Background and Objectives: Cognitive impairment is defined as a reduced ability to perform one or more cognitive functions, potentially leading to dementia if the condition worsens. With dementia being a rapidly growing public health issue affecting approximately 50 million people worldwide, understanding modifiable risk factors such as thyroid disease is crucial for prevention and early diagnosis. Thyroid hormones play a vital role in brain development and functioning, impacting processes such as neuron growth, myelination, and neurotransmitter synthesis. Recent decades have seen thyroid disorders emerging as potential independent risk factors for reversible cognitive impairment. Materials and Methods: The review adheres to PRISMA guidelines, utilizing a structured PICO question to explore whether individuals with thyroid diseases have a higher risk of developing dementia and cognitive impairments compared to those without. The literature search was conducted in PubMed, Cochrane, and ScienceDirect databases, including studies published from 1 January 2019 to 31 December 2023. The literature review discusses nine selected articles. Results: The findings highlight a complex association between thyroid dysfunction and cognitive decline, with some studies indicating significant links, particularly with hypothyroidism, and others suggesting the relationship may depend on the specific type of thyroid dysfunction or cognitive domain affected. Six out of nine articles found a link between thyroid disease and cognitive impairment, while three articles refuted this link. Conclusions: The review reveals a complex and ambiguous relationship between thyroid dysfunction and cognitive impairment. Further research is needed to elucidate the mechanisms underlying these associations and to determine whether thyroid dysfunction may be a modifiable risk factor for dementia.

Background and Objectives: The aging population has led to a rise in cognitive impairments, including dementia, often associated with multimorbidity. Early diagnosis of cognitive decline is crucial, especially in primary care, where time constraints and the limitations of diagnostic tools may hinder accurate detection. This study aims to assess the cognitive functions of multimorbid patients using the Mini-Mental State Examination (MMSE) and the Lithuanian version of the General Practitioner Assessment of Cognition (LT-GPCOG). We hypothesized that the LT-GPCOG would perform similarly to the MMSE in suspecting cognitive impairments. Materials and Methods: This cross-sectional study, conducted from 2021 to 2022, included 796 patients aged 40–85, with arterial hypertension and at least one other chronic disease, recruited from seven Lithuanian primary health care centers. Cognitive function was assessed using the MMSE and LT-GPCOG, and statistical analyses were performed using SPSS to determine the association between cognitive impairment and various demographic and clinical variables. Results: Out of 796 participants, 793 completed the study. Cognitive impairment was suspected in 5.1% of participants based on MMSE and 4.2% based on the LT-GPCOG. Statistically significant associations were found between cognitive impairment and chronic obstructive pulmonary disease (COPD) (p = 0.008 and p = 0.003) in both tests and chronic kidney disease (CKD) (p = 0.005) while testing with the MMSE. Lower education and unemployment were also correlated with cognitive impairment (p = 0.008 and p < 0.001). Conclusions: The findings suggest that regular cognitive assessments should be integrated into the management of multimorbid patients, particularly those with COPD and CKD. The LT-GPCOG proved to be an efficient alternative to the MMSE in primary care settings, demonstrating comparable diagnostic accuracy. Further studies are also needed to assess the sensitivity and specificity of the LT-GPCOG test.