. In GEE analyses, the overall five-yearly change in EAS% intake was not significantly associated with body weight change (Ptrend = 0.837). Furthermore, no significant associations were observed between changes in EAS% intake from either beverage or non-beverage sources and changes in body weight (Ptrend for beverage sources = 0.621 and Ptrend for non-beverage sources = 0.626).Conclusion: The findings of this older Australian cohort do not support the association between changes in EAS% intake and body weight, regardless of AS food sources (beverage or non-beverage).

The Combination of Healthy Diet and Healthy Body Weight Is Associated with Lower Risk of Nuclear Cataract in the Blue Mountains Eye Study

Greater adherence to dietary guidelines has previously been found to be associated with decreased risk of visual impairment. However, whether or not this association extends to age-related cataract, 1 of the leading causes of visual impairment, is unknown. The aim of this study was to assess the association between adherence to dietary guidelines, using total diet score, and incidence of age-related cataract. Of 3654 baseline participants of the population-based Blue Mountains Eye Study cohort (1992-1994), 2334 (75.8% survivors) and 1952 (76.7% survivors) were examined after 5 and 10 y, respectively. Cataract was assessed from lens photographs using the Wisconsin Cataract Grading System. Baseline total diet score was calculated from FFQ data following a modified version of the Healthy Eating Index for Australians. OR with 95% CI were estimated using discrete logistic regression analyses, adjusting for age, sex, and other confounders. To test interaction, a cross-product term of 2 factors was included in regression models. Of 2173 participants (84.7% of those returned for 1 or both follow-ups) with total diet score estimated, 57% were women, mean baseline age was 63.9±8.4y, and mean baseline BMI was 26.3±4.3 kg/m2. After multivariable adjustment, baseline total diet score was not associated with incidence of any cataract. A multiplicative interaction was observed between total diet score and BMI for incident nuclear cataract (P-interaction=0.04): increasing baseline total diet score was associated with decreased risk of nuclear cataract among participants with BMI <25 (per unit increased total diet score, OR: 0.90; 95% CI: 0.81, 0.99; P=0.02), but not among participants with BMI ≥25 (OR: 1.00; 95% CI: 0.92, 1.10; P=0.95). Adherence to dietary guidelines had no appreciable influence on cataract development overall in this older Australian population. However, adherence to dietary guidelines combined with healthy BMI is associated with decreased risk of nuclear cataract, an aging marker.

Association of Open-Angle Glaucoma Loci With Incident Glaucoma in the Blue Mountains Eye Study

PurposeTo determine if open-angle glaucoma (OAG)-associated single nucleotide polymorphisms (SNPs) are associated with incident glaucoma and if such genetic information is useful in OAG risk prediction.DesignCase-control from within a population-based longitudinal study.Methodsstudy population: Individuals aged over 49 years of age living in the Blue Mountains region west of Sydney and enrolled in the Blue Mountains Eye Study. observation: Cases for this sub-study (n = 67) developed incident OAG between baseline and 10-year visits, in either eye, while controls (n = 1919) had no evidence for OAG at any visit. All participants had an ocular examination and DNA genotyped for reported OAG risk SNPs. main outcome measure: Incident OAG.ResultsTwo loci also known to be associated with cup-to-disc ratio as well as OAG (9p21 near CDKN2B-AS1 and SIX1/SIX6) were both significantly associated with incident OAG in the Blue Mountains Eye Study cohort (P = .006 and P = .004, respectively). The TMCO1 locus was nominally associated (P = .012), while the CAV1/CAV2 and 8q22 loci were not associated. Multivariate logistic regression and neural network analysis both indicated that the genetic risk factors contributed positively to the predictive models incorporating traditional risk factors.ConclusionsThis study shows that previously reported genetic variations related to OAG and cup-to-disc ratio are associated with the onset of OAG and thus may become useful in risk prediction algorithms designed to target early treatment to those most at risk of developing glaucoma.

Correction of Visual Impairment by Cataract Surgery and Improved Survival in Older Persons: The Blue Mountains Eye Study Cohort

Objective We assessed whether correction of visual impairment (VI) by cataract surgery was associated with improved long-term survival in an older Australian population. Design Population-based cohort study. Participants In the Blue Mountains Eye Study, 354 participants, aged ≥49 years, had both cataract and VI or had undergone cataract surgery before baseline examinations. They were subsequently examined after 5- and 10-year follow-ups. Methods Associations between the mortality risk and the surgical correction of VI (visual acuity [VA] <20/40, attributable to cataract) were assessed in Cox proportional hazard regression models, after multivariate adjustment, using time-dependent variables for the study factor. Main Outcome Measures All-cause mortality. Results The 15-year crude mortality of participants who had undergone cataract surgery at baseline with no subsequent VI (71.8%) was relatively similar to that in participants with cataract-related VI who had not yet undergone surgery (79.4%). However, after adjusting for age and sex, participants who underwent cataract surgery before baseline or during follow-up and no longer had VI had significantly lower long-term mortality risk (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.46–0.77) than participants with VI due to cataract who had not undergone cataract surgery. This lower mortality risk in the group with surgically corrected VI (HR, 0.54; 95% CI, 0.41–0.73) persisted after further adjustment for smoking, body mass index, home ownership, qualifications, poor self-rated health, the presence of poor mobility, hypertension, diabetes, self-reported history of angina, myocardial infarction, stroke, cancer, asthma, and arthritis. This finding remained significant (HR, 0.55; 95% CI, 0.41–0.73) after additional adjustment for the number of medications taken (continuous variable) and the number (≥5 vs. <5) of comorbid conditions (poor mobility, hypertension, diabetes, angina, myocardial infarction, stroke, cancer, asthma, or arthritis) as indicators of frailty. Conclusions Surgical correction of VI due to cataract was associated with significantly better long-term survival of older persons after accounting for known cataract and mortality risk factors, and indicators of general health. Whether some uncontrolled factors (frailty or general health) could have influenced decisions not to perform cataract surgery in some participants is unknown. However, this finding strongly supports many previous reports linking VI with poor survival. Financial Disclosure(s) Proprietary or commercial disclosure may be found after the references. We assessed whether correction of visual impairment (VI) by cataract surgery was associated with improved long-term survival in an older Australian population. Population-based cohort study. In the Blue Mountains Eye Study, 354 participants, aged ≥49 years, had both cataract and VI or had undergone cataract surgery before baseline examinations. They were subsequently examined after 5- and 10-year follow-ups. Associations between the mortality risk and the surgical correction of VI (visual acuity [VA] <20/40, attributable to cataract) were assessed in Cox proportional hazard regression models, after multivariate adjustment, using time-dependent variables for the study factor. All-cause mortality. The 15-year crude mortality of participants who had undergone cataract surgery at baseline with no subsequent VI (71.8%) was relatively similar to that in participants with cataract-related VI who had not yet undergone surgery (79.4%). However, after adjusting for age and sex, participants who underwent cataract surgery before baseline or during follow-up and no longer had VI had significantly lower long-term mortality risk (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.46–0.77) than participants with VI due to cataract who had not undergone cataract surgery. This lower mortality risk in the group with surgically corrected VI (HR, 0.54; 95% CI, 0.41–0.73) persisted after further adjustment for smoking, body mass index, home ownership, qualifications, poor self-rated health, the presence of poor mobility, hypertension, diabetes, self-reported history of angina, myocardial infarction, stroke, cancer, asthma, and arthritis. This finding remained significant (HR, 0.55; 95% CI, 0.41–0.73) after additional adjustment for the number of medications taken (continuous variable) and the number (≥5 vs. <5) of comorbid conditions (poor mobility, hypertension, diabetes, angina, myocardial infarction, stroke, cancer, asthma, or arthritis) as indicators of frailty. Surgical correction of VI due to cataract was associated with significantly better long-term survival of older persons after accounting for known cataract and mortality risk factors, and indicators of general health. Whether some uncontrolled factors (frailty or general health) could have influenced decisions not to perform cataract surgery in some participants is unknown. However, this finding strongly supports many previous reports linking VI with poor survival.

Genetic Association of Refractive Error and Axial Length with 15q14 but Not 15q25 in the Blue Mountains Eye Study Cohort

Myopia is a common complex condition influenced by genetic and environmental factors. Two recent genome-wide association studies have identified loci on chromosomes 15q25 and 15q14 associated with refractive error in Caucasian populations. Our study aimed to assess the association of these 2 loci with refractive error and ocular biometric measures in an independent ethnically matched Caucasian cohort. Genetic association study using unrelated individuals. Blue Mountains Eye Study (BMES) cohort. A total of 1571 individuals were included in this study. Single nucleotide polymorphism (SNP) genotype data were collected from the BMES cohort as part of the Wellcome Trust Case Control Consortium 2. Imputation was performed using MACH version 1.1.16, and statistical analysis was conducted using PLINK. Association tests were performed at both loci using refractive error (spherical equivalent), axial length, corneal curvature, and anterior chamber depth as the phenotypes. Refractive error, axial length, corneal curvature, and anterior chamber depth. A total of 1571 individuals were available from the BMES for analysis. A statistically significant association for refractive error was evident for SNPs at the 15q14 locus, with P values ranging from 1.5 × 10(-2) at rs685352 to 6.4 × 10(-4) at rs560764, whereas association could not be confirmed for SNPs at the 15q25 locus, with P values ranging from 8.0 × 10(-1) to 6.4 × 10(-1). Ocular biometric analysis revealed that axial length was the most likely trait underlying the refractive error association at the 15q14 locus for SNPs rs560766 (P=0.0054), rs634990 (P=0.0086), and rs8032019 (P=0.0081). Our results confirm the association with refractive error at the 15q14 locus but do not support the association observed at the 15q25 locus. Axial length seemed to be a major parameter at the 15q14 locus, underscoring the importance of this locus in myopia and future clinical treatment.

Five-Year Incidence and Progression of Hearing Impairment in an Older Population

There are few epidemiological surveys that have examined age-related hearing loss in an older Australian population. This study reports the prevalence, 5-yr incidence, and progression of hearing impairment in a representative sample of older persons. The Blue Mountains Hearing Study (BMHS) is a population-based survey of age-related hearing loss conducted among participants of the Blue Mountains Eye Study cohort. During the period 1997-1999, 2956 had audiometric testing done. Of these, 870 participants without hearing loss and 439 with hearing loss were re-examined from 2002 to 2004. Some degree of hearing loss was present in 33.0% of this population at baseline. Prevalence of hearing loss increased with age, sex-adjusted (odds ratio [OR] 3.5, 95% confidence interval [CI] 3.1-3.9), with men 70% more likely than women to have hearing loss. The 5-yr incidence of hearing impairment was 17.9%. For each decade of age older than 60 yrs, the risk of hearing loss increased threefold, OR 3.9 (CI 2.3-3.8). Gender was not associated with incident hearing loss OR. However, high occupational prestige was associated with decreased incidence of hearing loss OR 0.6 (CI 0.40-0.94). The 5-yr progression of hearing loss defined as a difference in pure-tone average that exceeded 10 dB was relatively high (15.7%). At the baseline hearing study and at the 5-yr follow-up hearing study, 57.4% and 59.7% of hearing impaired subjects, respectively, reported using a hearing aid for a maximum of 5 yrs. Hearing loss was a frequent sensory disability, with one in three persons having a hearing impairment, and of these, almost one in two showing a decline in hearing over a 5-yr period. This information can potentially contribute to the planning and resource investment in auditory rehabilitation services for older Australians.

The LOC387715 Polymorphism, Inflammatory Markers, Smoking, and Age-Related Macular Degeneration : A Population-Based Case–Control Study

To assess combined effects on the risk of age-related macular degeneration (AMD) by the LOC387715 polymorphism, smoking, and inflammatory or hemostatic factors. Population-based case-control study. Two hundred seventy-eight AMD cases (224 early, 54 late) and 557 controls matched for age, gender, and smoking, drawn from the Blue Mountains Eye Study cohort. Subjects were genotyped for the LOC387715 Ala69Ser polymorphism (rs# 10490924). Smoking was self-reported. Serum high-sensitivity C-reactive protein (CRP), interleukin 6 (IL-6), soluble intercellular adhesion molecule 1 (sICAM-1), fibrinogen, homocysteine, plasminogen activator inhibitor 1 (PAI-1), von Willebrand factor, and white cell count (WCC) were measured. Combined effects of this genetic variant plus any of these study factors on AMD risk were assessed using logistic regression models, adjusted for age and smoking. We defined interaction if the influence of 2 factors departed from the multiplicative scale, confirmed by a statistically significant interaction term. Otherwise, the combined effect was used. Age-related macular degeneration was graded using the Wisconsin grading system. Combined effects on the likelihood of early or late AMD were demonstrated for the LOC387715 Ala69Ser G/T and T/T genotypes with the markers high-sensitivity CRP (odds ratios [ORs], 1.2 for the highest tertile alone, 1.6 for G/T and T/T genotypes alone, and 2.2 for both G/T and T/T genotypes plus the highest tertile, compared with the G/G genotype with the 2 lower tertiles), IL-6 (corresponding ORs, 1.1, 1.6, and 2.2), sICAM-1 (ORs, 1.0, 1.5, and 2.3, respectively), and PAI-1 (ORs, 1.3, 1.7, and 2.3, respectively), but not with WCC, fibrinogen, homocysteine, and von Willebrand factor. Findings were similar for early and late AMD separately. Current smokers with G/T and T/T genotypes had strong combined effects on late AMD risk compared with those who never smoked or past smokers with the G/G genotype (ORs, 1.2 for current smokers alone, 1.8 for G/T and T/T genotypes alone, and 6.1 for current smokers plus G/T and T/T genotypes). We found no significant interaction but combined effects for the LOC387715 genotypes with 3 inflammatory markers and PAI-1 on the risk of early or late AMD, and with current smoking on the risk of late AMD.

Regular aspirin use and retinal microvascular signs: the Blue Mountains Eye Study

Hypertension is closely related to microvascular abnormalities and there is increasing interest in agents that target the microvasculature. The effect of aspirin on the microvasculature has not been well studied. We examined the cross-sectional and longitudinal associations between regular aspirin use and retinal microvascular signs. We digitized retinal photographs from participants of the Blue Mountains Eye Study cohort (1992-1994, n = 3654, aged over 49 years, and 1997-1999, n = 2335) and used a computer-assisted method to measure average retinal arteriolar and venular diameters. Information on the frequency of aspirin use was collected, with regular aspirin use defined as weekly or daily. Regular aspirin users comprised 21.2% (n = 775) of the baseline population. At baseline and in individuals who were on one or more antihypertensive medication, regular aspirin use was found to be associated with retinal arterioles on average 3.6 mum (95% confidence interval 1.0, 6.2) wider than those of non-users or occasional aspirin users, after adjusting for age, blood pressure, smoking, diabetes, non-steroidal anti-inflammatory drug use and other variables. Increasing frequency of aspirin use was associated with increasing retinal arteriolar diameter (Ptrend < 0.01). At 5-year follow-up, regular users of aspirin and antihypertensive medication(s) had wider retinal arterioles than those who used aspirin less regularly. Neither antihypertensive medication use alone nor aspirin use alone was associated with wider retinal vessels. Our finding of a possible association between the combined use of aspirin and antihypertensive agent(s) and wider retinal arteriolar diameter warrants further investigation into the effects of aspirin on the microvasculature.

Hypermetropia Is Not Associated With Hypertension: The Blue Mountains Eye Study

An association between hypermetropia and hypertension was recently reported. We sought to verify this finding in the Blue Mountains Eye Study cohort (n = 3654; ages 49 to 97 years). Cohort study. We defined hypermetropia as mean spheric equivalent refraction (SER) > 1.00 diopter, myopia as mean SER < -1.00 diopters, and emmetropia as mean SER < or = 1.00 diopters and > or = -1.00 diopters, inclusive. We used the 2003 World Health Organization/International Society of Hypertension guidelines to define severe hypertension as grade 2 or higher. Of 1290 people who were at risk of the development of hypertension, 378 people developed incident severe hypertension after five years. The multivariate-adjusted relative risk of incident hypertension in persons with hypermetropia compared with those with emmetropia was 1.06 (95% CI, 0.89 to 1.26); the relative risk in persons with myopia was 1.22 (95% CI, 0.96 to 1.56). Neither hypermetropia nor myopia was associated with incident hypertension in this older population.

Low Hemoglobin, Chronic Kidney Disease, and Risk for Coronary Heart Disease–Related Death

A recent report found that chronic kidney disease (CKD) increased the risk for coronary heart disease (CHD) events in people with anemia but not in those without anemia. This study aimed to verify these findings in the Blue Mountains Eye Study cohort, a prospective Australian population-based study of 3654 residents aged 49 to 97 yr. Fasting blood samples were obtained at baseline and confirmed CHD-related deaths over 9 yr with the Australian National Death Index. "Low hemoglobin" was defined as levels in the lowest quintile of the cohort. Body surface area-adjusted GFR was estimated using a variety of methods (Cockcroft-Gault, abbreviated Modification of Diet in Renal Disease, and Bjornsson equations). People with CKD (GFR <60 ml/min per 1.73 m2 as estimated using the Cockcroft-Gault equation) and low hemoglobin (mean 13.2 g/dl; range 7.6 to 14.6 g/dl) had an increased risk for CHD-related death (multivariable-adjusted hazard risk ratio 1.49; 95% confidence interval 1.08 to 2.06) compared with people with CKD but in higher hemoglobin quintiles. This effect was not evident in people without CKD. The interaction between GFR and hemoglobin was significant (P = 0.05) when GFR was estimated using either the Cockcroft-Gault or Bjornsson equations or when serum creatinine instead of GFR was used in the analyses but not when GFR was estimated using the abbreviated Modification of Diet in Renal Disease equation. In conclusion, this study found that low hemoglobin, even within the normal range, together with CKD increased the risk for CHD-related death.