ABSTRACT
Imbalances in thyroid hormones have been linked with Alzheimer's dementia. Several studies have reported an association between thyroid disorders, such as hyper- or hypothyroidism, with Alzheimer's disease. However, there remains no consensus about the precise role of thyroid dysfunction in Alzheimer's disease. In this study we systematically searched PubMed, Embase and Scopus for clinical studies which reported the prevalence of hyper- or hypothyroidism in people with Alzheimer's disease compared to controls. Meta-analysis was performed to compare thyroid disorder prevalence in Alzheimer's disease and controls. Subgroup analysis was performed to assess the clinical and subclinical thyroid dysfunction, separately. Seven studies, including 1189 people with Alzheimer's disease and 72711 controls, were included in our sample. Hypothyroidism was significantly more prevalent in Alzheimer's disease compared with controls (6.4% vs 2.4%, p=0.01). Subgroup analysis showed that clinical hypothyroidism was not significantly different between Alzheimer's disease compared to controls (10.0% vs 5.3%, p=0.35). There was no difference in the crude overall prevalence of clinical and subclinical hyperthyroidism in Alzheimer's disease versus controls (2.4 vs 1.9%, p=0.73). Our analyses revealed a higher prevalence of hypothyroidism in Alzheimer's disease. Whether this finding is explained by hypothyroidism being a risk factor for, or consequence of, Alzheimer's disease requires longitudinal analysis. Our review supports further work into a potential role for treatment of hypothyroidism in the prevention or delay of Alzheimer's disease.
Subject(s)
Alzheimer Disease , Hyperthyroidism , Hypothyroidism , Thyroid Gland , Humans , Alzheimer Disease/complications , Alzheimer Disease/epidemiology , Hyperthyroidism/complications , Hyperthyroidism/epidemiology , Hypothyroidism/complications , Hypothyroidism/epidemiology , Thyroid Gland/physiology , Thyroid Gland/physiopathologyABSTRACT
Parkinson's disease (PD) is a neurodegenerative disorder characterized by loss of dopaminergic neurons. Dopaminergic system is interconnected with the hypothalamic-pituitary-thyroid axis. Dopamine (DA) upregulates thyrotropin releasing hormone (TRH) while downregulating thyroid stimulating hormone (TSH) and thyroid hormones. Moreover, TRH stimulates DA release. PD is associated with impaired regulation of TSH and thyroid hormones (TH) levels, which in turn associate with severity and different subtypes of PD, while levodopa and bromocriptine treatment can interfere with hypothalamic-pituitary-thyroid axis. Thyroid disturbances, including hypothyroidism, Hashimoto's thyroiditis (HT), hyperthyroidism and Graves' disease (GD) not only increase the risk of PD but also share some clinical signs with PD. Also, several genes including RASD2, WSB1, MAPT, GIRK2, LRRK2 and gene products like neurotensin and NOX/DUOX affect the risk for both PD and thyroid disease. Hypothyroidism is associated with obesity, hypercholesterolemia, anemia and altered cerebral blood flow which are associated with PD pathology. Herein we provide a comprehensive view on the association between PD and thyroid hormones regulation and dysregulations, hoping to provide new avenues towards targeted treatment of PD. We performed a comprehensive search in literature using Pubmed and Scopus, yielding to a total number of 36 original articles that had addressed the association between thyroid hormone disorders and PD.
Subject(s)
Parkinson Disease/pathology , Thyroid Diseases/pathology , Thyroid Hormones/blood , Animals , Humans , Parkinson Disease/blood , Parkinson Disease/complications , Risk Factors , Thyroid Diseases/blood , Thyroid Diseases/complicationsSubject(s)
AIDS Vaccines/therapeutic use , Acquired Immunodeficiency Syndrome/immunology , SAIDS Vaccines/therapeutic use , Simian Acquired Immunodeficiency Syndrome/immunology , Acquired Immunodeficiency Syndrome/prevention & control , Animals , Macaca , Pan troglodytes , Simian Acquired Immunodeficiency Syndrome/prevention & control , VaccinationSubject(s)
AIDS Vaccines/pharmacology , Simian Immunodeficiency Virus/immunology , Viral Vaccines/pharmacology , AIDS Vaccines/isolation & purification , Animals , Data Collection , Databases, Factual , Disease Models, Animal , HIV Infections/prevention & control , Primates , Research Design , Simian Acquired Immunodeficiency Syndrome/prevention & control , Viral Vaccines/isolation & purificationABSTRACT
An AIDS Vaccine Surveillance System (AVSS) was designed and implemented to track the rapidly growing international database supporting the development of promising AIDS vaccines. Both preclinical nonhuman primate (NHP) and clinical human trials are tracked by the AVSS. This report presents summary data generated from the AVSS on the NHP AIDS vaccine/live virus challenge studies only. Summary data on more than 100 preclinical HIV/SIV vaccines are presented within the framework of 1) 13 arbitrary Vaccine Types, 2) studies grouped by animal model (i.e., chimpanzee/HIV-1, and macaque/SIV, HIV-2), and 3) immunization approach (i.e., active and passive). Systematic and timely presentations of these summary data, both here and in future reports, aim to promote a clearer understanding of both earlier and more recent preclinical AIDS vaccine developments.
