Incidence of dementia after age 90 in a multiracial cohort

Introduction

Little is known about dementia incidence in diverse populations of oldest-old, the age group with highest dementia incidence.

Depression in type 1 diabetes and risk of dementia

Objective: Depression afflicts 14% of individuals with type 1 diabetes (T1D). Depression is a robust risk factor for dementia but it is unknown if this holds true for individuals with T1D, who recently started living to an age conferring dementia risk. We examined if depression is a dementia risk factor among elderly individuals with T1D.

Methods: 3,742 individuals with T1D age ≥50 were followed for dementia from 1/1/96-9/30/2015. Depression, dementia, and comorbidities were abstracted from electronic medical records. Cox proportional hazard models estimated the association between depression and dementia adjusting for demographics, glycosylated hemoglobin, severe dysglycemic epidsodes, stroke, heart disease, nephropathy, and end stage renal disease. The cumulative incidence of dementia by depression was estimated conditional on survival dementia-free to age 55.

Results: Five percent (N = 182) were diagnosed with dementia and 20% had baseline depression. Depression was associated with a 72% increase in dementia (fully adjusted HR = 1.72; 95% CI:1.12-2.65). The 25-year cumulative incidence of dementia was more than double for those with versus without depression (27% vs. 12%).

Conclusions: For people with T1D, depression significantly increases dementia risk. Given the pervasiveness of depression in T1D, this has major implications for successful aging in this population recently living to old age.     

Habitual physical activity and menopausal symptoms: a case-control study

A case-control study design was used to examine whether habitual physical activity prior to the final menstrual period (FMP) was associated with reduced risk of vasomotor and other symptoms during the perimenopausal period. Both cases and controls were identified through a screening interview with randomly selected women members, ages 48-52, of a large health maintenance organization. Cases (n = 82) were defined as women 3-12 months past their FMP who reported regularly having hot flashes or night sweats at least once a day or night during the 3 months following their FMP. Controls (n = 89) were of the same biologic age with respect to the FMP but reported vasomotor symptoms less than once a week during the reference time period. Neither cases nor controls had a history of hormone replacement therapy (HRT), hysterectomy, or bilateral oophorectomy. Case-control status, habitual physical activity (including recreational, housework, child care, and occupational activity), and psychological and somatic symptoms were assessed by self-report. Participation in vigorous recreational activity during the year prior to the FMP was not associated with reduced risk of frequent vasomotor symptoms after the FMP (odds ratio [OR] = 1.03 for a 50-unit increase in activity score, 95% confidence interval [CI] = 0.97-1.1). This lack of relationship was observed in all domains of activity. Factors that were associated with decreased risk included higher body mass index (BMI) (weight in kg/(height in meters)2) (OR = 0.95 per 1 unit increase in BMI, 95% CI = 0.90-1.00) and higher education (having a college degree relative to less education) (OR = 0.56, 95% CI = 0.40-0.80). Physical activity was also unassociated with reduced risk of psychologic distress, depressive feelings, or somatic symptoms, but, relative to controls, having vasomotor symptoms (being a case) was strongly associated with increased risk of experiencing those symptoms (OR ranging from 1.83 for psychologic distress to 2.84 for depressive feelings). These findings suggest that regular physical activity before the FMP may not reduce the likelihood of experiencing symptoms during the perimenopause, although the small sample size may limit the inferences that can be drawn.     

Association of total and central adiposity measures with fasting insulin in a biracial population of young adults with normal glucose tolerance: the CARDIA study.

OBJECTIVE: To determine the association of computed tomography (CT)-measured visceral adipose tissue (AT) and other measures of adiposity with fasting insulin in a biracial (African American and Caucasian) study population of young adults. RESEARCH METHODS AND PROCEDURES: The study population consisted of 251 young adults with normal glucose tolerance (NGT), ages 28-40 years, who were volunteers from the Birmingham, Alabama, and Oakland, California centers of the Coronary Artery Risk Development in Young Adults (CARDIA) study. RESULTS: In regression models with total adiposity measures (body mass index or dual-energy X-ray absorptiometry-measured percent fat), visceral AT (measured as a cross-sectional area in cm2) was generally a stronger predictor of insulin than overall adiposity in all race/gender groups (partial correlation coefficients ranging from 0.31 to 0.47) except for black men, in whom the associations were nonsignificant. Partial correlation coefficients between waist circumference and insulin, controlling for percent fat, were nearly identical to those between visceral AT and insulin in women and in white men. Analyses performed on 2060 NGT CARDIA subjects who were not in this study of visceral AT showed significant correlations of waist circumference with insulin in all race/gender groups, including black men, and that black men in the visceral AT study group were significantly leaner than other black male CARDIA subjects. DISCUSSION: We conclude that visceral AT was associated with fasting insulin in NGT participants in three of the four race/gender groups (black men excepted) and that waist circumference was a good surrogate for visceral AT in examining associations of central adiposity with fasting insulin.     

Differences in resource use and costs of primary care in a large HMO according to physician specialty.

OBJECTIVE: To determine if primary care physician specialty is associated with differences in use of health services. DATA SOURCES: Automated outpatient diagnostic, utilization, and cost data on 15,223 members (35-85 years of age) of a large group model HMO. STUDY DESIGN: One-year prospective comparison of primary care provided by 245 general internists (GIMs), 60 family physicians (FPs), and 55 subspecialty internists (SIMs) with case-mix assessed during a nine-month baseline period using Ambulatory Diagnostic Groups. PRINCIPAL FINDINGS: Adjusting for demographics and case mix, patients of GIMs and FPs had similar hospitalization and ambulatory visit rates, and similar laboratory and radiology costs. Patients of FPs made fewer visits to dermatology, psychiatry, and gynecology (combined visit rate ratio: 0.86, 95% CI: 0.74-0.96). However, they made more urgent care visits (rate ratio 1.19, 95% CI: 1.07-1.23). Patients of SIMs had higher hospitalization rates than those of GIMs (rate ratio 1.33, 95% CI: 1.06-1.68), greater use of urgent care (rate ratio: 1.14, 95% CI: 1.04-1.25), and higher costs for pharmacy (cost ratio: 1.17, 95% CI: 0.93-1.18) and radiologic services (cost ratio: 1.14, 95% CI: 1.01-1.30). The hospitalization difference was due partly to the inclusion of patients with specialty-related diagnoses in panels of SIMs. Radiology and pharmacy differences persisted after excluding these patients. CONCLUSIONS: In this uniform practice environment, specialty differences in primary care practice were small. Subspecialists used slightly more resources than generalists. The broader practice style of FPs may have created access problems for their patients.     

Plain Language for Patient Education

Low health literacy continues to be a barrier in patient education. One solution to low health literacy is creating or providing patient education materials written in plain language. Plain language follows guidelines created for federal agencies to ensure that documents are written in clear and accessible language for all audiences. Health care professionals and librarians can locate or recommend plain language health information from many reputable consumer health websites.     

Incidence of hepatocellular carcinoma among individuals with hepatitis B virus infection identified using an automated data algorithm

The purpose of this study was to develop an algorithm for identifying patients with chronic hepatitis B virus (HBV) using automated data sources from two US health systems and evaluate the algorithm's performance by quantifying the incidence of hepatocellular carcinoma (HCC) among chronic HBV patients. To allow comparisons with estimates from automated databases that may not contain all data elements used in this algorithm, we created three definitions of chronic HBV infection and used these definitions to create three overlapping cohorts. We compared the incidence of HCC in each cohort with the incidence of HCC in a matched general population comparison cohort with no evidence of HBV. Patients who met the most stringent criteria for chronic HBV infection (based on the standard definition of 6 months of infection using repeat laboratory tests and record review) were 146 times more likely to develop HCC than matched comparison patients (adjusted hazard ratio = 146.5, 95% CI: 74.0-289.8). Those not meeting the stringent criteria, but who met the criterion of at least one positive hepatitis B surface antigen test were 30 times more likely to develop HCC than comparison patients (adjusted hazard ratio = 29.8, 95% CI: 16.5-53.6). Finally, patients who met the criterion based on at least one HBV diagnosis were 38 times more likely to develop HCC than matched comparison patients (adjusted hazard ratio = 37.8, 95% CI: 25.9-55.1). The magnitude of the relative increase in HCC risk seen using different criteria used to define HBV infection indicate that these automated data algorithms can identify patients with chronic HBV infection.     

The effect of lithium on growth factor production in long-term bone marrow cultures

We have previously reported that lithium chloride (LiCl) stimulates the production of granulocyte-macrophage colony-forming cells (GM-CFC), pluripotent stem cells (CFU-S), and differentiated granulocytes, macrophages and megakaryocytes in murine Dexter marrow cultures and that this effect appears to be mediated indirectly by a radioresistant adherent marrow cell. In this study we have established that exposure of murine Dexter cultures to LiCl (4 mEq/L) causes an increase of colony-forming cell megakaryocytes (CFU-meg) over 1 to 6 weeks of culture in both supernatant (188% to 611%) and stromal phases (123% to 246%). Moreover, we have shown that lithium treatment of either irradiated (1,100 rad) or unirradiated stromal cells increased production of activities stimulating formation of megakaryocyte, granulocyte, macrophage, and mixed lineage colonies and proliferation of the factor-dependent cell line, FDC-P1. This FDC-P1 stimulatory activity was completely blocked by an antibody to purified recombinant granulocyte-macrophage colony stimulating factor (rGM-CSF). The baseline or lithium-induced--stromal-derived bone marrow colony stimulating activity was partially blocked by the antibody to rGM-CSF and by an antibody to purified colony stimulating factor I (CSF-1); the two antibodies combined resulted in greater than 90% inhibition of the lithium-induced marrow stimulatory activity. In addition, radioimmunoassay (RIA) showed that although CSF-1 was detectable in supernatants of these cultures, exposure to lithium did not increase CSF-1 levels. These data indicate that Dexter stromal cells produce CSF- 1 and GM-CSF and that lithium appears to exert its stimulatory effects on in vitro myelopoiesis by inducing production of GM-CSF.     

AKI Recovery Induced by Mesenchymal Stromal Cell-Derived Extracellular Vesicles Carrying MicroRNAs

Phenotypic changes induced by extracellular vesicles have been implicated in mesenchymal stromal cell–promoted recovery of AKI. MicroRNAs are potential candidates for cell reprogramming toward a proregenerative phenotype. The aim of this study was to evaluate whether microRNA deregulation inhibits the regenerative potential of mesenchymal stromal cells and derived extracellular vesicles in a model of glycerol-induced AKI in severe combined immunodeficient mice. We generated mesenchymal stromal cells depleted of Drosha to alter microRNA expression. Drosha-knockdown cells produced extracellular vesicles that did not differ from those of wild-type cells in quantity, surface molecule expression, and internalization within renal tubular epithelial cells. However, these vesicles showed global downregulation of microRNAs. Whereas wild-type mesenchymal stromal cells and derived vesicles administered intravenously induced morphologic and functional recovery in AKI, the Drosha-knockdown counterparts were ineffective. RNA sequencing analysis showed that kidney genes deregulated after injury were restored by treatment with mesenchymal stromal cells and derived vesicles but not with Drosha-knockdown cells and vesicles. Gene ontology analysis showed in AKI an association of downregulated genes with fatty acid metabolism and upregulated genes with inflammation, matrix-receptor interaction, and cell adhesion molecules. These alterations reverted after treatment with wild-type mesenchymal stromal cells and extracellular vesicles but not after treatment with the Drosha-knockdown counterparts. In conclusion, microRNA depletion in mesenchymal stromal cells and extracellular vesicles significantly reduced their intrinsic regenerative potential in AKI, suggesting a critical role of microRNAs in recovery after AKI.