APOE Variants in an Iberian Alzheimer Cohort Detected through an Optimized Sanger Sequencing Protocol

Age, sex, and APOE gene-specific associations between dynapenic obesity and dementia in a large cohort

OBJECTIVE

To investigate the associations between dynapenic obesity and the risk of dementia, and the modifying effects of age, sex, and the APOE gene, using a large population-based cohort.

METHODS

279,884 participants aged 55 and above from the UK Biobank were included. The participants were classified into four categories based on body mass index and hand grip strength: healthy, obesity, dynapenia, and dynapenic obesity. The incident dementia was identified based on linked hospital records and death register data. Cox proportional hazards regression models were used to estimate the associations, followed by age-, sex-, and apolipoprotein E (APOE) gene-stratified analyses.

RESULTS

During the median follow-up of 12.4 years, 5,170 (1.8%) participants developed dementia. Compared with the healthy group, participants with dynapenic obesity had 67% higher dementia risk (hazard ratio [HR]: 1.67, 95% confidence interval [CI]: 1.44-1.94). Compared with the healthy group, higher risks of dementia in participants with dynapenic obesity were respectively observed in male (HR: 2.03, 95% CI: 1.65-2.50), younger (<65 years, HR: 1.97, 95% CI: 1.55-2.50), and non-ε4-carrier (HR: 1.97, 95% CI: 1.60-2.44) (all P for interaction <0.05). In participants under 65 years and non-ε4-carrier, those with dynapenic obesity had the highest risk of dementia (HR: 2.63, 95% CI: 1.91-3.62), compared with the healthy group (P for second order interaction = 0.026).

CONCLUSIONS

Dynapenic obesity is associated with increased risks of dementia, especially in participants under 65 years and non-ε4-carrier, suggesting the importance of managing dynapenic obesity in the prevention of cognition-related disorders.

Simple visualization method for the c.577del of erythropoietin variant: CRISPR/dCas9-based single nucleotide polymorphism diagnosis

One of the single nucleotide polymorphisms (SNPs) in human erythropoietin (hEPO), the c.577del variant, can produces 26 amino acids longer than the wild-type hEPO, posing a risk of misinterpretation in routine doping analysis. To prevent this, the World Anti-Doping Agency (WADA) included a procedure for reporting the sequencing results regarding the presence or absence of SNPs for suspected cases in the new version of the technical document for recombinant EPO in 2022. However, it is very expensive for anti-doping laboratories to purchase a gene sequencing analyzer, which costs hundreds of thousands of dollars, and only a few companies provide specific gene sequencing services with accredited certification. Therefore, in this study, we developed a simple visualization method for the c.577del of the EPO variant at the gene level. The gene fragment of the EPO gene, including c.577del, was amplified using a fast polymerase chain reaction (PCR), and the PCR products were incubated with the clustered regularly interspaced short palindromic repeats (CRISPR)/deadCas9 system using variant-specific single-guide RNA (sgRNA). This ribonucleoprotein complex binds specifically to the EPO variant gene fragment, causing a band shift on native-PAGE. We designed 4 sgRNAs that can bind only to the EPO variant or wild-type gene. In addition, an electrophoretic mobility shift assay on a gel demonstrated that one of the sgRNAs had a high level of specificity. Consequently, the c.577del variant was selectively detected by visualizing the target fragment of the gene on the gel within 3 h using only 3 μl of the whole blood.

Androgen Deprivation Therapy Unrelated to Alzheimer's Disease in the UK Biobank Cohort

BACKGROUND/AIM

In a meta-analysis of 14 studies, men who received androgen deprivation therapy (ADT) for prostate cancer had a higher risk of dementia and/or Alzheimer disease (AD) than men who did not receive ADT. The effect was more pronounced when ADT was given for more than 12 months. However, in all these analyses, two of the strongest AD risk factors after age, family history of AD and the apolipoprotein e4 allele, were not included. In the current study, we have used data from the UK Biobank (UKB) that incorporates these two factors.

PATIENTS AND METHODS

Our analysis included all subjects with prostate cancer and AD. Prostate cancer diagnosis was ascertained using the 10th Revision of the International Classification of Diseases (ICD10), C61. AD diagnosis was ascertained using the 10th Revision of the International Classification of Diseases (ICD10) G30. Single nucleotide polymorphism (SNP) data for rs429358 and rs7412 were used to determine ApoE genotypes. ADT was in UKB field 20003, Treatment/medication code, Medications. Family history of AD was in UKB data fields 20107, Illnesses of father; 20110, Illnesses of mother; 20111, Illnesses of siblings.

RESULTS

We studied 13,203 men with prostate cancer. The age of 132 subjects that received ADT was 64±5.6 (mean±standard deviation), and the age of 13,071 subjects that did not receive ADT was 62±5.6 (p<0.001). ADT was not associated with AD, but Apoe3e3 was significantly associated with diminished risk of AD when compared to e4e4. Moreover, every year of age was associated with increased risk of AD. ADT was unrelated to AD (p=0.997).

CONCLUSION

Our UK Biobank data analysis does not confirm that ADT causes AD in men with prostate cancer. Large studies that include family history of AD and ApoeE genotype are needed. Mendelian randomization would also be desirable for a more definitive result.

Long-covid cognitive impairment: Cognitive assessment and apolipoprotein E (APOE) genotyping correlation in a Brazilian cohort

INTRODUCTION

Few studies have objectively evaluated cognitive deficits after the acute phase of COVID-19 disease. Moreover, the role of apolipoprotein E (APOE) genotypes in cognitive decline in patients with COVID-19 has not been evaluated yet.

METHODS

This cross-sectional study was conducted in confirmed cases of COVID-19 patients with neurological symptoms that persisted for more than 3 months from the onset. We determined APOE genotypes.

RESULTS

The final sample consisted of 141 patients. The most frequent APOE genotype was E3/E3 (N = 95; 67.3%). In total, 93 patients (65.9%) had memory impairment symptoms as the main complaint, objectively confirmed through screening tests in 25 patients (17.7%). Patients with cognitive impairment had a lower frequency of anosmia than the normal and subjective cognitive decline (SCD) groups (p = 0.005). In addition, depression was recurrent in the cognitive impairment group and the SCD group (p = 0.046). Cognitive impairment was significantly more frequent in hospitalized patients and those with a lower education level. Cognitive status was not associated with APOE genotypes.

DISCUSSION

Hospitalized patients had more severe infection with a greater possibility of systemic complications, greater inflammatory response, and prolonged hospitalization, which could impact cognitive performance. Cognitive impairment in patients with COVID-19 does not necessarily involve specific APOE polymorphisms. However, psychiatric disorders may also be responsible for cognitive complaints. Cognitive complaints are frequent in patients with COVID-19, even after the acute phase of the disease and in mild cases. Hospitalized participants and depressed patients may have a higher risk of cognitive impairment. APOE genotypes or haplotypes may not significantly play a role in COVID-19 cognitive impairment.