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.     

Acquired pure red cell aplasia: a study of six cases

Persistent infection by parvovirus B19 associated with pure red cell aplasia (PRCA) has been documented in immunocompromised patients. Bone marrow failure is associated with conditions in which immune surveillance is impaired, and in these instances occult parvovirus infection may be suspected. In this study we have assessed by serological and molecular methods whether parvovirus B19 infection may be a more frequent cause of PRCA than hitherto suspected and whether it may be present in the absence of a typical bone marrow picture. Six patients with PRCA — two with isolated PRCA and no apparent underlying disease, two with a lymphoproliferative disease, one with thymoma, and one with chronic myelomonocytic leukemia — have been studied. Four of the six patients had overt PCRA and were clearly immunocompromised. Parvovirus B19 was not detected in any of the six patients by PCR analysis and serology investigating the presence of IgM or IgG antibodies. Although parvovirus B19 infection needs to be ruled out in PRCA it represents only one, and probably not the most frequent, etiological factor of PRCA.     

Physical Activity Benefits the Skeleton of Children Genetically Predisposed to Lower Bone Density in Adulthood

Both genetics and physical activity (PA) contribute to bone mineral density (BMD), but it is unknown if the benefits of physical activity on childhood bone accretion depend on genetic risk. We, therefore, aimed to determine if PA influenced the effect of bone fragility genetic variants on BMD in childhood. Our sample comprised US children of European ancestry enrolled in the Bone Mineral Density in Childhood Study (N = 918, aged 5 to 19 years, and 52.4% female). We used a questionnaire to estimate hours per day spent in total, high‐, and low‐impact PA. We calculated a BMD genetic score (% BMD lowering alleles) using adult genome‐wide association study (GWAS)‐implicated BMD variants. We used dual‐energy X‐ray absorptiometry to estimate femoral neck, total hip, and spine areal‐BMD and total body less head (TBLH) bone mineral content (BMC) Z‐scores. The BMD genetic score was negatively associated with each bone Z‐score (eg, TBLH‐BMC: estimate = –0.03, p = 1.3 × 10^?6). Total PA was positively associated with bone Z‐scores; these associations were driven by time spent in high‐impact PA (eg, TBLH‐BMC: estimate = 0.05, p = 4.0 × 10^?10) and were observed even for children with lower than average bone Z‐scores. We found no evidence of PA‐adult genetic score interactions (p interaction > 0.05) at any skeletal site, and there was no evidence of PA‐genetic score–Tanner stage interactions at any skeletal site (p interaction > 0.05). However, exploratory analyses at the individual variant level revealed that PA statistically interacted with rs2887571 (ERC1/WNT5B) to influence TBLH‐BMC in males (p interaction = 7.1 × 10^?5), where PA was associated with higher TBLH‐BMC Z‐score among the BMD‐lowering allele carriers (rs2887571 AA homozygotes: estimate = 0.08 [95% CI 0.06, 0.11], p = 2.7 × 10^?9). In conclusion, the beneficial effect of PA on bone, especially high‐impact PA, applies to the average child and those genetically predisposed to lower adult BMD (based on GWAS‐implicated BMD variants). Independent replication of our exploratory individual variant findings is warranted. © 2016 American Society for Bone and Mineral Research.     

A half century (1961-2011) of applying microsurgery to experimental liver research

The development of microsurgery has been dependent on experimental animals. Microsurgery could be a very valuable technique to improve experimental models of liver diseases. Microdissection and microsutures are the two main microsurgical techniques that can be considered for classifying the experimental models developed for liver research in the rat. Partial portal vein ligation, extrahepatic cholestasis and hepatectomies are all models based on microdissection. On the other hand, in portacaval shunts, orthotopic liver transplantation and partial heterotopic liver transplantation, the microsuture techniques stand out. By reducing surgical complications, these microsurgical techniques allow for improving the resulting experimental models. If good experimental models for liver research are successfully developed, the results obtained from their study might be particularly useful in patients with liver disease. Therefore experimental liver microsurgery could be an invaluable way to translate laboratory data on liver research into new clinical diagnostic and therapeutic strategies.