Blood laboratory parameters of carefully selected healthy elderly people

Reasons for Exclusion of Apparently Healthy Mature Adult and Senior Dogs From a Clinical Trial

Background: Interventional clinical trials intended to maintain health in aging dogs are unusual and require particular attention to exclusion criteria.

Objectives: To describe reasons for exclusion when a mature adult and senior canine population with normal health status was sought.

Animals: Fifty six companion dogs nominated for a randomized controlled trial (RCT).

Procedures: Exclusions occurred within Stage 1 (S1): owner-provided survey information; Stage 2 (S2): medical records review; and Stage 3 (S3): screening examination and within Owner, Dog, or Other factor categories.

Results: Of 56 nominated dogs, 39 were excluded at S1 (n = 19), S2 (n = 5), and S3 (n = 15), respectively. Dogs were excluded for Owner (n = 4), Dog (n = 27), Other (n = 6), and concurrent (Owner + Dog; n = 2) factors. The most common exclusion period was S1 (n = 19), with weight outside the target range being the most common exclusion factor in that stage (n = 10). Heart murmurs were the second most common exclusion factor (S1: n = 1; S3: n = 5); suspected or confirmed systemic illness was third most common (S1: n = 2; S2: n = 3; S3: n = 2). Among dogs who passed S1 and S2 screening (n = 32), 15 dogs (48%) were excluded at S3, for heart murmur > grade II/VI (n = 5), cardiac arrhythmias (n = 2), and clinicopathologic abnormalities (n = 2).

Conclusions and Clinical Relevance: Dogs nominated for a clinical trial for healthy mature adult and senior dogs were excluded for size, previous diagnoses, and newly discovered cardiac abnormalities. For future interventions in mature adult and senior dogs of normal health status, it is important to define expected age-related abnormalities to ensure that meaningful exclusion criteria are used.

Predictors of self-reported prospective and retrospective memory in a population-based sample of older adults

In this article, the authors examined predictors of self-reported everyday memory failures using the Prospective and Retrospective Questionnaire (PRMQ; Smith, Della Sala, Logie, & Maylor, 2000) in a population-based sample of older adults (age range = 60-90 years; N = 250). The results showed that a higher frequency of reported failures was associated with lower scores on the personality dimension of self-directedness as assessed by the Temperament and Character Inventory (TCI; Cloninger, Dragan, Svrakic, & Przybeck, 1993) and more depressive symptoms on the Center for Epidemiological Studies Depression Scale (CES-D; Radloff, 1977). However, PRMQ scores showed no relationships with objective memory ability, as reflected by a series of retrospective memory measures and a measure of prospective memory. Neither were the PRMQ scales associated with general cognitive functioning as assessed by the Mini-Mental State Examination (MMSE; Folstein, Folstein, & McHugh, 1977). Taken together, the results indicate that within the older population, self-reported memory as assessed by the PRMQ may reflect mood-state and personality factors rather than individual differences in memory and cognitive ability.

Effect of age on the activity of ceruloplasmin of human blood

Aminoxidase activity of ceruloplasmin was measured in the serum of 120 people (between 45 and 102 years of age) using the p-phenylenediamine method. A negative linear age-correlation (-30% for the whole lifespan; P < 0.01) was established in this activity with increasing age, nevertheless the total copper content of blood did not change in the same age-range as measured by an atomic absorption spectrophotometric method. Increasing ionic strength, in vitro, caused an exponential decline in blood ceruloplasmin aminoxidase activity of both middle aged and elderly subjects. The age-dependent decrease in ceruloplasmin activity could have a negative effect on the antioxidant functions of blood, and finally on the aging process itself.

Age-dependent variations of human PMNL elastase activity as a function of pH, ionic strength and calcium concentration

Human leukocyte elastase (HLE) has been implicated in the pathomechanism of various diseases, such as emphysema and atherosclerosis. The incidence of these diseases is increasing with aging. Therefore, it can be supposed that the HLE activity is changing with aging according to the well known age-related physiological alterations. Thus, the effects of pH, NaCl and calcium concentrations on HLE activity, separated from polymorphonculear leucocytes (PMNLs) of healthy, young (<35 years) and elderly (>75 years) subjects, were studied by measuring the activity with synthetic substrate and with bovine and human atherosclerotic and non-atherosclerotic aortic elastin. From our results, it may be concluded, that the elastolytic activity of HLE separated from PMNLs of elderly subjects is more sensitive to ionic strength, to pH and to the calcium concentration of the medium, than the HLE activity of young subjects. The elastolytic activity of HLE, of both young and old subjects, increases dramatically on atherosclerotic aortic elastin in the presence of calcium. These findings might explain, at least partly, the increased incidence of atherosclerosis with aging.

Clinical characteristics of individuals with subjective memory loss in Western Australia: results from a cross-sectional survey

Subjective memory complaint is common in later life. Its relationship to future risk of dementia is unclear, although many reports have found a positive association. We designed the present cross-sectional survey to investigate the clinical features associated with subjective memory impairment. One hundred and eight volunteers and 38 non-complainers acting as age-matched controls were recruited. Eleven subjects with memory complaints were excluded because of prior stroke or low MMSE score. The CAMCOG was used to measure cognition; complainers had significantly lower scores (p<0.001). Univariate analysis showed that complainers had greater prevalence of depression, anxiety, insomnia, psychotic phenomenon, difficulties with ADL and word-finding difficulties. The frequency distribution of the apolipoprotein E epsilon4 allele was similar for both groups (p=0.469). Logistic regression analysis indicated that CAMCOG scores (p=0.002) and word-finding difficulty (p=0.002) were independently associated with memory complaints. These results show that memory complainers have worse cognitive performance than non-complainers and support the findings of other studies that suggest that subjective memory loss may be a reliable indicator of cognitive decline.

A comparison of anthropometry, biochemical variables and plasma amino acids among centenarians, elderly and young subjects

OBJECTIVE

Aging health is associated with nutritional changes which are not well understood and were therefore evaluated in this study by comparing the nutritional status of centenarians and elderly (in their 70s) relative to young subjects.

SUBJECTS

The participants were 27 young subjects (10 males, 17 females), 40 healthy elderly (20 males, 20 females) and 32 centenarians (9 males, 23 females).

METHODS

The activities of daily living (ADL), height, weight, body mass index (BMI), biochemical variables (total protein, albumin, triglycerides as well as total, HDL, LDL and VLDL cholesterol) and plasma amino acid profiles were evaluated.

RESULTS

Compared with young subjects, lower (p<0.05) height, weight, total protein, albumin and albumin/globulin (A/G) ratio and total cholesterol for centenarians and height, albumin and A/G ratio for elderly were observed in both genders. Total cholesterol of male centenarians was lower than in young and elderly subjects and total and LDL cholesterol concentrations of female elderly were higher than those of young and centenarian subjects. However, the cholesterol concentrations of all the centenarians were within the reference range. The ratios of essential amino acids to nonessential amino acids were significantly lower (p<0.05) in the centenarians than the young subjects. Clear changes in individual amino acids with aging were lower (p<0.05) branched chain amino acids and methionine and higher proline and cystine, which are similar to the amino acid profiles in liver deterioration.

CONCLUSION

The results suggest that the centenarians had poor nutritional status, which may be due to their decreased metabolism and the possibility that only short, slender individuals with low lipids, protein and essential amino acids are those that tend to survive to be centenarians.

Age-dependent changes of K-elastin stimulated effector functions of human phagocytic cells: relevance for atherogenesis

Effector functions of the elastin receptor on human phagocytic cells from young and older individuals were studied. In cells of young healthy subjects the elastin peptides, the agonists of receptor, stimulated both superoxide anion release from PMNs and phagocytosis of coated human red cells by monocytes. Elastin appeared to inhibit the cholesterol synthesis in monocytes, measured by the incorporation of 14C-acetate. In comparison with phagocytic cells of young (< or = 25 +/- 6 years) subjects. PMNs of elderly donors (> or = 75 +/- 10 years) bore a similar number of binding sites for soluble elastin peptides, and the affinity of the elastin receptor was unchanged as shown by Scatchard analysis. The phagocytosis of coated human red cells stimulated by elastin peptides was also similar in the two age groups. However, several differences were found between phagocytic cells of young and elderly donors 1) PMNs of elderly released increased amounts of elastase from both resting and elastin peptide stimulated cells, and 2) monocytes of elderly showed a lack of inhibition of cholesterol synthesis by elastin peptides when maintained in cholesterol-free medium. These changes in effector functions of phagocytic cells from elderly donors might contribute to the age-dependent increase of susceptibility to the development of atherosclerotic lesions.

Alteration of lymphocyte membrane phospholipids and intracellular free calcium concentrations in hyperlipidemic subjects

Hypercholesterolemia has been proposed to influence cell functions via changes in membrane composition. The aim of the present study was to determine whether the membrane phospholipid composition of human lymphocytes is modified in hypercholesterolemia and whether these changes are accompanied by functional modifications. The phospholipid fatty acid contents and intracellular free calcium concentrations were determined in peripheral blood lymphocytes from 13 subjects with serum total cholesterol levels ranging from 4.6 to 8.8 mmol/l. The spontaneous basal rate of thymidine incorporation in lymphocyte of hypercholesterolemic individuals increased, while its relative stimulation by ConA was less effective. Important changes in membrane lipid composition, consisting mainly of decrease of the mass of phospholipids, and of associated polyunsaturated fatty acids were observed in hypercholesterolemia. In contrast, the cell cholesterol content was significantly increased. The intracellular free calcium concentration was enhanced and strongly associated with circulating cholesterol levels, cell cholesterol content and phospholipid fatty acids. These results indicate that hypercholesterolemia is accompanied by profound changes in lymphocyte membrane lipid composition and Ca(2+) handling.

Age-dependent changes in transmembrane signalling: identification of G proteins in human lymphocytes and polymorphonuclear leukocytes

In human neutrophils (PMNLs) we found that in the elderly IP3 formation was significantly decreased compared to that of young subjects. For FMLP receptor binding affinity and number no measurable differences occurred upon ageing, studying both the low or the high affinity receptors. The amount of ADP-ribosylated G proteins, catalysed by pertussis toxin (PT) or cholera toxin (CT), was significantly increased in PMNLs of the elderly. In lymphocytes, the PT-catalysed ADP ribosylation of G proteins was also increased with ageing, while the CT-catalysed ribosylation was decreased. The autoradiogram of [32P]ADP-ribosylated proteins by CT in lymphocytes of young individuals showed a major polypeptide of 40,000 M(r). In contrast, in lymphocytes of the elderly, the major polypeptide was 45,000 M(r). In PMNLs, CT labelled quite strongly the 45,000 M(r) band, mainly in the elderly. When PT was used, no age-related pattern changes could be demonstrated, while differences could be observed between the two types of cells. The use of antiserum P680 (G alpha common) showed no age-related pattern changes, while the intensity of the labelled proteins varies with age and cell type. The antiserum U46 (Go alpha) could identify in lymphocytes of young subjects two polypeptides 68,000 and 41,000 M(r). The prominent polypeptide in lymphocytes of the elderly was the 70,000 M(r) and no other polypeptides could be recognized. In PMNLs of young subjects the U46 and serum identified a range of species. In PMNLs of the elderly all these bands were weakly labelled. The present data indicate changes in the pattern and the quantity of G proteins in lymphocytes and PMNLs of elderly subjects.