Acute effects of acylated ghrelin on salbutamol-induced metabolic actions in humans.

The aim of this study is to describe a potential modulatory effect of acute acylated ghrelin (AG) administration on the glucose, insulin, and free fatty acids (FFA) responses to salbutamol (SALBU). Six healthy young male volunteers underwent the following four testing sessions in random order at least 7 days apart: (a) acute AG administration (1.0 µg/kg i.v. as bolus at 0'); (b) SALBU infusion (0.06 µg/kg/min i.v. from -15' to +45'); (c) SALBU infusion+AG; and (d) isotonic saline infusion. Blood samples for glucose, insulin, and FFA levels were collected every 15 min. As expected, with respect to saline, SALBU infusion induced a remarkable increase in glucose (10.8±5.6 mmol/l×min; P<0.05), insulin (2436.8±556.9 pmol/l×min; P<0.05), and FFA (18.9±4.5 mmol/l×min; P<0.01) levels. A significant increase in glucose (7.4±3.9 mmol/l×min; P<0.05) and FFA levels (10.0±2.8 mmol/l×min; P<0.01) without significant variations in insulin levels were recorded after AG administration. Interestingly, the hyperglycemic effect of AG appeared to be significantly potentiated during SALBU infusion (26.7±4.8 mmol/l×min; P<0.05). On the other hand, the stimulatory effect of SALBU on insulin and FFA was not significantly modified by AG administration. The results of this study show that acute AG administration has a synergic effect with ß2-adrenergic receptor activation by SALBU on blood glucose increase, suggesting that their pharmacological hyperglycemic action takes place via different mechanisms. On the other hand, AG has a negligible influence on the other pharmacological metabolic effects of SALBU infusion.

Impact of short-term treatment with benzodiazepines and imidazopyridines on glucose metabolism in healthy subjects.

AIM: In the last years there has been a progressive reduction of the average duration of sleep and an increase in the incidence of sleep disturbances. At the same time, an increase of the incidence of the metabolic syndrome has been described, partly attributable to the progressive worsening of dietary habits and the increase in sedentary lifestyle. Recent studies suggest that adequate sleep is essential to maintain good glucose metabolism and sleep disturbances may contribute to the manifestation of the metabolic syndrome. Benzodiazepines (BZ), such as brotizolam, and imidazopyridines, such as zolpidem, are frequently used as hypnotics but their potential impact on glucose metabolism has never been evaluated so far. METHODS: In 12 healthy volunteers [age (mean ± SEM) 38.3 ± 8.1 years; body mass index (BMI) 21.9 ± 0.8 kg/m²] we studied glucose and insulin responses to oral glucose tolerance test (OGTT, 75 g) before and after 15 days treatment with brotizolam 0.25 mg/day or zolpidem 10 mg/day. RESULTS: Brotizolam increased glucose delta area under curve response to the OGTT by 122 % (p < 0.01) and zolpidem by 86 % (p < 0.01) without significant variations of insulin levels, suggesting an impact on insulin sensitivity and/or insulin secretion. CONCLUSIONS: This study suggests that BZ and imidazopyridines have a rapid glucometabolic effect that is detectable as early as after 15 days treatment.

The GH-releasing effect of acylated ghrelin in normal subjects is refractory to GH acute auto-feedback but is inhibited after short-term GH administration inducing IGF1 increase.

OBJECTIVE: GH secretion is regulated by an interplay between GH-releasing hormone (GHRH), somatostatin (SST), and other central and peripheral signals. Acylated ghrelin (AG) amplifies GH pulsatility acting, at least partially, independently from GHRH and SST. The GH response to GHRH is inhibited by recombinant human GH (rhGH), likely due to a SST-mediated negative GH auto-feedback. The effect of exogenous rhGH on the GH-releasing effect of AG has never been tested. DESIGN AND METHODS: In six healthy volunteers, we studied the GH response to acute AG administration (1.0 µg/kg i.v.) during saline or rhGH infusion (4.0 µg/kg per h i.v.) or after 4-day rhGH (10.0 µg/kg s.c.) administration. RESULTS: Compared with saline, rhGH infusion increased GH levels (P<0.01). During saline, acute i.v. AG induced a marked increase (P<0.01) in GH levels similar to those observed after AG administration during rhGH infusion. During s.c. rhGH, IGF1 levels rose from day 0 to day 5 (P<0.01). After 4-day s.c. rhGH, i.v. AG increased (P<0.01) GH levels, though significantly (P<0.05) less than on day 0. CONCLUSIONS: The marked somatotroph-releasing effect of AG is refractory to a direct GH auto-feedback whereas is markedly inhibited after 4-day rhGH administration, suggesting the possibility of a selective IGF1-mediated inhibitory feedback.

The metabolic response to the activation of the beta-adrenergic receptor by salbutamol is amplified by acylated ghrelin.

BACKGROUND: It is well recognized that beta-adrenergic receptors mediate important endocrine and metabolic actions. In fact, beta-adrenergic receptor activation negatively influences GH secretion while exerting relevant metabolic actions such as the stimulation of insulin secretion, glycogenolysis, and lipolysis. AIM: We have already shown that the activation of the GH secretagogue receptor (GHS-R)-1a by acylated ghrelin (AG) counteracts the inhibitory effect of salbutamol (SALB), a beta2-adrenergic agonist, on GH release. The aim of the present study in humans was to clarify whether the metabolic response to SALB is affected by the infusion of AG, also known to exert significant metabolic actions. METHODS: Six healthy young male volunteers underwent the following testing sessions in random order at least 5 days apart: a) SALB (0.06 microg/kg/min iv from 0 to 60 min) alone; b) SALB in combination with AG (1.0 microg/kg/min iv from -60 to 60 min); c) isotonic saline. Insulin, glucose, and free fatty acids (FFA) levels were evaluated every 15 min. RESULTS: As expected, with respect to saline, SALB administration tended to increase both insulin secretion [Delta area under the curve (DeltaAUC): 0.16+/-0.09 vs 0.003+/-0.077 x 10(3) microU/ml/min; p>0.05] and FFA levels (DeltaAUC: 8.0+/-7.3 vs -4.0+/-4.0 mEq/l/min; p>0.05), while glucose levels did not change. The metabolic response to SALB was significantly modified under the exposure of AG. In fact, under AG infusion, SALB elicited a more marked increase of FFA (DeltaAUC: 22.3+/-3.2 vs 8.0+/-7.3 mEq/l/min; p<0.05) as well as a slight elevation in insulin (DeltaAUC: 0.37+/-0.11 vs 0.16+/-0.09 x 10(3) microU/ml/min; p>0.05). Under AG, the baseline glucose levels were more elevated but, again, in combination with AG, SALB did not significantly modify glucose levels. CONCLUSIONS: Beta-adrenergic receptors and AG are likely to interact at the metabolic level. In humans, the lypolitic response to a beta2-adrenergic agonist such as SALB is amplified by AG. Meanwhile, during the co-treatment, the marginal insulinotropic effect was not associated with an increase in glycemia.

Circulating obestatin levels in normal and Type 2 diabetic subjects.

BACKGROUND: Obestatin has been discovered as a new product of the ghrelin gene. Its physiological actions are still a matter of debate, but it seems that this peptide is likely to be involved in the control of insulin secretion and action as well as of adipocyte function. It has been already shown that obestatin secretion in humans is negatively modulated by food intake. AIM: To clarify obestatin secretion in normal subjects and in patients with Type 2 diabetes (T2D) in basal conditions and after a standardized meal. SUBJECTS/METHODS: Five normal subjects and 5 T2D patients were studied during infusion of saline (iv for over 5 h from -120 to +180 min). A standardized lunch was served at 0 min. Obestatin, glucose, and insulin levels were assayed at -120, -90, -60, -45, -30, -15, 0, 15, 30, 45, 60, 90, 120, 150, and 180 min. RESULTS: From -120 to 0 min, obestatin levels in normal and T2D subjects were similar (area under the curve: 32.3+/-5.6 pg/ml/min vs 31.1+/-1.0 pg/ml/min). After the meal, circulating obestatin levels underwent a clear decrease in normal subjects (0 min: 300.6+/-34.7 pg/ml vs nadir at 60 min: 161.8+/-29.4 pg/ml; p=0.002) but not in diabetic patients (0 min: 267.2+/-16.5 pg/ml vs nadir at 180 min: 226.0+/-10.5 pg/ml). CONCLUSION: This study shows that normal and diabetic subjects display similar levels of circulating obestatin in fasting condition. However patients with T2D look refractory to the inhibitory effect of meal on obestatin secretion.

Sleep abnormalities in type 2 diabetes may be associated with glycemic control.

Sleep disturbances may be associated with impaired glucose metabolism. The aim of this study was to evaluate sleep duration and quality in relation to glycemic control in patients with type 2 diabetes. In a cross-sectional study, sleep duration and quality were assessed in 47 middle-aged patients with type 2 diabetes treated with oral agents and without sleep disturbing complications and 23 healthy control subjects similar by age, sex, body mass index, occupation and schooling. Sleep was recorded by wrist-actigraphy for three consecutive days under free-living conditions. Univariate analysis showed lower sleep maintenance (P = 0.002) and sleep efficiency (P = 0.005), and higher fragmentation index (P < 0.0001), total activity score (P = 0.05) and moving time (P < 0.0001) in patients with type 2 diabetes. After adjusting for age, gender and schooling, fragmentation index and moving time remained significantly higher in the patients with diabetes (P < 0.05, both). HbA1c correlated inversely with sleep efficiency (r = -0.29; P = 0.047) and positively with moving time (r = 0.31; P = 0.031). These findings suggest that type 2 diabetes is associated with sleep disruptions even in the absence of complications or obesity. The relevance of sleep abnormalities to metabolic control and possible strategies to improve sleep quality in type 2 diabetes deserve further investigation.

The locus of control in patients with Type 1 and Type 2 diabetes managed by individual and group care.

AIMS: The locus of control theory distinguishes people (internals) who attribute events in life to their own control, and those (externals) who attribute events to external circumstances. It is used to assess self-management behaviour in chronic illnesses. Group care is a model of systemic group education that improves lifestyle behaviour and quality of life in patients with Type 1 and Type 2 diabetes. This study investigated the locus of control in Type 1 and Type 2 diabetes and the possible differences between patients managed by group care and control subjects followed by traditional one-to-one care. METHODS: Cross-sectional administration of two questionnaires (one specific for diabetes and one generic for chronic diseases) to 83 patients followed for at least 5 years by group care (27 Type 1 and 56 Type 2) and 79 control subjects (28 Type 1 and 51 Type 2) of similar sex, age and diabetes duration. Both tools explore internal control of disease, the role of chance in changing it and reliance upon others (family, friends and health professionals). RESULTS: Patients with Type 1 diabetes had lower internal control, greater fatalistic attitudes and less trust in others. Patients with either type of diabetes receiving group care had higher internal control and lower fatalism; the higher trust in others in those with Type 1 diabetes was not statistically significant. The differences associated with group care were independent of sex, age and diabetes duration. CONCLUSIONS: Patients with Type 1 diabetes may have lower internal control, fatalism and reliance upon others than those with Type 2 diabetes. Receiving group care is associated with higher internal control, reduced fatalism and, in Type 1 diabetes, increased trust in others.

Perception of, and anxiety levels induced by, laser treatment in patients with sight-threatening diabetic retinopathy. A multicentre study.

AIMS: To investigate how laser treatment is perceived, in terms of anxiety and awareness, by diabetic patients attending four centres in Northern Italy with specific interest and expertise in diabetic retinopathy, where work settings and flow are organized differently. METHODS: The Hospital Anxiety and Depression Scale (HADS), Family Apgar-List of Threatening Experiences (FA-LTE), State-Trait Anxiety Inventories 1 and 2 (STAI-1 and STAI-2) questionnaires were completed by 259 patients, 131 waiting for laser treatment and 128 control subejcts awaiting non-intervention visits. Open questions were also asked on whether patients had ever heard the word 'laser' and whether they could describe laser treatment. RESULTS: High scores were detected by HADS, STAI-1 and STAI-2 among patients waiting for photocoagulation. Anxiety was greater in women and people with poor schooling. After controlling for centres, gender, previous laser treatment and schooling, HADS and STAI-1 remained significantly lower among persons waiting for non-intervention visits. Having received photocoagulation previously did not modify anxiety. Anxiety was lower in those centres where facilities and resources were more patient-oriented. Most patients could neither describe photocoagulation nor explain why they were about to receive it, but had a negative perception and some described it with words evoking cruelty and pain. CONCLUSIONS: These data suggest that laser treatment is experienced as an event that causes anxiety. Preoperative education and counselling may help to reduce fear and patients' avoidance of treatment.

Evaluation of the locus of control in patients with type 2 diabetes after long-term management by group care.

AIM: To investigate the locus of control in patients with type 2 diabetes followed by systemic group education (Group Care) and traditional one-to-one care. METHODS: In a post-hoc analysis, two questionnaires were administered to 56 patients who had been followed for 5-7 years by Group Care and 51 controls followed by individual care, similar by age, sex, diabetes duration, glycaemia, insulinaemia, weight and other clinical variables. Patients on Group Care had lower HbA1c (7.40 +/- 1.21%) than controls (7.99 +/- 1.48%), P = 0.027. The Peyrot and Rubin questionnaire, specific for diabetes, and the Wallston and Wallston questionnaire, more generic for chronic diseases, were administered. Both questionnaires explore 3 areas: internal control of disease, and the role of chance or powerful other people, including health operators, in changing the disease. RESULTS: Both questionnaires showed lower scores for chance in patients followed by Group Care (P < 0.001), while scores for powerful others did not differ from those of patients followed by traditional care. The Peyrot and Rubin tool showed increased Internal Control (P < 0.001) in the patients followed by Group Care. Multivariate analysis showed that the HOMA index of insulin resistance was inversely related to Internal Control (B = -0.144, P = 0.005) independently of BMI and HbA1c. CONCLUSION: Fatalistic attitudes were lower and internal control higher in patients with type 2 diabetes followed by Group Care. These changes may be related to insulin resistance, above and beyond the effects of body weight and metabolic control.

A 3-year prospective randomized controlled clinical trial of group care in type 1 diabetes.

BACKGROUND AND AIMS: We showed that continuing education can be embedded into routine diabetes care by seeing patients in small groups rather than individually. Group care was cost-effective in improving quality of life, knowledge of diabetes, health behaviours and clinical outcomes in people with type 2 diabetes. The aim of this study was to verify if group care can also be applied to type 1 diabetes. METHODS AND RESULTS: Randomized, controlled clinical trial comparing 31 patients managed by group care with 31 managed by traditional one-to-one care. A syllabus was built and later remodulated with the patients in a series of focus-group meetings. The primary end-point was changes in quality of life. Secondary end-points were: knowledge of diabetes, health behaviours, HbA1c and circulating lipids. Differential costs to the Italian National Health System and to the patients were also calculated. After 3 years, quality of life improved among patients on group care, along with knowledge and health behaviours (p<0.001, all). Knowledge added its effects to those of group care by independently influencing behaviours (p=0.004) while quality of life changed independently of either (p<0.001). Among controls, quality of life worsened (p<0.001) whereas knowledge and behaviours remained unchanged. HDL cholesterol increased among patients on group care (p=0.027) and total cholesterol decreased in the controls (p<0.05). HbA1c decreased, though not significantly, in both. Direct costs for group and one-to-one care were Euros 933.19 and Euros 697.10 per patient, respectively, giving a cost-effectiveness ratio of Euros 19.42 spent per point gained in the quality of life scale. CONCLUSIONS: Group care is applicable and also cost-effective in type 1 diabetes. It improves quality of life, knowledge and behaviours. Future programme adjustments should strive to impact more on metabolic control.