IGF-1, the cross road of the nutritional, inflammatory and hormonal pathways to frailty

Antioxidants linked with physical, cognitive and psychological frailty: Analysis of candidate biomarkers and markers derived from the MARK-AGE study

Frailty among elderly people leads to an increased risk for negative health outcomes. To prevent frailty, we need a better understanding of the underlying mechanisms and early detection of individuals at risk. Both may be served by identifying candidate (bio)markers, i.e. biomarkers and markers, for the physical, cognitive, and psychological frailty domains. We used univariate (Rank-ANOVA) and multivariate (elastic net) approaches on the RASIG study population (age range: 35-74 years, n = 2220) of the MARK-AGE study to study up to 331 (bio)markers between individuals with and without frailty for each domain. Biomarkers and markers identified by both approaches were studied further regarding their association with frailty using logistic regression. Univariately, we found lower levels of antioxidants, including β-cryptoxanthin and zeaxanthin, in those who were physically, cognitively or psychologically frail. Additionally, self-reported health was worse in these three frail groups. Multivariately, we observed lower levels of β-cryptoxanthin and zeaxanthin in the cognitively frail. Levels of these carotenoids were inversely associated with the risk of being cognitively frail after adjusting for confounders. Antioxidants and self-reported health are potential (bio)markers to detect persons at risk of becoming frail. The biomarkers identified may indicate the involvement of inflammation in frailty, especially for physical and cognitive frailty.

A role for nutritional intervention in addressing the aging neuromuscular junction

The purpose of this review is to discuss the structural and physiological changes that underlie age-related neuromuscular dysfunction and to summarize current evidence on the potential role of nutritional interventions on neuromuscular dysfunction-associated pathways. Age-related neuromuscular deficits are known to coincide with distinct changes in the central and peripheral nervous system, in the neuromuscular system, and systemically. Although many features contribute to the age-related decline in neuromuscular function, a comprehensive understanding of their integration and temporal relationship is needed. Nonetheless, many nutrients and ingredients show promise in modulating neuromuscular output by counteracting the age-related changes that coincide with neuromuscular dysfunction. In particular, dietary supplements, such as vitamin D, omega-3 fatty acids, β-hydroxy-β-methylbutyrate, creatine, and dietary phospholipids, demonstrate potential in ameliorating age-related neuromuscular dysfunction. However, current evidence seldom directly assesses neuromuscular outcomes and is not always in the context of aging. Additional clinical research studies are needed to confirm the benefits of dietary supplements on neuromuscular function, as well as to define the appropriate population, dosage, and duration for intervention.

Nutritional Status Improvement in Malnourished Rat (Rattus norvegicus) after Seluang Fish (Rasbora spp.) Treatment

Prevalence of malnutrition in Indonesia is still high although it has some potential source of nutrients. Seluang fish (Rasbora spp.) is a river fish consumed by the people of South Kalimantan, Indonesia. This study analyzed the improvement of nutritional status in the malnourished rats after treatment with Seluang Fish. The study used malnourished white rats (Rattus norvegicus) using a low protein and fat diet for 8 weeks. The rats were divided into three groups; malnourished group (M) without other dietary treatment, standard diet (P1) and seluang diet (P2) for a period of four weeks. The malnourished group was sacrificed first, and after four weeks treatment, other groups were sacrificed; blood and bones were taken for weight, protein levels, hemoglobin levels, bone length, bone calcium levels and IGF-1 levels. The results showed that the average of body weight for all the studied groups ranged between 190 to 220g. Seluang diet had the highest serum protein levels (4.388 mg/dL), hemoglobin (19.7 mg/dL) and IGF levels (388.7 ng/mL). Standard diet had the longest bone length (3.547 cm) and the highest Calcium levels of 1.68 mg/g. Based on these results, it was concluded that Seluang fish may have the potential to improve the nutritional status of malnourished rats.

Effects of Low-Dose Dairy Protein Plus Micronutrient Supplementation during Resistance Exercise on Muscle Mass and Physical Performance in Older Adults: A Randomized, Controlled Trial

OBJECTIVES

To investigate whether supplementation with low-dose dairy protein plus micronutrients augments the effects of resistance exercise (RE) on muscle mass and physical performance compared with RE alone among older adults.

DESIGN

Randomized controlled trial.

SETTING

Tokyo, Japan.

PARTICIPANTS

Eighty-two community-dwelling older adults (mean age, 73.5 years) were randomly allocated to an RE plus dairy protein and micronutrient supplementation group or an RE only group (n = 41 each).

INTERVENTION

The RE plus supplementation group participants ingested supplements with dairy protein (10.5 g/day) and micronutrients (8.0 mg zinc, 12 μg vitamin B12, 200 μg folic acid, 200 IU vitamin D, and others/day). Both groups performed the same twice-weekly RE program for 12 weeks.

MEASUREMENTS

Whole-body, appendicular, and leg lean soft-tissue mass (WBLM, ALM, and LLM, respectively) with dual-energy X-ray absorptiometry, physical performance, biochemical characteristics, nutritional intake, and physical activity were measured before and after the intervention. Data were analyzed by using linear mixed-effects models.

RESULTS

The groups exhibited similar significant improvements in maximum gait speed, Timed Up-and-Go, and 5-repetition and 30-s chair stand tests. As compared with RE only, RE plus supplementation significantly increased WBLM (0.63 kg, 95% confidence interval [CI]: 0.31-0.95), ALM (0.37 kg, 95% CI: 0.16-0.58), LLM (0.27 kg, 95% CI: 0.10-0.46), and serum concentrations of 25-hydroxyvitamin D (4.7 ng/mL, 95% CI: 1.6-7.9), vitamin B12 (72.4 pg/mL, 95% CI: 12.9-131.9), and folic acid (12.9 ng/mL, 95% CI: 10.3-15.5) (all P < 0.05 for group-by-time interactions). Changes over time in physical activity and nutritional intake excluding the supplemented nutrients were similar between groups.

CONCLUSION

Low-dose dairy protein plus micronutrient supplementation during RE significantly increased muscle mass in older adults but did not further improve physical performance.

Aging Gut Microbiota at the Cross-Road between Nutrition, Physical Frailty, and Sarcopenia: Is There a Gut-Muscle Axis?

Inadequate nutrition and physical inactivity are the mainstays of primary sarcopenia-physiopathology in older individuals. Gut microbiota composition is strongly dependent on both of these elements, and conversely, can also influence the host physiology by modulating systemic inflammation, anabolism, insulin sensitivity, and energy production. The bacterial metabolism of nutrients theoretically influences skeletal muscle cell functionality through producing mediators that drive all of these systemic effects. In this study, we review the scientific literature supporting the concept of the involvement of gut microbiota in primary sarcopenia physiopathology. First, we examine studies associating fecal microbiota alterations with physical frailty, i.e., the loss of muscle performance and normal muscle mass. Then, we consider studies exploring the effects of exercise on gut microbiota composition. Finally, we examine studies demonstrating the possible effects of mediators produced by gut microbiota on skeletal muscle, and intervention studies considering the effects of prebiotic or probiotic administration on muscle function. Even if there is no evidence of a distinct gut microbiota composition in older sarcopenic patients, we conclude that the literature supports the possible presence of a "gut-muscle axis", whereby gut microbiota may act as the mediator of the effects of nutrition on muscle cells.

WITHDRAWN: Role of osmolytes in protein folding and aggregation in cells and its applications in biotechnology

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Is It Time to Begin a Public Campaign Concerning Frailty and Pre-frailty? A Review Article

Frailty is a state that encompasses losses in physical, psychological or social domains. Therefore, frail people demonstrate a reduced potential to manage external stressors and to respond to life incidents. Consequently, such persons are prone to various adverse consequences such as falls, cognitive decline, infections, hospitalization, disability, institutionalization, and death. Pre-frailty is a condition predisposing and usually preceding the frailty state. Early detection of frailty (i.e., pre-frailty) may present an opportunity to introduce effective management to improve outcomes. Exercise training appears to be the basis of such management in addition to periodic monitoring of food intake and body weight. However, various nutritional supplements and other probable interventions, such as treatment with vitamin D or androgen, require further investigation. Notably, many societies are not conscious of frailty as a health problem. In fact, people generally do not realize that they can change this unfavorable trajectory to senility. As populations age, it is reasonable to begin treating frailty similarly to other population-affecting disorders (e.g., obesity, diabetes or cardiovascular diseases) and implement appropriate preventative measures. Social campaigns should inform societies about age-related frailty and pre-frailty and suggest appropriate lifestyles to avoid or delay these conditions. In this article, we review current information concerning therapeutic interventions in frailty and pre-frailty and discuss whether a greater public awareness of such conditions and some preventative and therapeutic measures may decrease their prevalence.

Increase in insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 1 after supplementation with selenium and coenzyme Q10. A prospective randomized double-blind placebo-controlled trial among elderly Swedish citizens

Background

Insulin-like growth factor-1(IGF-1) has a multitude of effects besides cell growth and metabolism. Reports also indicate anti-inflammatory and antioxidative effects. The concentrations of IGF-1 decrease with age and during inflammation. As selenium and coenzyme Q10 are involved in both the antioxidative defense and the inflammatory response, the present study aimed to examine the effects of supplementation with selenium and coenzyme Q10 on concentrations of IGF-1 and its binding protein IGFBP-1 in a population showing reduced cardiovascular mortality following such supplementation.

Methods

215 elderly individuals were included and given the intervention for four years. A clinical examination was performed and blood samples were taken at the start and after 48 months. Evaluations of IGF-1, the age adjusted IGF-1 SD score and IGFBP-1 were performed using group mean values, and repeated measures of variance.

Findings

After supplementation with selenium and coenzyme Q10, applying group mean evaluations, significantly higher IGF-1 and IGF-1 SD scores could be seen in the active treatment group, whereas a decrease in concentration could be seen of the same biomarkers in the placebo group.

Applying the repeated measures of variance evaluations, the same significant increase in concentrations of IGF-1 (F = 68; P>0.0001), IGF-1 SD score (F = 29; P<0.0001) and of IGFBP-1 (F = 6.88; P = 0.009) could be seen, indicating the effect of selenium and coenzyme Q10 also on the expression of IGF-1 as one of the mechanistic effects of the intervention.

Conclusion

Supplementation with selenium and coenzyme Q10 over four years resulted in increased levels of IGF-1 and the postprandial IGFBP-1, and an increase in the age-corrected IGF-1 SD score, compared with placebo. The effects could be part of the mechanistic explanation behind the surprisingly positive clinical effects on cardiovascular morbidity and mortality reported earlier. However, as the effects of IGF-1 are complex, more research on the result of intervention with selenium and coenzyme Q10 is needed.

Betaine promotes cell differentiation of human osteoblasts in primary culture

BACKGROUND

Betaine (BET), a component of many foods, is an essential osmolyte and a source of methyl groups; it also shows an antioxidant activity. Moreover, BET stimulates muscle differentiation via insulin like growth factor I (IGF-I). The processes of myogenesis and osteogenesis involve common mechanisms with skeletal muscle cells and osteoblasts sharing the same precursor. Therefore, we have hypothesized that BET might be effective on osteoblast cell differentiation.

METHODS

The effect of BET was tested in human osteoblasts (hObs) derived from trabecular bone samples obtained from waste material of orthopedic surgery. Cells were treated with 10 mM BET at 5, 15, 60 min and 3, 6 and 24 h. The possible effects of BET on hObs differentiation were evaluated by real time PCR, western blot and immunofluorescence analysis. Calcium imaging was used to monitor intracellular calcium changes.

RESULTS

Real time PCR results showed that BET stimulated significantly the expression of RUNX2, osterix, bone sialoprotein and osteopontin. Western blot and immunofluorescence confirmed BET stimulation of osteopontin protein synthesis. BET stimulated ERK signaling, key pathway involved in osteoblastogenesis and calcium signaling. BET induced a rise of intracellular calcium by means of the calcium ions influx from the extracellular milieu through the L-type calcium channels and CaMKII signaling activation. A significant rise in IGF-I mRNA at 3 and 6 h and a significant increase of IGF-I protein at 6 and 24 h after BET stimulus was detected. Furthermore, BET was able to increase significantly both SOD2 gene expression and protein content.

CONCLUSIONS

Our study showed that three signaling pathways, i.e. cytosolic calcium influx, ERK activation and IGF-I production, are enhanced by BET in human osteoblasts. These pathways could have synergistic effects on osteogenic gene expression and protein synthesis, thus potentially leading to enhanced bone formation. Taken together, these results suggest that BET could be a promising nutraceutical therapeutic agent in the strategy to counteract the concomitant and interacting impact of sarcopenia and osteoporosis, i.e. the major determinants of senile frailty and related mortality.

Mortality is associated with inflammation, anemia, specific diseases and treatments, and molecular markers

Lifespan is a complex trait, and longitudinal data for humans are naturally scarce. We report the results of Cox regression and Pearson correlation analyses using data of the Study of Health in Pomerania (SHIP), with mortality data of 1518 participants (113 of which died), over a time span of more than 10 years. We found that in the Cox regression model based on the Bayesian information criterion, apart from chronological age of the participant, six baseline variables were considerably associated with higher mortality rates: smoking, mean attachment loss (i.e. loss of tooth supporting tissue), fibrinogen concentration, albumin/creatinine ratio, treated gastritis, and medication during the last 7 days. Except for smoking, the causative contribution of these variables to mortality was deemed inconclusive. In turn, four variables were found to be associated with decreased mortality rates: treatment of benign prostatic hypertrophy, treatment of dyslipidemia, IGF-1 and being female. Here, being female was an undisputed causative variable, the causal role of IFG-1 was deemed inconclusive, and the treatment effects were deemed protective to the degree that treated subjects feature better survival than respective controls. Using Cox modeling based on the Akaike information criterion, diabetes, mean corpuscular hemoglobin concentration, red blood cell count and serum calcium were also associated with mortality. The latter two, together with albumin and fibrinogen, aligned with an”integrated albunemia” model of aging proposed recently.

Insulin-Like Growth Factor 1: At the Crossroads of Brain Development and Aging

Insulin-like growth factor 1 (IGF1) is a polypeptide hormone structurally similar to insulin. It is central to the somatotropic axis, acting downstream of growth hormone (GH). It activates both the mitogen-activated protein (MAP) kinase and PI3K signaling pathways, acting in almost every tissue in the body to promote tissue growth and maturation through upregulation of anabolic processes. Overall GH and IGF1 signaling falls with age, suggesting that it is this reduced IGF1 activity that leads to age-related changes in organisms. However, mutations that reduce IGF1-signaling activity can dramatically extend the lifespan of organisms. Therefore, the role of IGF1 in the overall aging process is unclear. This review article will focus on the role of IGF1 in brain development and aging. The evidence points towards a role for IGF1 in neurodevelopment both prenatally and in the early post-natal period, and in plasticity and remodeling throughout life. This review article will then discuss the hallmarks of aging and cognitive decline associated with falls in IGF1 levels towards the end of life. Finally, the role of IGF1 will be discussed within the context of both neuropsychiatric disorders caused by impaired development of the nervous system, and neurodegenerative disorders associated with aging. IGF1 and its derivatives are shown to improve the symptoms of certain neuropsychiatric disorders caused by deranged neurodevelopment and these effects have been correlated with changes in the underlying biology in both in vitro and in vivo studies. On the other hand, studies looking at IGF1 in neurodegenerative diseases have been conflicting, supporting both a role for increased and decreased IGF1 signaling in the underlying pathogenesis of these diseases.

Supplementation with nutrients modulating insulin-like growth factor-1 negatively correlated with changes in the levels of pro-inflammatory cytokines in community-dwelling elderly people at risk of undernutrition

BACKGROUND

Suboptimal nutrition accompanied by chronic low-grade increases in circulating cytokine levels is more common in elderly people. We explored the improvement in nutritional status, especially in the level of insulin-like growth factor-1 (IGF-1) and its relationship with changes in circulating cytokine levels, after providing extra protein and energy content to community-dwelling older adults at risk of undernutrition.

METHODS

Sixty nondiabetic subjects, aged ≥65 years and living independently in a community for elderly people, with a serum pre-albumin level ≤30 mg dL^-1 and a body mass index <25 kg m^-2 , were recruited. The subjects were followed for a 2-week pre-intervention period, during which they maintained routine dietary habits. This was followed by an intervention period, during which they received oral nutritional supplementation for 2 weeks.

RESULTS

Following 2 weeks of intervention, there were significant increases in total lymphocyte count (TLC) and insulin-like growth factor (IGF)-1, pre-albumin and transferrin compared to baseline. Body weight and mid-arm circumference significantly increased without alteration of tricep skinfold thickness at the end of the intervention. There was a significant reduction in interleukin (IL)-6 levels and a trend toward a decrease in the tumor necrosis factor (TNF)-α levels. At baseline, age was negatively correlated with IGF-1 levels and positively correlated with IL-6 and TNF-α levels. The change (▵, from baseline) in IGF-1 level was positively correlated with age and negatively correlated with ▵IL-6 and ▵TNF-α.

CONCLUSIONS

A 2-week intervention with oral nutritional supplementation improved nutritional status and decreased circulating cytokine levels. Specifically, ▵IGF-1 was negatively correlated with changes in pro-inflammatory cytokine levels in community-dwelling elderly people at risk of undernutrition. (Clinicaltrials.gov: NCT02656186).

The Prognostic Value of High-sensitivity C-reactive Protein and Prealbumin for Short-term Mortality in Acutely Hospitalized Multimorbid Elderly Patients: A Prospective Cohort Study

OBJECTIVES

To establish the predictive value on mortality after 2 months from hospital admission of two laboratory markers of nutritional and inflammatory status, high-sensitivity C-reactive protein (hs-CRP) and prealbumin, in a cohort of frail multimorbid elderly without terminal illness.

DESIGN

Prospective cohort study.

SETTING

Internal medicine ward of a large teaching hospital in Italy.

PARTICIPANTS

544 Caucasian patients with acute disease consecutively admitted from January to June 2013. 102 were excluded for being younger than 65 years old, having life expectancy <30 days or not having frailty syndrome. Further 42 patients were excluded for missing data or withdrawn at follow-up. Final analysis was performed on 400 subjects (179 M, 221 F, mean age 79±10).

MEASUREMENTS

Serum prealbumin and hs-CRP were measured at admission. Death within 2 months from hospital admission was assessed through a telephonic interview with the caregiver for each patient discharged alive. Inhospital mortality was also recorded. Survival was calculated from date of admission to our unit.

RESULTS

Mean prealbumin at admission was 17.3±7.7 mg/dl, while hs-CRP median was 24.2 mg/L (IQR 8.7 to 51.8). 108 patients (27%) died within two months from admission. In an age- and sex-adjusted analysis, log(hs-CRP) levels at admission, but not prealbumin, were independently associated with an increased risk for mortality (HR 1.40, 95% CI 1.18 to 1.66, p<0.001). After multiple adjustments for covariates, including comorbidity burden measured through Charlson score, log(hs-CRP) remained significantly associated with mortality (HR 1.38, 95% CI 1.08 to 1.76, p=0.01). A Receiver Operating Characteristic (ROC) curve was performed to test the predictive value of hs-CRP at admission on two-month mortality (AUC 0.68, 95% CI 0.63 to 0.72, p<0.001). Cut-off value was set at 38.4 mg/L. After dichotomization of hs-CRP values according to this cut-off, hs-CRP≥38.4 mg/L at admission proved to be a significant risk factor for mortality (HR 2.10, 95% CI 1.23 to 3.58, p=0.006).

CONCLUSION

Serum hs-CRP, but not prealbumin, values at admission are predictors of short-term mortality at hospital admission in elderly multimorbid patients. Inflammation seems to affect prognosis more than malnutrition in this setting and may therefore guide clinicians' attitude towards therapeutic choices.

Malnutrition and Laboratory Markers in Geriatric Patients. A Comparison of Neurologic-psychiatric, Internal and Trauma Surgical Diseases

OBJECTIVES

There is minimal information on malnutrition in neurologic-psychiatric patients compared to internal and trauma-surgical patients. The aim of the present study was to explore if there is a correlation of these different disease groups with the nutritional assessment and biochemical markers.

DESIGN

Cross - sectional study.

SETTING AND PARTICIPANTS

The study was done in a department of geriatric medicine with subspecialisation in neurologic diseases and stroke unit. 338 patients (m / f = 136 / 202, mean age 81.4 ± 7.3 years) were evaluated.

MEASUREMENTS

The nutritional status was evaluated by using the short form of the Mini Nutritional Assessment (MNA-SF) and seven biochemical markers (hemoglobin, iron, ferritin, vitamin B 12, folic acid, albumin and cholinesterase) were measured.

RESULTS

There were 74 (22%) patients with MNA ≤ 7 points (malnutrition), 148 (44%) patients with an MNA 8 - 11 points (risk of malnutrition) and 116 (34%) patients with an MNA ≥ 12 points (good nutritional status). The mean MNA score of the three major disease groups trauma-surgery, internal medicine and neurology-psychiatry was 9.1 ± 3.2 vs. 9.9 ± 3.1 vs. 10.0 ± 2.8 (p=0.236). There were significant differences of laboratory markers between the disease groups. A deficit of albumin, cholinesterase and hemoglobin was found more often in trauma-surgical and internal patients than in neurological-psychiatric patients (albumin: 21.4%, 15.7%, 5.3%; p=0.001; cholinesterase 16.7%, 16.9%, 6.3%; p=0.007; hemoglobin 78.6%, 61.4%, 50.0%; p=0.002).

CONCLUSIONS

Following Mini Nutritional Assessment, the additional measurement of albumin, cholinesterase and hemoglobin allowed a more precise grading of malnutrition. There were significant differences between the disease groups. A deficit of albumin, cholinesterase and hemoglobin was found more often in multimorbid trauma-surgical and internal patients than in neurologic-psychiatric patients.

Nutrition and Inflammation in Older Individuals: Focus on Vitamin D, n-3 Polyunsaturated Fatty Acids and Whey Proteins

Chronic activation of the inflammatory response, defined as inflammaging, is the key physio-pathological substrate for anabolic resistance, sarcopenia and frailty in older individuals. Nutrients can theoretically modulate this phenomenon. The underlying molecular mechanisms reducing the synthesis of pro-inflammatory mediators have been elucidated, particularly for vitamin D, n-3 polyunsaturated fatty acids (PUFA) and whey proteins. In this paper, we review the current evidence emerging from observational and intervention studies, performed in older individuals, either community-dwelling or hospitalized with acute disease, and evaluating the effects of intake of vitamin D, n-3 PUFA and whey proteins on inflammatory markers, such as C-Reactive Protein (CRP), interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α). After the analysis, we conclude that there is sufficient evidence for an anti-inflammatory effect in aging only for n-3 PUFA intake, while the few existing intervention studies do not support a similar activity for vitamin D and whey supplements. There is need in the future of large, high-quality studies testing the effects of combined dietary interventions including the above mentioned nutrients on inflammation and health-related outcomes.

Low energy intake during the first 4 weeks of life increases the risk for severe retinopathy of prematurity in extremely preterm infants

OBJECTIVES

Poor weight gain during the first weeks of life in preterm infants is closely associated with the risk of developing the retinopathy of prematurity (ROP) and insufficient nutrition might be an important contributing factor. This study aimed to evaluate the effect of energy and macronutrient intakes during the first 4 weeks of life on the risk for severe ROP (stages 3-5).

STUDY DESIGN

A population-based study including all Swedish extremely preterm infants born before 27 gestational weeks during a 3-year period. Each infant was classified according to the maximum stage of ROP in either eye as assessed prospectively until full retinal vascularisation. The detailed daily data of actual intakes of enteral and parenteral nutrition and growth data were obtained from hospital records.

RESULTS

Of the included 498 infants, 172 (34.5%) had severe ROP and 96 (19.3%) were treated. Energy and macronutrient intakes were less than recommended and the infants showed severe postnatal growth failure. Higher intakes of energy, fat and carbohydrates, but not protein, were significantly associated with a lower risk of severe ROP. Adjusting for morbidity, an increased energy intake of 10 kcal/kg/day was associated with a 24% decrease in severe ROP.

CONCLUSIONS

We showed that low energy intake during the first 4 weeks of life was an independent risk factor for severe ROP. This implies that the provision of adequate energy from parenteral and enteral sources during the first 4 weeks of life may be an effective method for reducing the risk of severe ROP in extremely preterm infants.

Innovative biomarkers for predicting type 2 diabetes mellitus: relevance to dietary management of frailty in older adults

Type 2 diabetes mellitus (T2DM) increases in prevalence in the elderly. There is evidence for significant muscle loss and accelerated cognitive impairment in older adults with T2DM; these comorbidities are critical features of frailty. In the early stages of T2DM, insulin sensitivity can be improved by a "healthy" diet. Management of insulin resistance by diet in people over 65 years of age should be carefully re-evaluated because of the risk for falling due to hypoglycaemia. To date, an optimal dietary programme for older adults with insulin resistance and T2DM has not been described. The use of biomarkers to identify those at risk for T2DM will enable clinicians to offer early dietary advice that will delay onset of disease and of frailty. Here we have used an in silico literature search for putative novel biomarkers of T2DM risk and frailty. We suggest that plasma bilirubin, plasma, urinary DPP4-positive microparticles and plasma pigment epithelium-derived factor merit further investigation as predictive biomarkers for T2DM and frailty risk in older adults. Bilirubin is screened routinely in clinical practice. Measurement of specific microparticle frequency in urine is less invasive than a blood sample so is a good choice for biomonitoring. Future studies should investigate whether early dietary changes, such as increased intake of whey protein and micronutrients that improve muscle function and insulin sensitivity, affect biomarkers and can reduce the longer term complication of frailty in people at risk for T2DM.

Role of selected amino acids on plasma IGF-I concentration in infants

PURPOSE

Insulin-like growth factor-I (IGF-I) is related to growth and its secretion is modified by protein intake in early infancy. We examined the relationship of dietary protein and circulating amino acids on plasma IGF-I levels and early growth.

METHODS

Healthy formula-fed infants (n = 213) were randomly assigned to receive either a protein-reduced infant formula with alpha-lactalbumin-enriched whey and free tryptophan and phenylalanine (IF) or an isocaloric standard formula without free amino acids (CF) for the first 120 days of life. A group of breastfed (BF) infants was studied as a non-randomized reference cohort. Biochemical variables were measured shortly after birth (subpopulation) and at an age of 120 days. A path analysis was used to explore the relationship between IGF-I, insulin and amino acids. Results are derived from secondary analyses of a randomized controlled trial.

RESULTS

Plasma concentrations of IGF-I at 120 days were significantly higher in IF than in CF infants [58.5 (15.0) vs. 53.7 (9.95) ng/mL; p = 0.020]. BF infants showed lower IGF-I concentrations of 41.6 (10.7) ng/mL. All amino acids but Thr and Cit had a more marked effect on insulin than on IGF-I level. Considering weight, sex and feeding group, Trp explained an equal percentage of variance of IGF-I and insulin (total R ² 12.5 % of IGF-I and 12.3 % of insulin), while branched-chain AA explained an up to twofold higher variance of insulin than IGF-I. Compared to CF, IF explained 18.9 % of the IGF-I level (p = 0.03), while for insulin no direct effect was detectable.

CONCLUSION

Higher IGF-I concentrations and growth velocities in infants receiving protein-reduced IF indicate that the protein concentration of an infant formula alone does not control IGF-I levels and growth. Other components (e.g., selected amino acids) of infant formulae might control directly or indirectly via insulin influence IGF-I.

Interaction network analysis of differentially expressed genes and screening of cancer marker in the urine of patients with invasive bladder cancer

OBJECTIVE

To detect the expression profile of bladder cancer and to delineate the interaction network of these genes in invasive bladder cancer.

METHODS

A total of 126 differentially expressed genes were identified, and input into STRING online database to delineate interaction network. The network data were screened with central nodes. The expression of genes with the most evident change in the exfoliated cells of urine was detected. RNA markers with over-expression in stage Ta tumor and/or T1 to T4 tumors but low expression in blood or inflammatory cells were characterized.

RESULTS

On the basis of assay of 21,639 whole-genome oligonucleotide microarray, a total of 126 differentially expressed genes were identified, of which 69 had up-regulated expression and 57 had down-regulated expression. STRING screening showed there were interactions among 103 genes in the bladder cancer which formed a complex network. A total of 23 central nodes were screened with Cytoscape and are involved in multiple signaling pathways related to tumorigenesis. The test specificity was 80% for the 30 control patients with urinary tract infections. The combination of BLCA-4 and HOXA13 could distinguish between low and high grade tumors, with specificity and sensitivity of 80%.

CONCLUSION

The interaction network of differentially expressed genes, especially the central nodes of this network, can provide evidence for the early diagnosis and molecular targeted therapy of invasive bladder cancer, and combined detection of IGF-1, hTERT, BLCA-4 and HOXA13 genes is helpful to evaluate BTCC at different stages.

Multiple hormonal dysregulation as determinant of low physical performance and mobility in older persons

Mobility-disability is a common condition in older individuals. Many factors, including the age-related hormonal dysregulation, may concur to the development of disability in the elderly. In fact, during the aging process it is observed an imbalance between anabolic hormones that decrease (testosterone, dehydroepiandrosterone sulphate (DHEAS), estradiol, insulin like growth factor-1 (IGF-1) and Vitamin D) and catabolic hormones (cortisol, thyroid hormones) that increase. We start this review focusing on the mechanisms by which anabolic and catabolic hormones may affect physical performance and mobility. To address the role of the hormonal dysregulation to mobility-disability, we start to discuss the contribution of the single hormonal derangement. The studies used in this review were selected according to the period of time of publication, ranging from 2002 to 2013, and the age of the participants (≥65 years). We devoted particular attention to the effects of anabolic hormones (DHEAS, testosterone, estradiol, Vitamin D and IGF-1) on both skeletal muscle mass and strength, as well as other objective indicators of physical performance. We also analyzed the reasons beyond the inconclusive data coming from RCTs using sex hormones, thyroid hormones, and vitamin D (dosage, duration of treatment, baseline hormonal values and reached hormonal levels). We finally hypothesized that the parallel decline of anabolic hormones has a higher impact than a single hormonal derangement on adverse mobility outcomes in older population. Given the multifactorial origin of low mobility, we underlined the need of future synergistic optional treatments (micronutrients and exercise) to improve the effectiveness of hormonal treatment and to safely ameliorate the anabolic hormonal status and mobility in older individuals.

Transient hypothermia in HIV-1 with insulin-like growth factor-1 deficiency and severe protein calorie malnutrition

Hypothermia is a multifactorial process that results from decreased heat production or increased heat loss, with the former due to, but not limited to, endocrine dysfunction, malnutrition, and central nervous system pathologies. We report an HIV-1 patient with transient hypothermia secondary to severe protein calorie malnutrition and elevated HIV viral load. In this patient, it is hypothesized that the etiology of the hypothermia was multifactorial due to severe protein calorie malnutrition, evidenced by decreased insulin-like growth factor-1 levels, severe hypothyroidism, and an elevated HIV viral load, since the patient began to improve with the initiation of highly active antiretroviral therapy, improved nutrition, and continuation of thyroid supplementation.

The Neuromuscular Junction: Aging at the Crossroad between Nerves and Muscle

Aging is associated with a progressive loss of muscle mass and strength and a decline in neurophysiological functions. Age-related neuromuscular junction (NMJ) plays a key role in musculoskeletal impairment that occurs with aging. However, whether changes in the NMJ precede or follow the decline of muscle mass and strength remains unresolved. Many factors such as mitochondrial dysfunction, oxidative stress, inflammation, changes in the innervation of muscle fibers, and mechanical properties of the motor units probably perform an important role in NMJ degeneration and muscle mass and strength decline in late life. This review addresses the primary events that might lead to NMJ dysfunction with aging, including studies on biomarkers, signaling pathways, and animal models. Interventions such as caloric restriction and exercise may positively affect the NMJ through this mechanism and attenuate the age-related progressive impairment in motor function.

The Interplay between Magnesium and Testosterone in Modulating Physical Function in Men

The role of nutritional status as key factor of successful aging is very well recognized. Among the different mechanisms by which nutrients may exert their beneficial effects is the modulation of the hormonal anabolic milieu, which is significantly reduced with aging. Undernutrition and anabolic hormonal deficiency frequently coexist in older individuals determining an increased risk of mobility impairment and other adverse outcomes. Mineral assessment has received attention as an important determinant of physical performance. In particular, there is evidence that magnesium exerts a positive influence on anabolic hormonal status, including Testosterone, in men. In this review we summarize data from observational and intervention studies about the role of magnesium in Testosterone bioactivity and the potential underlying mechanisms of this relationship in male subjects. If larger studies will confirm these pivotal data, the combination of hormonal and mineral replacements might be adopted to prevent or delay the onset of disability in the elderly.