Creatinine- versus cystatin C-based renal function assessment in the Northern Manhattan Study.

BACKGROUND: Accurate glomerular filtration rate estimation informs drug dosing and risk stratification. Body composition heterogeneity influences creatinine production and the precision of creatinine-based estimated glomerular filtration rate (eGFRcr) in the elderly. We compared chronic kidney disease (CKD) categorization using eGFRcr and cystatin C-based estimated GFR (eGFRcys) in an elderly, racially/ethnically diverse cohort to determine their concordance. METHODS: The Northern Manhattan Study (NOMAS) is a predominantly elderly, multi-ethnic cohort with a primary aim to study cardiovascular disease epidemiology. We included participants with concurrently measured creatinine and cystatin C. eGFRcr was calculated using the CKD-EPI 2009 equation. eGFRcys was calculated using the CKD-EPI 2012 equation. Logistic regression was used to estimate odds ratios and 95% confidence intervals of factors associated with reclassification from eGFRcr≥60ml/min/1.73m2 to eGFRcys<60ml/min/1.73m2. RESULTS: Participants (n = 2988, mean age 69±10yrs) were predominantly Hispanic, female, and overweight/obese. eGFRcys was lower than eGFRcr by mean 23mL/min/1.73m2. 51% of participants' CKD status was discordant, and only 28% maintained the same CKD stage by both measures. Most participants (78%) had eGFRcr≥60mL/min/1.73m2; among these, 64% had eGFRcys<60mL/min/1.73m2. Among participants with eGFRcr≥60mL/min/1.73m2, eGFRcys-based reclassification was more likely in those with age >65 years, obesity, current smoking, white race, and female sex. CONCLUSIONS: In a large, multiethnic, elderly cohort, we found a highly discrepant prevalence of CKD with eGFRcys versus eGFRcr. Determining the optimal method to estimate GFR in elderly populations needs urgent further study to improve risk stratification and drug dosing.

Electrocardiographic left atrial abnormality and silent vascular brain injury: The Northern Manhattan Study.

HYPOTHESIS: We hypothesized that P wave terminal Force in the V1 lead (PTFV1) would be associated with leukoaraiosis and subclinical infarcts, especially cortical infarcts, in a population-based, multi-ethnic cohort. METHODS: PTFV1 was collected manually from baseline electrocardiograms of clinically stroke-free Northern Manhattan Study participants. Investigators read brain MRIs for superficial infarcts, deep infarcts, and white matter hyperintensity volume (WMHV). WMHV was adjusted for head size and log transformed, achieving a normal distribution. Logistic regression models investigated the association of PTFV1 with cortical and with all subclinical infarcts. Linear regression models examined logWMHV. Models were adjusted for demographics and risk factors. RESULTS: Among 1174 participants with PTFV1 measurements, the mean age at MRI was 70 ± 9 years. Participants were 14.4% white, 17.6% black, and 65.8% Hispanic. Mean PTFV1 was 3587.35 ± 2315.62 µV-ms. Of the 170 subclinical infarcts, 40 were cortical. PTFV1 ≥ 5000 µV-ms was associated with WMHV in a fully adjusted model (mean difference in logWMHV 0.15, 95% confidence interval 0.01-0.28). PTFV1 exhibited a trend toward an association with cortical infarcts (unadjusted OR per SD change logPTFV1 1.30, 95% CI 0.94-1.81), but not with all subclinical infarcts. CONCLUSION: Electrocardiographic evidence of left atrial abnormality was associated with leukoaraiosis.

Brain Arterial Diameters and Cognitive Performance: The Northern Manhattan Study.

OBJECTIVES: To test the hypothesis that brain arterial diameters are associated with cognitive performance, particularly in arteries supplying domain-specific territories. METHODS: Stroke-free participants in the Northern Manhattan Study were invited to have a brain MRI from 2003-2008. The luminal diameters of 13 intracranial arterial segments were obtained using time-of-flight magnetic resonance angiogram (MRA), and then averaged and normalized into a global score and region-specific arterial diameters. Z-Scores for executive function, semantic memory, episodic memory and processing speed were obtained at MRI and during follow-up. Adjusted generalized additive models were used to assess for associations. RESULTS: Among the 1034 participants with neurocognitive testing and brain MRI, there were non-linear relationships between left anterior (ACA) and middle cerebral artery (MCA) diameter and semantic memory Z-scores (χ2=10.00; DF=3; p=.019), and left posterior cerebral artery (PCA) and posterior communicating artery (Pcomm) mean diameter and episodic memory Z-scores (χ2=9.88; DF=3; p=.020). Among the 745 participants who returned for 2nd neuropsychological testing, on average 5.0±0.4 years after their MRI, semantic memory change was associated non-linearly with the left PCA/Pcomm mean diameter (χ2=13.09; DF=3; p=.004) and with the right MCA/ACA mean diameter (χ2=8.43; DF=3; p=.03). In both cross-sectional and longitudinal analyses, participants with the larger brain arterial diameters had more consistently lower Z-scores and greater decline than the rest of the participants. CONCLUSIONS: Brain arterial diameters may have downstream effects in brain function presenting as poorer cognition. Identifying the mechanisms and the directionality of such interactions may increase the understanding of the vascular contribution to cognitive impairment and dementia. (JINS, 2018, 24, 335-346).

Physical activity and cognition in the northern Manhattan study.

BACKGROUND: To test the hypothesis that leisure time physical activity (PA) is associated with cognitive status. METHODS: We assessed cognition using the Mini-Mental Status Examination (MMSE) at enrollment and using the modified Telephone Interview for Cognitive Status (TICS-m) administered annually since 2001 in the Northern Manhattan Study. Baseline measures of leisure time PA were collected via in-person questionnaires. Total PA was categorized into 3 groups based on the metabolic equivalent (MET) score, a composite of total reported intensity and time. We used linear regression models to examine the association of PA with MMSE, and generalized estimating equations for change in TICS-m over time. RESULTS: There were 3,298 stroke-free participants with MMSE data (mean MMSE 26.0 ± 3.8) and 2,279 with TICS-m scores available. Compared to no PA, those with the upper quartile of MET scores had greater baseline MMSE scores (adjusted ß = 0.4, p = 0.01) but no association with change in TICS-m over time. There were interactions (p < 0.05) between PA and both insurance and education; compared to no PA, those in the upper quartile of MET scores had a greater MMSE score only among those with Medicaid/no insurance (adjusted ß = 0.83, p = 0.0005) and those who did not complete high school (adjusted ß = 0.68, p = 0.001). CONCLUSIONS: Increased levels of PA were associated with better baseline MMSE, particularly among those with socioeconomic disadvantages, but not with cognitive decline.