The relationship between atherosclerosis and dementia.

OBJECTIVE: The main objective is to confirm a hypothesis that atherosclerosis, through various mechanisms, considerably influences cognitive impairment and significantly increases the risk for developing dementia. Complete sample should be 920 individuals. The present study aimed to analyse epidemiological data from a questionnaire survey. METHODS: The work was carried out in the form of an epidemiological case control study. Subjects are enrolled in the study based on results of the following examinations carried out in neurology departments and outpatient centres during the project NU20-09-00119 from 2020 to 2023. Respondents were divided into four research groups according to the results of clinical examination for the presence of atherosclerosis and dementia. The survey was mainly concerned with risk factors for both atherosclerosis and dementia. It contained questions on lifestyle factors, cardiovascular risk factors, leisure activities, and hobbies. RESULTS: Analysis of the as yet incomplete sample of 877 subjects has yielded the following selected results: on average, 16% of subjects without dementia had primary education while the proportion was 45.2% in the group with both dementia and atherosclerosis. Subjects with dementia did mainly physical work. Low physical activity was more frequently noted in dementia groups (Group 2 - 54.4% and Group 3 - 47.2%) than in subjects without dementia (Group 1 - 19.6% and Group 4 - 25.8%). Coronary heart disease was more frequently reported by dementia patients (33.95%) than those without dementia (16.05%). CONCLUSION: Cognitively impaired individuals, in particular those with vascular cognitive impairment, have poorer quality of life and shorter survival. Risk factors contributing to such impairment are similar to those for ischaemic or haemorrhagic stroke. It may be concluded that most of the analysed risk factors play a role in the development of both atherosclerosis and dementia.

Cognitive impairment, neurodegenerative disorders, and olfactory impairment: A literature review.

<br><b>Introduction:</b> The early detection and diagnosis of dementia are of key importance in treatment, slowing disease progression, or suppressing symptoms. The possible role of changes in the sense of smell is considered with regard to potential markers for early detection of Alzheimer's disease (AD).</br> <br><b>Materials and methods:</b> A literature search was conducted using the electronic databases PubMed, Scopus, and Web of Science between May 30, 2022 and August 2, 2022. The term "dementia" was searched with keyword combinations related to olfaction.</br> <br><b>Results:</b> A total of 1,288 records were identified through the database search. Of these articles, 49 were ultimately included in the analysis. The results showed the potential role of changes in the sense of smell as potential biomarkers for early detection of AD. Multiple studies have shown that olfactory impairment may be observed in patients with AD, PD, MCI, or other types of dementia. Even though smell tests are able to detect olfactory loss caused by neurodegenerative diseases, they cannot reliably distinguish between certain diseases.</br> <br><b>Conclusions:</b> In individuals with cognitive impairment or neurodegenerative diseases, olfactory assessment has repeatedly been reported to be used for early diagnosis, but not for differential diagnosis.</br>.

Association between polymorphism rs2421943 of the insulin-degrading enzyme and schizophrenia: Preliminary report.

BACKGROUND: Insulin-degrading enzyme (IDE) is an important gene in studies of the pathophysiology of type 2 diabetes mellitus (T2DM). Recent studies have suggested a possible link between type 2 diabetes mellitus (T2DM) and the pathophysiology of schizophrenia (SZ). At the same time, significant changes in insulin-degrading enzyme (IDE) gene expression have been found in the brains of people with schizophrenia. These findings highlight the need to further investigate the role of IDE in schizophrenia pathogenesis. METHODS: We enrolled 733 participants from the Czech Republic, including 383 patients with schizophrenia and 350 healthy controls. Our study focused on the single nucleotide polymorphism (SNP) rs2421943 in the IDE gene, which has previously been associated with the pathogenesis of Alzheimer's disease. The SNP was analyzed using the PCR-RFLP method. RESULTS: The G allele of the rs2421943 polymorphism was found to significantly increase the risk of developing SZ (p < 0.01) when a gender-based analysis showed that both AG and GG genotypes were associated with a more than 1.55 times increased risk of SZ in females (p < 0.03) but not in males. Besides, we identified a potential binding site at the G allele locus for has-miR-7110-5p, providing a potential mechanism for the observed association. CONCLUSION: Our results confirm the role of the IDE gene in schizophrenia pathogenesis and suggest that future research should investigate the relationship between miRNA and estrogen influence on IDE expression in schizophrenia pathogenesis.

HPV and RAD51 as Prognostic Factors for Survival in Inoperable Oral and Oropharyngeal Cancer in Patients Unfit for Chemotherapy Treated with Hyperfractionated Radiotherapy.

INTRODUCTION: The incidence of advanced oral cavity and oropharyngeal cancers is generally high. Treatment outcomes for patients, especially those unfit for comprehensive cancer treatment, are unsatisfactory. Therefore, the search for factors to predict response to treatment and increase overall survival is underway. OBJECTIVE: This study aimed to analyze the presence of 32 HPV genotypes in tumor samples of 34 patients and the effect of HPV status and RAD51 on overall survival. METHOD: Tumor samples of 34 patients with locally advanced oropharyngeal or oral cavity cancer treated with accelerated radiotherapy in monotherapy were analyzed using reverse hybridization and immunohistochemistry for the presence of HPV and RAD51. Its effect on overall survival was examined. RESULTS: Only two types of HPV were identified-HPV 16 (dominant) and HPV 66 (two samples). The HPV positivity was associated with a borderline insignificant improvement in 2-year (p = 0.083), 5-year (p = 0.159), and overall survival (p = 0.083). Similarly, the RAD51 overexpression was associated with borderline insignificant improvement in 2-year (p = 0.083) and 5-year (p = 0.159) survival. CONCLUSION: We found no statistically significant differences but detected trends toward improvement in the survival of HPV-positive and RAD51 overexpressing patients unfit for surgical treatment or chemotherapy treated with hyperfractionated radiotherapy. The trends, however, indicate that in a larger group of patients, the effects of these two parameters would likely be statistically significant.

Is Alzheimer's disease a type 3 diabetes? A review.

OBJECTIVES: This is a review article that deals with the question of whether type 2 diabetes is a risk factor for the development of Alzheimer's disease. METHODS: We searched the PubMed database and relevant publications were selected for review. The introduction, which describes the possibilities of how type 2 diabetes can affect the development of Alzheimer's disease, is followed by other questions related to this issue: May on the contrary Alzheimer's disease induce type 2 diabetes? What is a relative risk for type 2 diabetes to induce dementia? How type 2 diabetes influence conversion of mild cognitive impairment to Alzheimer's disease? What is the role of antidiabetic medication? Proposition of term "type 3 diabetes" for Alzheimer's disease. RESULTS: Type 2 diabetes mellitus has been shown to increase the risk for cognitive decline and dementia, such as Alzheimer's disease and vascular dementia. Despite extensive research and numerous publications, the mechanisms underlying these associations remain unclear. CONCLUSIONS: Because of similar molecular and cellular features among type 1 and type 2 diabetes and insulin resistance associated with memory deficit and cognitive decline, some researches proposed the term "type 3 diabetes" for Alzheimer's disease.

What are the real associations of homeostasis model assessment (HOMA) with body mass index and age?

INTRODUCTION: Insulin resistance (IR), a key pathogenesis mechanism of metabolic disorders, can be tested using homeostatic model assessment (HOMA). HOMA-IR quantifies peripheral tissue IR, whereas HOMA-ß determines insulin secretion. The cross-sectional study aimed to examine non-linear associations of HOMA indices with age when adjusting for body mass index (BMI), and thus to investigate the indices' ability to reflect the real development of glucose metabolism disorders over time. MATERIAL AND METHODS: The sample comprised 3406 individuals without diabetes mellitus (DM) divided into those with normal glucose metabolism (NGT, n = 1947) and prediabetes (n = 1459) after undergoing biochemical analyses. Polynomial multiple multivariate regression was applied to objectify associations of HOMA with both age and BMI. RESULTS: Mean values of HOMA-IR and HOMA-ß in individuals with NGT were 1.5 and 82.8, respectively, while in prediabetics they were 2.2 and 74.3, respectively. The regression proved an inverse non-linear dependence of pancreatic b dysfunction, expressed by HOMA-ß, on age, but did not prove a dependence on age for HOMA-IR. Both indices were positively, statistically significantly related to BMI, with a unit increase in BMI representing an increase in HOMA-IR by 0.1 and in HOMA-ß by 3.2. CONCLUSIONS: The mean values of HOMA indices showed that, compared with NGT, prediabetes is associated with more developed IR but lower insulin secretion. Both HOMA-IR and HOMA-b are predicted by BMI, but only HOMA-ß is predicted by age. HOMA indices can reflect non-linear, closer-to-reality dependencies on age, which in many epidemiological studies are simplified to linear ones. The assessment of glucose metabolism using HOMA indices is beneficial for the primary prevention of IR and thus DM.

Evaluation of breast stiffness pathology based on breast compression during mammography: Proposal for novel breast stiffness scale classification.

Breast cancer is diagnosed through a patient's Breast Self-Examination (BSE), Clinical Breast Examination (CBE), or para-clinical methods. False negativity of PCM in breast cancer diagnostics leads to a persisting problem associated with breast tumors diagnosed only in advanced stages. As the tumor volume/size at which it becomes invasive is not clear, BSE and CBE play an exceedingly important role in the early diagnosis of breast cancer. The quality and effectiveness of BSE and CBE depend on several factors, among which breast stiffness is the most important one. In this study, the authors present four methods for evaluating breast stiffness pathology during mammography examination based on the outputs obtained during the breast compression process, id est, without exposing the patient to X-Ray radiation. Based on the subjective assessment of breast stiffness by experienced medical examiners, a novel breast stiffness classification was designed, and the best method of its objective measurement was calibrated to fit the scale. Hence, this study provides an objective tool for the identification of patients who, being unable to perform valid BSE, could benefit from an increased frequency of mammography screening. Dum vivimus servimus.

Polymorphism Rs2421943 of the Insulin-Degrading Enzyme Gene and the Risk of Late-Onset Alzheimer's Disease.

BACKGROUND: Insulin-degrading enzyme (IDE) is a widely distributed Zn2+-binding metalloprotease that cleaves multiple short and medium-sized peptides prone to form ß-structures. These include insulin and amyloid-ß peptides. Accumulation and fibrillation of amyloid-ß peptides leading to the formation of amyloid plaques is a characteristic sign of Alzheimer's disease (AD) pathology. OBJECTIVE: The study investigated the rs2421943 single nucleotide polymorphism (SNP) of the IDE gene as a risk factor for MCI (mild cognitive impairment) and AD. METHODS: Two independent groups of 1670 patients and controls were included. The AD group consisted of 595 patients and 400 controls; the MCI group involved 135 patients and 540 matched controls. PCR and restriction fragment length analysis were used to analyze the rs2421943 polymorphism. Using the miRBase and RNA22 prediction tools in silico indicated that the rs2421943 polymorphism is a potential target for a specific miRNA (hsa-miR-7110-5p). RESULTS: AG and GG genotypes of rs2421943 significantly increased the risk of AD, and the AG genotype increased the risk of MCI. It seems the G allele both increases the risk of AD and accelerates the transition through the MCI phase. In silico study revealed that rs2421943 is inside the sequence binding miRNA hsa-miR-7110-5p. The polymorphism could affect the rate of IDE pre-RNA (heterogeneous nuclear RNA, hnRNA) processing, resulting in slower translation, lower levels of IDE, deficient removal of amyloid-ß fragments, and greater risk of and/or accelerated progression of AD. CONCLUSION: GG and AG genotypes of the single nucleotide polymorphism rs2421943 of insulindegrading enzyme gene increase the risk of AD and MCI.

Neuropsychological tests and prediction of dementia in association with the degree of carotid stenosis.

This study constitutes a cross sectional analysis of the association between cognitive impairment defined by neuropsychological tests and carotid stenosis. The main objective was to compare the results of the Mini-Mental State Examination (MMSE) and Addenbrooke's Cognitive Examination-Revised (ACE-R) with regard to the degree of carotid stenosis. The sample comprised 744 patients who underwent a carotid duplex ultrasound and cognitive function testing (by ACE-R and MMSE). A multivariable analysis of potential confounding factors was completed. The significance of the different number of positive (MMSE ≤ 27, ACE-R ≤ 88) and negative (MMSE ≥ 28, ACE-R ≥ 89) results of the neuropsychological tests was analysed with regard to the degree of carotid stenosis (50-99%). Neuropsychological test results were also compared between carotid stenosis of 50-69%, 70-89%, and 90-99%. For both the MMSE and ACE-R, a difference was observed between positive and negative test results when higher degrees of stenosis were present. However, for the ACE-R only, more severe stenosis (80-89%, 90-99%) was predominantly associated with positive test results (p-value < 0.017). The same dependence for ACE-R (although not statistically significant) was observed in the group of patients without an ischemic stroke (confounding factor). In the case of the MMSE and more severe stenosis, negative results predominated, regardless of the confounding factor. There were no statistically significant differences in test results between carotid stenosis of 50-69%, 70-89%, and 90-99%. The results suggest that for assessing the early risk of cognitive impairment in patients with carotid atherosclerosis, the ACE-R appears more suitable than the MMSE.

Evaluation of breast stiffness pathology based on breast compression during mammography: Proposal for novel breast stiffness scale classification

Abstract Breast cancer is diagnosed through a patient's Breast Self-Examination (BSE), Clinical Breast Examination (CBE), or para-clinical methods. False negativity of PCM in breast cancer diagnostics leads to a persisting problem associated with breast tumors diagnosed only in advanced stages. As the tumor volume/size at which it becomes invasive is not clear, BSE and CBE play an exceedingly important role in the early diagnosis of breast cancer. The quality and effectiveness of BSE and CBE depend on several factors, among which breast stiffness is the most important one. In this study, the authors present four methods for evaluating breast stiffness pathology during mammography examination based on the outputs obtained during the breast compression process, id est, without exposing the patient to X-Ray radiation. Based on the subjective assessment of breast stiffness by experienced medical examiners, a novel breast stiffness classification was designed, and the best method of its objective measurement was calibrated to fit the scale. Hence, this study provides an objective tool for the identification of patients who, being unable to perform valid BSE, could benefit from an increased frequency of mammography screening. Dum vivimus servimus.

Risk Factors for Alzheimer's Disease: An Epidemiological Study.

INTRODUCTION: Dementia becomes a major public health challenge in both the Czech Republic and worldwide. The most common form of dementia is Alzheimer's disease (AD). OBJECTIVE: We conducted two successive epidemiological projects in 2012-2015 and 2016-2019. Their aim was to study the effect of selected potential genetic, vascular and psychosocial risk factors on the development of AD by comparing their frequencies in AD patients and controls. METHODS: Epidemiological case-control studies were conducted. In total, data from 2106 participants (1096 cases, 1010 controls) were analyzed. RESULTS: Three times more females than males suffered from AD. The highest proportion of cases were those with primary education, unlike controls. There were statistically significantly more manual workers among cases than among controls. Of selected vascular risk factors, coronary heart disease was found to be statistically significantly more frequent in cases than in controls. The onset of hypertension and diabetes mellitus was earlier in controls than in cases. As for hobbies and interests, there were statistically significant differences in physical activity, reading and solving crosswords between the groups, with these activities being more common in controls. CONCLUSION: The prevalence of chronic neurodegenerative diseases, in particular AD, is currently increasing. Given the aging of the population, these conditions may be expected to rise in prevalence. Potential risk of AD needs to be studied, analyzed and confirmed; a detailed knowledge of the risks of AD and early detection of the pathology may therefore be very beneficial for prevention and early treatment of this condition.

Assessment of toe brachial index validity in diabetic patients - interim results.

INTRODUCTION: The toe brachial index (TBI) is recommended for the detection of lower extremity arterial disease (LEAD) in case of reduced efficacy of the ankle brachial index (ABI), which most often occurs in diabetics. In this case, TBI is expected to give more accurate results. There are not many studies dealing with the use of TBI specifically in diabetics and the results are different. OBJECTIVE: The purpose of this work is to present the interim results of the study, whose main objective is to assess the validity of TBI in diabetics and to determine whether this method provides improvements over the ABI. METHODS: In the first phase of the study, 42 limbs were examined in 21 patients with type 2 diabetes. ABI was measured using the automatic oscillometric method (ABI OSC) and the manual method using the pencil doppler (ABI DPP). TBI was determined using an automatic plethysmographic method. The reference examination of the arteries of the lower limbs was performed using duplex ultrasonography (DUS). A paired t-test was used to compare the individual TBI and ABI methods. Cut-off points ABI < 0.9; TBI < 0.7; and DUS stenosis > 50 % were used to evaluate validity parameters. RESULTS: The individual ABI and TBI methods gave different results (p < 0.05). In eight limbs of the total number, LEAD was demonstrated using DUS. The best validity parameters were demonstrated by the TBI - sensitivity 0.88; specificity 0.88; positive predictive value 0.64; negative predictive value 0.97, positive likelihood ratio 7.44; negative likelihood ratio 0.14. The ABI method of calculation, that uses lower systolic blood pressure determined from two measurement sites on the ankle as a numerator, had a higher validity parameters. The ABI OSC did not correctly detect a single limb with stenosis > 50 % in this cohort. CONCLUSION: According to the interim results of this work, the TBI was more suitable for the detection of LEAD in diabetics in comparison with ABI.

The Importance of Screening for Hearing Loss in the Elderly.

<b>Aim:</b> The aim was to compare hearing loss between men and women over 65 in pure tone audiometry and to evaluate the sensitivity of the abbreviated version of the Hearing Handicap Inventory (HHIE-S). This questionnaire highlights hearing handicaps in understanding speech. </br></br><b> Materials and Methods:</b> The data was collected in the years 2011-2015 from respondents above 18 years of age using a standar-dized HHIE-S questionnaire and specialized tests. The cohort was divided into groups based on the severity of hearing loss in the better ear according to the World Health Organization (WHO) as measured by tone threshold audiometry at 500 Hertz (Hz), 1000 Hz, 2000 Hz and 4000 Hz. </br></br> <b> Results:</b> Of the 7070 people (61.8% female and 38.2% male), 68.93% had hearing impairment. Most people had a slight he-aring loss. Based on HHIE-S, 56.94% reported impaired hearing. A statistically significant difference was found between the genders, but according to HHIE-S, females with impaired hearing were not statistically significantly more numerous than males. The diagnostic sensitivity of the HHIE-S was assessed in particular by its sensitivity (75.43%) and specificity (82.53%). The probability that a person has a hearing impairment when the HHIE-S test is positive is 90.21%. </br></br> <b> Conclusions:</b> The HHIE-S is fast, inexpensive and short, and can be included as a screening test for hearing impairment in ca-ring for the elderly. Even a minor hearing impairment can be a significant handicap in elderly patients by restricting not only social interactions but also weakening mental functioning.

Free triiodothyronine/free thyroxine (FT3/FT4) ratio is strongly associated with insulin resistance in euthyroid and hypothyroid adults: a cross-sectional study.

INTRODUCTION: Insulin resistance (IR) is a key and early pathogenetic mechanism of cardiometabolic diseases with huge potential if detected early and mitigated, for lowering the burden of the disease. Available data are conflicting to what extent adult thyroid dysfunction is associated with IR. Therefore, we aimed to investigate the association and to identify which thyroid parameters are predictors of IR. MATERIAL AND METHODS: After undergoing basic anthropometric and biochemical studies including thyroid hormones, oral glucose tolerance test (OGTT), and insulin, 1425 middle-aged individuals were divided into three groups according to thyroid parameters: overt hypothyroidism (OH), subclinical hypothyroidism (SH), and euthyroidism (EU). RESULTS: The homeostasis model assessment of IR (HOMA-IR), fasting insulin, and two-hour glucose levels of OGTT showed a steady, yet insignificant, increase from EU through SH to OH. The strongest noted correlations were those of insulin levels with free triiodothyronine/free thyroxine (FT3/FT4) ratio (r = 0.206, p < 0.001) and FT3 (r = 0.205, p < 0.001). Also in the case of HOMA-IR, the only statistically significant correlations were observed for FT3 (r = 0.181, p < 0.001) and the FT3/FT4 ratio (r = 0.165, p < 0.001). Among other thyroid hormones, linear logistic regression proved the FT3/FT4 ratio as the only significant predictor of HOMA-IR (linear coefficient = 5.26, p = 0.027) and insulin levels (linear coefficient = 18.01, p = 0.023), respectively. Thyroid-stimulating hormone was not associated with IR in either correlation or regression analysis. CONCLUSIONS: The FT3/FT4 ratio should be more emphasised in the diagnosis and treatment of thyroid disorders. Patients could benefit from a pharmacological reduction of the FT3/FT4 ratio, potentially leading to a decrease in insulin resistance, and thus a corresponding decrease in the risk of the cardiometabolic diseases.

Single Nucleotide Polymorphism rs11136000 of CLU Gene (Clusterin, ApoJ) and the Risk of Late-Onset Alzheimer's Disease in a Central European Population.

Clusterin (CLU; also known as apolipoprotein J, ApoJ) is a protein of inconstant structure known to be involved in diverse processes inside and outside of brain cells. CLU can act as a protein chaperon or protein solubilizer, lipid transporter as well as redox sensor and be anti- or proapoptotic, depending on context. Primary structure of CLU is encoded by CLU gene which contains single nucleotide polymorphisms (SNP's) associated with the risk of late-onset Alzheimer's disease (LOAD). Studying a sample of Czech population and using the case-control association approach we identified C allele of the SNP rs11136000 as conferring a reduced risk of LOAD, more so in females than in males. Additionally, data from two smaller subsets of the population sample suggested a possible association of rs11136000 with diabetes mellitus. In a parallel study, we found no association between rs11136000 and mild cognitive impairment (MCI). Our findings on rs11136000 and LOAD contradict those of some previous studies done elsewhere. We discuss the multiple roles of CLU in a broad range of molecular mechanisms that may contribute to the variability of genetic studies of CLU in various ethnic groups. The above discordance notwithstanding, our conclusions support the association of rs1113600 with the risk of LOAD.

Polymorphism rs11867353 of Tyrosine Kinase Non-Receptor 1 (TNK1) Gene Is a Novel Genetic Marker for Alzheimer's Disease.

Several single-nucleotide polymorphisms (SNPs) and rare variants of non-receptor tyrosine kinase 1 gene (TNK1) have been associated with Alzheimer's disease (AD). To date, none of the associations have proven to be of practical importance in predicting the risk of AD either because the evidence is not conclusive, or the risk alleles occur at very low frequency. In the present study, we are evaluating the associations between rs11867353 polymorphism of TNK1 gene and both AD and mild cognitive impairment (MCI) in a group of 1656 persons. While the association with AD was found to be highly statistically significant (p < 0.0001 for the risk genotype CC), no statistically significant association with MCI could be established. Possible explanation of the apparent discrepancy could be rapid progression of MCI to AD in persons with the CC genotype. Additional findings of the study are statistically significant associations of rs11867353 polymorphism with body mass index, body weight, and body height. The patients with AD and CC genotype had significantly lower values of body mass index and body weight compared with patients with other genotypes. The main outcome of the study is the finding of a previously never described association between the rs11867353 polymorphism of the TNK1 gene and AD. The rs11867353 polymorphism has a potential to become a significant genetic marker when predicting the risk of AD.

Epidemiological study on more accurate diagnosis of prostate cancer.

OBJECTIVE: The study aimed at assessing the potential benefit of prostate health index (PHI) for early detection of prostate cancer (PCa) and the use of PHI as a marker predicting the presence of PCa before performing prostate biopsy. METHODS: The study comprised 55 males who underwent prostate biopsy. Before the procedure, blood samples were collected to test prostate specific antigen (PSA) and free/total PSA ratio (%fPSA) and PHI was calculated. Receiver operating characteristic (ROC) analysis was used to assess the benefit of these values for predicting the presence of PCa. RESULTS: Based on histological examination 31 males were diagnosed with PCa, the remaining 24 were negative. Among the PCa patients, 39% had a Gleason score of 6, 26% had a score of 7 and 35% had a score of 8-10. There were statistically significant differences in PHI and PSA between males with and without PCa. The areas under the ROC curve for %fPSA, total PSA and PHI were 0.712, 0.746 and 0.789, respectively. PHI showed the best predictive ability to estimate biopsy results. If the cut-off criterion PHI > 36.4 (77.42% sensitivity, 66.67% specificity) had been used, 41.7% of males would have avoided unnecessary biopsy. CONCLUSION: The use of PHI may considerably improve the accuracy of PCa detection in patients with elevated PSA and thus reduce the number of unnecessary biopsies.

Alterations of glycaemia, insulin resistance and body mass index within the C-peptide optimal range in non-diabetic patients.

The study focused on changes or cut-offs of glycaemia, insulin resistance and body mass index within the C-peptide reference range (260-1730 pmol/l). The metabolic profile of individuals in the Czech Republic without diabetes (n = 3186) was classified by whiskers and quartiles of C-peptide into four groups with the following ranges: 290-510 (n = 694), 511-710 (n = 780), 711-950 (n = 720) and 951-1560 pmol/l (n = 673). Fasting levels of glucose, insulin, HOMA IR (Homeostasis Model Assessment for Insulin Resistance) and BMI (body mass index) were compared by a relevant C-peptide range. Participants taking medication to control glycaemia were excluded. The evaluation involved correlations between C-peptides and the above parameters, F-test and t-test. Changes in glucose levels (from 5.3 to 5.6 mmol/l) between the groups were lower in comparison to insulin, which reached relatively greater changes (from 4.0 to 14.2 mIU/l). HOMA IR increased considerably with growing C-peptide concentrations (0.9, 1.5, 2.2 and 3.5) and BMI values showed a similar trend (28.3, 31.0, 33.6 and 37.4). Considerable changes were observed for insulin (5.2 mIU/l, 57.8%) and HOMA IR (1.3, 61.3%) between groups with C-peptide ranges of 711-950 and 951-1560 pmol/l. Although correlations involving C-peptide, insulin, glucose and BMI seemed to be non-significant (up to rxy = 0.25), the mean values of insulin, HOMA IR and BMI showed statistically significant changes between all groups with various C-peptide concentrations (p ≤ 0.001). Generally, most important differences appeared in glucose metabolism and body mass index between C-peptide ranges of 711-950 and 951-1560 pmol/l. Absolute and relative changes of C-peptide concentrations are possible to use for the assessment of glucose regulatory mechanism. The spectrum of investigated parameters could be a useful tool to prevent the risks linked with the alterations of glycaemia.

Optimal Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) Cut-Offs: A Cross-Sectional Study in the Czech Population.

Background and Objectives: The key pathogenetic mechanism of glucose metabolism disorders, insulin resistance (IR), can be assessed using the Homeostasis Model Assessment of IR (HOMA-IR). However, its application in clinical practice is limited due to the absence of cut-offs. In this study, we aimed to define the cut-offs for the Czech population. Methods: After undergoing anthropometric and biochemical studies, the sample of 3539 individuals was divided into either nondiabetics, including both subjects with normal glucose tolerance (NGT, n = 1947) and prediabetics (n = 1459), or diabetics (n = 133). The optimal HOMA-IR cut-offs between subgroups were determined to maximize the sum of the sensitivity and specificity for diagnosing type 2 diabetes mellitus (T2DM) or prediabetes. The predictive accuracy was illustrated using receiver operating characteristic (ROC) curves. Logistic regression was performed to assess the association between a target variable (presence/absence of T2DM) depending on the HOMA-IR score as well as on the age and sex. Results: The HOMA-IR cut-off between nondiabetics and diabetics for both sexes together was 3.63, with a sensitivity of 0.56 and a specificity of 0.86. The area under the ROC curve was 0.73 for T2DM diagnosing in both sexes. The HOMA-IR cut-off between the NGT subjects and prediabetics was 1.82, with a sensitivity of 0.60 and a specificity of 0.66. Logistic regression showed that increased HOMA-IR is a risk factor for the presence of T2DM (odds ratio (OR) 1.2, 95% confidence interval (CI) 1.14-1.28, p < 0.0001). The predictive ability of HOMA-IR in diagnosing T2DM is statistically significantly lower in females (OR 0.66, 95% CI 0.44-0.98). The results are valid for middle-aged European adults. Conclusions: The results suggest the existence of HOMA-IR cut-offs signaling established IR. Introduction of the instrument into common clinical practice, together with the known cut-offs, may contribute to preventing T2DM.

CHAT gene polymorphism rs3810950 is associated with the risk of Alzheimer's disease in the Czech population.

BACKGROUND: Cholinergic hypothesis of Alzheimer's disease (AD) is based on the findings that a reduced and/or perturbed cholinergic activity in the central nervous system correlates with cognitive decline in patients with Alzheimer's disease. The hypothesis resulted in the development of centrally-acting agents potentiating cholinergic neurotransmission; these drugs, however, only slowed down the cognitive decline and could not prevent it. Consequently, the perturbation of the central cholinergic signalling has been accepted as a part of the Alzheimer's aetiology but not necessarily the primary cause of the disease. In the present study we have focused on the rs3810950 polymorphism of ChAT (choline acetyltransferase) gene that has not been studied in Czech population before. METHODS: We carried out an association study to test for a relationship between the rs3810950 polymorphism and Alzheimer's disease in a group of 1186 persons; 759 patients with Alzheimer's disease and 427 control subjects. Furthermore, we performed molecular modelling of the terminal domain (1st-126th amino acid residue) of one of the ChAT isoforms (M) to visualise in silico whether the rs3810950 polymorphism (A120T) can change any features of the tertiary structure of the protein which would have a potential to alter its function. RESULTS: The AA genotype of CHAT was associated with a 1.25 times higher risk of AD (p <  0.002) thus demonstrating that the rs3810950 polymorphism can have a modest but statistically significant effect on the risk of AD in the Czech population. Furthermore, the molecular modelling indicated that the polymorphism is likely to be associated with significant variations in the tertiary structure of the protein molecule which may impact its enzyme activity. CONCLUSIONS: Our findings are consistent with the results of the meta-analytical studies of the relationship between rs3810950 polymorphism and AD and provide further material evidence for a direct (primary) involvement of cholinergic mechanisms in the etiopathogenesis of AD, particularly as a factor in cognitive decline and perturbed conscious awareness commonly observed in patients with AD.