Different circulating ghrelin responses to isoglucidic snack food in healthy individuals

The last decade has seen much debate on ghrelin as a potential target for treating obesity. Despite a close connection between snack food intake and obesity, snacking is controversially reviewed as a good habit in a healthy nutritional regimen. The aim of the study was to evaluate whether a different nutrient composition influences postprandial ghrelin levels and glucose increments induced by 6 isoglucidic snack food. 20 healthy individuals (10 M/10 F; BMI 23.1\ub10.5; age 33\ub10.67 years, mean and SE) from H San Raffaele Scientific Institute and Milan University were enrolled. The subjects underwent OGTT (50 g) and 6 isoglucidic test-meal loads to assess the ghrelin circulating levels and the area under glycemic curves induced by 6 commercial snacks. 3 h after hazelnut chocolate intake, ghrelin was significantly lower than with wafer chocolate intake (p<0.002). As a response to all snacks, the glycemic curves were not different even though hazelnut chocolate showed the lowest glycemic curve. Moreover, snack fat content was found to be inversely correlated to 3-h plasma ghrelin levels (p<0.0001; R2=0.77) and positively associated with satiety scores (p<0.02; R2=0.28). Also energy load was inversely correlated to 3-h plasma ghrelin (p<0.0001; R 2=0.73). Our results indicate that snack food administered in equivalent glucidic loads elicits postprandial ghrelin suppression and satiety ratings in different ways. Further studies are needed to elucidate the role of ghrelin as hunger-hormone in the regulation of energy balance

Metformin Treatment Prevents Sedentariness Related Damages in Mice

Metformin (METF), historical antihyperglycemic drug, is a likely candidate for lifespan extension, treatment and prevention of sedentariness damages, insulin resistance, and obesity. Skeletal muscle is a highly adaptable tissue, capable of hypertrophy response to resistance training and of regeneration after damage. Aims of this work were to investigate METF ability to prevent sedentariness damage and to enhance skeletal muscle function. Sedentary 12-week-old C57BL/6 mice were treated with METF (250 mg/kg per day, in drinking water) for 60 days. METF role on skeletal muscle differentiation was studied in vitro using murine C2C12 myoblasts. Muscular performance evaluation revealed that METF enhanced mice physical performance (Estimated VO2max). Biochemical analyses of hepatic and muscular tissues indicated that in liver METF increased AMPK and CAMKII signaling. In contrast, METF inactivated ERKs, the principal kinases involved in hepatic stress. In skeletal muscle, METF activated AKT, key kinase in skeletal muscle mass maintenance. In in vitro studies, METF did not modify the C2C12 proliferation capacity, while it positively influenced the differentiation process and myotube maturation. In conclusion, our novel results suggest that METF has a positive action not only on the promotion of healthy aging but also on the prevention of sedentariness damages

Circulating irisn is reduced in male patients with type 1 and type 2 Myotonic Dystrophies

Context: Myotonic dystrophies (DM) are dominantly inherited muscle disorders characterized by myotonia, muscle weakness, and wasting. The reasons for sarcopenia in DMs are uncleared and multiple factors are involved. Irisin, a positive hormone regulator of muscle growth and bone, may play a role. Objectives: To investigate (1) circulating irisin in a series of DM1 and DM2 male patients compared with healthy controls and (2) the relationships between irisin and anthropometric, metabolic and hormonal parameters. Design and study participants: This is a cross-sectional study. Fasting blood samples for glucometabolic, gonadic, bone markers, and irisin were collected from 28 ambulatory DM1, 10 DM2, and 23 age-matched healthy male subjects. Body composition and bone mineralization [bone mineral density (BMD)] were measured by DEXA. Echocardiographic assessment and visceral adiposity, namely, liver and epicardial fat, were investigated by ultrasound. Irisin released from cultured myotubes derived from 3 DM1, 3 DM2, and 3 healthy donors was assayed. Results: Plasma irisin levels were definitely lower in both DM1 and DM2 patients than in controls with no difference between DM1 and DM2. Irisin released from DM1 and DM2 myotubes was similar to that released from myotubes of the non-DM donors, though diabetic DM2 myotubes released more irisin than DM1 myotubes. There was no correlation between irisin and muscle strength or lean mass in both DM1 and DM2 patients. In DM1 patients, plasma irisin levels correlated negatively with oxygen consumption and positively with insulin resistance, while in DM2 patients plasma irisin levels positively correlated with fat mass at arms and legs levels. No correlation with visceral fat, left ventricular mass, and gonadal hormones could be detected. In both DM1 and DM2 patients, legs BMD parameters positively correlated with plasma irisin levels. Conclusion: Plasma irisin is reduced in both DM1 and DM2 male patients likely reflecting muscle mass reduction. Moreover, insulin resistance may contribute to modulation of plasma irisin in DM1 patients. The irisin-mediated cross talk muscle\u2013adipose tissue\u2013bone may be active also in the male myotonic dystrophies\u2019 model

Effect of Sugar versus Mixed Breakfast on Metabolic and Neurofunctional Responses in Healthy Individuals

We investigated the effects of glucose and diverse breakfasts on glucose increment and ghrelin suppression and cognitive processing of sensory information assessed by frontal P300 evoked potentials. In a randomized crossover design, 12 healthy individuals (6M/6F; BMI 22.2\u2009\ub1\u20090.4\u2009kg/m2; 27\u2009\ub1\u20091.3 years, mean\u2009\ub1\u2009SEM) underwent 50\u2009g OGTT (A) and 3 breakfasts (B1: milk and cereals; B2: milk, apple, and chocolate cream-filled sponge cake; B3: milk, apple, bread, and hazelnut chocolate cream) to assess plasma glucose-, insulin-, and ghrelin excursions. An electroencephalography was performed before and 100\u2009min after consumption of each load to measure the latency of frontal P300 evoked potentials as index of cognitive performance. Breakfasts B1 and B2 exhibited significantly lower glycemic and insulinemic responses as compared to A. Breakfast B3 exhibited significantly lower glycemic, but not insulinemic response, as compared to A. Final plasma ghrelin inhibition was more pronounced, albeit not significantly, in all breakfasts with respect to A. P300 latency tended to decrease following each of the three breakfasts, but B3 was the only breakfast capable to elicit a statistically significant reduction in P300 latency with respect to A (), suggesting ameliorated cognitive performance. Such amelioration was correlated with the 2-hour final inhibition of plasma ghrelin concentration (r = 0.61, p = 0.01)

Developing surrogate markers for predicting antibiotic resistance "hot spots" in rivers where limited data are available

Pinpointing environmental antibiotic resistance (AR) hot spots in low-and middle-income countries (LMICs) is hindered by a lack of available and comparable AR monitoring data relevant to such settings. Addressing this problem, we performed a comprehensive spatial and seasonal assessment of water quality and AR conditions in a Malaysian river catchment to identify potential "simple"surrogates that mirror elevated AR. We screened for resistant coliforms, 22 antibiotics, 287 AR genes and integrons, and routine water quality parameters, covering absolute concentrations and mass loadings. To understand relationships, we introduced standardized "effect sizes"(Cohen's D) for AR monitoring to improve comparability of field studies. Overall, water quality generally declined and environmental AR levels increased as one moved down the catchment without major seasonal variations, except total antibiotic concentrations that were higher in the dry season (Cohen's D > 0.8, P < 0.05). Among simple surrogates, dissolved oxygen (DO) most strongly correlated (inversely) with total AR gene concentrations (Spearman's ρ 0.81, P < 0.05). We suspect this results from minimally treated sewage inputs, which also contain AR bacteria and genes, depleting DO in the most impacted reaches. Thus, although DO is not a measure of AR, lower DO levels reflect wastewater inputs, flagging possible AR hot spots. DO measurement is inexpensive, already monitored in many catchments, and exists in many numerical water quality models (e.g., oxygen sag curves). Therefore, we propose combining DO data and prospective modeling to guide local interventions, especially in LMIC rivers with limited data

Different postprandial plasma ghrelin responses elicited by intake of 6 commercial snack foods in healthy subjects

Snacking is controversially discussed as a good habit in a healthy nutritional regimen. Obviously snack foods may be very different in determining glycemic and hormonal responses related to appetite and satiety. Serving-size, composition, macronutrients are only some of the factors that could trigger a wide hormonal cascade and therefore causing potential deleterious effects on metabolism. In the last decade there has been a great deal of interest to consider ghrelin as a potential target for treating obesity. It has been previously shown that rodents vaccinated against endogenous ghrelin could slow weight gain by decreasing feed efficiency, thus suggesting a primary role played by this hormone in energy homeostasis. Here, 20 healthy individuals (10M/10F; BMI 23.3\ub11.6; 35\ub16 yrs) underwent to OGTT (50-g) and 6 isoglucidic test-meal loads to assess glycemic index (GI), plasma insulin and ghrelin circulating levels induced by 6 commercial snack foods. Ghrelin was significantly lower 3 hours after the snack intake with respect to the basal condition in half of the snack foods (hazelnut chocolate: P<0.001; sponge cake2: P<0.001; chilled cake: P=0.02), whereas no differences were detected in plasma insulin and GI among all snack foods. If ghrelin could be meant as a crucial biomarker of satiation, those 3 snacks drove a nutritional status more propending for a long-lasting hunger-free period. Our results indicate that snack foods are diverse in inducing plasma ghrelin levels under equivalent metabolic conditions. Further studies are needed to elucidate the role of ghrelin as hunger-hormone in the regulation of energy balance