Primary Hypothyroidism and Alzheimer's Disease: A Tale of Two.

Hypothyroidism (HPT) HPT could be a risk factor for the development and progression of Alzheimer's disease (AD). In addition, progressive neurodegeneration in AD may affect the metabolism of thyroid hormones (THs) in the brain causing local brain HPT. Hence, the present review aimed to clarify the potential association between HPT and AD. HPT promotes the progression of AD by inducing the production of amyloid beta (Aß) and tau protein phosphorylation with the development of synaptic plasticity and memory dysfunction. Besides, the metabolism of THs is dysregulated in AD due to the accumulation of Aß and tau protein phosphorylation leading to local brain HPT. Additionally, HPT can affect AD neuropathology through various mechanistic pathways including dysregulation of transthyretin, oxidative stress, ER stress, autophagy dysfunction mitochondrial dysfunction, and inhibition of brain-derived neurotrophic factor. Taken together there is a potential link between HPT and AD, as HPT adversely impacts AD neuropathology and the reverse is also true.

Effects of neprilysin and neprilysin inhibitors on glucose homeostasis: Controversial points and a promising arena.

Neprilysin (NEP) is a transmembrane zinc-dependent metalloproteinase that inactivates various peptide hormones including glucagon-like peptide 1 (GLP-1). NEP inhibitors may be effective in the management of type 2 diabetes mellitus (T2DM) by increasing the circulating level of GLP-1. However, acute-effect NEP inhibitors may lead to detrimental effects by increasing blood glucose independent of GLP-1. These findings suggest a controversial point regarding the potential role of NEP inhibitors on glucose homeostasis in T2DM patients. Therefore, this perspective aimed to clarify the controversial points concerning the role of NEP inhibitors on glucose homeostasis in T2DM. NEP inhibitors may lead to beneficial effects by inhibition of NEP, which is involved in the impairment of glucose homeostasis through modulation of insulin resistance. NEP increases dipeptidyl peptidase-4 (DPP4) activity and contributes to increasing active GLP-1 proteolysis so NEP inhibitors may improve glycemic control through increasing endogenous GLP-1 activity and reduction of DPP4 activity. Thus, NEP inhibitors could be effective alone or in combination with antidiabetic agents in treating T2DM patients. However, long-term and short-term effects of NEP inhibitors may lead to a detrimental effect on insulin sensitivity and glucose homeostasis through different mechanisms including augmentation of substrates and pancreatic amyloid deposition. These findings are confirmed in animal but not in humans. In conclusion, NEP inhibitors produce beneficial rather than detrimental effects on glucose homeostasis and insulin sensitivity in humans though most of the detrimental effects of NEP inhibitors are confirmed in animal studies.

A Cross-Sectional Study to Assess mRNA-COVID-19 Vaccine Safety among Indian Children (5-17 Years) Living in Saudi Arabia.

The objective of this study is to assess the frequency and severity of adverse events following immunization (AEFI) in Indian children aged 5-17 years who received the Pfizer-BioNTech mRNA COVID-19 vaccine, as well as to investigate for predictors of AEFI. To examine AEFI following the first and second doses of Pfizer's vaccine, semi-structured questionnaires were distributed as Google forms at Indian schools in Saudi Arabia. The 385 responses included 48.1% male and 51.9% female children, with 136 responses of children aged 5-11 years (group A) and 249 responses from children aged 12-17 years (group B). Overall, 84.4% of children had two shots. The frequency of AEFI was reported to be higher after the first dose than after the second (OR = 2.12, 95% CI = 1.57-2.86). The reported AEFIs included myalgia, rhinitis, local reaction with fever, a temperature of 102 °F or higher, and mild to moderate injection site reactions. While group B frequently reported multiple AEFIs, group A typically reported just one. Local reaction with low grade fever was more frequently reported in group B after the first dose (24.1%) and second dose (15.4%), while local reaction without low grade fever was most frequently observed in group A after the first (36.8%) and second dose (30%). Only prior COVID-19 infection (OR = 2.98, 95% CI = 1.44-6.2) was associated with AEFI after the second dose in the study sample, whereas male gender (OR = 1.71, 95% CI = 1.13-2.6) and prior COVID-19 infection (OR = 2.95, 95% CI = 1.38-6.3) were predictors of AEFI after the first dose. Non-serious myocarditis was reported by only one child. According to the analysis conducted, the Pfizer's mRNA COVID-19 vaccination was found to be safe in Indian children.