Purpose

Rural US adults have increased risk of poor outcomes after cancer, including increased cancer mortality. Rural-urban differences in health behaviors have been identified in the general population and may contribute to cancer health disparities, but have not yet been examined among US survivors. We examined rural-urban differences in health behaviors among cancer survivors and associations with self-reported health and health-related unemployment.

Methods

We identified rural (n = 1,642) and urban (n = 6,162) survivors from the cross-sectional National Health Interview Survey (2006-2010) and calculated the prevalence of smoking, physical activity, overweight/obesity, and alcohol consumption. Multivariable models were used to examine the associations of fair/poor health and health-related unemployment with health behaviors and rural-urban residence.

Results

The prevalence of fair/poor health (rural 36.7 %, urban 26.6 %), health-related unemployment (rural 18.5 %, urban 10.6 %), smoking (rural 25.3 %, urban 15.8 %), and physical inactivity (rural 50.7 %, urban 38.7 %) was significantly higher in rural survivors (all p < .05); alcohol consumption was lower (rural 46.3 %, urban 58.6 %), and there were no significant differences in overweight/obesity (rural 65.4 %, urban 62.6 %). All health behaviors were significantly associated with fair/poor health and health-related unemployment in both univariate and multivariable models. After adjustment for behaviors, rural survivors remained more likely than urban survivors to report fair/poor health (OR = 1.21, 95 % CI 1.03-1.43) and health-related unemployment (OR = 1.49, 95 % CI 1.18-1.88).

Conclusions

Rural survivors may need tailored, accessible health promotion interventions to address health-compromising behaviors and improve outcomes after cancer.

Background

Routine follow-up care is recommended to promote the well-being of cancer survivors, but financial difficulties may interfere. Rural-urban disparities in forgoing healthcare due to cost have been observed in the general population; however, it is unknown whether this disparity persists among survivors. The purpose of this study was to examine rural-urban disparities in forgoing healthcare after cancer due to cost.

Methods

We analyzed data from 7,804 cancer survivors in the 2006 to 2010 National Health Interview Survey. Logistic regression models, adjusting for sociodemographic and clinical characteristics, were used to assess rural-urban disparities in forgoing medical care, prescription medications, and dental care due to cost, stratified by age (younger: 18-64, older: 65+).

Results

Compared with urban survivors, younger rural survivors were more likely to forgo medical care (P < 0.001) and prescription medications (P < 0.001) due to cost; older rural survivors were more likely to forgo medical (P < 0.001) and dental care (P = 0.05). Rural-urban disparities did not persist among younger survivors in adjusted analyses; however, older rural survivors remained more likely to forgo medical [OR = 1.66, 95% confidence interval (CI) = 1.11-2.48] and dental care (OR = 1.54, 95%CI = 1.08-2.20).

Conclusions

Adjustment for health insurance and other sociodemographic characteristics attenuates rural-urban disparities in forgoing healthcare among younger survivors, but not older survivors. Financial factors relating to healthcare use among rural survivors should be a topic of continued investigation.

Impact

Addressing out-of-pocket costs may be an important step in reducing rural-urban disparities in healthcare, especially for older survivors. It will be important to monitor how healthcare reform efforts impact disparities observed in this vulnerable population.

Objectives

We examined racial/ethnic disparities in health care receipt among a nationally representative sample of male cancer survivors.

Methods

We identified men aged 18 years and older from the 2006-2010 National Health Interview Survey who reported a history of cancer. We assessed health care receipt in 4 self-reported measures: primary care visit, specialist visit, flu vaccination, and pneumococcal vaccination. We used hierarchical logistic regression modeling, stratified by age (< 65 years vs ≥ 65 years).

Results

In adjusted models, older African American and Hispanic survivors were approximately twice as likely as were non-Hispanic Whites to not see a specialist (odds ratio [OR] = 1.78; 95% confidence interval [CI] = 1.19, 2.68 and OR = 2.09; 95% CI = 1.18, 3.70, respectively), not receive the flu vaccine (OR = 2.21; 95% CI = 1.45, 3.37 and OR = 2.20; 95% CI = 1.21, 4.01, respectively), and not receive the pneumococcal vaccine (OR = 2.24; 95% CI = 1.54, 3.24 and OR = 3.10; 95% CI = 1.75, 5.51, respectively).

Conclusions

Racial/ethnic disparities in health care receipt are evident among older, but not younger, cancer survivors, despite access to Medicare. These survivors may be less likely to see specialists, including oncologists, and receive basic preventive care.

Background

Coronary artery calcification (CAC) and carotid artery intima-media thickness (cIMT) are measures of subclinical atherosclerosis in asymptomatic individuals and strong risk factors for cardiovascular disease. Type 2 diabetes (T2D) is an independent cardiovascular disease risk factor that accelerates atherosclerosis.

Methods

We performed meta-analyses of genome-wide association studies in up to 2500 T2D individuals of European ancestry (EA) and 1590 T2D individuals of African ancestry with or without exclusion of prevalent cardiovascular disease, for CAC measured by cardiac computed tomography, and 3608 individuals of EA and 838 individuals of African ancestry with T2D for cIMT measured by ultrasonography within the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) Consortium.

Results

We replicated 2 loci (rs9369640 and rs9349379 near PHACTR1 and rs10757278 near CDKN2B) for CAC and one locus for cIMT (rs7412 and rs445925 near APOE-APOC1) that were previously reported in the general EA populations. We identified one novel CAC locus (rs8000449 near CSNK1A1L/LINC00547/POSTN at 13q13.3) at P=2.0×10^-8 in EA. No additional loci were identified with the meta-analyses of EA and African ancestry. The expression quantitative trait loci analysis with nearby expressed genes derived from arterial wall and metabolic tissues from the Genotype-Tissue Expression project pinpoints POSTN, encoding a matricellular protein involved in bone formation and bone matrix organization, as the potential candidate gene at this locus. In addition, we found significant associations (P<3.1×10^-4) for 3 previously reported coronary artery disease loci for these subclinical atherosclerotic phenotypes (rs2891168 near CDKN2B-AS1 and rs11170820 near FLJ12825 for CAC, and rs7412 near APOE for cIMT).

Conclusions

Our results provide potential biological mechanisms that could link CAC and cIMT to increased cardiovascular disease risk in individuals with T2D.

Aortic calcification is an important independent predictor of future cardiovascular events. We performed a genome-wide association meta-analysis to determine SNPs associated with the extent of abdominal aortic calcification (n = 9,417) or descending thoracic aortic calcification (n = 8,422). Two genetic loci, HDAC9 and RAP1GAP, were associated with abdominal aortic calcification at a genome-wide level (P < 5.0 × 10^-8). No SNPs were associated with thoracic aortic calcification at the genome-wide threshold. Increased expression of HDAC9 in human aortic smooth muscle cells promoted calcification and reduced contractility, while inhibition of HDAC9 in human aortic smooth muscle cells inhibited calcification and enhanced cell contractility. In matrix Gla protein-deficient mice, a model of human vascular calcification, mice lacking HDAC9 had a 40% reduction in aortic calcification and improved survival. This translational genomic study identifies the first genetic risk locus associated with calcification of the abdominal aorta and describes a previously unknown role for HDAC9 in the development of vascular calcification.

Variation in body fat distribution contributes to the metabolic sequelae of obesity. The genetic determinants of body fat distribution are poorly understood. The goal of this study was to gain new insights into the underlying genetics of body fat distribution by conducting sample-size-weighted fixed-effects genome-wide association meta-analyses in up to 9,594 women and 8,738 men of European, African, Hispanic and Chinese ancestry, with and without sex stratification, for six traits associated with ectopic fat (hereinafter referred to as ectopic-fat traits). In total, we identified seven new loci associated with ectopic-fat traits (ATXN1, UBE2E2, EBF1, RREB1, GSDMB, GRAMD3 and ENSA; P < 5 × 10^-8; false discovery rate < 1%). Functional analysis of these genes showed that loss of function of either Atxn1 or Ube2e2 in primary mouse adipose progenitor cells impaired adipocyte differentiation, suggesting physiological roles for ATXN1 and UBE2E2 in adipogenesis. Future studies are necessary to further explore the mechanisms by which these genes affect adipocyte biology and how their perturbations contribute to systemic metabolic disease.

Carotid artery intima media thickness (cIMT) and carotid plaque are measures of subclinical atherosclerosis associated with ischemic stroke and coronary heart disease (CHD). Here, we undertake meta-analyses of genome-wide association studies (GWAS) in 71,128 individuals for cIMT, and 48,434 individuals for carotid plaque traits. We identify eight novel susceptibility loci for cIMT, one independent association at the previously-identified PINX1 locus, and one novel locus for carotid plaque. Colocalization analysis with nearby vascular expression quantitative loci (cis-eQTLs) derived from arterial wall and metabolic tissues obtained from patients with CHD identifies candidate genes at two potentially additional loci, ADAMTS9 and LOXL4. LD score regression reveals significant genetic correlations between cIMT and plaque traits, and both cIMT and plaque with CHD, any stroke subtype and ischemic stroke. Our study provides insights into genes and tissue-specific regulatory mechanisms linking atherosclerosis both to its functional genomic origins and its clinical consequences in humans.

African Americans are disproportionately affected by type 2 diabetes (T2DM) yet few studies have examined T2DM using genome-wide association approaches in this ethnicity. The aim of this study was to identify genes associated with T2DM in the African American population. We performed a Genome Wide Association Study (GWAS) using the Affymetrix 6.0 array in 965 African-American cases with T2DM and end-stage renal disease (T2DM-ESRD) and 1029 population-based controls. The most significant SNPs (n = 550 independent loci) were genotyped in a replication cohort and 122 SNPs (n = 98 independent loci) were further tested through genotyping three additional validation cohorts followed by meta-analysis in all five cohorts totaling 3,132 cases and 3,317 controls. Twelve SNPs had evidence of association in the GWAS (P<0.0071), were directionally consistent in the Replication cohort and were associated with T2DM in subjects without nephropathy (P<0.05). Meta-analysis in all cases and controls revealed a single SNP reaching genome-wide significance (P<2.5×10(-8)). SNP rs7560163 (P = 7.0×10(-9), OR (95% CI) = 0.75 (0.67-0.84)) is located intergenically between RND3 and RBM43. Four additional loci (rs7542900, rs4659485, rs2722769 and rs7107217) were associated with T2DM (P<0.05) and reached more nominal levels of significance (P<2.5×10(-5)) in the overall analysis and may represent novel loci that contribute to T2DM. We have identified novel T2DM-susceptibility variants in the African-American population. Notably, T2DM risk was associated with the major allele and implies an interesting genetic architecture in this population. These results suggest that multiple loci underlie T2DM susceptibility in the African-American population and that these loci are distinct from those identified in other ethnic populations.