Turner, Stephen T.

Objectives To examine associations between adiposity and adiposity change (loss, stable, gain) and subsequent longitudinal cognitive performance in African Americans in mid and late life. Design Cohort study using linear mixed models. Setting Genetic Epidemiology Network of Arteriopathy. Participants African‐American sibships with hypertension in Jackson, Mississippi (N = 1,108). Measurements Waist circumference and body mass index ( BMI ) were measured at two examinations 5 years apart. Stable adiposity was defined as values within 5% of the first measure. A composite cognitive Z ‐score was derived from individual cognitive test Z ‐scores at two study visits 6 years apart. Results Larger waist circumference was associated with greater rate of cognitive decline during follow‐up (beta = −0.0009 per year, P = .001); BMI , change in waist circumference, and change in BMI were not associated with rate of decline. Loss of adiposity in midlife was associated with higher cognitive Z ‐scores in middle‐aged individuals, and loss of adiposity in late life was associated with lower Z ‐scores in older adults ( P = .01 for interaction between waist circumference and age; P = .04 for interaction between BMI and age). Simultaneous inclusion of waist circumference and BMI in the cross‐sectional model suggested an association between larger waist circumference and poorer cognitive performance (beta = −0.009, P = .006) and between higher BMI and better cognitive performance (beta = 0.014, P = .06). Conclusion The results suggested a differential pattern of the relationship between adiposity and cognition according to age (mid‐ or late life) and regional distribution of adiposity.

Genome-wide association studies have identified >50 common variants associated with kidney function, but these variants do not fully explain the variation in eGFR. We performed a two-stage meta-analysis of associations between genotypes from the Illumina exome array and eGFR on the basis of serum creatinine (eGFRcrea) among participants of European ancestry from the CKDGen Consortium ( n Stage1 : 111,666; n Stage2 : 48,343). In single-variant analyses, we identified single nucleotide polymorphisms at seven new loci associated with eGFRcrea ( PPM1J , EDEM3, ACP1, SPEG, EYA4, CYP1A1 , and ATXN2L ; P Stage1 <3.7×10 −7 ), of which most were common and annotated as nonsynonymous variants. Gene-based analysis identified associations of functional rare variants in three genes with eGFRcrea, including a novel association with the SOS Ras/Rho guanine nucleotide exchange factor 2 gene, SOS2 ( P =5.4×10 −8 by sequence kernel association test). Experimental follow-up in zebrafish embryos revealed changes in glomerular gene expression and renal tubule morphology in the embryonic kidney of acp1- and sos2 -knockdowns. These developmental abnormalities associated with altered blood clearance rate and heightened prevalence of edema. This study expands the number of loci associated with kidney function and identifies novel genes with potential roles in kidney formation.

Abstract Background. We recently published and validated the new serum creatinine (Scr)-based full-age-spectrum equation (FAScrea) for estimating the glomerular filtration rate (GFR) for healthy and kidney–diseased subjects of all ages. The equation was based on the concept of normalized Scr and shows equivalent to superior prediction performance to the currently recommended equations for children, adolescents, adults and older adults. Methods. Based on an evaluation of the serum cystatin C (ScysC) distribution, we defined normalization constants for ScysC (QcysC = 0.82 mg/L for ages &lt;70 years and QcysC = 0.95 mg/L for ages ≥70 years). By replacing Scr/Qcrea in the FAScrea equation with ScysC/QcysC, or with the average of both normalized biomarkers, we obtained new ScysC-based (FAScysC) and combined Scr-/ScysC-based FAS equations (FAScombi). To validate the new FAScysC and FAScombi we collected data on measured GFR, Scr, ScysC, age, gender, height and weight from 11 different cohorts including n = 6132 unique white subjects (368 children, aged ≤18 years, 4295 adults and 1469 older adults, aged ≥70 years). Results. In children and adolescents, the new FAScysC equation showed significantly better performance [percentage of patients within 30% of mGFR (P30) = 86.1%] than the Caucasian Asian Paediatric Adult Cohort equation (P30 = 76.6%; P &lt; 0.0001), or the ScysC-based Schwartz equation (P30 = 68.8%; P &lt; 0.0001) and the FAScombi equation outperformed all equations with P30 = 92.1% (P &lt; 0.0001). In adults, the FAScysC equation (P30 = 82.6%) performed equally as well as the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPIcysC) (P30 = 80.4%) and the FAScombi equation (P30 = 89.9%) was also equal to the combined CKD-EPI equation (P30 = 88.2%). In older adults, FAScysC was superior (P30 = 88.2%) to CKD-EPIcysC (P30 = 84.4%; P &lt; 0.0001) and the FAScombi equation (P30 = 91.2%) showed significantly higher performance than the combined CKD-EPI equation (P30 = 85.6%) (P &lt; 0.0001). Conclusion. The FAS equation is not only applicable to all ages, but also for all recommended renal biomarkers and their combinations.

Objectives To quantify associations between inflammatory biomarkers and hippocampal volume ( HV ) and to examine effect modification according to sex, race, and age. Design Cross‐sectional analyses using generalized estimating equations to account for familial clustering; standardized β ‐coefficients adjusted for age, sex, race, and education. Setting Community cohorts in Jackson, Mississippi and Rochester, Minnesota. Participants The Genetic Epidemiology Network of Arteriopathy study. Measurements C‐reactive protein ( CRP ), interleukin‐6 ( IL ‐6), and soluble tumor necrosis factor receptors 1 ( sTNFR ‐1) and 2 ( sTNFR ‐2) from peripheral blood were measured in a sample of 773 non‐Hispanic whites (61% women, aged 60.2 ± 9.8) and 514 African Americans (70% women, aged 63.9 ± 8.1) who also underwent brain magnetic resonance imaging. Biomarkers were standardized and compared according to sex, race and age with HV. Results In the full sample, higher sTNFR ‐1 and sTNFR ‐2 were associated with smaller HV . Each standard deviation ( SD ) increase in sTNFR ‐1 was associated with 59.1 mm 3 (95% confidence interval ( CI ) = −101.4 to −16.7 mm 3 ) smaller HV and each SD increase in sTNFR ‐2 associated with 48.8 mm 3 (95% CI = −92.2 to −5.3 mm 3 ) smaller HV . Relationships were stronger for sTNFR ‐2 in men ( HV = −116.6 mm 3 for each SD increase, 95% CI = −201.0 to −32.1) than women ( HV = −26.0 per SD increase, 95% CI = −72.4–20.5) and sTNFR ‐1 in non‐Hispanic whites ( HV = −84.7 mm 3 per SD increase, 95% CI = −142.2 to −27.1) than African Americans ( HV = −14.1 mm 3 per SD increase, 95% CI = −78.3–50.1). Associations between IL ‐6 or CRP and HV were not supported. Conclusion Higher levels of sTNFR s were associated cross‐sectionally with smaller hippocampi. Longitudinal data are needed to determine whether these biomarkers may help to identify risk of late‐life cognitive impairment.

Objectives To examine associations between inflammation and physical function and potential mediation by white matter hyperintensities ( WMH s) in African Americans ( AA s) and European Americans ( EA s). Design Cross‐sectional analysis using linear and logistic models with generalized estimating equations to account for family clustering, reporting results as regression coefficients (β) and odds ratios ( OR s) adjusted for education, alcohol, exercise, body mass index, hypertension, diabetes mellitus, heart disease, cognition, ankle–brachial index, race (site), and supported interactions. Setting Genetic Epidemiology Network of Arteriopathy‐Genetics of Microangiopathic Brain Injury Study cohort. Participants AA and EA sibships with two or more siblings with hypertension before age 60 (N = 1,960; 65% female, 51% AA , aged 26–91, 50% obese, 72% hypertensive). Measurements Inflammation (C‐reactive protein ( CRP ), interleukin‐6 ( IL 6), soluble tumor necrosis factor receptors ( sTNFR s) 1 and 2, WMH volume (cm 3 ) according to magnetic resonance imaging), walking speed (cm/s) over 25 feet, and mobility difficulty (any self‐reported difficulty walking half a mile). Results In separate models, inflammatory markers were associated with walking speed ( sTNFR 1: β = −2.74, P < .001; sTNFR 2: β = −1.23, P = .03; CRP : β = −1.95, P = .001; IL 6: β = −1.24, P = .03) and mobility difficulty ( sTNFR 1: OR = 1.36, P = .001; sTNFR 2: OR = 1.25, P = .005; CRP : OR = 1.22, P = .005; IL 6: OR = 1.18, P = .02); the association between WMH volume and sTNFR 1 in AA (β = 0.07, P = .06) did not reach typical statistical thresholds. WMH volume was associated with walking speed in AA (β = −3.17, P = .02) but not with mobility difficulty ( OR = 1.10, P = .54). Adjusting for WMH did not change associations. Conclusion In young, middle‐aged, and older adults with prevalent cardiovascular risk factors, multiple inflammatory biomarkers were associated with slower walking speed independent of microvascular disease in the brain. There was little evidence of mediation by brain WMH volume. Inflammation may contribute to physical function impairments through pathways other than brain microvascular disease, particularly in AA s.

Background— Hypertensive pregnancy disorders have been associated with subjective cognitive complaints or brain white-matter lesions 5 to 10 years after the hypertensive pregnancy. The long-term effects of hypertensive pregnancies on brain structure and cognitive function remain unknown. Methods and Results— This study included 1279 women who participated in the Family Blood Pressure Project Genetic Epidemiology Network of Arteriopathy (GENOA) study. As part of the ancillary Genetics of Microangiopathic Brain Injury (GMBI) study, a neurocognitive battery was administered; 1075 also had a brain magnetic resonance imaging. A history of a hypertensive pregnancy disorder was obtained by a self-report using a validated questionnaire. Linear models fit with generalized estimating equations were used to assess the association between hypertensive pregnancy disorders and cognition, adjusting for age, race, education, body mass index, smoking, current hypertension, hypertension duration, and family history of hypertension. Regression models for the brain magnetic resonance imaging outcomes also were adjusted for total intracranial volume. Women with histories of hypertensive pregnancy disorders performed worse on all measures of processing speed (Digital Symbol Substitution Test [mean score, 41.2 versus 43.4; P =0.005], Trail Making Test Part A [mean seconds, 45.1 versus 42.2; P =0.035], and Stroop [mean score, 173.9 versus 181.0; P =0.002]) and had smaller brain volumes compared with women with histories of normotensive pregnancies (286 versus 297; P =0.023). Conclusions— Hypertensive pregnancy disorders are associated with worse performance on tests of processing speed and smaller brain volumes decades later. Population-based studies are needed to provide critical insight as to the contribution of hypertensive pregnancies to risk of cognitive decline and dementia.