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.

Improvement of blood glucose control and insulin sensitivity during a long-term (60 weeks) randomized study with amino acid dietary supplements in elderly subjects with type 2 diabetes mellitus.

A decrease in lean muscular mass causes sarcopenia, a disease frequently found in the elderly population. The reduction of muscle mass may be responsible for reduced insulin sensitivity and decreased glucose uptake, thus increasing the risk for hyperglycemia and insulin-resistance syndrome in elderly subjects with type 2 diabetes mellitus. We therefore wanted to determine the effect of a special mixture of oral amino acids (AAs) on elderly subjects with type 2 diabetes. A randomized, open-label, crossover study was conducted in 34 subjects with diabetes (age range, 65-85 years) assigned to 2 distinct treatments (AAs and placebo). In spite of treatment with oral hypoglycemic drugs or insulin, all subjects were in poor metabolic control (glycated hemoglobin [HbA(1c)] >7%). The subjects studied had normal body weight (ie, body mass index within 19-23). AAs consisted of 70.6 kcal/day (1 kcal = 4.2 kJ) of 8 g of AA snacks, given at 10.00 am and 5.00 pm. Fasting and postprandial (1 hour and 2 hours) 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 of HbA(1c) levels was found throughout the study. No significant adverse effects were observed during the active treatment. We suggest that nutritional supplementation with a special mixture of oral AAs is safe and significantly improves metabolic control and insulin sensitivity in poorly controlled elderly subjects with type 2 diabetes. This effect was consistent during the long-term observation period of 60 weeks and was also present after the crossover from AAs to placebo.

Unbalanced serum leptin and ghrelin dynamics prolong postprandial satiety and inhibit hunger in healthy elderly: another reason for the "anorexia of aging".

BACKGROUND: In healthy elderly, a reduction from the appetite and food intake of younger years has been defined as the "anorexia of aging," which may cause malnutrition. Leptin and ghrelin may alter the control of hunger and satiety and thus lead to anorexia. OBJECTIVE: The aim of this study was to investigate how aging affects serum leptin and ghrelin concentrations in response to a meal and the relation of those hormones to hunger and satiety sensations. DESIGN: We studied 8 community-dwelling elderly (x +/- SD age: 78 +/- 1 y) subjects and 8 younger (29.5 +/- 1 y) control subjects. Under fasting conditions and for 4 h after an 800-kcal mixed meal, satiety and hunger were evaluated at intervals, by using a visual analogic scale. Blood samples for leptin, ghrelin, and insulin measurements were collected at the following times: 30 min before and immediately and 30, 60, 120, and 240 min after the meal. RESULTS: Postprandial satiety lasted significantly longer in the elderly than in the control subjects, and hunger was suppressed in the elderly throughout the observation. Fasting leptin was higher in the elderly than in the young (x +/- SE: 4.3 +/- 1.9 and 1.3 +/- 0.4 ng/mL, respectively; P < 0.05), and postprandial fluctuation was not significant. Fasting insulin also was significantly higher in the elderly than in the young (6.8 +/- 1.3 and 3.5 +/- 0.6 mU/L, respectively; P < 0.05), and the postprandial insulin rise was greater in the elderly. Fasting and postprandial ghrelin values did not differ significantly between the 2 groups. Insulin was inversely correlated with hunger and directly correlated with satiety scores. CONCLUSIONS: In healthy elderly, anorexigenic signals prevail over orexigenic signals, and they contribute to prolonged satiety and inhibition of hunger. This condition may lead to a calorie deficit and finally to malnutrition in the elderly.

Association of the metabolic syndrome and insulin resistance with silent myocardial ischemia in patients with type 2 diabetes mellitus.

Metabolic syndrome is associated with elevated morbidity and mortality for overt coronary artery disease (CAD). In diabetic patients, CAD is often silent. The relation between metabolic syndrome and silent CAD has never been studied. We investigated whether metabolic syndrome is associated with silent CAD in patients with type 2 diabetes mellitus. We evaluated the prevalence of metabolic syndrome in 169 patients with uncomplicated diabetes and angiographically verified silent CAD and in 158 diabetic patients without myocardial ischemia on exercise electrocardiography, 48-hours ambulatory electrocardiography, and stress echocardiography. The groups were comparable for gender, age, glycemic control, and diabetes duration. Metabolic syndrome was defined according to the National Cholesterol Education Program criteria. To estimate insulin resistance in patients treated with diet alone or oral agents (122 patients with CAD and 115 patients without CAD), the Homeostasis Model Insulin-Resistance Assessment (HOMA) was used. The prevalence of metabolic syndrome (59.8% vs 44.3%, p = 0.005) and HOMA (5.4 +/- 2.1 vs 4.9 +/- 2.8, p = 0.044) were significantly higher in those with CAD than in those without CAD. Multiple logistic regression analysis showed that the metabolic syndrome was associated with silent CAD (odds ratio 2.44, 95% confidence interval 1.19 to 5.02, p = 0.015). Among patients on diet alone or oral agents, the HOMA was the strongest predictor of silent CAD (odds ratio 10.16, 95% confidence interval 2.60 to 39.63, p < 0.001). In conclusion, our data have shown an independent association of metabolic syndrome and insulin resistance with silent CAD in patients with type 2 diabetes mellitus. Other studies are needed to establish whether metabolic syndrome and HOMA are reliable markers to identify diabetic patients for additional screening for silent CAD.

Relationship between erectile dysfunction and silent myocardial ischemia in apparently uncomplicated type 2 diabetic patients.

BACKGROUND: Erectile dysfunction (ED) is associated with coronary artery disease (CAD). In diabetic patients, CAD is often silent. Among diabetic patients with silent CAD, the prevalence of ED has never been evaluated. We investigated whether ED is associated with asymptomatic CAD in type 2 diabetic patients. METHODS AND RESULTS: We evaluated the prevalence of ED in 133 uncomplicated diabetic men with angiographically verified silent CAD and in 127 diabetic men without myocardial ischemia at exercise ECG, 48-hour ambulatory ECG, and stress echocardiography. The groups were comparable for age and diabetes duration. Patients were screened for ED using the validated International Index of Erectile Function (IIEF-5) questionnaire. The prevalence of ED was significantly higher in patients with than in those without silent CAD (33.8% versus 4.7%; P=0.000). Multiple logistic regression analysis showed that ED, apolipoprotein(a) polymorphism, smoking, microalbuminuria, HDL, and LDL were significantly associated with silent CAD; among these risk factors, ED appeared to be the most efficient predictor of silent CAD (OR, 14.8; 95% CI, 3.8 to 56.9). CONCLUSIONS: Our study first shows a strong and independent association between ED and silent CAD in apparently uncomplicated type 2 diabetic patients. If our findings are confirmed, ED may become a potential marker to identify diabetic patients to screen for silent CAD. Moreover, the high prevalence of ED among diabetics with silent CAD suggests the need to perform an exercise ECG before starting a treatment for ED, especially in patients with additional cardiovascular risk factors.

Delayed postprandial gastric emptying and impaired gallbladder contraction together with elevated cholecystokinin and peptide YY serum levels sustain satiety and inhibit hunger in healthy elderly persons.

BACKGROUND: Altered gastric and cholecystic motility are risk factors for malnutrition in elderly persons, mainly through impaired satiety-appetite rhythm. Contrasting data have been published about this topic. The aim of this study was to evaluate, in healthy elderly participant, postprandial gastric and cholecystic emptying in relation to serum CCK (cholecystokinin) and PYY (peptide YY), as well as satiety and hunger sensations. METHODS: We studied 10 community-dwelling elderly persons, (77 +/- 3 years old) and 9 younger adult persons (32 +/- 8 years old). Using ultrasonography, we measured gastric antrum area and cholecystic volume in fasting condition and after an 800-kcal mixed meal. Time for gastric and cholecystic emptying, and percentage of cholecystic emptying were calculated. Satiety and hunger were evaluated every 30 minutes using visual analogue scales. CCK and PYY serum levels were assayed 30 minutes before and at times 0, 30, 60, 120, and 240 minutes after the meal. RESULTS: Elderly participants showed a longer gastric emptying time compared to younger participants (448 +/- 104 vs 306 +/- 57 minutes, p <.002). Postprandial cholecystic emptying was significantly reduced in the older group (maximum contraction, 69% vs 84%; p <.05). After the meal, CCK and PYY levels showed higher, persistent elevation in elderly participants. In this group, postprandial satiety lasted significantly longer than in younger participants, and hunger was suppressed throughout the postprandial period. Antral area directly correlated with satiety and inversely with hunger. Gallbladder volume inversely correlated to satiety. CONCLUSIONS: This study showed, in a group of healthy elderly people, delayed gastric emptying associated to reduced cholecystic contractility together with higher CCK and PYY serum levels. These modifications facilitated long-lasting satiety and hunger suppression after a meal. This condition may lead to caloric restriction and finally to malnutrition at older ages.

Metabolic effects of orally administered amino acid mixture in elderly subjects with poorly controlled type 2 diabetes mellitus.

The reduction of muscle mass and increased protein catabolism in aging can determine the occurrence of metabolic alterations-such as hyperglycemia and reduced insulin sensitivity-in elderly subjects with diabetes mellitus. Therefore, the aim of the study was to evaluate the effect of nutritional supplementation with oral amino acid mixture (OAAM) in elderly subjects with type 2 diabetes. This approach was conducted in an attempt to antagonize muscle catabolism by means of increased endogenous protein synthesis and to improve glucose metabolism and insulin sensitivity. A randomized, open-label, crossover study was conducted in poorly controlled (glycosylated hemoglobin level [HbA(1c)] >7%) elderly subjects (age range, 65 to 85 years) with type 2 diabetes. OAAM significantly reduced fasting and postprandial blood glucose and HbA(1c), whereas all parameters remained substantially unchanged in the group treated with placebo. Fasting insulin levels and insulin resistance increased at baseline in all subjects with diabetes and decreased during OAAM supplementation. These results persisted also after crossover from OAAM to placebo. No changes in blood lipid levels, creatinine, homocysteine, and urinary albumin excretion rate were observed throughout the study, whereas a mild but significant increase of high-density lipoprotein cholesterol was found after OAAM supplementation. We suggest that increased amino acid availability for skeletal muscle function and strength could ameliorate metabolic control and insulin sensitivity in elderly patients with poorly controlled type 2 diabetes.

Transcutaneous oxygen tension as a potential predictor of cardiovascular events in type 2 diabetes: comparison with ankle-brachial index.

OBJECTIVE: Transcutaneous oxygen tension (TcPO2) measures tissue perfusion and is important in the management of peripheral artery disease (PAD). Ankle brachial index (ABI) is used for the diagnosis of PAD and represents a predictor of major adverse cardiovascular events (MACE), even if in diabetes its diagnostic and predictive value seems to be reduced. No study has evaluated TcPO2 as a predictor of cardiovascular events. Aim of this longitudinal study was to assess whether TcPO2 is better than ABI at predicting MACE in type 2 diabetic patients. RESEARCH DESIGN AND METHODS: Among 361 consecutive patients with apparently uncomplicated diabetes, 67 MACE occurred during a follow-up period of 45.8 ± 23.2 months. RESULTS: The percentage of both subjects with low ABI (≤ 0.9) and subjects with low TcPO2 (≤ 46 mmHg as measured by a receiver operating characteristic curve) was significantly (<0.001) greater among patients with than among those without MACEs (ABI 64.2 vs. 40.8; TcPO2 58.2 vs. 34%). The Kaplan-Meier method showed that both low ABI (Mantel log-rank test, 4.087; P = 0.043) and low TcPO2 (Mantel log-rank test, 33.748; P > 0.0001) were associated with a higher rate of MACEs. Cox regression analysis showed that low TcPO2 (hazard ratio 1.78 [95% CI 1.44-2.23]; P < 0.001) was a significant predictor of MACE, while ABI did not enter the model. CONCLUSIONS: This longitudinal study showed that TcPO2 may be a potential predictor of MACE among patients with uncomplicated type 2 diabetes and that its predictive value seems to be greater than that of ABI.

Lipoprotein(a) and homocysteine as genetic risk factors for vascular and neuropathic diabetic foot in type 2 diabetes mellitus.

Neuropathy and peripheral artery disease represent the main pathophysiological conditions underlying diabetic foot. Several studies showed that Lipoprotein(a)-Lp(a)-and homocysteine (Hcy) can be associated with diabetic complications, but their relationship with diabetic foot is unclear. Aim of this study was to investigate whether Lp(a) and Hcy were associated with diabetic foot ulcerations, classified according to the presence of peripheral artery disease (PAD) or neuropathy. From among consecutive type 2 diabetic attending at the Diabetic Foot Clinic 27 subjects with vascular diabetic foot (VDF), 43 with neuropathic diabetic foot (NDF) and 52 controls without foot ulceration, neuropathy, and PAD were enrolled. Both Lp(a) (26.1 ± 22.7 vs. 14.9 ± 19.5 mg/dl; P = 0.003) and Hcy levels (15.4 ± 5.7 vs. 12.2 ± 5.1 µmol/l; P = 0.022) were significantly greater in the VDF group than in controls. Lp(a) levels were significantly lower in the NDF group than in controls (6.9 ± 8.1 versus 14.9 ± 19.5 mg/dl; P = 0.009), while no difference in Hcy levels was found. Multiple logistic regression analysis showed that Hcy was associated with VDF (OR: 1.11; 95% CI: 1.07-14.1; P = 0.048). Lp(a) did not enter the model, but its P-value was very near to the significant level (OR: 1.09; 95% CI: 0.99-12.05; P = 0.059). Moreover, low Lp(a) levels were associated with NDF (OR: 0.84; 95% CI: 0.21-0.96; P = 0.039). Our study has shown for the first time that high Lp(a) and Hcy levels are associated with the development of VDF, while low Lp(a) levels appear to be associated with delayed wound healing in patients with neuropathic foot ulcerations.

Erectile dysfunction can improve the effectiveness of the current guidelines for the screening for asymptomatic coronary artery disease in diabetes.

About 40% of diabetic patients with asymptomatic coronary artery disease (CAD) are missed on the basis of the current screening guidelines. Erectile Dysfunction (ED) is a powerful marker of asymptomatic CAD. Aim of the study is to evaluate whether ED can improve the effectiveness of the current guidelines for the screening of CAD in diabetes. From among 299 consecutive men with newly diagnosed type 2 diabetes without any apparent vascular complication, 293 (mean age 56.6±5.9 years) were enrolled. Among them, 219 did not have myocardial ischemia (NO CAD group) and 74 men had a coronary stenosis angiographically proven (CAD group). Five risk factors (RFs) of the current screening guidelines (hypertension, dyslipidemia, family history for CAD, smoking e micro/macroalbuminuria) and ED were assessed. ED was significantly more prevalent in the CAD than in the NO CAD group (37.8 versus 15.1%; P<0.001) and was a predictor of asymptomatic CAD (OR: 4.4; 95%CI: 2.1-9.0; P<0.001). If ED is added to the list of RFs, it can increase the sensitivity of the current guidelines from 62 to 89%, without a significant variation in specificity (from 60 to 57%). The negative predictive value can increase from 82 to 94%. ED can reduce from 37.84 to 10.81% the percentage of patients with silent CAD missed at the screening. This study first shows that ED can improve the effectiveness in discriminating diabetic men to screen for asymptomatic CAD, when it is added to the list of RFs of the current screening guidelines.

Erectile dysfunction as a predictor of cardiovascular events and death in diabetic patients with angiographically proven asymptomatic coronary artery disease: a potential protective role for statins and 5-phosphodiesterase inhibitors.

OBJECTIVES: We sought to investigate whether erectile dysfunction (ED) is a predictor of future cardiovascular events and death in diabetic patients with silent coronary artery disease (CAD) and whether there are predictors of cardiovascular events and death among CAD diabetic patients with ED. BACKGROUND: Case-control studies showed that ED is associated with CAD in diabetic patients, but no prospective study is available. METHODS: Type 2 diabetic men (n = 291) with silent CAD angiographically documented were recruited. Erectile dysfunction was assessed by the International Index Erectile Function-5 questionnaire. RESULTS: During a follow-up period of 47.2 +/- 21.8 months (range 4 to 82 months), 49 patients experienced major adverse cardiac events (MACE). The difference in ED prevalence between patients with and those without MACE was significant (61.2% vs. 36.4%; p = 0.001). Cox regression analysis showed that ED predicted MACE (hazard ratio [HR] 2.1; 95% confidence interval [CI] 1.6 to 2.6; p < 0.001). Among patients with CAD and ED, the Kaplan-Meier method showed that the statin (Mantel log-rank test: 3.921; p = 0.048) and 5-phosphodiesterase (5-PDE) inhibitor use (Mantel log-rank test: 4.608; p = 0.032) were associated with a lower rate of MACE. Cox regression analysis showed that statin use (HR 0.66; 95% CI 0.46 to 0.97; p = 0.036) reduced MACE. Treatment with 5-PDE inhibitors did not enter the model, but its p value was very near to the significant level (HR 0.68; 95% CI 0.46 to 1.01; p = 0.056). CONCLUSIONS: Our data first show that ED is a powerful predictor of cardiovascular morbidity and mortality in diabetic patients with silent CAD and that the treatment with statins and 5-PDE inhibitors might reduce the occurrence of MACE among CAD diabetic patients with ED.