👤 Hannes F Alber

The Timed Up and Go (TUG) is a 20-foot gait assessment, with TUG-dual task (DT) serial subtractions to determine dual-task cost. Alzheimer's disease (AD) risk is established using plasma biomarkers and APOE genotyping. We investigated: 1) TUG/TUG-DT differences between AD low-risk cognitively unimpaired (CU) older adults (N = 74), AD high-risk CU older adults (N = 87), and mild cognitively impaired (MCI) older adults (N = 33) and 2) the relationship between TUG/TUG-DT performance and plasma biomarkers. One hundred and ninety-four older adults ages 55-80 completed TUG/TUG-DT, a fasting blood draw, and APOE genotyping. Scores on the Clinical Dementia Rating Scale (CU = 0; CI = ≥0.5) and Montreal Cognitive Assessment (CU ≥ 24; CI = ≤23) determined whether participants were placed into the CU low-risk, CU high-risk, or MCI groups. Risk level for CU participants were assessed by APOE genotyping. Those participants who carried at least one copy of the APOE ε4 allele were designated to the high-risk group (n = 87). Participants with no APOE ε4 allele were assigned to the low-risk group (n = 75). MCI participants took longer to perform the TUG than CU participants ( Step count may be more sensitive, compared to speed alone, in identifying those in preclinical AD stages. Gait metrics (speed and efficiency) played a key role as a clinical manifestation of early AD pathophysiology determined by blood-based biomarker concentration. Combining these assessments offers a multidimensional, cost-effective approach for preclinical-AD screening and potential early intervention. Show less

Recent studies showed lower apolipoprotein A-IV (apoA-IV) plasma concentrations in patients with coronary artery disease (CAD). The actual distribution of the antiatherogenic apoA-IV in human plasma, however, is discussed controversially and it was never investigated in CAD patients. We therefore developed a gentle technique to separate the various apoA-IV-containing plasma fractions. Using a combination of precipitation of all lipoproteins with 40% phosphotungstic acid and 4 M MgCl2, as well as immunoprecipitation of all apoA-I-containing particles with an anti-apoA-I antibody, we obtained three fractions of apoA-IV: lipid-free apoA-IV (about 4% of total apoA-IV), apoA-IV associated with apoA-I (LpA-I:A-IV, 12%), and apoA-I-unbound but lipoprotein-containing apoA-IV (LpA-IV, 84%). We compared these three apoA-IV fractions between 52 patients with a history of CAD and 52 age- and sex-matched healthy controls. Patients had significantly lower apoA-IV levels when compared to controls (10.28 +/- 3.67 mg/dl vs. 11.85 +/- 2.82 mg/dl, P = 0.029), but no major differences for the three plasma apoA-IV fractions. We conclude that our gentle separation method reveals a different distribution of apoA-IV than in many earlier studies. No major differences exist in the apoA-IV plasma distribution pattern between CAD patients and controls. Therefore, the antiatherogenic effect of apoA-IV has to be explained by other functional properties of apoA-IV (e.g., the antioxidative characteristics). Show less