Steroid-induced elevation of glucose in Alzheimer's disease: relationship to gender, apolipoprotein E genotype and cognition

Sex-dependent neuro-deconvolution analysis of Alzheimer's disease brain transcriptomes according to CHI3L1 expression levels

Glial activation and related neuroinflammatory processes play a key role in the aging and progression of Alzheimer's disease (AD). CHI3L1/ YKL40 is a widely investigated chitinase in neurodegenerative diseases and recent studies have shown its involvement in aging and AD. Nevertheless, the biological function of CHI3L1 in AD is still unknown. Here, we collected microarray datasets from the National Center for Biotechnology Information (NCBI) brain samples of not demented healthy controls (NDHC) who died from causes not attributable to neurodegenerative disorders (n = 460), and of deceased patients suffering from Alzheimer's disease (AD) (n = 697). The NDHC and AD patients were stratified according to CHI3L1 expression levels as a cut-off. We identified two groups both males and females, subsequently used for our statistical comparisons: the high CHI3L1 expression group (HCEG) and the low CHI3L1 expression group (LCEG). Comparing HCEG to LCEG, we attained four signatures according to the sex of patients, in order to identify the healthy and AD brain cellular architecture, performing a genomic deconvolution analysis. We used neurological signatures (NS) belonging to six neurological cells populations and nine signatures that included the main physiological neurological processes. We discovered that, in the brains of NDHC the high expression levels of CHI3L1 were associated with astrocyte activation profile, while in AD males and females we showed an inflammatory profile microglia-mediated. The low CHI3L1 brain expression levels in NDHC and AD patients highlighted a neuronal activation profile. Furthermore, using drugs opposing CHI3L1 transcriptomic signatures, we found a specific drug profile for AD males and females characterized by high levels of CHI3L1 composed of fostamatinib, rucaparib, cephaeline, prednisolone, and dinoprostone. Brain levels of CHI3L1 in AD patients represent a biological signature that allows distinguishing between males and females and their likely cellular brain architecture.

The Effects of Daily Prednisone and Tocilizumab on Hemoglobin A1c During the Treatment of Giant Cell Arteritis

OBJECTIVE

To study the longitudinal effects of both glucocorticoids and tocilizumab, an interleukin-6 receptor inhibitor, on hemoglobin A_1c (HbA_1c ) levels during glucocorticoid tapering.

METHODS

We analyzed patients with complete data from the Tocilizumab in Giant Cell Arteritis (GiACTA) trial to investigate the impact of both glycemic and nonglycemic factors on changes in HbA_1c levels over the 52-week trial. Giant cell arteritis (GCA) patients were randomized to receive either tocilizumab or placebo in addition to glucocorticoids. We used a multivariable mixed-effects model to evaluate associations of HbA_1c level with daily glucocorticoid dose, randomization to receive tocilizumab, and red blood cell count in patients with and those without diabetes mellitus at baseline, over 52 weeks.

RESULTS

In 209 patients, the median HbA_1c level decreased by 0.50% (P < 0.01) in the group that received both tocilizumab and glucocorticoids (tocilizumab/glucocorticoid) and by 0.10% (P < 0.01) in the glucocorticoid-only group. Randomization to tocilizumab/glucocorticoid was associated with lower HbA_1c (β = -0.209% in those without diabetes, P < 0.01; β = -0.290% in those with diabetes, P = 0.23). These changes had a sizable impact on glucose tolerance classification: 42.5% of patients in the tocilizumab/glucocorticoid group improved from prediabetes status to normal, compared to only 12.5% of patients treated with glucocorticoids alone. Daily glucocorticoid dose was associated with HbA_1c level in patients with baseline diabetes (β = 0.018%/mg, P < 0.01) and those without baseline diabetes (β = 0.005%/mg, P < 0.01).

CONCLUSION

Tocilizumab treatment was associated with a substantial reduction in HbA_1c level, independent of glucocorticoid exposure, which may be achieved through a combination of glycemic and nonglycemic effects.

Preventing dementia? Interventional approaches in mild cognitive impairment

Mild cognitive impairment (MCI) is defined as an intermediate state between normal cognitive aging and dementia. It describes a status of the subjective impression of cognitive decline and objectively detectible memory impairment beyond normal age-related changes. Activities of daily living are not affected. As the population ages, there is a growing need for early, proactive programs that can delay the consequences of dementia and improve the well-being of people with MCI and their caregivers. Various forms and approaches of intervention for older people with MCI have been suggested to delay cognitive decline. Pharmacological as well as non-pharmacological approaches (cognitive, physiological, nutritional supplementation, electric stimulation, psychosocial therapeutic) and multicomponent interventions have been proposed. Interventional approaches in MCI from 2009 to April 2019 concerning the cognitive performance are presented in this review.

Sex differences in the pharmacology of itch therapies-a narrative review

BACKGROUND

Chronic itch is the most common skin-related condition, associated with a high psychosocial and economic burden. In recent years, increasing evidence of sex differences in the perception, clinical presentation and treatment requirements of itch points towards potential benefits when using sex-adapted therapies. It is well-known that body composition, absorption, metabolism, elimination and adverse drug reactions (ADRs) differ between sexes, but only little is known about the impact of sex in the pharmacology of itch treatments, which could help to rationalise sex-adapted treatment strategies.

AIM

To evaluate and review sex effects in the pharmacokinetics and /-dynamics of drugs used to treat itch.

METHODS

In this narrative review we performed a PubMed and MEDLINE (Ovid) search using the terms (itch OR pruritus) AND (gender OR sex) AND (drug OR medication OR pharmacokinetics OR pharmacodynamics). Additional searches were performed for the topical and systemic drugs recommended by the European Guideline on Chronic Pruritus.

RESULTS

We found numerous reports with variable levels of evidence of sex effects with respect to the pharmacokinetics and/or pharmacodynamics of 14 drug classes used for the treatment of itch, including a total of 19 systemic and 3 topical drugs. Women seem to present higher plasma levels of several drugs used in itch treatment, including tri- and tetracyclic antidepressants (e.g. doxepin, amitriptyline, mirtazapine), serotonin reuptake inhibitors (e.g. paroxetine, sertraline, fluoxetine), immunosuppressive drugs (e.g. cyclosporine, mycophenolate mofetil), serotonin receptor antagonists (e.g. ondansetron) and betablockers (e.g. propranolol). Adverse drug reactions (ADRs) were generally more common in women. Being female was reported to be an independent risk factor for QTc-prolongation associated with antihistamines and tetracyclic antidepressants. Additionally, women seem to be more prone to sedative effects of antihistamines, and to suffer from a higher frequency as well as severity of side effects with systemic calcineurin inhibitors, opioid agonists, and opioid antagonists. Women were also sensitised more often to topically applied drugs. Of note, apart from only one experimental study with capsaicin, none of these reports were designed specifically to assess the effect of sex (and gender) in the treatment of itch.

DISCUSSION/CONCLUSION

Our review supports previous reports that sex is of importance in the pharmacokinetics and /-dynamics of several drugs used to treat itch although those drugs were mostly evaluated for non-itch indications. However, the results are limited by methodological limitations evident in most studies such as underrepresentation of women in clinical trials. This emphasises the need to study the impact of sex (and gender) in future itch trials to yield better outcomes and prevent ADRs in both sexes.

Epistasis, physical capacity-related genes and exceptional longevity: FNDC5 gene interactions with candidate genes FOXOA3 and APOE

BACKGROUND

Forkhead box O3A (FOXOA3) and apolipoprotein E (APOE) are arguably the strongest gene candidates to influence human exceptional longevity (EL, i.e., being a centenarian), but inconsistency exists among cohorts. Epistasis, defined as the effect of one locus being dependent on the presence of 'modifier genes', may contribute to explain the missing heritability of complex phenotypes such as EL. We assessed the potential association of epistasis among candidate polymorphisms related to physical capacity, as well as antioxidant defense and cardiometabolic traits, and EL in the Japanese population. A total of 1565 individuals were studied, subdivided into 822 middle-aged controls and 743 centenarians.

RESULTS

We found a FOXOA3 rs2802292 T-allele-dependent association of fibronectin type III domain-containing 5 (FDNC5) rs16835198 with EL: the frequency of carriers of the FOXOA3 rs2802292 T-allele among individuals with the rs16835198 GG genotype was significantly higher in cases than in controls (P < 0.05). On the other hand, among non-carriers of the APOE 'risk' ε4-allele, the frequency of the FDNC5 rs16835198 G-allele was higher in cases than in controls (48.4% vs. 43.6%, P < 0.05). Among carriers of the 'non-risk' APOE ε2-allele, the frequency of the rs16835198 G-allele was higher in cases than in controls (49% vs. 37.3%, P < 0.05).

CONCLUSIONS

The association of FDNC5 rs16835198 with EL seems to depend on the presence of the FOXOA3 rs2802292 T-allele and we report a novel association between FNDC5 rs16835198 stratified by the presence of the APOE ε2/ε4-allele and EL. More research on 'gene*gene' and 'gene*environment' effects is needed in the field of EL.

Sex and ApoE genotype differences in treatment response to two doses of intranasal insulin in adults with mild cognitive impairment or Alzheimer's disease

A previous clinical trial demonstrated that four months of treatment with intranasal insulin improves cognition and function for patients with Alzheimer's disease (AD) or mild cognitive impairment (MCI), but prior studies suggest that response to insulin treatment may differ by sex and ApoE ε4 carriage. Thus, responder analyses using repeated measures analysis of covariance were completed on the trial's 104 participants with MCI or AD who received either placebo or 20 or 40 IU of insulin for 4 months, administered by a nasal delivery device. Results indicate that men and women with memory impairment responded differently to intranasal insulin treatment. On delayed story memory, men and women showed cognitive improvement when taking 20 IU of intranasal insulin, but only men showed cognitive improvement for the 40 IU dose. The sex difference was most apparent for ApoE ε4 negative individuals. For the 40 IU dose, ApoE ε4 negative men improved while ApoE ε4 negative women worsened. Their ApoE ε4 positive counterparts remained cognitively stable. This sex effect was not detected in functional measures. However, functional abilities were relatively preserved for women on either dose of intranasal insulin compared with men. Unlike previous studies with young adults, neither men nor women taking intranasal insulin exhibited a significant change in weight over 4 months of treatment.

Aspirin, steroidal and non-steroidal anti-inflammatory drugs for the treatment of Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is the most common form of dementia. The incidence of AD rises exponentially with age and its prevalence will increase significantly worldwide in the next few decades. Inflammatory processes have been suspected in the pathogenesis of the disease.

OBJECTIVES

To review the efficacy and side effects of aspirin, steroidal and non-steroidal anti-inflammatory drugs (NSAIDs) in the treatment of AD, compared to placebo.

SEARCH METHODS

We searched ALOIS: the Cochrane Dementia and Cognitive Improvement Group's Specialized Register on 12 April 2011 using the terms: aspirin OR "cyclooxygenase 2 inhibitor" OR aceclofenac OR acemetacin OR betamethasone OR celecoxib OR cortisone OR deflazacort OR dexamethasone OR dexibruprofen OR dexketoprofen OR diclofenac sodium OR diflunisal OR diflusinal OR etodolac OR etoricoxib OR fenbufen OR fenoprofen OR flurbiprofen OR hydrocortisone OR ibuprofen OR indometacin OR indomethacin OR ketoprofen OR lumiracoxib OR mefenamic OR meloxicam OR methylprednisolone OR nabumetone OR naproxen OR nimesulide OR "anti-inflammatory" OR prednisone OR piroxicam OR sulindac OR tenoxicam OR tiaprofenic acid OR triamcinolone OR NSAIDS OR NSAID. ALOIS contains records of clinical trials identified from monthly searches of a number of major healthcare databases (including MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS), numerous trial registries (including national, international and pharmacuetical registries) and grey literature sources.

SELECTION CRITERIA

All randomised controlled trials assessing the efficacy of aspirin, steroidal and non-steroidal anti-inflammatory drugs in AD.

DATA COLLECTION AND ANALYSIS

One author assessed risk of bias of each study and extracted data. A second author verified data selection.

MAIN RESULTS

Our search identified 604 potentially relevant studies. Of these, 14 studies (15 interventions) were RCTs and met our inclusion criteria. The numbers of participants were 352, 138 and 1745 for aspirin, steroid and NSAIDs groups, respectively. One selected study comprised two separate interventions. Interventions assessed in these studies were grouped into four categories: aspirin (three interventions), steroids (one intervention), traditional NSAIDs (six interventions), and selective cyclooxygenase-2 (COX-2) inhibitors (five interventions). All studies were evaluated for internal validity using a risk of bias assessment tool. The risk of bias was low for five studies, high for seven studies, and unclear for two studies.There was no significant improvement in cognitive decline for aspirin, steroid, traditional NSAIDs and selective COX-2 inhibitors. Compared to controls, patients receiving aspirin experienced more bleeding while patients receiving steroid experienced more hyperglycaemia, abnormal lab results and face edema. Patients receiving NSAIDs experienced nausea, vomiting, elevated creatinine, elevated LFT and hypertension. A trend towards higher death rates was observed among patients treated with NSAIDS compared with placebo and this was somewhat higher for selective COX-2 inhibitors than for traditional NSAIDs.

AUTHORS' CONCLUSIONS

Based on the studies carried out so far, the efficacy of aspirin, steroid and NSAIDs (traditional NSAIDs and COX-2 inhibitors) is not proven. Therefore, these drugs cannot be recommended for the treatment of AD.

Therapy Insight: type 2 diabetes mellitus and the risk of late-onset Alzheimer's disease

A number of well-designed epidemiological studies have linked type 2 diabetes mellitus (T2DM) with an increased risk of Alzheimer's disease (AD). Several mechanisms could help to explain this proposed link, including insulin and insulin resistance, inflammatory cytokines, and oxidative stress. Obesity or physical inactivity might also influence AD through effects on hypertension, insulin sensitivity or inflammation. Typical AD pathology, such as amyloid-beta deposits, might be exacerbated by insulin dysregulation, T2DM itself, or microvascular disease that is a consequence of T2DM. T2DM patients are not routinely evaluated for cognitive outcomes, and cognitive impairment in T2DM is rarely treated. Similarly, AD patients are not routinely evaluated for T2DM or hyperinsulinemia. Current treatments for AD have only modest benefits, and several drugs that target metabolic and inflammatory pathways are being evaluated, most notably the statins, which reduce LDL and inflammation but might not influence amyloid- deposition, an important precursor for AD. Although some evidence supports a potentially important role for peroxisome proliferative activated receptor agonists such as glitazones, at present there are no published randomized clinical trials in AD patients of any drugs that target insulin or insulin resistance. Clinical implications of the T2DM-AD link include cognitive evaluations of patients with T2DM, and potential benefits for such patients through treatment with statins or diabetes drugs that target insulin.

Does diabetes protect or provoke Alzheimer's disease? Insights into the pathobiology and future treatment of Alzheimer's disease

Diabetes mellitus has long been considered a risk factor for the development of vascular dementia. Epidemiologic evidence has suggested that diabetes mellitus significantly increases risk for the development of Alzheimer's disease, independent of vascular risk factors. As insulin's role as a neuromodulator in the brain has been described, its significance for AD has also emerged. Insulin dysregulation may contribute to AD pathology through several mechanisms including decreased cortical glucose utilization particularly in the hippocampus and entorhinal cortex; increased oxidative stress through the formation of advanced glycation end-products; increased Tau phosphorylation and neurofibrillary tangle formation; increased b-amyloid aggregation through inhibition of insulin-degrading enzyme. Future treatment of AD might involve pharmacologic and dietary manipulations of insulin and glucose regulation.