The cortisol burden in elderly subjects with metabolic syndrome and its association with low-grade inflammation.

BACKGROUND: Elderly people are exposed to an increased load of stressful events and neuro-hormonal stimulation is a key finding in metabolic syndrome and its related disorders. AIMS: To determine the role of cortisol in elderly subjects, with or without metabolic syndrome (MetS), by means of a national multicentre observational study, AGICO (AGIng and Cortisol). METHODS: From 2012 to 2017, the AGICO study enrolled n.339 subjects (aged > 65), after obtaining their informed consent. The investigators assessed a cardio-metabolic panel (including electrocardiogram, carotid ultrasonography and echocardiography), the presence of MetS (on Adult Treatment Panel III criteria), a neurological examination (including brain imaging), and cortisol activity (using a consecutive collection of diurnal and nocturnal urine). RESULTS: In the patients presenting with MetS, the standardized diurnal and nocturnal cortisol excretion rates were 210.7 ± 145.5 and 173.7 ± 118.1 (mean ± standard deviation) µg/g creatinine/12 h; in those without MetS, the standardized diurnal and nocturnal cortisol excretion rates were 188.7 ± 92.7 and 144.1 ± 82.3 µg/g creatinine/12 h, respectively (nocturnal urinary cortisol in patients with MetS versus those without MetS p = 0.05, female patients with MetS vs female patients without MetS, p < 0.025). A significant positive correlation was found between the CRP levels and both the diurnal and nocturnal urinary cortisol levels with r = 0.187 (p < 0.025) and r = 0.411 (p < 0.00000001), respectively. DISCUSSION: The elderly patients with MetS showed a trend towards increased standardized nocturnal cortisol excretions, with particular regard to the female subjects. CONCLUSION: The positive correlation between cortisol excretion and low-grade inflammation suggests a common mechanism driving both hormonal and inflammatory changes.

Management of diabetes in older adults.

Type 2 diabetes prevalence is high in older adults and is expected to rise in the next decades. Diabetes in the population of frail older adults is accompanied by functional disability, several comorbidities, and premature mortality. A comprehensive geriatric assessment, including functional, cognitive, mental and social status, is advisable for identifying the glycemic targets and glucose-lowering therapies, focused on patient preferences, needs, and risks. The therapeutic options for older adults with diabetes are like those for the adult population. However, the pharmacological treatments must be carefully prescribed and monitored, taking into consideration the patient cognitive capacities, the potentially life-threatening drug-drug interactions, the cardiovascular risk, and with the main goal of avoiding hypoglycemia. Also, a careful nutritional evaluation with appropriate tools, as well as a balanced and periodically monitored physical activity, contribute to an effective tailored care plan, as needed by older adults with diabetes. This review evaluates the currently available hypoglycemic drugs and the current indications to the Italian diabetology community, specifically with regard to the treatment of adults aged 75 years or older with diabetes, including the unmet needs by the guidelines.

Telemonitoring in heart failure patients treated by cardiac resynchronisation therapy with defibrillator (CRT-D): the TELECART Study.

AIM: Telemonitoring (TM) is a safe and efficient monitoring system for internal cardioverter defibrillator device (ICD) recipients. TM has been used to track info on the clinical status of heart failure patients treated by ICD and/or cardiac resynchronisation therapy defibrillator (CRT-D). The aim of this study was to investigate the impact of TM on clinical outcomes in a population of CRT-D patients with heart failure. METHODS: In a multicentre, randomised study, patients with chronic heart failure, New York Heart Association (NYHA) functional class II or III, left bundle branch block, severe left ventricle ejection fraction reduction (LVEF < 35%) have been identified and screened. RESULTS: One hundred and ninety-one patients have been randomised to receive either a CRT-D with TM or a CRT-D with traditional ambulatory monitoring (control group) and completed the 12-month study follow-up. Primary endpoints were all cause death, cardiac death and hospital admission for heart failure. Secondary endpoints were atrial fibrillation, sustained episodes, non-sustained and self terminated ventricular tachyarrhythmia, sustained ventricular tachycardia, and ventricular fibrillation, ICD shocks and percentage of CRT-D responder patients. Univariate analysis identified the following factors predicting hospitalisation: TM, age, chronic kidney disease, hypercholesterolaemia, LVEF and NYHA class. At multivariate analysis, TM was the only factor predicting heart failure hospitalisation (hazard ratio 0.6, 0.42-0.79, 95% CI, p = 0.002), without affecting overall mortality and cardiac deaths events. CONCLUSIONS: Taken together, our data indicate the importance of TM in predicting heart failure hospitalisation in patients treated with CRT-D.

Diabetes-related quality of life is enhanced by glycaemic improvement in older people.

AIMS: To investigate the validity and reliability of the Audit of Diabetes-Dependent Quality of Life instrument in older Italians with diabetes and to test the association of diabetes-related quality of life with glycaemic control over time. METHODS: A total of 558 outpatients with Type 2 diabetes from the Diabetic Unit of the Italian National Research Centre on Aging Hospital in Ancona were enrolled to complete questionnaires (Audit of Diabetes-Dependent Quality of Life-19 and the Short-Form-12), and to undergo clinical and biochemical testing at baseline and at 12 months of follow-up. The overall impact of diabetes using the average weighted impact score from the Audit of Diabetes-Dependent Quality of Life questionnaire was calculated. Participants were categorized according to this score as having either less or more negative diabetes-related quality of life. RESULTS: Participants had a mean ± SD age of 67.7 ± 9.2 years and 51.8% were male. Factor analysis and Cronbach's coefficient of internal consistency (Cronbach's α = 0.931) confirmed that the 19 domain-specific Audit of Diabetes-Dependent Quality of Life items could be combined into a single scale in this Italian population. The impact score correlated with the physical (r = 0.275; P < 0.001) and mental components (r = 0.291; P < 0.001) of the Short-Form-12 questionnaire. Significant differences were found according to diabetic complications in specific Audit of Diabetes-Dependent Quality of Life items and impact scores. Insulin use had a greater association with a more negative quality of life compared with other antidiabetic agents. A multivariate linear regression model with restricted linear spline application showed that the relationship between HbA1c and impact score was not linear and that the change in the impact score was associated with improved glycaemic control in those with a less negative diabetes-related quality of life at 12 months. CONCLUSIONS: The Audit of Diabetes-Dependent Quality of Life-19 is a valid tool for measuring the impact of diabetes on quality of life in older Italians. Perception of diabetes-related quality of life is associated with glycaemic control over time.

The management of hip fracture in the older population. Joint position statement by Gruppo Italiano Ortogeriatria (GIOG).

This document is a Joint Position Statement by Gruppo Italiano di OrtoGeriatria (GIOG) supported by Società Italiana di Gerontologia e Geriatria (SIGG), and Associazione Italiana Psicogeriatria (AIP) on management of hip fracture older patients. Orthogeriatric care is at present the best model of care to improve results in older patients after hip fracture. The implementation of orthogeriatric model of care, based on the collaboration between orthopaedic surgeons and geriatricians, must take into account the local availability of resources and facilities and should be integrated into the local context. At the same time the programme must be based on the best available evidences and planned following accepted quality standards that ensure the efficacy of the intervention. The position paper focused on eight quality standards for the management of hip fracture older patients in orthogeriatric model of care. The GIOG promotes the development of a clinic database with the aim of obtaining a qualitative improvement in the management of hip fracture.

Poor glycaemic control in type 2 diabetes patients reduces endothelial progenitor cell number by influencing SIRT1 signalling via platelet-activating factor receptor activation.

AIMS/HYPOTHESIS: Downregulation of levels of endothelial progenitor cells (EPCs) during in-vitro short-term exposure to high glucose concentrations relates to reduced activity of silent information regulator 1 (SIRT1) and increased synthesis of platelet-activating factor (PAF). We investigated the possible relationship between PAF and SIRT1 pathways in EPCs during altered glucose homeostasis. METHODS: SIRT1 and PAF receptor (PAF-R) levels were determined by western blot, RT-PCR and confocal laser-scanning microscopy. In-vivo experiments were performed on 48 type 2 diabetic patients (25 with poor glycaemic control and 23 with good glycaemic control) and 20 control individuals. In-vitro experiments with the PAF-R antagonist CV3988 were performed on EPCs isolated from leucocyte-rich buffy coat of healthy human donors. RESULTS: Decreased SIRT1 protein levels were observed in EPCs from type 2 diabetic patients compared with control individuals (p < 0.01). Notably, the SIRT1 level was consistently lower in patients with poor glycaemic control than in those with good glycaemic control (p < 0.01). Diabetic patients also showed an upregulation of PAF-Rs; this response occurred to a greater extent in individuals with poor glycaemic control than in those with good glycaemic control. In-vitro experiments confirmed that EPCs respond to PAF stimulation with decreased SIRT1 protein and SIRT1 mRNA levels. Moreover, reduction of SIRT1 levels and activity were abolished by CV3988. CONCLUSIONS/INTERPRETATION: These findings unveil a link between PAF and SIRT1 pathways in EPCs that contributes to the deleterious effect of hyperglycaemia on the functional properties of EPCs, crucial in diabetes and peripheral vascular complications.

Magnesium and anabolic hormones in older men.

Optimal nutritional and hormonal statuses are determinants of successful ageing. The age associated decline in anabolic hormones such as testosterone and insulin-like growth factor 1 (IGF-1) is a strong predictor of metabolic syndrome, diabetes and mortality in older men. Studies have shown that magnesium intake affects the secretion of total IGF-1 and increase testosterone bioactivity. This observation suggests that magnesium can be a modulator of the anabolic/catabolic equilibrium disrupted in the elderly people. However, the relationship between magnesium and anabolic hormones in men has not been investigated. We evaluated 399 ≥65-year-old men of CHIANTI in a study population representative of two municipalities of Tuscany (Italy) with complete data on testosterone, total IGF-1, sex hormone binding globulin (SHBG), dehydroepiandrosterone sulphate (DHEAS) and serum magnesium levels. Linear regression models were used to test the relationship between magnesium and testosterone and IGF-1. Mean age of the population was 74.18 ± 6.43 (years ± SD, age range 65.2-92.4). After adjusting for age, magnesium was positively associated with total testosterone (ß ± SE, 34.9 ± 10.3; p = 0.001) and with total IGF-1 (ß ± SE, 15.9 ± 4.8; p = 0.001). After further adjustment for body mass index (BMI), log (IL-6), log (DHEAS), log (SHBG), log (insulin), total IGF-1, grip strength, Parkinson's disease and chronic heart failure, the relationship between magnesium and total testosterone remained strong and highly significant (ß ± SE, 48.72 ± 12.61; p = 0.001). In the multivariate analysis adjusted for age, BMI, log (IL-6), liver function, energy intake, log (insulin), log (DHEAS), selenium, magnesium levels were also still significantly associated with IGF-1 (ß ± SE, 16.43 ± 4.90; p = 0.001) and remained significant after adjusting for total testosterone (ß ± SE, 14.4 ± 4.9; p = 0.01). In a cohort of older men, magnesium levels are strongly and independently associated with the anabolic hormones testosterone and IGF-1.

-94 ins/del ATTG NFKB1 gene variant is associated with lower susceptibility to myocardial infarction.

BACKGROUND AND AIMS: An imbalance of Nuclear Factor Kappa B (NFкB) and Inhibitor Kappa B (IкB) is involved in various human diseases including atherogenesis. We aimed to evaluate the relationship between NFKB1 and NFKBIA polymorphism and susceptibility to myocardial infarction (MI). METHODS AND RESULTS: Genotyping was performed for NFKB1 and NFKBIA gene variants in 253 subjects (86 patients affected by myocardial infarction and 167 control subjects). In 40 patients, biopsy specimens were taken from the left ventricle area of presumed ischemia for p50, p65 and IкBα quantification. The allele frequency and genotype distribution of NFKBIA gene polymorphism did not differ between MI and control group while control subjects had a higher D allele frequency of -94 ins/del ATTG NFKB1 polymorphism, compared to the MI group (P<0.001; OR=0.304; 95% CI=0.177-0.522). Subjects carrying the D allele had significantly lower plasma fibrinogen and CRP (C-reactive protein) levels compared to no carriers (P<0.05). Fibrinogen-genotype interaction was found to have a significant effect on susceptibility to myocardial infarction. Myocardial p50 (r=0.627; P=0.012) and p65 (r=0.683; P=0.005) levels significantly correlated with plasma fibrinogen levels while subjects carrying the D allele of the NFкB1 gene variant had lower myocardial p50 (P=0.007) and p65 (P=0.009) levels compared to no carriers. CONCLUSION: -94 ins/del ATTG NFKB1 gene variant may contribute to lower MI susceptibility via the potential reduction of activated NFкB which in turn is related to plasma inflammatory marker reduction.

Frailty and muscle metabolism dysregulation in the elderly.

The frailty syndrome is increasingly recognized by geriatricians to identify elders at an extreme risk of adverse health outcomes. The physiological changes that result in frailty are complex and up to now have been extremely difficult to characterize due to the frequent coexistence of acute and chronic illness. Frailty is characterized by an decline in the functional reserve with several alterations in diverse physiological systems, including lower energy metabolism, decreased skeletal muscle mass and quality, altered hormonal and inflammatory functions. This altered network leads to an extreme vulnerability for disease, functional dependency, hospitalization and death. One of the most important core components of the frailty syndrome is a decreased reserve in skeletal muscle functioning which is clinically characterized by a loss in muscle mass and strength (sarcopenia), in walking performance and in endurance associated with a perception of exhaustion and fatigue. There are a number of physiological changes that occur in senescent muscle tissues that have a critical effect on body metabolism. The causes of sarcopenia are multi-factorial and can include disuse, changing hormonal function, chronic diseases, inflammation, insulin resistance, and nutritional deficiencies. In this review, we will explore the dysregulation of some biological mechanisms that may contribute to the pathophysiology of the frailty syndrome through age-related changes in skeletal muscle mass and function.

Negative impact of hyperglycaemia on tocilizumab therapy in Covid-19 patients.

Tocilizumab (TCZ) is used for treating moderate-to-severe Covid-19 pneumonia by targeting interleukin-6 receptors (IL-6Rs) and reducing cytokine release. Yet, in spite of this therapy, patients with vs. patients without diabetes have an adverse disease course. In fact, glucose homoeostasis has influenced the outcomes of diabetes patients with infectious diseases. Of the 475 Covid-19-positive patients admitted to infectious disease departments (University of Bologna, University Vanvitelli of Napoli, San Sebastiano Caserta Hospital) in Italy since 1 March 2020, 31 (39.7%) hyperglycaemic and 47 (60.3%) normoglycaemic patients (blood glucose levels ≥140mg/dL) were retrospectively evaluated at admission and during their hospital stay. Of note, 20 (64%) hyperglycaemic and 11 (23.4%) normoglycaemic patients had diabetes (P<0.01). At admission, hyperglycaemic vs. normoglycaemic patients had fivefold higher IL-6 levels, which persisted even after TCZ administration (P<0.05). Intriguingly, in a risk-adjusted Cox regression analysis, TCZ in hyperglycaemic patients failed to attenuate risk of severe outcomes as it did in normoglycaemic patients (P<0.009). Also, in hyperglycaemic patients, higher IL-6 plasma levels reduced the effects of TCZ, while adding IL-6 levels to the Cox regression model led to loss of significance (P<0.07) of its effects. Moreover, there was evidence that optimal Covid-19 infection management with TCZ is not achieved during hyperglycaemia in both diabetic and non-diabetic patients. These data may be of interest to currently ongoing clinical trials of TCZ effects in Covid-19 patients and of optimal control of glycaemia in this patient subset.

The ratio between kidney volume and function increases with the progression of nephropathy in Type 2 diabetes.

OBJECTIVE: In Type 2 diabetes, it is not clear if renal size is constantly related to the glomerular filtration rate. In addition, it is not known if kidney volume (KV) is associated with an increased urinary albumin and IgG excretion. METHODS: The relationship between kidney volume, creatinine clearance (CrCl), urinary albumin and IgG excretion in 95 Type 2 diabetic patients with different stages of nephropathy (1 - 4 Stage sec NKDF-QD) was elevated and compared to 85 non-diabetic subjects with similar degree of kidney function. RESULTS: In Type 2 diabetic patients the KV/CrCl ratio was increased, in comparison with the control subjects, from about 15% in Stage 1 to 53% in Stage 4. In T2D subjects, significant correlations were found between KV and urinary albumin excretion (r = 0.665, p < 0.05), and between KV and urinary IgG excretion (r = 0.800, p < 0.001). CONCLUSION: The present study finds that Type 2 diabetic subjects, are characterized by an increased ratio between KV/CrCl, throughout the different progressive stages of nephropathy. In Type 2 diabetes relationships between KV and urinary albumin and between KV and IgG excretion also were found to be significant, suggesting a role for the impaired size selectivity of proteinuria as a possible determinant of KV.

Metabolic aspects of the extreme longevity.

Starting from young to very old subjects, aging is associated with a progressive remodeling. Such an age-dependent remodeling process mainly affects anthropometrics, endocrine and thus, also metabolic factors. Interestingly, it occurs in some individuals successfully, while in others unsuccessfully. Centenarians in good health conditions are a very selected group of subjects representing an exceptional condition. Why the centenarians reach the extreme human life span is still unknown. Thus, in this article we will review the best known causes of age-related insulin resistance, outline the main metabolic differences between aged subjects and healthy centenarians, underline the clinical relevance of insulin resistance in the elderly and finally, we will try to propose a unifying hypothesis for explaining the development of insulin resistance with aging.

Sex hormone binding globulin levels across the adult lifespan in women--the role of body mass index and fasting insulin.

SHBG is a major carrier of androgens. In men, SHBG levels increase with age, while in women data are scant. There is evidence that body mass index (BMI) and fasting insulin influence SHBG concentration. Since low SHBG levels are predictors of insulin resistance and diabetes, understanding the relationship of SHBG with age, insulin, and BMI is important to gain insight into the role of SHBG as a cardiovascular risk factor in women. Differences in SHBG across adult life span and their relationship with insulin and BMI were evaluated in a representative cohort of 616 Italian women free of diabetes and not on hormone replacement therapy enrolled in the InCHIANTI Study. The relationship of SHBG with age, BMI, and fasting insulin levels was analyzed using linear regression and by loess smoother. Serum SHBG levels showed a U-shaped trajectory with age, declining from the 2nd to the 6th decade of life and increasing after the 6th decade (p<0.0001). Age-related trends for BMI and fasting insulin mirrored the trend observed for SHBG. After adjusting for fasting insulin, the relationship between log (SHBG) and age square was attenuated (beta coefficient from 0.00044 to 0.00039) and was further reduced after adjustment for BMI (from 0.00039 to 0.00028). SHBG levels show an age-related U-shaped trajectory. These changes mirror the age-related changes in BMI and fasting insulin, suggesting that BMI and insulin negatively influence SHBG concentration.

An amino acid substitution in the human intestinal fatty acid binding protein is associated with increased fatty acid binding, increased fat oxidation, and insulin resistance.

The intestinal fatty acid binding protein locus (FABP2) was investigated as a possible genetic factor in determining insulin action in the Pima Indian population. A polymorphism at codon 54 of FABP2 was identified that results in an alanine-encoding allele (frequency 0.71) and a threonine-encoding allele (frequency 0.29). Pimas who were homozygous or heterozygous for the threonine-encoding allele were found to have a higher mean fasting plasma insulin concentration, a lower mean insulin-stimulated glucose uptake rate, a higher mean insulin response to oral glucose and a mixed meal, and a higher mean fat oxidation rate compared with Pimas who were homozygous for the alanine-encoding allele. Since the FABP2 threonine-encoding allele was found to be associated with insulin resistance and increased fat oxidation in vivo, we further analyzed the FABP2 gene products for potential functional differences. Titration microcalorimetry studies with purified recombinant protein showed that the threonine-containing protein had a twofold greater affinity for long-chain fatty acids than the alanine-containing protein. We conclude that the threonine-containing protein may increase absorption and/or processing of dietary fatty acids by the intestine and thereby increase fat oxidation, which has been shown to reduce insulin action.

Dipeptidyl peptidase 4 (DPP-4) inhibitors and their role in Type 2 diabetes management.

Dipeptidyl peptidase 4 (DPP-4) inhibitors are a new pharmacological class of drugs for treating Type 2 diabetes. They improve the capacity of the organism to control glycemia by increasing the levels of active incretins. Their mechanism of action is thus radically different from those of other anti-diabetic drugs currently available. DDP-4 inhibitors use a physiological mechanism to control hyperglycemia, by stimulating the secretion of insulin from beta-cells, decreasing the secretion of glucagon from pancreatic alpha-cells, and at the same time reducing the production of glucose by the liver. DDP-4 inhibitors have shown significant efficacy in maintaining reduced levels of glycosylated hemoglobin for up to 1 year. In vitro and animal studies have shown that they can inhibit apoptosis of beta-cells and favor their regeneration and differentiation. The oral DPP-4 inhibitors vildagliptin, sitagliptin, and saxagliptin are efficacious both alone and in association with other oral anti-diabetic agents and may be administered in a single daily dose. Lastly, they have substantial advantages with respect to other anti-diabetic drugs, since they involve a low risk of hypoglycemia and do not affect body weight.

Genes, ageing and longevity in humans: problems, advantages and perspectives.

Many epidemiological data indicate the presence of a strong familial component of longevity that is largely determined by genetics, and a number of possible associations between longevity and allelic variants of genes have been described. A breakthrough strategy to get insight into the genetics of longevity is the study of centenarians, the best example of successful ageing. We review the main results regarding nuclear genes as well as the mitochondrial genome, focusing on the investigations performed on Italian centenarians, compared to those from other countries. These studies produced interesting results on many putative "longevity genes". Nevertheless, many discrepancies are reported, likely due to the population-specific interactions between gene pools and environment. New approaches, including large-scale studies using high-throughput techniques, are urgently needed to overcome the limits of traditional association studies performed on a limited number of polymorphisms in order to make substantial progress to disentangle the genetics of a trait as complex as human longevity.

Interleukin-6-174 G > C polymorphism affects the association between IL-6 plasma levels and insulin resistance in type 2 diabetic patients.

Interleukin-6 (IL-6), a powerful inflammatory mediator, plays a pivotal role in the pathogenesis of insulin resistance and type 2 diabetes. Recently, the IL-6 promoter polymorphism, at position -174 (G > C), has been associated to insulin sensitivity although contrasting data have been reported. The aim of this study was to evaluate the effect of the IL-6-174 G > C polymorphism on insulin resistance. In 238 type 2 diabetic patients without diabetic complications and in 255 control subjects, age and gender-matched, we evaluated the IL-6 -174 G > C genotype, the IL-6 plasma levels and the insulin resistance by the homeostasis model assessment (HOMA). The levels of IL-6 and HOMA were not genotype-dependent and were higher in diabetic patients (p < 0.01). Control subjects, both C+ (CG + CC genotypes) and C- (GG genotype) carriers, showed IL-6 plasma levels significantly related to BMI, fasting insulin and HOMA. The same relationships were found in C+ diabetic carriers. Differently, diabetic C- carriers did not show any relationship between IL-6 levels and all the evaluated variables. Interestingly, all the correlations were dependent on BMI. These findings highlight that IL-6-174 G > C polymorphism affects insulin resistance in type 2 diabetes, where C+ carriers have an insulin resistance "IL-6-sensitive", while C- carriers do not. The identification of two categories of diabetic patients may, therefore, lead to different therapeutic strategies in the management of insulin resistance.

The effects of cesium chloride on insulin release, ionic fluxes and membrane potential in pancreatic B-cells.

Cs+ decreases K+ permeability in nerve and muscle cells. Its effects on the pancreatic B-cell function were studied with mouse islets. In the presence of 3 mM glucose, Cs+ substitution for K+ steadily inhibited 86Rb+ efflux and hyperpolarized the B-cell membrane. Addition of Cs+ to a K+-medium also inhibited 86Rb+ efflux, but depolarized the B-cell membrane. None of these changes altered insulin release. Substitution of Cs+ for K+ in a medium containing 10 mM glucose caused a Ca2+-dependent stimulation of insulin release and 45Ca2+ efflux, produced an initial fall and a secondary rise in 86Rb+ efflux and augmented the electrical activity in B-cells. Reintroduction of K+ to the medium was followed by a marked and transient inhibition of insulin release, that was blocked by ouabain and accompanied by an inhibition of 45Ca2+ and 86Rb+ efflux and by a hyperpolarization of the B-cell membrane. Addition of Cs+ to a K+ medium containing 10 mM glucose stimulated insulin release, 45Ca2+ efflux and 86Rb+ efflux. It also increased the electrical activity in B-cells. In the absence of Ca2+, however, Cs+ addition decreased the rate of 86Rb+ efflux. The effects of Cs+ on the B-cell function may be explained by its ability to decrease K+ permeability of the plasma membrane, by its inability to activate the sodium pump, and by a third unidentified effect likely brought about by the accumulation of intracellular Cs+.

Circulating adhesion molecules in humans: role of hyperglycemia and hyperinsulinemia.

BACKGROUND: We assessed the role of glucose and insulin in the regulation of circulating levels of soluble intercellular adhesion molecule-1 (sICAM-1) and vascular adhesion molecule-1 (sVCAM-1) in normal subjects and in patients with type 2 diabetes. METHODS AND RESULTS: Plasma glucose concentrations were acutely raised in 10 normal subjects and 10 newly diagnosed, complication-free type 2 diabetic patients and maintained at 15 mmol/L for 2 hours. In normal subjects, plasma sICAM-1, but not sVCAM-1, levels rose significantly (P<0.01) at 1 hour and returned to basal values at 2 hours. In another study, octreotide was infused during the hyperglycemic clamp to block the release of endogenous insulin; this prevented the late fall of plasma sICAM-l levels observed in under control clamp conditions. The diabetic patients had plasma sICAM-1 levels significantly higher (P<0.01) than those of the control subjects; plasma sVCAM-1 levels were similar. Both sICAM-l and sVCAM-1 concentrations did not change significantly during the control hyperglycemic clamp; however, octreotide infusion increased plasma sICAM-1 levels, which remained significantly (P<0.05) above baseline during the whole clamp. In an additional 10 type 2 diabetic patients, overnight euglycemia (plasma glucose 5.5 mmol/L) obtained with the aid of an artificial pancreas or supplementation with l-arginine (10 g PO for 30 days), the natural precursor of NO, normalized the increased plasma sICAM-1 levels. CONCLUSIONS: Acute hyperglycemia increases circulating sICAM-1 levels in normal subjects, whereas the correction of hyperglycemia with insulin or l-arginine supplementation restored to normal levels the increased plasma sICAM-1 levels of type 2 diabetic patients.

Resting metabolic rate and respiratory quotient in human longevity.

Significant changes in body composition, body fat distribution, and resting metabolic rate (RMR) occur with aging. Interestingly, studies on human longevity pointed out that long-lived subjects are less prone to the anthropometrics and metabolic derangement normally observed in the elderly. Indeed, the relationship between energy expenditure and longevity has been poorly investigated. Thus, energy expenditure parameters of 28 long-lived subjects were assessed and compared with those of 26 adults and 27 younger elderly. All subjects enrolled were female. In the whole population, RMR was negatively correlated with age (P < 0.05), waist to hip ratio (WHR) (P < 0.001), fat mass (P < 0.001), and percent body fat (P < 0.03); respiratory quotient (Rq) displayed an age-related decrease (P < 0.001) and was negatively correlated with WHR (P < 0.001) and fat-free mass (FFM) (P < 0.006). In multivariate analysis, both RMR and Rq had FFM, WHR, but not body mass index as significant and independent determinants. Splitting the whole study group into subgroups according to age, long-lived subjects had oxygen volume, carbon dioxide volume, and Rq significantly higher than aged subjects but lower than adult subjects. In addition, long-lived subjects had total volume of expired air and RMR greater than aged subjects but not different from ones found in adults. In long-lived subjects, Rq was negatively correlated with percent body fat (P < 0.02), plasma glucose (P < 0.05), free fatty acid (P < 0.05), and WHR (P < 0.05), whereas RMR was negatively correlated with WHR (P < 0.05). No significant associations of RMR and Rq with FFM were found. In conclusion, our data demonstrate that human longevity seems protected toward an age-related decline. It is likely that the lack of the anthropometrics derangement may preserve long-lived subjects from the age-related decrease in energy metabolism.