Oxidized Low-Density Lipoprotein and the Incidence of Proliferative Diabetic Retinopathy and Clinically Significant Macular Edema Determined From Fundus Photographs

IMPORTANCE

Studies have shown oxidized low-density lipoprotein to be associated with the incidence of proliferative retinopathy and other complications of type 1 diabetes mellitus. Because low-risk interventions are available to modify oxidized low-density lipoprotein, it is important to examine the relationships between this factor and the incidence of proliferative retinopathy and of macular edema, 2 important causes of visual impairment in people with type 1 diabetes.

OBJECTIVE

To determine the association of oxidized low-density lipoprotein with the worsening of diabetic retinopathy and the incidence of proliferative retinopathy and of macular edema.

DESIGN, SETTING, AND PARTICIPANTS

Of 996 participants with type 1 diabetes in the Wisconsin Epidemiologic Study of Diabetic Retinopathy, 730 were examined up to 4 times (1990-1992, 1994-1996, 2005-2007, and 2012-2014) over 24 years and had assays of oxidized low-density lipoprotein and fundus photographs gradable for diabetic retinopathy and macular edema. Analyses started July 2014 and ended February 2015.

MAIN OUTCOMES AND MEASURES

Worsening of diabetic retinopathy, incidence of proliferative diabetic retinopathy, and incidence of macular edema as assessed via grading of color stereo film fundus photographs. The levels of oxidized low-density lipoprotein collected from serum samples at the time of each examination were measured in 2013 and 2014 from frozen serum.

RESULTS

The cohort at baseline had a mean (SD) level of oxidized low-density lipoprotein of 30.0 (8.5) U/L. While adjusting for duration of diabetes, glycated hemoglobin A1c level, and other factors, we found that neither the level of oxidized low-density lipoprotein at the beginning of a period nor the change in it over a certain period was associated with the incidence of proliferative diabetic retinopathy (hazard ratio [HR], 1.11 [95% CI, 0.91-1.35], P = .30; odds ratio [OR], 1.77 [95% CI, 0.99-3.17], P = .06), the incidence of macular edema (HR, 1.04 [95% CI, 0.83-1.29], P = .74; OR, 1.08 [95% CI, 0.44-2.61], P = .87), or the worsening of diabetic retinopathy (HR, 0.94 [95% CI, 0.83-1.07], P = .34; OR, 1.32 [95% CI, 0.83-2.09], P = .24).

CONCLUSIONS AND RELEVANCE

Our findings do not provide evidence for a relationship between increasing levels of serum oxidized low-density lipoprotein and the incidence of macular edema or the worsening of diabetic retinopathy in persons with type 1 diabetes. The potential increase in the HR for incident proliferative retinopathy, with an increase in oxidized low-density lipoprotein level over the preceding period, warrants further investigation of this relationship.

Increasing Discussion Rates of Incontinence in Primary Care: A Randomized Controlled Trial

BACKGROUND

A minority of women with urinary incontinence (UI) and even fewer with fecal incontinence (FI) report having discussed it with a health care provider in the past year. Thus our aim was to evaluate whether the use of an electronic pelvic floor assessment questionnaire (ePAQ-PF) improves communication about incontinence in primary care.

METHODS

Women 40 years and older who were scheduled for an annual wellness physical at an internal medicine clinic between August 2007 and August 2008 were randomized to complete the ePAQ-PF prior to (n = 145) or after (n = 139) their visit. Clinicians of women in the intervention group received the ePAQ-PF report prior to the visit. Outcome measures from clinic note abstraction included mention of UI (primary) and FI. Participant-reported outcome measures included discussion of UI and FI and initiator of discussion.

RESULTS

Discussions of UI was more common in the intervention group than the control group: (27% vs. 19%; odds ratio [OR], 1.6 95% confidence interval [95%CI] 0.9-2.8, particularly for women over 60 (33% vs. 12%; OR 3.8, 95%CI 1.2-11.8) and for women with UI (42% vs. 25%; OR 2.2, 95%CI 1.1-4.1). The intervention primarily led to an increase in clinician-initiated UI discussions which were more common in the intervention group (18% vs. 4%, OR 4.8, 95%CI 1.9-12.0) Participants in the intervention group more frequently reported discussion of FI (14% vs. 6%; OR 2.5, 95%CI 1.1-6.0) which was clinician initiated in over half the cases (9% vs. 3%; OR 3.5, 95%CI 1.1-11.0).

CONCLUSIONS

Use of the ePAQ-PF prior to clinic visits increases discussion of UI and FI, particularly clinician-initiated discussion. These findings suggest that such instruments may increase the detection and treatment of this often "silent" affliction.

Sex-related differences in pulmonary physiologic outcome measures in a high-risk birth cohort

BACKGROUND

Sex influences the risk of wheezing illnesses and the prevalence of asthma throughout childhood.

OBJECTIVE

To better understand the mechanisms of these effects, we analyzed longitudinal relationships between sex, lung physiology, and asthma in the Childhood Origins of ASThma birth cohort study.

METHODS

Childhood Origins of ASThma birth cohort study children were followed prospectively from birth and assessed annually. Results of spirometry, fractional exhaled nitric oxide (Feno), mannitol provocation testing, and (3)He gas magnetic resonance imaging were assessed by sex using multivariate models including age, asthma diagnosis, and wheezing histories.

RESULTS

Girls had higher prebronchodilator forced expiratory volume in 0.5 seconds/forced vital capacity values than did boys (mean difference, 0.017; 95% CI, 0.000-0.034; P = .05) of equivalent age. Postbronchodilator findings were more pronounced, with boys demonstrating reduced forced expiratory volume in 0.5 seconds/forced vital capacity values than did girls of equivalent age (mean difference, 0.032; 95% CI, 0.014-0.049; P = .0005). Conversely, girls were noted to have higher ventilation defects on (3)He magnetic resonance imaging than did boys (P = .01). No differences were noted in the rate of positive responses to mannitol provocation or Feno measurements.

CONCLUSIONS

Lower airflow values are present by spirometry for prepubertal boys than for age-matched girls; however, greater (3)He ventilation defects were noted in girls. This could represent a greater degree of subclinical air trapping in prepubertal girls because residual volumes are not detected on standard spirometric readings. No differences were noted between the 2 sexes with airway hyperresponsiveness (mannitol provocation testing) or inflammation (Feno). Prospective peripubertal follow-up will determine whether these differences persist or change with the de novo expression and remission of asthma based on sex and age.

Variation in Breast Cancer-Risk Factor Associations by Method of Detection: Results From a Series of Case-Control Studies

Concerns about breast cancer overdiagnosis have increased the need to understand how cancers detected through screening mammography differ from those first detected by a woman or her clinician. We investigated risk factor associations for invasive breast cancer by method of detection within a series of case-control studies (1992-2007) carried out in Wisconsin, Massachusetts, and New Hampshire (n=15,648 invasive breast cancer patients and 17,602 controls aged 40-79 years). Approximately half of case women reported that their cancer had been detected by mammographic screening and half that they or their clinician had detected it. In polytomous logistic regression models, parity and age at first birth were more strongly associated with risk of mammography-detected breast cancer than with risk of woman/clinician-detected breast cancer (P≤0.01; adjusted for mammography utilization). Among postmenopausal women, estrogen-progestin hormone use was predominantly associated with risk of woman/clinician-detected breast cancer (odds ratio (OR)=1.49, 95% confidence interval (CI): 1.29, 1.72), whereas obesity was predominantly associated with risk of mammography-detected breast cancer (OR=1.72, 95% CI: 1.54, 1.92). Among regularly screened premenopausal women, obesity was not associated with increased risk of mammography-detected breast cancer (OR=0.99, 95% CI: 0.83, 1.18), but it was associated with reduced risk of woman/clinician-detected breast cancer (OR=0.53, 95% CI: 0.43, 0.64). These findings indicate important differences in breast cancer risk factors according to method of detection.

Severity of age-related macular degeneration in 1 eye and the incidence and progression of age-related macular degeneration in the fellow eye: the Beaver Dam Eye Study

IMPORTANCE

Previous studies regarding the severity of age-related macular degeneration (AMD) in 1 eye and its prognostic implications for the fellow eye have focused on the incidence of neovascular AMD in the fellow eye of participants with neovascular AMD in the other eye. It is unclear to what extent the severity of AMD in 1 eye affects the incidence, progression, and regression of AMD in its fellow eye across the entire range of AMD severity.

OBJECTIVE

To investigate the effect of the severity of AMD in 1 eye on the incidence, progression, and regression of AMD in the fellow eye.

DESIGN, SETTING AND PARTICIPANTS

The Beaver Dam Eye Study is a longitudinal population-based study of age-related eye diseases conducted in the city and township of Beaver Dam, Wisconsin. Examinations were performed every 5 years over a 20-year period (from the baseline examination in 1988-1990 to 2008-2010). Study participants (n = 4379) were 43 to 86 years of age at the baseline examination. At baseline and in up to 4 subsequent examinations, retinal photographs were taken.

MAIN OUTCOMES AND MEASURES

Incidence, progression, and regression of AMD (assessed by use of the Wisconsin Age-Related Maculopathy Grading System on retinal photographs and adjusted for age, sex, and the Y402H polymorphism in the complement factor H gene on chromosome 1q) and mortality.

RESULTS

More severe AMD in 1 eye was associated with increased incidence of AMD and accelerated progression in its fellow eye (levels 1-2: hazard ratio [HR], 4.90 [95% CI, 4.26-5.63]; levels 2-3: HR, 2.09 [95% CI, 1.42-3.06]; levels 3-4: HR, 2.38 [95% CI, 1.74-3.25]; levels 4-5: HR, 2.46 [95% CI, 1.65-3.66]). Less severe AMD in 1 eye was associated with less progression of AMD in its fellow eye (levels 2-3: HR, 0.42 [95% CI, 0.33-0.55]; levels 3-4: HR, 0.50 [95% CI, 0.34-0.83]). We estimate that 51% of participants who develop any AMD always maintain AMD severity states within 1 step of each other between eyes; 90% of participants stay within 2 steps.

CONCLUSIONS AND RELEVANCE

Using multistate models, we show that AMD severity in 1 eye tracks AMD severity in its fellow eye.

The contribution of mammography screening to breast cancer incidence trends in the United States: an updated age-period-cohort model

BACKGROUND

The impact of screening mammography on breast cancer incidence is difficult to disentangle from cohort- and age-related effects on incidence.

METHODS

We developed an age-period-cohort model of ductal carcinoma in situ (DCIS) and invasive breast cancer incidence in U.S. females using cancer registry data. Five functions were included in the model to estimate stage-specific effects for age, premenopausal birth cohorts, postmenopausal birth cohorts, period (for all years of diagnosis), and a mammography period effect limited to women ages ≥ 40 years after 1982. Incidence with and without the mammography period effect was calculated.

RESULTS

More recent birth cohorts have elevated underlying risk compared with earlier cohorts for both pre- and postmenopausal women. Comparing models with and without the mammography period effect showed that overall breast cancer incidence would have been 23.1% lower in the absence of mammography in 2010 (95% confidence intervals, 18.8-27.4), including 14.7% (9.5-19.3) lower for invasive breast cancer and 54.5% (47.4-59.6) lower for DCIS. Incidence of distant-staged breast cancer in 2010 would have been 29.0% (13.1-48.1) greater in the absence of mammography screening.

CONCLUSIONS

Mammography contributes to markedly elevated rates of DCIS and early-stage invasive cancers, but also contributes to substantial reductions in the incidence of metastatic breast cancer.

IMPACT

Mammography is an important tool for reducing the burden of breast cancer, but future work is needed to identify risk factors accounting for increasing underlying incidence and to distinguish between indolent and potentially lethal early-stage breast cancers that are detected via mammography.

Dose-response relationships between sedentary behaviour and the metabolic syndrome and its components

AIMS/HYPOTHESIS

The aim of this study was to examine the relationship among sedentary behaviour (SB) and the metabolic syndrome and its components by age, moderate-to-vigorous physical activity (MVPA) and sex.

METHODS

A cross-sectional analysis was performed on 2003-2006 National Health and Nutrition Examination Survey data from 5,076 adults aged ≥18 years (mean ± SD = 43.8 ± 19.5). SB was measured using ActiGraph accelerometers worn for 1 week and defined as <100 counts/min. Metabolic syndrome was defined using the Adult Treatment Panel III criteria. Natural cubic spline logistic regression models were used to estimate the odds of meeting criteria for the metabolic syndrome and its components by total daily SB time and breaks in SB. Statistical interactions between SB and age, sex and MVPA were explored.

RESULTS

The prevalence of the metabolic syndrome was 19% and the average daily SB time was 8.1 ± 2.8 h, with 90 ± 25 breaks/day. The relationship between daily SB time and the metabolic syndrome was linear and characterised by an OR of 1.09 (95% CI 1.01, 1.18) for each hour of SB. Total SB was associated with the following components: high triacylglycerol, low HDL-cholesterol and high fasting glucose. All three associations were modified by MVPA level. No relationship between breaks in SB and the metabolic syndrome was found.

CONCLUSIONS/INTERPRETATION

There appears to be no SB threshold at which the risk of the metabolic syndrome is elevated. Therefore, an effort should be made to maintain low levels of total time spent in SB and so lessen the risk of the metabolic syndrome.

Sparse modeling of spatial environmental variables associated with asthma

Geographically distributed environmental factors influence the burden of diseases such as asthma. Our objective was to identify sparse environmental variables associated with asthma diagnosis gathered from a large electronic health record (EHR) dataset while controlling for spatial variation. An EHR dataset from the University of Wisconsin's Family Medicine, Internal Medicine and Pediatrics Departments was obtained for 199,220 patients aged 5-50years over a three-year period. Each patient's home address was geocoded to one of 3456 geographic census block groups. Over one thousand block group variables were obtained from a commercial database. We developed a Sparse Spatial Environmental Analysis (SASEA). Using this method, the environmental variables were first dimensionally reduced with sparse principal component analysis. Logistic thin plate regression spline modeling was then used to identify block group variables associated with asthma from sparse principal components. The addresses of patients from the EHR dataset were distributed throughout the majority of Wisconsin's geography. Logistic thin plate regression spline modeling captured spatial variation of asthma. Four sparse principal components identified via model selection consisted of food at home, dog ownership, household size, and disposable income variables. In rural areas, dog ownership and renter occupied housing units from significant sparse principal components were associated with asthma. Our main contribution is the incorporation of sparsity in spatial modeling. SASEA sequentially added sparse principal components to Logistic thin plate regression spline modeling. This method allowed association of geographically distributed environmental factors with asthma using EHR and environmental datasets. SASEA can be applied to other diseases with environmental risk factors.

Abstract 5102: Telomeres and survival in stage III colon cancers: Findings from NCCTG N0147 (Alliance) study

Introduction: Peripheral blood leukocyte (PBL) telomere length is associated with colon cancer (CC) risk, but the relationship of PBL telomere length to survival in CC patients receiving chemotherapy is unknown.

Methods: We measured relative telomere length (RTL) by qPCR of PBL DNA from 2,748 cases (53% male, 85% white, median age 58 yrs) in the North American Phase III Intergroup Trial N0147 that compared disease-free survival (DFS) among completely resected Stage III CC treated with mFOLFOX6 +/- cetuximab. Tumor markers were assessed, and 12% were BRAF mutant; 35% Kras mutant, and 12% deficient mismatch repair (dMMR). Linear and non-linear prognostic associations of PBL RTL to the primary endpoint of DFS were assessed by Cox models. Optimal categories of RTL were developed using cumulative martingale residual plots, designated from shortest to longest RTL (Table 1).

Results: Never smokers had longer PBL RTL (p = 0.0006) than past or current smokers. Those with diabetes mellitus (DM) had longer PBL RTL than those without DM (p = 0.0165). PBL RTL was not associated with any tumor markers (MMR status; p = 0.7174; BRAF mutant vs wild-type (wt); p =0.4039; Kras mutant vs wt; p= 0.1149). PBL RTL was significantly associated with DFS in a non-linear form (p = 0.0389). Cases in the longer RTL category had more favorable DFS than those with shorter or longest RTL, (Table), which remained after adjusting for age, sex , T/N stage, grade, tumor markers, and treatment (p = 0.0230). We observed no significant interaction (p = 0.1490) between RTL categories and treatment.

Conclusion: We observed a non-linear association between RTL and DFS in stage III CC, suggesting that an optimal range telomere length can influence tumor behavior in CC patients. Future studies of telomere maintenance mechanisms may help to explain the association of RTL with improved DFS. RTL is associated with smoking and DM in CC cases but further studies are needed to determine if either tobacco use or DM affect survival from CC by modulating PBL telomere length.

Citation Format: Nivedita Basu, Ruth A. Johnson, Qian Shi, Garth D. Nelson, Julie M. Cunningham, Richard M. Goldberg, Frank A. Sinicrope, Daniel J. Sargent, Steven R. Alberts, Gloria M. Petersen, Stephen N. Thibodeau, Halcyon G. Skinner, Kristin Litzelman, Songwon Seo, Russell J. Vanderboom, Ronald E. Gangnon, Corinne D. Engelman, David N. Rider, Lisa A. Boardman. Telomeres and survival in stage III colon cancers: Findings from NCCTG N0147 (Alliance) study. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5102. doi:10.1158/1538-7445.AM2014-5102

Trends of postmenopausal estrogen plus progestin prevalence in the United States between 1970 and 2010

OBJECTIVE

To estimate long term trends in estrogen-progestin prevalence for the U.S. female population by year and age.

METHODS

We integrated data on oral estrogen-progestin use from the National Health and Nutrition Examination Survey 1999-2010 with data from the National Prescription Audit 1970-2003. Distributions of estrogen-progestin by age from the National Health and Nutrition Examination Survey were applied to the prescription data, and calibration and interpolation procedures were used to generate estrogen-progestin prevalence estimates by single year of age and single calendar year for 1970-2010.

RESULTS

Estimated prevalence of oral estrogen-progestin was below 0.5% in the 1970s, began to rise in the early 1980s, and almost tripled between 1990 and the late 1990s. The age-adjusted prevalence for women aged 45-64 years peaked at 13.5% in 1999 with highest use among 57-year-old women (23.2%). Prevalence of estrogen-progestin use declined dramatically in the early 2000s with only 2.7% of women aged 45-64 years using estrogen-progestin in 2010, which is comparable to prevalence levels in the mid-1980s.

CONCLUSION

The dramatic rise and fall of estrogen-progestin use over the past 40 years provides an illuminating case study of prescription practices before, during, and after the development of evidence regarding benefits and harms.

LEVEL OF EVIDENCE

: II.

Prevalence of mammographically dense breasts in the United States

BACKGROUND

National legislation is under consideration that would require women with mammographically dense breasts to be informed of their breast density and encouraged to discuss supplemental breast cancer screening with their health care providers. The number of US women potentially affected by this legislation is unknown.

METHODS

We determined the mammographic breast density distribution by age and body mass index (BMI) using data from 1518 599 mammograms conducted from 2007 through 2010 at mammography facilities in the Breast Cancer Surveillance Consortium (BCSC). We applied these breast density distributions to age- and BMI-specific counts of the US female population derived from the 2010 US Census and the National Health and Nutrition Examination Survey (NHANES) to estimate the number of US women with dense breasts.

RESULTS

Overall, 43.3% (95% confidence interval [CI] = 43.1% to 43.4%) of women 40 to 74 years of age had heterogeneously or extremely dense breasts, and this proportion was inversely associated with age and BMI. Based on the age and BMI distribution of US women, we estimated that 27.6 million women (95% CI = 27.5 to 27.7 million) aged 40 to 74 years in the United States have heterogeneously or extremely dense breasts. Women aged 40 to 49 years (N = 12.3 million) accounted for 44.3% of this group.

CONCLUSION

The prevalence of dense breasts among US women of common breast cancer screening ages exceeds 25 million. Policymakers and healthcare providers should consider this large prevalence when debating breast density notification legislation and designing strategies to ensure that women who are notified have opportunities to evaluate breast cancer risk and discuss and pursue supplemental screening options if deemed appropriate.

Factors associated with systemic hypertension in asthma

PURPOSE

Asthmatics have unique characteristics that may influence cardiovascular morbidity. We tested the association of lower airway caliber, obstructive sleep apnea (OSA), and other asthma-related factors, with systemic hypertension (HTN).

METHODS

Asthma individuals at specialty clinics completed the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ). Medical records were reviewed for diagnosed HTN, OSA and comorbidities, spirometry, and current medications. FEV1% predicted was categorized as ≥ 80 (reference), 70-79, 60-69, and < 60. SA-SDQ ≥ 36 for men and ≥ 32 for women defined high OSA risk.

RESULTS

Among 812 asthmatics (mean age ± standard deviation: 46 ± 14 years), HTN was diagnosed in 191 (24%), OSA in 65 (8%), and OSA or high OSA risk (combined OSA variable) in 239 (29%). HTN was more prevalent in lower FEV1% categories (p < 0.0001), in subjects with OSA, and those with combined OSA variable (55 vs. 21% and 46 vs. 14%, respectively, both p < 0.0001). With adjustment for covariates, associations with HTN remained significant for some FEV1% categories (70-79% odds ratio = 1.60 [95% CI 0.90-2.87]; 60-69% 2.73 [1.28-5.79]; < 60% 0.96 [0.43-2.14]), and for OSA (2.20 [1.16-4.19]). The combined OSA variable in comparison with OSA alone demonstrated a stronger association with HTN (3.17 [1.99-5.04]) in a reiteration of this model. Inhaled corticosteroids (ICS) at lowest doses, in comparison to no ICS use had an independent "protective" association with HTN (0.44 [0.22-0.90]).

CONCLUSIONS

In this young population, worse lower airways obstruction and OSA were associated with HTN. In contrast, lower ICS doses attenuated likelihood for HTN. Adequate control of airway inflammation at appropriate ICS doses, and screening for OSA may reduce the burden of HTN in asthma.

Association between informal caregiving and cellular aging in the survey of the health of wisconsin: the role of caregiving characteristics, stress, and strain

The pathophysiological consequences of caregiving have not been fully elucidated. We evaluated how caregiving, stress, and caregiver strain were associated with shorter relative telomere length (RTL), a marker of cellular aging. Caregivers (n = 240) and some noncaregivers (n = 98) in the 2008-2010 Survey of the Health of Wisconsin, comprising a representative sample of Wisconsin adults aged 21-74 years, reported their sociodemographic, health, and psychological characteristics. RTL was assayed from blood or saliva samples. Median T and S values were used to determine the telomere-to-single copy gene ratio (T/S) for each sample, and log(T/S) was used as the dependent variable in analyses. Multivariable generalized additive models showed that RTL did not differ between caregivers and noncaregivers (difference in log(T/S) = -0.03; P > 0.05), but moderate-to-high levels of stress versus low stress were associated with longer RTL (difference = 0.15; P = 0.04). Among caregivers, more hours per week of care, caring for a young person, and greater strain were associated with shorter RTL (P < 0.05). Caregivers with discordant levels of stress and strain (i.e., low perceived stress/high strain) compared with low stress/low strain had the shortest RTL (difference = -0.24; P = 0.02, Pinteraction = 0.13), corresponding to approximately 10-15 additional years of aging. Caregivers with these characteristics may be at increased risk for accelerated aging. Future work is necessary to better elucidate these relationships and develop interventions to improve the long-term health and well-being of caregivers.

Evaluation of the modified asthma predictive index in high-risk preschool children

BACKGROUND

Prediction of subsequent school-age asthma during the preschool years has proven challenging.

OBJECTIVE

To confirm in a post hoc analysis the predictive ability of the modified Asthma Predictive Index (mAPI) ina high-risk cohort and a theoretical unselected population. We also tested a potential mAPI modification with a 2-wheezing episode requirement (m2API) in the same populations.

METHODS

Subjects (n [ 289) with a family history of allergy and/or asthma were used to predict asthma at age 6, 8, and 11 years with the use of characteristics collected during the first 3 years of life. The mAPI and the m2API were tested for predictive value.

RESULTS

For the mAPI and m2API, school-age asthma prediction improved from 1 to 3 years of age. The mAPI had high predictive value after a positive test (positive likelihood ratio ranging from 4.9 to 55) for asthma development at years 6,8, and 11. Lowering the number of wheezing episodes to 2(m2API) lowered the predictive value after a positive test(positive likelihood ratio ranging from 1.91 to 13.1) without meaningfully improving the predictive value of a negative test.Posttest probabilities for a positive mAPI reached 72% and 90%in unselected and high-risk populations, respectively.

CONCLUSIONS

In a high-risk cohort, a positive mAPI greatly increased future asthma probability (eg, 30% pretest probability to 90% posttest probability) and is a preferred predictive test to them 2API. With its more favorable positive posttest probability,the mAPI can aid clinical decision making in assessing future asthma risk for preschool-age children.

Reproductive windows, genetic loci, and breast cancer risk

PURPOSE

The reproductive windows between age at menarche and age at first birth (standardized age at first birth) and from menarche to menopause (reproductive lifespan) may interact with genetic variants in association with breast cancer risk.

METHODS

We assessed this hypothesis in 6131 breast cancer cases and 7274 controls who participated in the population-based Collaborative Breast Cancer Study. Risk factor information was collected through telephone interviews, and DNA samples were collected on a subsample (N= 1484 cases, 1307 controls) to genotype for 13 genome-wide association study-identified loci. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated, and P values for the interaction between reproductive windows and genotypes were obtained by adding cross-product terms to statistical models.

RESULTS

For standardized age at first birth, the OR was 1.52 (CI, 1.36-1.71) comparing the highest quintile with the lowest quintile. Carrier status for rs10941679 (5p12) and rs10483813 (RAD51B) appeared to modify this relationship (P = .04 and P = .02, respectively). For reproductive lifespan, the OR comparing the highest quintile with the lowest quintiles was 1.62 (CI, 1.35-1.95). No interactions were detected between genotype and reproductive lifespan (all P > .05). All results were similar regardless of ductal versus lobular breast cancer subtype.

CONCLUSIONS

Our results suggest that the reproductive windows are associated with breast cancer risk and that associations may vary by genetic variants.

Markers of inflammation, oxidative stress, and endothelial dysfunction and the 20-year cumulative incidence of early age-related macular degeneration: the Beaver Dam Eye Study

IMPORTANCE Modifying levels of factors associated with age-related macular degeneration (AMD) may decrease the risk for visual impairment in older persons. OBJECTIVE To examine the relationships of markers of inflammation, oxidative stress, and endothelial dysfunction to the 20-year cumulative incidence of early AMD. DESIGN, SETTING, AND PARTICIPANTS This longitudinal population-based cohort study involved a random sample of 975 persons in the Beaver Dam Eye Study without signs of AMD who participated in the baseline examination in 1988-1990 and up to 4 follow-up examinations in 1993-1995, 1998-2000, 2003-2005, and 2008-2010. EXPOSURES Serum markers of inflammation (high-sensitivity C-reactive protein, tumor necrosis factor-α receptor 2, interleukin-6, and white blood cell count), oxidative stress (8-isoprostane and total carbonyl content), and endothelial dysfunction (soluble vascular cell adhesion molecule-1 and soluble intercellular adhesion molecule-1) were measured. Interactions with complement factor H (rs1061170), age-related maculopathy susceptibility 2 (rs10490924), complement component 3 (rs2230199), and complement component 2/complement factor B (rs4151667) were examined using multiplicative models. Age-related macular degeneration was assessed from fundus photographs. MAIN OUTCOMES AND MEASURES Early AMD defined by the presence of any size drusen and the presence of pigmentary abnormalities or by the presence of large-sized drusen (≥125-μm diameter) in the absence of late AMD. RESULTS The 20-year cumulative incidence of early AMD was 23.0%. Adjusting for age, sex, and other risk factors, high-sensitivity C-reactive protein (odds ratio comparing fourth with first quartile, 2.18; P = .005), tumor necrosis factor-α receptor 2 (odds ratio, 1.78; P = .04), and interleukin-6 (odds ratio, 1.78; P = .03) were associated with the incidence of early AMD. Increased incidence of early AMD was associated with soluble vascular cell adhesion molecule-1 (odds ratio per SD on the logarithmic scale, 1.21; P = .04). CONCLUSIONS AND RELEVANCE We found modest evidence of relationships of serum high-sensitivity C-reactive protein, tumor necrosis factor-α receptor 2, interleukin-6, and soluble vascular cell adhesion molecule-1 to the 20-year cumulative incidence of early AMD independent of age, smoking status, and other factors. It is not known whether these associations represent a cause and effect relationship or whether other unknown confounders accounted for the findings. Even if inflammatory processes are a cause of early AMD, it is not known whether interventions that reduce systemic inflammatory processes will reduce the incidence of early AMD.

Detection of pathogenic bacteria during rhinovirus infection is associated with increased respiratory symptoms and asthma exacerbations

BACKGROUND

Detection of either viral or bacterial pathogens is associated with wheezing in children; however, the influence of both bacteria and viruses on illness symptoms has not been described.

OBJECTIVE

We evaluated bacterial detection during the peak rhinovirus season in children with and without asthma to determine whether an association exists between bacterial infection and the severity of rhinovirus-induced illnesses.

METHODS

Three hundred eight children (166 with asthma and 142 without asthma) aged 4 to 12 years provided 5 consecutive weekly nasal samples during September and scored cold and asthma symptoms daily. Viral diagnostics and quantitative PCR for Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis were performed on all nasal samples.

RESULTS

Detection rates were 53%, 17%, and 11% for H influenzae, S pneumoniae, and M catarrhalis, respectively, with detection of rhinovirus increasing the risk of detecting bacteria within the same sample (odds ratio [OR], 2.0; 95% CI, 1.4-2.7; P < .0001) or the following week (OR, 1.6; 95% CI, 1.1-2.4; P = .02). In the absence of rhinovirus, S pneumoniae was associated with increased cold symptoms (mean, 2.7 [95% CI, 2.0-3.5] vs 1.8 [95% CI, 1.5-2.2]; P = .006) and moderate asthma exacerbations (18% [95% CI, 12% to 27%] vs 9.2% [95% CI, 6.7% to 12%]; P = .006). In the presence of rhinovirus, S pneumoniae was associated with increased moderate asthma exacerbations (22% [95% CI, 16% to 29%] vs 15% [95% CI, 11% to 20%]; P = .01). Furthermore, M catarrhalis detected alongside rhinovirus increased the likelihood of experiencing cold symptoms, asthma symptoms, or both compared with isolated detection of rhinovirus (OR, 2.0 [95% CI, 1.0-4.1]; P = .04). Regardless of rhinovirus status, H influenzae was not associated with respiratory symptoms.

CONCLUSION

Rhinovirus infection enhances detection of specific bacterial pathogens in children with and without asthma. Furthermore, these findings suggest that M catarrhalis and S pneumoniae contribute to the severity of respiratory tract illnesses, including asthma exacerbations.

Sedentary behavior, physical activity, and markers of health in older adults

INTRODUCTION

The purpose of this study was to examine the association between sedentary behavior (SB), cardiometabolic risk factors, and self-reported physical function by level of moderate-vigorous physical activity (MVPA).

METHODS

Cross-sectional analysis was completed on 1914 older adults age ≥ 65 yr from the 2003-2006 U.S. National Health and Nutrition Examination Survey. MVPA and SB were derived from ActiGraph accelerometers worn for 1 wk. MVPA was categorized as sufficient to meet the current U.S. guidelines (≥ 150 min · wk(-1)) or not; SB was split into quartiles. Various biomarkers were examined in laboratory analyses and physical exams, and the number of functional limitations was self-reported. Statistical interaction between SB and MVPA on the biomarker associations was the primary analysis, followed by an examination of their independent associations with relevant covariate adjustment.

RESULTS

Average SB was 9.4 ± 2.3 h · d(-1) (mean ± SD), and approximately 35% were classified as sufficiently active. Overall, no significant meaningful statistical interactions were found between SB and MVPA for any of the outcomes; however, strong independent positive associations were found between SB and weight (P < 0.01), body mass index (P < 0.01), waist circumference (P < 0.01), C-reactive protein (P < 0.01), plasma glucose (P = 0.04), and number of functional limitations (P < 0.01) after adjustment for MVPA. Similarly, MVPA was negatively associated with weight (P = 0.01), body mass index (P < 0.01), waist circumference (P < 0.01), diastolic blood pressure (P = 0.04), C-reactive protein (P < 0.01), and number of functional limitations (P < 0.01) after adjustment for SB.

CONCLUSIONS

The results suggest that sufficient MVPA did not ameliorate the negative associations between SB and cardiometabolic risk factors or functional limitations in the current sample and that there was independence on a multiplicative scale in their associations with the outcomes examined. Thus, older adults may benefit from the joint prescription to accumulate adequate MVPA and avoid prolonged sitting.

Misclassification can explain most apparent regression of age-related macular degeneration: results from multistate models with misclassification

PURPOSE

To investigate the impact of misclassification of age-related macular degeneration (AMD) on the baseline intensity and estimated effects of age, sex, and the Y402H variant in the complement factor H (CFH) gene on incidence, progression, and regression of AMD.

METHODS

The Beaver Dam Eye Study, a longitudinal population-based study of age-related eye diseases conducted in the city and township of Beaver Dam, Wisconsin, performed examinations every 5 years during a 20-year period (1988-1990 through 2008-2010). Study participants (N = 4379) aged 43 to 86 years at the baseline examination had retinal photographs taken at baseline and up to four subsequent examinations. Multistate models with misclassification in continuous time were used to model the effects of age, sex, and CFH genotype on incidence, progression, and regression of AMD and mortality.

RESULTS

After accounting for AMD misclassification, the occurrence of any AMD regression was rare (1%-4%), while it was relatively common (14%-21%) in models that do not account for misclassification. Failure to account for misclassification attenuated estimated age effects on incidence and progression to moderately severe early AMD and attenuated estimated CFH effects on incidence and progressions to moderately severe and severe early AMD.

CONCLUSIONS

Apparent regression of AMD can largely, if not completely, be explained by misclassification. Estimated age effects on incidence and progression to moderately severe early AMD and estimated CFH effects on incidence and progressions to moderately severe and severe early AMD were attenuated in multistate models that did not account for misclassification.

The association of telomere length with colorectal cancer differs by the age of cancer onset

OBJECTIVES:

Telomeres are nucleoprotein structures that cap the end of chromosomes and shorten with sequential cell divisions in normal aging. Short telomeres are also implicated in the incidence of many cancers, but the evidence is not conclusive for colorectal cancer (CRC). Therefore, the aim of this study was to assess the association of CRC and telomere length.

METHODS:

In this case–control study, we measured relative telomere length from peripheral blood leukocytes (PBLs) DNA with quantitative PCR in 598 CRC patients and 2,212 healthy controls.

RESULTS:

Multivariate analysis indicated that telomere length was associated with risk for CRC, and this association varied in an age-related manner; younger individuals (≤50 years of age) with longer telomeres (80–99 percentiles) had a 2–6 times higher risk of CRC, while older individuals (>50 years of age) with shortened telomeres (1–10 percentiles) had 2–12 times the risk for CRC. The risk for CRC varies with extremes in telomere length in an age-associated manner.

CONCLUSIONS:

Younger individuals with longer telomeres or older individuals with shorter telomeres are at higher risk for CRC. These findings indicate that the association of PBL telomere length varies according to the age of cancer onset and that CRC is likely associated with at minimum two different mechanisms of telomere dynamics.

Relation of smoking, drinking, and physical activity to changes in vision over a 20-year period: the Beaver Dam Eye Study

OBJECTIVE

To describe the relationships of lifestyle characteristics to changes in vision and incidence of visual impairment (VI) over a 20-year period in the Beaver Dam Eye Study (BDES).

DESIGN

Longitudinal, population-based cohort study.

PARTICIPANTS

A cohort of 4926 persons aged 43 to 86 years participated in the baseline examinations in 1988-1990, and 3721, 2962, 2375, and 1913 persons participated in follow-up examinations in 1993-1995, 1998-2000, 2003-2005, and 2008-2010, respectively.

METHODS

Best-corrected visual acuity (BCVA) measured by a modified Early Treatment Diabetic Retinopathy Study protocol.

MAIN OUTCOME MEASURES

Change in number of letters read correctly and incidence of VI based on BCVA in the better eye assessed at each examination over a 20-year period.

RESULTS

The 20-year cumulative incidence of VI was 5.4%. There was a mean loss of 1.6 letters between examinations, with a 20-year loss of 6.6 letters. While adjusting for age, income, and age-related macular degeneration (AMD) severity, being a current or past smoker was related to a greater change in the numbers of letters lost. Persons who had not consumed alcoholic beverages over the past year and sedentary persons had higher odds of incident VI than persons who drank occasionally or who were physically active. For example, in women with early AMD and annual household income less than $10,000, the estimated 20-year cumulative incidence of VI in those who drank occasionally and were physically active was 5.9% compared with 25.8% in women who had not consumed alcoholic beverages over the past year and were sedentary.

CONCLUSIONS

Three modifiable behaviors-smoking, drinking alcohol, and physical activity-were associated with changes in vision. Further evidence that changes in these behaviors will result in less loss of vision is needed because of the expected increase in the burden of VI due to the aging of the population.

Childhood asthma clusters and response to therapy in clinical trials

BACKGROUND

Childhood asthma clusters, or subclasses, have been developed by computational methods without evaluation of clinical utility.

OBJECTIVE

To replicate and determine whether childhood asthma clusters previously identified computationally in the Severe Asthma Research Program (SARP) are associated with treatment responses in Childhood Asthma Research and Education (CARE) Network clinical trials.

METHODS

A cluster assignment model was determined by using SARP participant data. A total of 611 participants 6 to 18 years old from 3 CARE trials were assigned to SARP pediatric clusters. Primary and secondary outcomes were analyzed by cluster in each trial.

RESULTS

CARE participants were assigned to SARP clusters with high accuracy. Baseline characteristics were similar between SARP and CARE children of the same cluster. Treatment response in CARE trials was generally similar across clusters. However, with the caveat of a smaller sample size, children in the early-onset/severe-lung function cluster had best response with fluticasone/salmeterol (64% vs 23% 2.5× fluticasone and 13% fluticasone/montelukast in the Best ADd-on Therapy Giving Effective Responses trial; P = .011) and children in the early-onset/comorbidity cluster had the least clinical efficacy to treatments (eg, -0.076% change in FEV1 in the Characterizing Response to Leukotriene Receptor Antagonist and Inhaled Corticosteroid trial).

CONCLUSIONS

In this study, we replicated SARP pediatric asthma clusters by using a separate, large clinical trials network. Early-onset/severe-lung function and early-onset/comorbidity clusters were associated with differential and limited response to therapy, respectively. Further prospective study of therapeutic response by cluster could provide new insights into childhood asthma treatment.