Is a Combination of Melatonin and Amino Acids Useful to Sarcopenic Elderly Patients? A Randomized Trial

This study evaluated the effectiveness of a 4-week intervention of melatonin and essential aminoacid supplementation on body composition, protein metabolism, strength and inflammation in 159 elderly sarcopenic patients (42/117, men/women), assigned to four groups: isocaloric placebo (P, n = 44), melatonin (M, 1 mg/daily, n = 42), essential amino acids (eAA 4 g/daily, n = 40) or eAA plus melatonin (eAAM, 4 g eAA and 1 mg melatonin/daily, n = 30). Data from body composition (dual X-ray absortiometry (DXA)), strength (handgrip test) and biochemical parameters for the assessment of protein metabolism (albumin) and inflammation (CRP) were collected at baseline and after the 4-week intervention. Compared with P and M, supplementation with eAA plus M increased total fat-free mass (vs. P: +2190 g; p < 0.01; vs. M: +2107 g; p < 0.05). M alone lowered albumin levels (vs. P: −0.39 g; p < 0.01; vs. eAA: −0.47 g; p < 0.01). This data on albumin was confirmed by within-group analysis (M −0.44g; p < 0.001; eAAM: −0.34 p < 0.05). M and eAA seemed to lower the percentage of gynoid fat (p < 0.05) and android fat (p < 0.01). No significant changes in inflammation or strength were reported. A 4-week intervention with eAA plus M together may be effective in enhancing fat-free-mass compared to M and P but not versus eAA. M alone demonstrates a negative effect on albumin level.

Influence of COMT Val158Met polymorphism on Alzheimer's disease and mild cognitive impairment in Italian patients

COMT (Catechol-O methyltransferase) gene is one of the key players in synaptic plasticity and in learning and memory mechanisms. A single nucleotide polymorphism (rs4680; G to A) in the COMT coding region causes Val158Met aminoacid substitution in the corresponding protein, with Val allele exhibiting a 3- to 4-fold increase in enzyme activity compared to Met. With the purpose of examining the influence of COMT as a genetic risk factor for cognitive impairment, we analyzed a sample of 248 healthy subjects, 276 patients affected by Alzheimer's disease (AD), and 70 subjects with mild cognitive impairment (MCI), the latter condition possibly representing a prodrome for dementia. All subjects were analyzed for COMT rs4680 polymorphism and APOE genotype. Our study strengthens data showing that APOE ε4 allele is an independent risk factor for AD and also a risk factor for MCI. Neither COMT alleles nor genotypes proved to be independently associated with the risk of AD or MCI in our sample. However, we found an association between COMT GG genotype (Val/Val) and APOE ε4 carrier status and the risk of AD and MCI. In particular, when GG genotype is included into the multinomial analysis, the risk of AD and MCI due to APOE ε4 allele is increased of about 2-3 fold; moreover, the risk conferred by the combination of G and ε4 alleles is more pronounced in male patients. To our knowledge, this synergistic effect is here shown for the first time on a population sample representative of Caucasian patients.

Nutritional assessment of demented patients: a descriptive study

BACKGROUND AND AIMS

It is well-known that subclinical and overt malnutrition are strong predictive indices of morbidity and mortality in old subjects, particularly in demented ones, and may deeply affect the quality of life. The aim of this study was evaluation of nutritional status in demented patients, as a whole and according to type of dementia, at the moment of hospital admission and before discharge.

METHODS

The study concerns 174 old demented patients, aged 80.2 +/- 8 SD, diagnosed as having Alzheimer's disease, vascular dementia, degenerative and vascular dementia, reversible dementia, and other types of dementia. In each subject, anthropometric measures, body composition analysis by the bioelectric impedance technique, Mini Nutritional Assessment (MNA) and cognitive, functional and affective assessment by conventional geriatric instruments were performed. A blood sample allowed assay of the main biochemical nutritional markers. At the end of the hospitalization period, the same cognitive, functional and nutritional assessment was repeated, in order to evaluate the effects of vitamin and protein supplements and of care during meals.

RESULTS

In all subgroups of demented patients, obtained according to type of dementia, the mean MNA score was indicative of risk for malnutrition. Furthermore, the MNA score was significantly related to severe cognitive impairment, functional status, comorbidity, BMI values, and transferrin and total protein serum levels. Malnourished patients and demented elderly at risk for malnutrition (according to the MNA score) were given oral nutritional supplements during hospitalization, lasting a mean of 45 days. Before discharge, these two subtypes of demented patients showed substantial maintenance of their cognitive, functional and nutritional status, whereas the subgroup of well-nourished demented patients exhibited significant worsening of the nutritional pattern.

CONCLUSIONS

Demented patients show a high percentage of malnutrition, particularly evident in subjects with deeper cognitive impairment. Nutritional status seems to be linked more to functional abilities than to duration of disease. However, nutritional intervention or special care during meals may act in synergy with specific pharmacologic therapy of dementia.

Circadian organization of serum electrolytes in physiological aging

Age-related structural and neurochemical changes occurring in the central nervous system have been related to changes in some rhythmometric parameters. In spite of their clinical importance, only a few studies have investigated the modifications over time of serum electrolytes in senescence. The aim of our study was to evaluate the circadian pattern of serum potassium, chloride, sodium, calcium and phosphorus in 30 clinically healthy elderly subjects, with no cognitive impairment, and to compare the findings with those given by 24 healthy young controls. The subjects were synchronized as regards their daily activities, sleeping/waking habits, time/quality of meals and dietary electrolyte intake. After an overnight fast, samples were taken beginning at 08.00 and every 4 h thereafter until 20.00, and every 2 h from 20.00 to 04.00. Both the young and the elderly subjects exhibited statistically significant circadian rhythms for all serum electrolytes considered. Our findings suggest that circadian organization of serum electrolytes is maintained in physiological aging, even though it should be noted that sodium and phosphorus acrophases differed significantly in the two experimental groups.

Circadian temporal organization of lipidic fractions in elderly people. Entrainment to the dietary schedule

BACKGROUND AND AIMS

Changes in some rhythmometric parameters have been reported in the elderly as a consequence of both structural and neurochemical changes occurring in the central nervous system. Since alterations of lipid and lipoprotein metabolism are directly involved in several age-related disorders, the aim of this study was to investigate the circadian temporal organization of some important lipidic fractions (total cholesterol, triacylglycerol, apolipoprotein A1 and B) in physiological aging.

METHODS

Thirty old hospitalized subjects were synchronized for daily activities, sleeping/waking habits, and time/quality of meals. Twenty-four healthy young individuals served as controls. After an overnight fast, samples were taken beginning at 08:00 every 4 hours until 20:00, and every 2 hours from 20:00 to 04:00. Rhythmometric data were analyzed by single and population mean Cosinor analysis, and by ANOVA; the comparison of the rhythm's parameters between elderly and young subjects was carried out by the Mesor test and the amplitude-acrophase using Hotelling's test.

RESULTS

Elderly subjects exhibited statistically significant circadian rhythms for total cholesterol (p<0.00002), triacylglycerol (p<0.000001), apo A-1 (p<0.0013), and apo B (p<O.0104). Young subjects also exhibited statistically significant daily fluctuations for total cholesterol (p<0. 0003), triacylglycerol (p<0. 03), apo A-1 (p<0.002) and apo B (p<0.003). The mean level of apo B rhythm was higher in old subjects than in controls.

CONCLUSIONS

These data suggest that the circadian temporal organization of lipidic fractions is maintained in physiological aging and underline the importance of the feeding schedule as a powerful synchronizer of the daily lipidic profile.

Age-related changes of the hypothalamic-pituitary-adrenal axis: pathophysiological correlates

The aim of this review was to examine the evidence for age-related changes of the hypothalamic-pituitary-adrenal (HPA) axis in both physiological and pathological aging, on the basis of the many data in the literature, as well as of our personal findings. A statistically significant circadian rhythmicity of serum cortisol was maintained in elderly subjects, even if with a reduced amplitude of the 24 h fluctuations and a trend to an increase of the serum levels in the evening and at night-time, in comparison with young controls. Furthermore, an age-related impairment of HPA sensitivity to steroid feedback was present in elderly people. The occurrence of senile dementia amplified the changes already present in physiological aging. While the cortisol secretion was generally well maintained in aging, the adrenal production of dehydroepiandrosterone and of its sulfate (DHEAS) exhibited an age-related decline. Therefore, the cortisol/DHEAS molar ratio was significantly higher in elderly subjects and even more in demented ones, than in young controls. Due to the opposite effects of cortisol and DHEAS on the brain and particularly on the hippocampal region, the imbalance between glucocorticoids and androgens occurring in physiological and even more in pathological aging, may have adverse effects on the function of this region, whose key role in learning and memory is well known.

Dehydroepiandrosterone sulfate decreases the interleukin-2-mediated overactivity of the natural killer cell compartment in senile dementia of the Alzheimer type

Since dehydroepiandrosterone sulfate (DHEAS) has been involved in the regulation of cellular immunity, the aim of the presence study was to evaluate whether the age-dependent reduction of DHEAS was associated with changes of natural killer (NK) immune function in healthy elderly subjects and in patients with senile dementia of the Alzheimer type (SDAT). Circulating DHEAS was determined throughout 24 h (circadian profile). NK cytotoxic activity was measured as spontaneous and induced cytotoxicity during exposure with DHEAS (10(-7) M), interleukin-2 (IL-2; 100 IU) and IL-2 (100 IU) coincubated with DHEAS (10(-7) M). DHEAS was significantly reduced in healthy elderly subjects (mesor M +/- SD = 2.3 +/- 0.5 micromol/l) and SDAT (1.6 +/- 0.4 micromol/l) patients compared to healthy young subjects (6.7 +/- 0.9 micromol/l; p < 0.001); significant differences were also found when healthy elderly subjects and SDAT patients were compared (p < 0.01). A significant inverse correlation between age and DHEAS levels was demonstrated in SDAT and healthy elderly subjects (p < 0.05). The decrease in 24-hour DHEAS secretion was associated with a higher NK cytotoxic response to DHEAS in the healthy elderly subject group than in healthy subjects of young age (p < 0.01). Increased NK cell activity during IL-2 incubation was found in patients with SDAT in comparison with the healthy elderly subject (p < 0.001). On the contrary, NK cell cytotoxic response of SDAT patients was less pronounced during DHEAS exposure and when DHEAS was coincubated with IL-2 (p < 0.001). These data suggest an immunomodulatory role of DHEAS on NK functional activity in physiological aging and SDAT. The antagonizing effect of DHEAS on NK overactivity during exposure with cytokines might counteract some neuroimmune components related to the pathogenesis and progression of the disease.

Changes in endocrine circadian rhythms as markers of physiological and pathological brain aging

We studied the circadian rhythm of plasma melatonin, growth hormone (GH), prolactin (PRL), adrenocorticotropic hormone (ACTH), and cortisol in 52 mentally healthy old subjects, 35 old demented patients, and 22 clinically healthy young controls. When compared to young controls, the circadian profile of plasma melatonin of old subjects, both demented or not, was clearly flattened, particularly during the night. The selective impairment of nocturnal melatonin secretion was significantly related to both the age and the severity of mental impairment (Mini Mental State Examination [MMSE] score). The PRL and GH circadian profiles were similar in the three groups during the day, but a significant lowering of the values recorded during the night occurred with aging. The impairment of the nocturnal secretion was related to the subjects' age and, for the GH secretory pattern only, also to the MMSE score. The ACTH circadian profile was similar in the three groups studied, even when old subjects exhibited higher ACTH levels throughout the 24 h cycle, compared to young controls. Significantly higher cortisol values at evening- and nighttime occurred in elderly subjects and particularly in the demented group. Both the mean levels and the nadir values of plasma cortisol were positively related to age and negatively to MMSE score. In order to verify the sensitivity of the hypothalamo-pituitary-adrenal (HPA) axis to the steroid feedback, the circadian profile of plasma cortisol was evaluated also after dexamethasone (DXM) administration (1 mg at 23:00 h); the sensitivity of the HPA axis was significantly impaired in old subjects and particularly in the demented ones. These findings suggest that the neuroendocrine alterations already present in physiological aging, due to both anatomical damages and unbalanced central neurotransmitters, are enhanced in senile dementia.

Chrono-neuroendocrine markers of the aging brain

The study of the neuroendocrine changes occurring in aging may give information about the CNS functions, and also explain the impaired plasticity of the aged organism. In 16 elderly women and in 14 young controls, the circadian rhythms of plasma melatonin, GH, PRL, ACTH and cortisol, and of oral temperature were simultaneously studied. The plasma cortisol circadian rhythm was also evaluated after DXM administration (1 mg orally at 23:00). The circadian profile of all the bioperiodic functions evaluated was clearly flattened in elderly subjects, and an impairment of the hormonal nocturnal secretion of GH, PRL and melatonin was apparent in elderly subjects when compared to young controls. The plasma ACTH levels throughout the 24-hour cycle were significantly higher in elderly than in young subjects. The cortisol circadian profile exhibited significantly higher values in the evening- and night-time in elderly subjects, compared to young controls; the cortisol nadir values were significantly age-related. A reduction of the sensitivity to DXM inhibition occurred in the elderly group. Both the selective impairment of nocturnal melatonin secretion, and the reduction of hypothalamo-pituitary-adrenal (HPA) sensitivity to steroid feed-back might be considered as markers of aging brain. The neuroendocrine alterations of physiological aging may be ascribable to both the structural and neurochemical changes occurring in the CNS.

Chrono-neuroendocrinological aspects of physiological aging and senile dementia

The circadian pattern of melatonin and cortisol secretion was evaluated in two groups of elderly subjects (aged 66-90 years), one with Alzheimer's type of multiinfarct dementia (n = 27) and the other without cognitive impairment (n = 16); 13 clinically healthy women aged 20 to 30 years were chosen as controls. All demented patients had severe mental impairment, corresponding to stage 6 of the Global Deterioration Scale. All subjects, either young or aged, were studied as in-patients and were well synchronized with respect to meal timing, diurnal activity and nocturnal rest. At the population mean cosinor analysis (Halberg, 1969) both melatonin and cortisol circadian rhythms reached statistical significance in the three groups of subjects. However, the melatonin circadian profile was clearly flattened in the two groups of elderly subjects by comparison with young controls, due to the selective impairment of melatonin nocturnal secretion. In both elderly groups, but particularly in demented patients, plasma cortisol levels were significantly higher by comparison to young controls, particularly at evening and night time. A significant direct relationship linked the subjects' age and the nadir values of plasma cortisol. Furthermore, the sensitivity of the hypothalamo-pituitary-adrenal axis to dexamethasone (DXM) suppression test (1 mg orally at 2300) was significantly reduced in both elderly groups, and especially in old demented patients, by comparison with young controls. Finally, plasma cortisol response to pulse i.v. injection of a small dose of synthetic corticotropin (Synacthen 2,500 ng) was significantly higher and more prolonged in old demented patients than in mentally healthy old subjects and in young controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Beta-endorphin and cold pressor test in the aged

In 8 young and 8 elderly subjects mean values of plasma beta-endorphin were nearly equal under basal conditions. In all subjects the cold pressor test provoked a marked increase of beta-endorphin, which was more evident in young subjects. Mean values of the areas of endorphin modifications were the same in both young and elderly subjects. These results may suggest that after a short-term stimulus, such as the cold pressor test, no marked differences in pituitary secretion between young and elderly subjects may be evidenced.