scholarly journals Arginine behaviour after arginine or citrulline administration in older subjects

2015 ◽  
Vol 115 (3) ◽  
pp. 399-404 ◽  
Author(s):  
C. Moinard ◽  
J. Maccario ◽  
S. Walrand ◽  
V. Lasserre ◽  
J. Marc ◽  
...  
Keyword(s):  
Plasma Concentrations ◽  
The Elderly ◽  
Volume Of Distribution ◽  
Elderly Subjects ◽  
Healthy Elderly ◽  
Age Related ◽  
Loading Tests ◽  
Kinetics Of ◽  
Healthy Elderly Subjects

AbstractArginine (ARG) and its precursor citrulline (CIT) are popular dietary supplements, especially for the elderly. However, age-related reductions in lean body mass and alterations in organ functions could change their bioavailability. Pharmacokinetics and tolerance to amino acid (AA) loads are poorly documented in elderly subjects. The objective here was to characterise the plasma kinetics of CIT and ARG in a single-dosing study design. Eight fasting elderly men underwent two separate isomolar oral loading tests (10 g of CIT or 9·94 g of ARG). Blood was withdrawn over an 8-h period to measure plasma AA concentrations. Only CIT, ornithine and ARG plasma concentrations were changed. Volume of distribution was not dependent on AA administered. Conversely, parameters related to ARG kinetics were strongly dependent on AA administered: after ARG load, elimination was higher (ARG>CIT; P=0·041) and admission period+time at peak concentration was lower (ARG<CIT; P=0·033), and the combination of both phenomena results in a marked increase in ARG availability when CIT was administered (ARG<CIT; P=0·033) compared with ARG administration itself. In conclusion, a single CIT administration in the elderly is safe and well tolerated, and CIT proves to be a better in vivo ARG precursor than ARG itself in healthy elderly subjects.

Effect of aging on susceptibility of low-density lipoproteins to oxidation

1995 ◽  
Vol 41 (11) ◽  
pp. 1628-1632 ◽  
Author(s):  
A Schmuck ◽  
C J Fuller ◽  
S Devaraj ◽  
I Jialal
Keyword(s):  
Time Course ◽  
Lipid Peroxides ◽  
Beta Carotene ◽  
The Elderly ◽  
Alpha Tocopherol ◽  
Ldl Oxidation ◽  
Elderly Subjects ◽  
Healthy Elderly ◽  
Kinetics Of ◽  
Healthy Elderly Subjects

Abstract According to the Adult Treatment Panel of the National Cholesterol Education Program, age is a major risk factor for heart disease. To assess the relation between age and LDL oxidizability, we studied copper-mediated LDL oxidation in 13 healthy elderly subjects (&gt; 59 years) and 13 sex-matched healthy young controls (&lt; 30 years). Total and LDL-cholesterol concentrations were increased in elderly subjects. The time course of copper-mediated LDL oxidation showed no significant differences between the two groups as assessed by formation of conjugated dienes, lipid peroxides, and apolipoprotein B fluorescence. Kinetics of LDL oxidation as quantified by lag time, oxidation rate, and maximal oxidation were not significantly different between the elderly and young groups. Although the concentrations of 16:0, 18:0, 18:1, 18:3, and 20:4 and total polyunsaturated fatty acids were significantly higher in the elderly group, LDL fatty acid concentrations were similar in both groups. Lipid-standardized alpha-tocopherol, beta-carotene, and ascorbate concentrations were not significantly different between the two groups. The findings of the present study suggest that in the healthy elderly, LDL oxidation may not be a crucial mediator for atherogenesis.

Effect of ‘Autonomic Blockade’ on Cardiac β-Adrenergic Chronotropic Responsiveness in Healthy Young, Healthy Elderly and Endurance-Trained Elderly Subjects

1994 ◽  
Vol 87 (3) ◽  
pp. 297-302 ◽  
Author(s):  
G. A. Ford ◽  
O. F. W. James
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Geometric Mean ◽  
Cardiovascular Responses ◽  
The Elderly ◽  
Elderly Subjects ◽  
Healthy Elderly ◽  
Age Related ◽  
Autonomic Blockade ◽  
Young Subjects

1. Cardiac chronotropic responses to isoprenaline are reduced with ageing in man. It is unclear whether this is due to reduced cardiac β-adrenergic sensitivity or to age-associated differences in reflex cardiovascular responses to the vasodilatory effects of isoprenaline. Age-associated changes in physical activity are also reported to influence β-adrenergic sensitivity. 2. The aim of the present study was to determine the contribution of alterations in reflex changes in parasympathetic and sympathetic influences and physical fitness to the age-associated reduction in cardiac chronotropic responses to β-adrenergic agonists. 3. The effect of ‘autonomic blockade’ with atropine (40 μg/kg intravenously) and clonidine (4 μg/kg intravenously) on blood pressure, heart rate and chronotropic responses to intravenous bolus isoprenaline doses was determined in eight healthy young (mean age 21 years), nine healthy elderly (72 years) and 10 endurance-trained elderly (69 years) subjects. 4. Elderly subjects had a reduced increase in heart rate after atropine (young, 49 ± 9 beats/min; elderly, 36 ± 5 beats/min; endurance-trained elderly, 34 ± 12 beats/min; P < 0.01) and did not demonstrate the transient increase in systolic blood pressure after clonidine observed in young subjects (young, 11 ± 10 mmHg; elderly, −12 ± 16 mmHg; endurance-trained elderly, −18 ± 11 mmHg; P < 0.01). 5. Cardiac chronotropic sensitivity to isoprenaline after ‘autonomic blockade’ increased in the young but decreased in the elderly subjects. The isoprenaline dose that increased heart rate by 25 beats/min before and after autonomic blockade' was: young, before 1.6 μg, after 2.8 μg, P < 0.01 (geometric mean, paired test); elderly, before 6.9 μg, after 3.6 μg, P < 0.05; endurance-trained elderly, before 5.9 μg, after 4.0 μg, P < 0.05. Cardiac chronotropic sensitivity to isoprenaline was significantly reduced in elderly compared with young subjects before (P < 0.01) but was similar after (P = 0.09) ‘autonomic blockade’. Chronotropic sensitivity did not differ between healthy and endurance-trained elderly subjects before or after ‘autonomic blockade’. 6. The age-associated reduction in cardiac chronotropic responses to bolus isoprenaline is primarily due to an age-related reduction in the influence of reflex cardiovascular responses on heart rate and not to an age-related reduction in cardiac β-adrenergic sensitivity. Endurance training is not associated with altered β-adrenergic chronotropic sensitivity in the elderly. The transient pressor response to intravenously administered clonidine may be lost in ageing man.

scholarly journals Mitochondrial Adaptations in Aged Skeletal Muscle: Effect of Exercise Training

2017 ◽  
pp. 1-14 ◽  
Author(s):  
M. M. ZIAALDINI ◽  
S. R. A. HOSSEINI ◽  
M. FATHI
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Mitochondrial Function ◽  
The Elderly ◽  
Elderly Subjects ◽  
Cellular Mechanisms ◽  
Healthy Elderly ◽  
Mitochondrial Functions ◽  
Healthy Elderly Subjects ◽  
Mitochondrial Adaptations

The aging process is associated with a decline in mitochondrial functions. Mitochondria dysfunction is involved in initiation and progression of many health problems including neuromuscular, metabolic and cardiovascular diseases. It is well known that endurance exercise improves mitochondrial function, especially in the elderly. However, recent studies have demonstrated that resistance training lead also to substantial increases in mitochondrial function in skeletal muscle. A comprehensive understanding of the cellular mechanisms involved in the skeletal muscle mitochondrial adaptations to exercise training in healthy elderly subjects, can help practitioners to design and prescribe more effective exercise trainings.

An Overview of Fluoxetine in Geriatric Depression

1988 ◽  
Vol 153 (S3) ◽  
pp. 105-108 ◽  
Author(s):  
John P. Feighner ◽  
William F. Boyer ◽  
Charles H. Meredith ◽  
Gordon Hendrickson
Keyword(s):  
General Population ◽  
Plasma Concentrations ◽  
The Elderly ◽  
The Body ◽  
Elderly Subjects ◽  
Aging Brain ◽  
Efficacy And Safety ◽  
Geriatric Depression ◽  
Double Blind ◽  
Age Related

During the past 75 years, the proportion of elderly individuals in the USA has grown twice as fast as the general population. Depression in this age-group occurs four times more frequently than in the general population (Butler, 1975), and the suicide rate for people over 65 years of age is 15 times greater than that of the general population (Lehman, 1980).The elderly may be more susceptible to depression due to biological and/or psychosocial variables. Elderly people experience significant losses associated with increasing age, including death of spouse and friends, loss of work, social status, and physical and mental abilities (Lehman, 1980). The biogenic amine hypothesis suggests that the aging brain may experience a decrease in the functional availability of neurotransmitters (Lehman, 1980); this decrease may also play a role in the aetiology of depression.Due to age-related changes in the body, the elderly can be more sensitive to drug therapy. Older patients may require careful dosage adjustments and may also be more prone to experiencing drug-related adverse events. The elderly often receive medication for various indications, and drug interactions are a concern (Thompson et al, 1983). Therefore, efficacy and safety studies of new antidepressants in elderly patients are particularly important. We pooled data from both double-blind and open-label studies to evaluate the efficacy and safety of fluoxetine in geriatric outpatients with DSM-III major depression. Positive results of fluoxetine in the treatment of geriatric depression were reported in one of these studies (Feighner & Cohn, 1985). The favourable safety and side-effect profile of fluoxetine in the general population has been discussed elsewhere (Wernicke, 1985). Plasma concentrations of fluoxetine in elderly subjects are similar to those in younger individuals (I.emberger et al, 1985). These findings, combined with a lack of cardiovascular effects (Fisch, 1985), and low lethality with overdose, indicated promise for fluoxetine as a geriatric antidepressant.

scholarly journals Influence of a combination ofLactobacillus acidophilusNCFM and lactitol on healthy elderly: intestinal and immune parameters

2008 ◽  
Vol 101 (3) ◽  
pp. 367-375 ◽  
Author(s):  
Arthur C. Ouwehand ◽  
Kirsti Tiihonen ◽  
Markku Saarinen ◽  
Heli Putaala ◽  
Nina Rautonen
Keyword(s):  
Intestinal Microbiota ◽  
Bowel Function ◽  
Elderly Subjects ◽  
Immune Markers ◽  
Double Blind ◽  
Healthy Elderly ◽  
Immune Parameters ◽  
Age Related ◽  
Over Time ◽  
Healthy Elderly Subjects

With increasing age, a number of physiological changes take place which are reflected in immune and bowel function. These changes may relate to the commonly assumed age-related changes in intestinal microbiota; most noticeably a reduction in bifidobacteria. The current study aimed at modifying the intestinal microbiota with a potential synbiotic on selected immune and microbiota markers. Healthy elderly subjects were randomised to consume during 2 weeks either a placebo (sucrose) or a combination of lactitol andLactobacillus acidophilusNCFM twice daily in a double-blind parallel trial. After the intervention, stool frequency was higher in the synbiotic group than in the placebo group and a significant increase in faecalL. acidophilusNCFM levels was observed in the synbiotic group, after baseline correction. In contrast to the generally held opinion, the study subjects had faecalBifidobacteriumlevels that were similar to those reported in healthy young adults. These levels were, nevertheless, significantly increased by the intervention. Levels of SCFA were not changed significantly. Of the measured immune markers, PGE2levels were different between treatments and IgA levels changed over time. These changes were modest which may relate to the fact that the volunteers were healthy. Spermidine levels changed over time which may suggest an improved mucosal integrity and intestinal motility. The results suggest that consumption of lactitol combined withL. acidophilusNCFM twice daily may improve some markers of the intestinal microbiota composition and mucosal functions.

scholarly journals Plasma lutein and zeaxanthin and the risk of age-related nuclear cataract among the elderly Finnish population

2011 ◽  
Vol 108 (1) ◽  
pp. 148-154 ◽  
Author(s):  
Jouni Karppi ◽  
Jari A. Laukkanen ◽  
Sudhir Kurl
Keyword(s):  
Elderly Population ◽  
Proportional Hazards Model ◽  
Disease Risk ◽  
Plasma Concentrations ◽  
The Elderly ◽  
Cox Proportional Hazards Model ◽  
Elderly Subjects ◽  
Nuclear Cataract ◽  
Age Related ◽  
History Of

Oxidative stress plays an important role in cataractogenesis. Previous studies have shown that long-term dietary intake of antioxidants (lutein and zeaxanthin) may decrease the risk of age-related cataracts. The aim of the present study was to examine whether plasma concentrations of lutein and zeaxanthin are related to age-related nuclear cataract in the elderly population. Subjects were participants in the Kuopio Ischaemic Heart Disease Risk Factor Study and they were classified into tertiles according to plasma concentrations of lutein and zeaxanthin. The association of plasma lutein and zeaxanthin concentrations with age-related nuclear cataract in 1689 elderly subjects (aged 61–80 years) was investigated in the present cross-sectional study by using the Cox proportional hazards model. A total of 113 cases of incident age-related cataracts were confirmed, of which 108 cases were nuclear cataracts. After adjustment for age, examination year, sex, BMI, smoking, alcohol consumption, serum LDL-cholesterol, serum HDL-cholesterol, years of education, use of oral corticosteroids, history of diabetes and history of hypertension with current use of antihypertensive medication, subjects in the highest tertiles of plasma concentrations of lutein and zeaxanthin had 42 and 41 % lower risks of nuclear cataract, respectively, compared with those in the lowest tertiles (relative risk (RR) = 0·58, 95 % CI 0·35, 0·98; P = 0·041 for lutein and RR = 0·59, 95 % CI 0·35, 0·99; P = 0·046 for zeaxanthin). In conclusion, we suggest that high plasma concentrations of lutein and zeaxanthin were associated with a decreased risk of age-related nuclear cataract in the elderly population.

scholarly journals Impact of Aging on Urinary Excretion of Iron and Zinc

2014 ◽  
Vol 7 ◽  
pp. NMI.S12977 ◽  
Author(s):  
Karina Pfrimer ◽  
Rutinéia Fátima Micheletto ◽  
Julio Sergio Marchini ◽  
Gilberto João Padovan ◽  
Julio cesar Moriguti ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
Graphite Furnace ◽  
The Elderly ◽  
Atomic Absorption Spectrophotometry ◽  
Elderly Subjects ◽  
Fasting Period ◽  
Younger Adults ◽  
Healthy Elderly ◽  
Iron And Zinc ◽  
Healthy Elderly Subjects

Project Data about the influence of aging on urinary excretion of iron and zinc are scarce. The objective of the present study was to compare the concentration of zinc and iron in the urine of healthy elderly subjects and younger adults. Procedure Seven healthy elderly subjects and seven younger adults were selected and submitted to biochemical, clinical, and nutritional tests. After a fasting period, 12-hour urine was collected for the determination of iron and zinc concentrations by graphite furnace atomic absorption spectrophotometry. Results Urinary zinc and iron concentrations of the elderly subjects were not significantly different from that of younger adults. However, the total zinc and iron urinary clearance in 24 hours for the elderly was significantly higher compared with that of younger adults. Conclusion There is an increase in urinary iron and zinc clearance with aging. The values reported in this manuscript may be used as references in future studies.

Effect of Age on Vascular α-Adrenoceptor Responsiveness in Man

1982 ◽  
Vol 63 (s8) ◽  
pp. 305s-308s ◽  
Author(s):  
Henry L. Elliott ◽  
David J. Sumner ◽  
Kathleen McLean ◽  
Peter C. Rubin ◽  
John L. Reid
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Systolic Pressure ◽  
The Elderly ◽  
Elderly Subjects ◽  
Comparable Amount ◽  
Healthy Elderly ◽  
Age Related ◽  
Significant Difference ◽  
Mean Heart Rate

1. The responsiveness of α-receptors was compared in six young and six healthy elderly subjects by evaluating the haemodynamic effects of the a, antagonist prazosin and the pressor responses to the a, agonist phenylephrine. 2. Oral prazosin (1 mg) lowered erect (but not supine) blood pressure in both groups by a comparable amount: in young and old groups the respective maximal falls in systolic pressure were 19.5 ± 15.7 and 29.3 ± 11.4 mmHg (mean ± sd) and for diastolic pressure the maximal falls were 13 ± 13.3 and 18 ± 11.1 mmHg. 3. This similar fall in blood pressure occurred in association with a significantly different heart rate response: in the young group mean heart rate increased to 103 beats/min but there was no corresponding increase in the elderly group, which had a mean heart rate of 80 beats/min. 4. Log dose-response curves were derived from incremental intravenous infusions of phenylephrine, and the doses required to raise mean arterial pressure by 20 mmHg (PD20) were compared: the mean PD20 was significantly different in the two groups: 2.5 ± 1.6 in the young compared with 4.6 ± 2.3 μg min−1 kg−1 in the elderly, consistent with reduced pressor responsiveness in the elderly. 5. No significant difference in PD20 was apparent when pressor responsiveness was determined after prazosin, but the elderly required a significantly smaller increase in phenylephrine dosage to overcome prazosin's α-receptor-blocking effects. 6. Although there is no evidence of an age-related increase in the sensitivity of α-adrenoceptor-mediated vasoconstriction, the results are not inconsistent with an age-related reduction in α-adrenoceptor responsiveness.

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