scholarly journals Calcium excretion, apparent calcium absorption and calcium balance in young and elderly subjects: influence of protein intake

1997 ◽  
Vol 77 (5) ◽  
pp. 721-729 ◽  
Author(s):  
Daphne L. E. Pannemans ◽  
Gertjan Schaafsma ◽  
Klaas R. Westerterp
Keyword(s):  
Young Adults ◽  
Total Energy ◽  
Protein Intake ◽  
Age Groups ◽  
The Elderly ◽  
Elderly Subjects ◽  
Calcium Excretion ◽  
Calcium Balance ◽  
Elderly Persons ◽  
Young And Elderly Subjects

The present study was conducted to investigate the effect of dietary protein on urinary Ca excretion, apparent Ca absorption and Ca balance in young and elderly subjects. Young adults (n 29) and elderly persons (n 26) consumed diets containing 12% (diet A) and 21% (diet B) of total energy as protein for 3 weeks according to a randomized crossover design. Results showed no differences between the two age groups with respect to the interaction between protein intake and Ca excretion (both in urine and in faeces), apparent Ca absorption and Ca balance. Therefore analyses were done for both age groups separately and also for the whole group. In elderly persons and in the whole group the Ca excretion in faeces (as a percentage of Ca intake) was lower during the higher protein intake (elderly: diet A, 106 (SEM 7)% diet B, 86 (SEM 7) % P = 0·018; whole group: diet A, 99 (SEM 4) % diet B, 84 (SEM 4) % P = 0·003). In young adults faecal Ca excretion tended to be lower when they consumed diet B (diet A: 94 (SEM 5)% diet B: 83 (SEM 6)% P = 0·093). Relative urinary Ca excretion was greater during the higher protein intake in young adults and in the whole group while relative urinary Ca excretion was not different in the elderly (diet A: 15 (SEM 1) %, 14 (SEM 1) %, 15 (SEM 1) % diet B: 16 (SEM 1) %, 16 (SEM 1) % 17 (SEM 2) % for the whole group, the young and elderly subjects respectively, P = 0·019; P = 0·016; P = 0·243).The resulting Ca balance was not influenced by the amount of protein in the diet in young adults. Values for the elderly and for the whole group showed that the Ca balance during diet A was significantly more negative compared with Ca balance during diet B, despite the higher urinary Ca excretion during diet B. It can be concluded that increasing the protein intake from 12 to 21% of total energy ntake had no negative effect on Ca balance.

Release from Multiple Maskers in Elderly Persons

1973 ◽  
Vol 16 (1) ◽  
pp. 152-160 ◽  
Author(s):  
Tom W. Tillman ◽  
Raymond Carhart ◽  
Sheina Nicholls
Keyword(s):  
Young Adults ◽  
Time Delay ◽  
White Noise ◽  
Duty Cycle ◽  
The Elderly ◽  
The Other ◽  
Elderly Subjects ◽  
Elderly Persons ◽  
Parallel Time ◽  
Dichotic Presentation

Masked thresholds for spondees were measured in 27 binaural conditions covering homophasic, antiphasic, parallel time-delayed, and opposed time-delayed listening in the presence of one to three competing maskers. One of the maskers was white noise modulated four times per second by 10 dB with 50% duty cycle; the other two were sentences spoken by different male talkers. These stimuli were variously combined to produce seven masker conditions. Subjects were 10 young adults, 23 women aged 70 to 85 years, and 22 men aged 63 to 88 years. Masking level differences (re homophasic performance) were observed in every instance of dichotic presentation. MLDs for the young adults were usually somewhat larger than those for the elderly subjects. Both groups showed (1) somewhat larger MLDs when the competing background included two talkers, (2) somewhat smaller MLDs during time-delay modes, and (3) smaller MLDs in opposed time-delay than in parallel time-delay. This last feature was particularly noteworthy for the elderly listeners, whose MLDs during opposed time delay averaged only 2.3 dB.

Walking with Visual Restrictions in Healthy Elderly and Young Adults

2002 ◽  
Vol 21 (2) ◽  
pp. 295-301 ◽  
Author(s):  
Sean Gallagher ◽  
Yves Lajoie ◽  
Michel Guay
Keyword(s):  
Young Adults ◽  
Visual Information ◽  
Older Persons ◽  
Visual Cues ◽  
Elderly Population ◽  
The Elderly ◽  
Elderly Subjects ◽  
Elderly Persons ◽  
Experimental Conditions ◽  
Healthy Elderly

ABSTRACTVisual requirements for a simple walking task were evaluated for young and elderly persons to determine if, with normal aging, elderly subjects require more visual information. Ten young adults and 10 elderly people were asked to complete a simple walking task within predetermined pathway boundaries under two conditions of visual restriction. In the reactive condition, subjects automatically received a 200 ms flash of visual information at the halfway point of the walkway. For the predictive condition, subjects did not receive any visual information during the walking trial, but were equipped with an emergency button that would provide 200 ms of visual information whenever they needed it. For both experimental conditions, subjects received additional flashes of visual information if they stepped out of the walkway boundaries. Results showed that older persons stepped out of bounds more often in the reactive condition and gave themselves more visual cues than the younger subjects in the predictive condition. The relative importance of vision during locomotion seems to be higher in the elderly population when compared to young adults.

Protein Requirements in the Elderly

2011 ◽  
Vol 81 (23) ◽  
pp. 109-119 ◽  
Author(s):  
Dorothee Volkert ◽  
Cornel Christian Sieber
Keyword(s):  
Body Weight ◽  
Nitrogen Balance ◽  
Protein Intake ◽  
Muscle Protein ◽  
The Elderly ◽  
Elderly Subjects ◽  
Elderly Persons ◽  
Current Recommendation ◽  
Healthy Elderly ◽  
Increased Risk

Adequate protein intake and the maintenance of nitrogen equilibrium are of particular importance in the elderly because this age group is at increased risk of illness and malnutrition. The current recommendation for protein intake of healthy elderly subjects is 0.8 g/kg body weight/day, the same as for younger adults. Nitrogen balance studies in the elderly, however, revealed conflicting results; some studies suggest that not all elderly can achieve a nitrogen balance with a protein intake of 0.8 g/kg body weight/day, particularly if energy supply is not adequate. Beyond the amount of protein needed for nitrogen balance, the optimal protein intake for preservation of lean body mass, body functions, and health is of paramount interest. At present, there is insufficient longer-term research with defined health outcomes to derive recommendations in this regard. Very little is also known about the protein needs of frail and unhealthy elderly. Until more evidence is available, it seems reasonable to ensure a protein intake of at least 0.8 g/kg body weight/day in all elderly persons, particularly in those at risk of malnutrition (e.g., frail and multimorbid elderly). In addition to ascertaining adequate protein and energy intake, physical activity should be encouraged in order to increase energy expenditure and food intake and to facilitate muscle protein anabolism.

scholarly journals Daily protein intakes and eating patterns in young and elderly French

2003 ◽  
Vol 90 (6) ◽  
pp. 1107-1115 ◽  
Author(s):  
Sylvie Rousset ◽  
Philippe Patureau Mirand ◽  
Marion Brandolini ◽  
Jean-François Martin ◽  
Yves Boirie
Keyword(s):  
Protein Intake ◽  
Meat Product ◽  
Age Groups ◽  
The Elderly ◽  
Elderly Subjects ◽  
Age Group ◽  
Food Groups ◽  
Protein Loss ◽  
Body Protein ◽  
Protein Rich

An adequate level of protein intake is required to limit the gradual body protein loss observed during ageing. Different factors (cohort age, sex, life conditions) may modify protein intake and distribution. However the precise amounts, as well as their daily distribution which affects protein utilisation and N retention, are unknown in both young and elderly individuals. The hypothesis was tested that protein intake and its distribution over daily meals could be different between the young and elderly. The consumption of six different protein-rich food groups by 292 healthy individuals aged 20–30 and 65–75 years was determined throughout each day for 1 week. The data of the total protein intake and protein intakes at each meal were analysed by ANOVA for each sex separately, using age group as the independent factor. The average protein intake of men was lower in the older age group whilst the opposite trend was seen in women. The distribution of protein intake was different between the two age groups: 56·5 % of the daily protein was eaten at lunch by the elderly but only 47 % (P<0·0001) by the younger subjects. In the elderly subjects, those eating larger amounts consumed a greater proportion of protein-rich foods at dinner than those eating small amounts (30·4 v. 26·2 %, P=0·05). A high level of protein intake was related to a higher meat-product consumption in both the elderly and young individuals. In conclusion, the pattern of protein intake differs significantly between age groups and sexes.

The influence of dynamic visual environments on postural sway in the elderly

1999 ◽  
Vol 9 (3) ◽  
pp. 197-205
Author(s):  
L.L. Borger ◽  
S.L. Whitney ◽  
M.S. Redfern ◽  
J.M. Furman
Keyword(s):  
Visual Information ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Age Groups ◽  
The Elderly ◽  
Visual Scene ◽  
Elderly Subjects ◽  
Mean Velocity ◽  
Healthy Elderly ◽  
Young Subjects

Postural sway during stance has been found to be sensitive to moving visual scenes in young adults, children, and those with vestibular disease. The effect of visual environments on balance in elderly individuals is relatively unknown. The purpose of this study was to compare postural sway responses of healthy elderly to those of young subjects when both groups were exposed to a moving visual scene. Peak to peak, root mean squared, and mean velocity of the center of pressure were analyzed under conditions combining four moving scene amplitudes ( 2 . 5 ∘ , 5 ∘ , 7 . 5 ∘ , 10 ∘ ) and two frequencies of scene movement (0.1 Hz, 0.25 Hz). Each visual condition was tested with a fixed floor and sway referenced platform. Results showed that elderly subjects swayed more than younger subjects when experiencing a moving visual scene under all conditions. The elderly were affected more than the young by sway referencing the platform. The differences between the two age groups were greater at increased amplitudes of scene movement. These results suggest that elderly are more influenced by dynamic visual information for balance than the young, particularly when cues from the ankles are altered.

Age Effects on Measures of Auditory Duration Discrimination

1994 ◽  
Vol 37 (3) ◽  
pp. 662-670 ◽  
Author(s):  
Peter J. Fitzgibbons ◽  
Sandra Gordon-Salant
Keyword(s):  
Hearing Loss ◽  
Stimulus Frequency ◽  
The Elderly ◽  
Duration Discrimination ◽  
Elderly Subjects ◽  
Hearing Sensitivity ◽  
Choice Procedure ◽  
Forced Choice Procedure ◽  
Tonal Stimuli ◽  
Young And Elderly Subjects

This study examined auditory temporal sensitivity in young adult and elderly listeners using psychophysical tasks that measured duration discrimination. Listeners in the experiments were divided into groups of young and elderly subjects with normal hearing sensitivity and with mild-to-moderate sloping sensorineural hearing loss. Temporal thresholds in all tasks were measured with an adaptive forced-choice procedure using tonal stimuli centered at 500 Hz and 4000 Hz. Difference limens for duration were measured for tone bursts (250 msec reference duration) and for silent intervals between tone bursts (250 msec and 6.4 msec reference durations). Results showed that the elderly listeners exhibited diminished duration discrimination for both tones and silent intervals when the reference duration was 250 msec. Hearing loss did not affect these results. Discrimination of the brief temporal gap (6.4 msec) was influenced by age and hearing loss, but these effects were not consistent across all listeners. Effects of stimulus frequency were not evident for most of the duration discrimination conditions.

Fat and carbohydrate metabolism during exercise in elderly and young subjects

1996 ◽  
Vol 271 (6) ◽  
pp. E983-E989 ◽  
Author(s):  
S. Sial ◽  
A. R. Coggan ◽  
R. Carroll ◽  
J. Goodwin ◽  
S. Klein
Keyword(s):  
Young Adults ◽  
Carbohydrate Metabolism ◽  
Relative Intensity ◽  
The Elderly ◽  
Absolute Intensity ◽  
Substrate Oxidation ◽  
Carbohydrate Oxidation ◽  
Moderate Intensity ◽  
Elderly Subjects ◽  
Moderate Intensity Exercise

We evaluated the effect of aging on fat and carbohydrate metabolism during moderate intensity exercise. Glycerol, free fatty acid (FFA), and glucose rate of appearance (Ra) in plasma and substrate oxidation were determined during 60 min of cycle ergometer exercise in six elderly (73 +/- 2 yr) and six young adults (26 +/- 2 yr) matched by gender and lean body mass. The elderly group was studied during exercise performed at 56 +/- 3% of maximum oxygen uptake, whereas the young adults were studied during exercise performed at the same absolute and at a similar relative intensity as the elderly subjects. Mean fat oxidation during exercise was 25-35% lower in the elderly subjects than in the young adults exercising at either the same absolute or similar relative intensities (P < 0.05). Mean carbohydrate oxidation in the elderly group was 35% higher than the young adults exercising at the same absolute intensity (P < 0.001) but 40% lower than the young adults exercising at the same relative intensity (P < 0.001). Average FFA Ra in the elderly subjects was 85% higher than in the young adults exercising at the same absolute intensity (P < 0.05) but 35% lower than the young adults exercising at a similar relative intensity (P < 0.05). We conclude that fat oxidation is decreased while carbohydrate oxidation is increased during moderate intensity exercise in elderly men and women. The shift in substrate oxidation was caused by age-related changes in skeletal muscle respiratory capacity because lipolytic rates and FFA availability were not rate limiting in the older subjects.

Atrial natriuretic peptide suppresses osmostimulated vasopressin release in young and elderly humans

1991 ◽  
Vol 261 (2) ◽  
pp. E252-E256 ◽  
Author(s):  
B. A. Clark ◽  
D. Elahi ◽  
L. Fish ◽  
M. McAloon-Dyke ◽  
K. Davis ◽  
...  
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Hypertonic Saline ◽  
Natriuretic Peptide ◽  
Serum Sodium ◽  
The Elderly ◽  
Sodium Concentration ◽  
Elderly Subjects ◽  
Vasopressin Release ◽  
Young And Elderly Subjects ◽  
Atrial Natriuretic

Atrial natriuretic peptide (ANP) may suppress vasopressin release, but the dynamics of this interaction as well as the influence of age have not been defined. We studied six or seven young (19-40 yr old) and seven elderly volunteers (65-83 yr old) under two circumstances: 1) after infusion of 5% saline (0.04 ml.kg-1.min-1) for 2 h and 2) after the same infusion given with simultaneous synthetic human ANP (0.05 micrograms.kg-1.min-1). Hypertonic saline alone produced a progressive rise in plasma vasopressin with increasing serum sodium. During hypertonic saline alone, vasopressin levels began to rise at an increment in serum sodium of 1.67 +/- 0.35 mM in the young and 1.43 +/- 0.32 mM in the elderly and rose linearly with increasing serum sodium. When ANP was infused with hypertonic saline (with peak ANP levels of approximately 1,000 pM), vasopressin levels began to rise at an increment in serum sodium of 4.43 +/- 0.67 mM in the young and 4.57 +/- 0.43 mM in the elderly (P less than 0.01 vs. saline alone). Furthermore, the vasopressin response for any given serum sodium was significantly reduced in both young and elderly subjects, resulting in a rightward displacement of the curve relating vasopressin response to sodium concentration (P less than 0.001). In conclusion, ANP not only suppresses vasopressin but raises the threshold for release of vasopressin in response to osmotic stimulation in both young and elderly individuals. High circulating ANP levels may be responsible in part for the suppression of vasopressin levels and water diuresis seen during states of volume expansion.

Training-related enhancement in the control of motor output in elderly humans

1994 ◽  
Vol 77 (6) ◽  
pp. 2648-2658 ◽  
Author(s):  
D. A. Keen ◽  
G. H. Yue ◽  
R. M. Enoka
Keyword(s):  
Training Program ◽  
Motor Unit ◽  
Maximum Voluntary Contraction ◽  
The Elderly ◽  
Voluntary Contraction ◽  
Elderly Subjects ◽  
Contraction Force ◽  
Unit Force ◽  
Young And Elderly Subjects ◽  
Elderly Humans

The increase in motor unit force that occurs with aging has been hypothesized to cause a decline in the ability to maintain a constant submaximal force. To test this hypothesis, young and elderly subjects performed a 12-wk strength-training program that was intended to increase motor unit force. The training program caused similar increases (%initial) in the training load (137.4 +/- 17.2%), twitch force (23.1 +/- 7.4%), and maximum voluntary contraction force (39.2 +/- 6.8%) of the first dorsal interosseus muscle for the young and elderly subjects. The increase in strength was associated with a modest increase in muscle volume (7% of initial value) and a nonmonotonic increase in the surface-recorded electromyogram that was significant at week 8 but not at week 12. The elderly subjects reduced the variability in force at the lower target forces (2.5, 5.0, and 20.0% maximum voluntary contraction force). This improvement, however, was unrelated to changes in the distribution of motor unit forces, which was not consistent with the hypothesis that the greater coefficient of variation for the force fluctuations is due to increased motor unit forces.

scholarly journals Characteristics of Lower Limb Muscle Activity in Elderly Persons After Ergometric Exercise

2020 ◽  
Vol 6 ◽  
pp. 233372142097980
Author(s):  
Kenichi Kaneko ◽  
Hitoshi Makabe ◽  
Kazuyuki Mito ◽  
Kazuyoshi Sakamoto ◽  
Yoshiya Kawanori ◽  
...  
Keyword(s):  
Lower Limb ◽  
Muscle Activity ◽  
The Elderly ◽  
Elderly Subjects ◽  
Elderly Persons ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Lower Limb Muscles ◽  
The Mean ◽  
Young Subjects

This study examined the characteristics of lower limb muscle activity in elderly persons after ergometric pedaling exercise for 1 month. To determine the effect of the exercise, surface electromyography (SEMG) of lower limb muscles was subjected to Daubechies-4 wavelet transformation, and mean wavelet coefficients were compared with the pre-exercise coefficients and the post-exercise coefficients in each wavelet level. The characteristics of muscle activity after pedaling exercise were also compared between the elderly subjects and young subjects. For the elderly subjects, the mean wavelet coefficients were significantly decreased in the tibialis anterior and the gastrocnemius medialis at wavelet levels of 3, 4, and 5 (125–62.5, 62.5–31.25, and 31.25–15.625 Hz, respectively), by pedaling exercise. However, the mean power of wavelet levels of 2 and 3 (250–125 and 125–62.5 Hz) within the rectus femoris and the biceps femoris were significantly increased in the young subjects. The effect of pedaling exercise is different from the effects of heavy-resistance training. It was suggested that the muscle coordination, motor unit (MU) firing frequency, and firing fiber type of lower limb muscles are changed with the different characteristics between elderly and young persons by pedaling exercise for 1 month.

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