Nicola Schifino

Nutritional Supplements with Oral Amino Acid Mixtures Increases Whole-Body Lean Mass and Insulin Sensitivity in Elderly Subjects with Sarcopenia

Decreases in whole-body lean mass can cause sarcopenia, a disease frequently found in the elderly. This condition is frequently associated with frailty and disability in aging as well as the onset and progression of several geriatric syndromes. Sarcopenia therefore must be managed with multidimensional approaches that include physical training, nutritional support, and metabolic and anabolic treatment. The purpose of our study was to assess the effect of an orally administered special mixture of amino acids (AAs) in elderly subjects with reduced lean body mass and sarcopenia. A randomized, open-label, crossover study was conducted in 41 elderly subjects (age range: 66-84 years) with sarcopenia, assigned to 2 distinct treatments (AAs and placebo). All subjects had normal body weight (body mass index within 19-23). The AA treatment consisted of 70.6 kcal/day (1 kcal = 4.2 kJ) of 8 g of essential AA snacks, given at 10:00 am and 5:00 pm. Lean mass was measured with dual-energy x-ray absorptiometry in leg, arm, and trunk tissues. Significant increases in whole-body lean mass in all areas were seen after 6 months and more consistently after 18 months of oral nutritional supplementation with AAs. Fasting blood glucose, serum insulin, and homeostatic model assessment of insulin resistance (an index of insulin resistance) significantly decreased during AA treatment. Furthermore, a significant reduction in serum tumor necrosis factor-alpha (TNF-alpha) and a significant increase in both insulin-like growth factor-1 (IGF-1) serum concentrations and in the IGF-1/TNF-alpha ratio were also found. No significant adverse effects were observed during AA treatment. These preliminary data indicate that nutritional supplements with the oral AA mixture significantly increased whole-body lean mass in elderly subjects with sarcopenia. The improvement in the amount of whole-body lean mass could be linked to increased insulin sensitivity and anabolic conditions related to IGF-1 availability.

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 µmol/l) and SDAT (1.6 ± 0.4 µmol/l) patients compared to healthy young subjects (6.7 ± 0.9 µmol/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.

Decreased Release of the Angiogenic Peptide Vascular Endothelial Growth Factor in Alzheimer’s Disease: Recovering Effect with Insulin and DHEA Sulfate

Changes of vascular endothelial growth factor (VEGF) secretion have recently been demonstrated in patients with Alzheimer’s disease (AD). Since VEGF has been involved in brain angiogenesis, neuroprotection and cerebromicrovascular exchange of substrates and nutrients, the study of VEGF could have important relapses into the pathogenesis and treatment of AD. Within this context, 35 healthy subjects (16 of young and 19 of old age), 18 patients with dementia of the vascular type (VAD) and 22 with dementia of the Alzheimer’s type (AD) were included in the study. VEGF levels were determined in the supernates of circulating natural killer (NK) immune cells isolated by immunomagnetic separation (pure CD16 + CD56 + NK cells at a final density of 7.75 × 106 cells/ml). VEGF was measured in spontaneous conditions (without modulation) and after exposure of NK cells with IL-2, lipopolysaccharide (LPS), dehydroepiandrosterone sulfate (DHEAS), LPS + insulin, amyloid-β (Aβ) fragment 1–42, the inactive sequence Aβ40–1 and Aβ1–42 + insulin. A significant decrease in VEGF released by NK cells was demonstrated in AD subjects compared to the other groups. No differences of VEGF levels were found between healthy subjects of old age and the VAD group. The incubation with LPS and DHEAS significantly increased, in a dose-dependent manner, VEGF levels in AD as well as in healthy subjects of young and old age and in VAD patients. The incubation of NK cells with Aβ1–42 completely suppressed VEGF generation in AD subjects, also reducing VEGF release in the other groups. The co-incubation of NK with LPS + insulin, at different molar concentrations, significantly restored (4- and 6-fold increase from LPS alone) VEGF in AD, also enhancing VEGF secretion in healthy subjects and the VAD group, while the co-incubation of NK with Aβ1–42 + insulin promptly abolished the negative effects of Aβ1–42 on VEGF release. These data might suggest that the decreased VEGF secretion by peripheral immune cells of AD subjects could have a negative role for brain angiogenesis, neuroprotection and for brain microvascular permeability to nutrients, increasing brain frailty towards hypoxic injuries. On the contrary, insulin and DHEAS could have beneficial effects in AD, as well as in VAD and in physiological aging, by increasing, in a dose-dependent fashion, VEGF availability by peripheral and resident immune and endothelial cells, so contributing to increase its circulating pool.

Pentoxifylline, total urinary protein excretion rate and arterial blood pressure in long-term insulin-dependent diabetic patients with overt nephropathy

SummaryA specific hemorheologic treatment might reduce urinary protein excretion and the decline in kidney function in diabetic patients with overt clinical nephropathy. Twenty-one insulin dependent (type I) diabetic patients were randomized and assigned to a treatment with conventional antihypertensive therapy (protocol I) or with pentoxifylline (Trental 400®) (protocol II). A marked improvement of blood rheology pattern, together with a reduction of urinary albumin excretion rate and total urinary protein excretion rate, was demonstrated throughout a 1-year follow-up study with pentoxifylline. Furthermore a decrease of systolic and diastolic blood pressure levels was found during the treatment. The modification of these parameters was followed by a significant increase of creatinine clearance in each of the patients studied. The results obtained during pentoxifylline therapy were comparable to those obtained in patients treated with conventional antihypertensive drugs. Pentoxifylline may therefore be used in the treatment of advanced nephropathy in diabetic patients.

Pentoxifylline, albumin excretion rate and proteinuria in type I and type II diabetic patients with microproteinuria. Results of a short-term randomized study.

SummaryAn association between renal microvascular complications and hemorheological alterations has been suggested in diabetes mellitus. Therefore, a hemorheologic approach in the treatment of diabetic microproteinuria has been proposed. Eighty-two type I and type II diabetic patients with microproteinuria were randomized and assigned to two different protocols: protocol A, patients treated with pentoxifylline (Trental 400Ŗ); protocol B, patients without hemorheologic treatment, in whom hypoglycemic therapy was just more strictly enforced. A significant improvement of the hemorheologic pattern and a significant marked reduction of albumin excretion rate and proteinuria was found in diabetic patients treated with pentoxifylline, independently of the degree of metabolic control. These results were readily achieved and were confirmed throughout the study. Moreover, these results were comparable to those obtained in diabetic patients of protocol B. Pentoxifylline might therefore be considered as the first useful therapeutic agent in the treatment of diabetic microproteinuria.

Plasma β-endorphin, free fatty acids and blood lipid changes in type 2 (non-insulin dependent) diabetic patients

A lipolytic activity for β-endorphin (βEP) has been recently suggested both in vitro and in vivo. In our study we evaluated the relationship between βEP and blood lipid pattern in Type 2 (non-insulin dependent) diabetic patients. Plasma βEP, together with plasma β-lipotropin (βLPH), ACTH, cortisol and plasma insulin (IRI), was measured by RIA after silicic acid plasma extraction and Sephedex G-75 column chromatography. Although reduced βEP (7.12 ± 3.8 fmol/ml) and increased βLPH (9.3 ± 3.7 fmol/ml) levels were found in diabetic patients, compared to controls (8.53 ± 3.3 fmol/ml, p< 0.05 and 8.34 ± 2.6 fmol/ml, p< 0.05, respectively), higher plasma βEP concentrations were demonstrated in hyperlipidemic diabetic patients (10.3 ± 3.9 fmol/ml) than in patients with normal blood lipid pattern (4.85 ± 1.45 fmol/ml, p< 0.001 ). Several positive correlations between βEP, plasma free fatty acids (r = 0.75, p< 0.001 ), triglycerides (r = 0.84, p< 0.001 ) and VLDL (r = 0.80, p< 0.001 ) were found in our patients independently of overweight, hypoglycemic treatment, plasma IRI levels and of the degree of metabolic control. A higher prevalence of micro- and macrovascular complications was demonstrated in hyperlipidemic than in normolipidemic patients. Blood lipid disorders mighttherefore be associated with increased plasma βEP levels in Type 2 diabetes.

Increased plasma apolipoprotein B levels and blood hyperviscosity in non-insulin-dependent diabetic patients: Role in the occurrence of arterial hypertension

SummaryAn association between arterial blood pressure and blood viscosity has been suggested in healthy and in diabetic subjects, and that the hemorheological pattern may be influenced by blood lipid alterations. In diabetic patients a relationship between arterial hypertension and blood lipid changes may therefore be suggested. This study concerns 19 type II diabetics with hyperlipidemia (triglycerides=3.2±1 mmol/l; total cholesterol=6.1±1.2 mmol/l; HDL-cholesterol=0.92±0.27 mmol/l; VLDL=29±5%) (group A), and 19 normolipidemic type II diabetics (triglycerides=1.15±0.5 mmol/l; total cholesterol=5.1±1 mmol/l; HDL-cholesterol =1.25±0.38 mmol/l; VLDL=20±5%) (group B). No differences concerning age, body weight, duration of diabetes and glycemic control were found in hyperlipidemic compared to normolipidemic diabetics. On the contrary, higher systolic and diastolic blood pressure levels were demonstrated in group A (167±14 mmHg and 101±5.2 mmHg, respectively) than in group B (144±15 mmHg, p<0.001 and 87±6.9 mmHg, p<0.001, respectively). An increase of plasma apolipoprotein B level (163±27 mg/dlvs 102±21 mg/dl, p<0.001), of plasma viscosity (1.81±0.08 mPasvs 1.51±0.07 mPas, p<0.001) and of blood viscosity (5.37±0.33 mPasvs 5.07±0.04 mPas, p<0.01, at shear-rate of 90 s−1; 18.4±1 mPasvs 14.1±0.9 mPas, p<0.001 at shear-rate of 2.25 s−1) was found in group A, compared to group B. Moreover several positive correlations (p<0.001) between apolipoprotein B level, plasma and blood viscosity were demonstrated in the hyperlipidemic diabetic patients. These findings suggest that blood changes in diabetes might be involved in the occurrence of blood pressure alterations.

Hemorheologic and hemostatic changes in long-standing insulin-dependent (type I) diabetic patients with peripheral and autonomic cardiovascular neuropathy

SummaryDiabetic microangiopathy may be associated with the pathogenesis and progression of autonomic and peripheral neuropathy. In 17 long-standing type I diabetic patients with peripheral and autonomic cardiovascular neuropathy, several hemorheological and hemostatic alterations were found compared to 13 matched type I patients without neuropathy. In particular, increased plasma von Willebrand factor antigen (p<0.001), fibronectin (p<0.001) and fibrinogen (p<0.001) levels were demonstrated in neuropathic in comparison with non-neuropathic diabetic patients. Moreover negative correlations between these parameters and both motor and sensitive conduction velocity of median, sural and peroneal nerves were observed in diabetic patients with neuropathy. Higher blood viscosity (p<0.05 at shear-rate of 450 and 225 s−1; p<0.01 at 90 s−1; p<0.001 at 4.5 and 2.25 s−1), plasma viscosity (p<0.001) and lower erythrocyte filtrability (p<0.001) were also found in neuropathic compared to non-neuropathic diabetics. Increased prevalence of retinopathy (p<0.01) and nephropathy (p<0.001) was finally reported in patients with autonomic and peripheral neuropathy. Microvascular disease may be involved in the development of neuropathy in long-term type I diabetes mellitus.

Determination of albuminuria in type 1 and type 2 diabetic patients with microproteinuria and overt nephropathy. Comparative evaluation between a radial immunodiffusion procedure and a highly sensitive radioimmunoassay.

SummaryWe have studied the correlation between urinary albumin excretion rate evaluated by a radial immunodiffusion technique and a highly sensitive radioimmunoassay in type 1 and type 2 diabetic patients with microproteinuria and overt clinical nephropathy. Several statistically significant correlations were found between urinary albumin excretion rate measured by radial immunodiffusion and by radioimmunoassay, both in patients with microproteinuria and overt nephropathy. Moreover, statistically significant correlations between urinary albumin excretion rate, albumin clearance and total urinary protein excretion rate were observed in each of the groups studied. The radial immunodiffusion procedure can therefore be considered a useful and sensitive method for the evaluation of urinary albumin excretion rate both in diabetic patients with microproteinuria and in patients with overt clinical nephropathy.

P3-281 : Advanced glycated end products peptides induce a pathologic release of inflammatory cytokines, expecially during amyloid-beta exposure, in subjects with Alzheimer’s disease

and PD patients as well as healthy young and aged-matched non-demented individuals (n 30 for all groups). Results: Our findings indicate that all elderly groups have a higher Treg (CD4 Foxp3 ) frequency compared to the young group, without any difference between the elderly groups. In addition, we observed increasing Treg activity for all elderly groups compared to the young group. However, no difference between the aged healthy individuals and AD patients could be observed. In contrast, Treg activity in PD patients was significantly higher compared to the aged healthy donors. The increase of suppressive activity was thereby independent of the Foxp3 expression level. Conclusion: Our observations, of quantitative and qualitative differences already in the total pool of peripheral Treg between young and elderly groups, identify Treg as an immunecell type undergoing immunological senescence. Taking into account that changes in Treg function increase with a neurodegenerative phenotype present in PD patients, our data support the hypothesis of an existing beneficial autoimmune effector mechanism in these patients, which is suppressed by Treg. Furthermore, we cannot exclude that by analyzing a more specialized subset of Treg in AD patients a similar result would be obtained for this group. Consequently, it will be of special interest to analyze Treg specific for CNS antigens relevant to AD and PD, in particular amyloid-beta and alpha-synuclein.