Non-coding variants in MYH11, FZD3, and SORCS3 are associated with dementia in women.

INTRODUCTION: Recent studies suggest that both sex-specific genetic risk factors and those shared between dementia and stroke are involved in dementia pathogenesis. METHODS: We performed both single-variant and gene-based genome-wide association studies of >11,000 whole genome sequences from the Women's Health Initiative cohort to discover loci associated with dementia, with adjustment for age, ethnicity, stroke, and venous thromboembolism status. Evidence for prior evidence of association and differential gene expression in dementia-related tissues and samples was gathered for each locus. RESULTS: Our multiethnic studies identified significant associations between variants within APOE, MYH11, FZD3, SORCS3, and GOLGA8B and risk of dementia. Ten genes implicated by these loci, including MYH11, FZD3, SORCS3, and GOLGA8B, were differentially expressed in the context of Alzheimer's disease. DISCUSSION: Our association of MYH11, FZD3, SORCS3, and GOLGA8B with dementia is supported by independent functional studies in human subjects, model systems, and associations with shared risk factors for stroke and dementia.

Fine Mapping and Identification of BMI Loci in African Americans.

Genome-wide association studies (GWASs) primarily performed in European-ancestry (EA) populations have identified numerous loci associated with body mass index (BMI). However, it is still unclear whether these GWAS loci can be generalized to other ethnic groups, such as African Americans (AAs). Furthermore, the putative functional variant or variants in these loci mostly remain under investigation. The overall lower linkage disequilibrium in AA compared to EA populations provides the opportunity to narrow in or fine-map these BMI-related loci. Therefore, we used the Metabochip to densely genotype and evaluate 21 BMI GWAS loci identified in EA studies in 29,151 AAs from the Population Architecture using Genomics and Epidemiology (PAGE) study. Eight of the 21 loci (SEC16B, TMEM18, ETV5, GNPDA2, TFAP2B, BDNF, FTO, and MC4R) were found to be associated with BMI in AAs at 5.8 × 10(-5). Within seven out of these eight loci, we found that, on average, a substantially smaller number of variants was correlated (r(2) > 0.5) with the most significant SNP in AA than in EA populations (16 versus 55). Conditional analyses revealed GNPDA2 harboring a potential additional independent signal. Moreover, Metabochip-wide discovery analyses revealed two BMI-related loci, BRE (rs116612809, p = 3.6 × 10(-8)) and DHX34 (rs4802349, p = 1.2 × 10(-7)), which were significant when adjustment was made for the total number of SNPs tested across the chip. These results demonstrate that fine mapping in AAs is a powerful approach for both narrowing in on the underlying causal variants in known loci and discovering BMI-related loci.

A systematic mapping approach of 16q12.2/FTO and BMI in more than 20,000 African Americans narrows in on the underlying functional variation: results from the Population Architecture using Genomics and Epidemiology (PAGE) study.

Genetic variants in intron 1 of the fat mass- and obesity-associated (FTO) gene have been consistently associated with body mass index (BMI) in Europeans. However, follow-up studies in African Americans (AA) have shown no support for some of the most consistently BMI-associated FTO index single nucleotide polymorphisms (SNPs). This is most likely explained by different race-specific linkage disequilibrium (LD) patterns and lower correlation overall in AA, which provides the opportunity to fine-map this region and narrow in on the functional variant. To comprehensively explore the 16q12.2/FTO locus and to search for second independent signals in the broader region, we fine-mapped a 646-kb region, encompassing the large FTO gene and the flanking gene RPGRIP1L by investigating a total of 3,756 variants (1,529 genotyped and 2,227 imputed variants) in 20,488 AAs across five studies. We observed associations between BMI and variants in the known FTO intron 1 locus: the SNP with the most significant p-value, rs56137030 (8.3 × 10(-6)) had not been highlighted in previous studies. While rs56137030was correlated at r(2)>0.5 with 103 SNPs in Europeans (including the GWAS index SNPs), this number was reduced to 28 SNPs in AA. Among rs56137030 and the 28 correlated SNPs, six were located within candidate intronic regulatory elements, including rs1421085, for which we predicted allele-specific binding affinity for the transcription factor CUX1, which has recently been implicated in the regulation of FTO. We did not find strong evidence for a second independent signal in the broader region. In summary, this large fine-mapping study in AA has substantially reduced the number of common alleles that are likely to be functional candidates of the known FTO locus. Importantly our study demonstrated that comprehensive fine-mapping in AA provides a powerful approach to narrow in on the functional candidate(s) underlying the initial GWAS findings in European populations.

Mammography interval and breast cancer mortality in women over the age of 75.

The purpose of this study is to evaluate the relationship between mammography interval and breast cancer mortality among older women with breast cancer. The study population included 1,914 women diagnosed with invasive breast cancer at age 75 or later during their participation in the Women's health initiative, with an average follow-up of 4.4 years (3.1 SD). Cause of death was based on medical record review. Mammography interval was defined as the time between the last self-reported mammogram 7 or more months prior to diagnosis, and the date of diagnosis. Multivariable adjusted hazard ratios (HR) and 95 % confidence intervals (CIs) for breast cancer mortality and all-cause mortality were computed from Cox proportional hazards analyses. Prior mammograms were reported by 73.0 % of women from 7 months to ≤2 year of diagnosis (referent group), 19.4 % (>2 to <5 years), and 7.5 % (≥5 years or no prior mammogram). Women with the longest versus shortest intervals had more poorly differentiated (28.5 % vs. 22.7 %), advanced stage (25.7 % vs. 22.9 %), and estrogen receptor negative tumors (20.9 % vs. 13.1 %). Compared to the referent group, women with intervals of >2 to <5 years or ≥5 years had an increased risk of breast cancer mortality (HR 1.62, 95 % CI 1.03-2.54) and (HR 2.80, 95 % CI 1.57-5.00), respectively, p trend = 0.0002. There was no significant relationship between mammography interval and other causes of death. These results suggest a continued role for screening mammography among women 75 years of age and older.

Does an index composed of clinical data reflect effects of inflammation, coagulation, and monocyte activation on mortality among those aging with HIV?

BACKGROUND: When added to age, CD4 count and human immunodeficiency virus type 1 (HIV-1) RNA alone (Restricted Index), hemoglobin, FIB-4 Index, hepatitis C virus (HCV), and estimated glomerular filtration rate improve prediction of mortality. Weighted and combined, these 7 routine clinical variables constitute the Veterans Aging Cohort Study (VACS) Index. Because nonroutine biomarkers of inflammation (interleukin 6 [IL-6]), coagulation (D-dimer), and monocyte activation (sCD14) also predict mortality, we test the association of these indices and biomarkers with each other and with mortality. METHODS: Samples from 1302 HIV-infected veterans on antiretroviral therapy were analyzed. Indices were calculated closest to date of collection. We calculated Spearman correlations stratified by HIV-1 RNA and HCV status and measured association with mortality using C statistics and net reclassification improvement (NRI). RESULTS: Of 1302 subjects, 915 had HIV-1 RNA <500 copies/mL and 154 died. The VACS Index was more correlated with IL-6, D-dimer, and sCD14 than the Restricted Index (P < .001). It was also more predictive of mortality (C statistic, 0.76; 95% confidence interval [CI], .72-.80) than any biomarker (C statistic, 0.66-0.70) or the Restricted Index (C statistic, 0.71; 95% CI, .67-.75). Compared to the Restricted Index alone, NRI resulted from incremental addition of VACS Index components (10%), D-dimer (7%), and sCD14 (4%), but not from IL-6 (0%). CONCLUSIONS: Among HIV-infected individuals, independent of CD4, HIV-1 RNA, and age, hemoglobin and markers of liver and renal injury are associated with inflammation. Addition of D-dimer and sCD14, but not IL-6, improves the predictive accuracy of the VACS Index for mortality.

Blood pressure variability and brain morphology in elderly women without cardiovascular disease.

OBJECTIVE: To examine the relationship between blood pressure (BP) variability (BPV), brain volumes, and cognitive functioning in postmenopausal women with few modifiable cardiovascular risk factors. METHODS: Study participants consisted of postmenopausal women enrolled in the Women's Health Initiative Memory MRI study (WHIMS-MRI) without cardiovascular disease, diabetes mellitus, hypertension, or current smoking at baseline (1996-1999). BP readings were taken at baseline and each annual follow-up visit. BPV was defined as the SD associated with a participant's mean BP across visits and the SD associated with the participant's regression line with BP regressed across visits. Brain MRI scans were performed between 2004 and 2006. Cognitive functioning was assessed at baseline and annually thereafter with the Modified Mini-Mental State Examination (3MSE) scoring until 2008. The final sample consisted of 558 women (mean age 69 years, median follow-up time [interquartile range] 8 [0.8] years). RESULTS: In adjusted models including mean systolic BP, women in the highest tertile of systolic BPV had lower hippocampal volumes and higher lesion volumes compared to women in the lowest tertile. No relationship between BPV and 3MSE scoring was detected. CONCLUSIONS: In postmenopausal women with few modifiable cardiovascular risk factors, greater visit-to-visit systolic BPV was associated with reductions in hippocampal volume and increases in lesion volumes at later life. These data add evidence to the emerging importance of BPV as a prognostic indicator even in the absence of documented cardiovascular risk factors.

Use of recovery biomarkers to calibrate nutrient consumption self-reports in the Women's Health Initiative.

Underreporting of energy consumption by self-report is well-recognized, but previous studies using recovery biomarkers have not been sufficiently large to establish whether participant characteristics predict misreporting. In 2004-2005, 544 participants in the Women's Health Initiative Dietary Modification Trial completed a doubly labeled water protocol (energy biomarker), 24-hour urine collection (protein biomarker), and self-reports of diet (assessed by food frequency questionnaire (FFQ)), exercise, and lifestyle habits; 111 women repeated all procedures after 6 months. Using linear regression, the authors estimated associations of participant characteristics with misreporting, defined as the extent to which the log ratio (self-reported FFQ/nutritional biomarker) was less than zero. Intervention women in the trial underreported energy intake by 32% (vs. 27% in the comparison arm) and protein intake by 15% (vs. 10%). Younger women had more underreporting of energy (p = 0.02) and protein (p = 0.001), while increasing body mass index predicted increased underreporting of energy and overreporting of percentage of energy derived from protein (p = 0.001 and p = 0.004, respectively). Blacks and Hispanics underreported more than did Caucasians. Correlations of initial measures with repeat measures (n = 111) were 0.72, 0.70, 0.46, and 0.64 for biomarker energy, FFQ energy, biomarker protein, and FFQ protein, respectively. Recovery biomarker data were used in regression equations to calibrate self-reports; the potential application of these equations to disease risk modeling is presented. The authors confirm the existence of systematic bias in dietary self-reports and provide methods of correcting for measurement error.

Moderate renal impairment and risk of dementia among older adults: the Cardiovascular Health Cognition Study.

Renal impairment is associated with an increased risk of carotid atherosclerosis and stroke, determinants of cognitive dysfunction and dementia. The purpose of this study was to determine whether moderate renal impairment is associated with incident dementia among community-dwelling older adults. Participants in the Cardiovascular Health Cognition Study without prevalent dementia (n = 3349) were included in the analysis. Incident dementia was confirmed through neurologic testing. Renal function at baseline was estimated by the inverse of serum creatinine (1/SCr); moderate renal impairment was defined as SCr > or = 1.3 mg/dl for women and > or = 1.5 mg/dl for men. Cox regression models were used to estimate the association of renal impairment with incident dementia. Because SCr is also a function of muscle mass, the authors determined whether the relationship between SCr and dementia was particularly strong among individuals without severe co-morbidity at baseline, as reflected by self-reported general health status. There were 477 incident dementia cases over a median 6 yr follow-up. After adjustment for potential confounders, moderate renal insufficiency was associated with a 37% increased risk of dementia (95% CI = 1.06 to 1.78). Similarly, a 0.5-unit decrement in 1/SCr (equivalent to an increase in SCr from 1.0 to 2.0 mg/dl) was associated with a 26% increased risk (95% CI = 1.02 to 1.60). These associations were present only among the 84% of older adults who reported good-excellent health. Among those in good-excellent health, higher SCr was associated with vascular-type dementia but not Alzheimer-type dementia. Moderate renal impairment, reflected by a higher SCr, is associated with an excess risk of incident dementia among individuals in good-excellent health. Strategies to prevent or delay the onset of dementia in patients with moderate renal impairment are needed.