Retinal microvascular complexity as a putative biomarker of biological age: a pilot study.

Physiological changes associated with aging increase the risk for the development of age-related diseases. This increase is non-specific to the type of age-related disease, although each disease develops through a unique pathophysiologic mechanism. People who age at a faster rate develop age-related diseases earlier in their life. They have an older "biological age" compared to their "chronological age". Early detection of individuals with accelerated aging would allow timely intervention to postpone the onset of age-related diseases. This would increase their life expectancy and their length of good quality life. The goal of this study was to investigate whether retinal microvascular complexity could be used as a biomarker of biological age. Retinal images of 68 participants ages ranging from 19 to 82 years were collected in an observational cross-sectional study. Twenty of the old participants had age-related diseases such as hypertension, type 2 diabetes, and/or Alzheimer's dementia. The rest of the participants were healthy. Retinal images were captured by a hand-held, non-mydriatic fundus camera and quantification of the microvascular complexity was performed by using Sholl's, box-counting fractal, and lacunarity analysis. In the healthy subjects, increasing chronological age was associated with lower retinal microvascular complexity measured by Sholl's analysis. Decreased box-counting fractal dimension was present in old patients, and this decrease was 2.1 times faster in participants who had age-related diseases (p = 0.047). Retinal microvascular complexity could be a promising new biomarker of biological age. The data from this study is the first of this kind collected in Montenegro. It is freely available for use.

VALIDATION OF THE BRIEF INTERNATIONAL COGNITIVE ASSESSMENT FOR MULTIPLE SCLEROSIS (BICAMS) IN A LARGE COHORT OF RELAPSING-REMITTING MS PATIENTS.

Cognitive impairment is one of the most frequently reported symptoms in persons with multiple sclerosis (MS). The Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) has been recommended as a standardized international screening and monitoring tool for brief cognitive assessment. The aim of our study was to assess the reliability and validity of the Serbian version of the BICAMS. A total of 500 relapsing-remitting MS (RRMS) patients and 69 age-, gender- and education-matched healthy control (HC) subjects were examined. All participants performed the BICAMS test battery, which includes the oral version of the Symbol Digit Modalities Test (SDMT), California Verbal Learning Test second edition (CVLT-II), and Brief Visuospatial Memory Test Revised (BVMTR). A randomly selected subset of patients were retested one to three weeks after baseline. Statistically significant differences between patients and HCs were evident on the SDMT and BVMTR (p<0.001). HCs had higher CVLT-II scores but this difference did not reach statistical significance (p=0.063). Cognitive impairment, defined as an abnormal test score on ≥1 subtest, was found in 62.9% of MS patients. There were statistically significant correlations between BICAMS scores and age, education, EDSS and disease duration in patient sample. Test-retest reliability was confirmed with Pearson correlation coefficient of 0.70 in all measures. This study supported the reliability and validity of the Serbian BICAMS, although the CVLT-II version tested here lacked sensitivity to detect MS compared to healthy volunteers.

Inflammation-Related microRNAs-146a and -155 Are Upregulated in Mild Cognitive Impairment Subjects Among Older Age Population in Montenegro.

BACKGROUND: Pathological and clinical features of Alzheimer's disease (AD) are in temporal discrepancy and currently accepted clinical tests provide the diagnosis decades after the initial pathophysiological events. In order to enable a more timely detection of AD, research efforts are directed to identification of biomarkers of the early symptomatic stage. Neuroinflammatory signaling pathways and inflammation-related microRNAs (miRNAs) could possibly have a crucial role in AD, making them promising potential biomarkers. OBJECTIVE: We examined the expression of circulatory miRNAs with a documented role in AD pathophysiology: miR-29a/b, miR-101, miR-125b, miR-146a, and miR-155 in the plasma of AD patients (AD, n = 12), people with mild cognitive impairment (MCI, n = 9), and normocognitive group (CTRL, n = 18). We hypothesized that these miRNA expression levels could correlate with the level of participants' cognitive decline. METHODS: The study participants completed the standardized interview, neurological examination, neuropsychological assessment, and biochemical analyses. miRNA expression levels were assessed by RT-PCR. RESULTS: Neurological and laboratory findings could not account for MCI, but miR-146a and -155 were upregulated in the MCI group compared to the control. miR-146a, known to mediate early neuroinflammatory AD events, was also upregulated in the MCI compared to AD group. ROC curve analysis for miRNA-146a showed 77.8% sensitivity and 94.4% specificity and 66.7% sensitivity and 88.9% specificity for miR-155. CONCLUSION: Determination of circulatory inflamma-miRs-146a and -155 expression, together with neuropsychological screening, could become a non-invasive tool for detecting individuals with an increased risk for AD, but research on a larger cohort is warranted.