Growth hormone and ghrelin secretion in severely obese women before and after bariatric surgery

Objective: The objective was to evaluate ghrelin and growth hormone (GH) interactions and responses to a growth hormone‐releasing hormone (GHRH)/arginine test in severe obesity before and after surgically‐induced weight loss. Research Methods and Procedures: Our study population included 11 severely obese women 39 ± 12 years of age, with a mean BMI of 48.6 ± 2.4 kg/m², re‐studied in a phase of stabilized body weight, with a BMI of 33.4 ± 1.2 kg/m², 18 months after having successfully undergone biliopancreatic diversion (BPD). A GHRH/arginine test was performed before and 18 months after BPD to evaluate ghrelin and GH interactions. Active ghrelin, measured by radioimmunoassay (RIA), and GH, measured by chemiluminescence assay, were assayed before and after the GHRH/arginine test. Results: Fasting serum GH levels and GH area under the curve (AUC) significantly increased from 0.2 ± 0.05 ng/mL to 1 ± 0.3 ng/mL (p < 0.05) and from 514.76 ± 98.7 ng/mL for 120 minutes to 1957.3 ± 665.1 ng/mL for 120 minutes after bariatric surgery (p < 0.05), respectively. Although no significant change in fasting ghrelin levels was observed (573 ± 77.9 before BPD vs. 574.1 ± 32.7 after BPD), ghrelin AUC significantly increased from ?3253.9 ± 2180.9 pg/mL for 120 minutes to 1142.3 ± 916.4 pg/mL for 120 minutes after BPD (p < 0.05). Fasting serum insulin‐like growth factor (IGF)‐1 concentration did not change significantly (133.6 ± 9.9 ng/mL before vs. 153.3 ± 25.2 ng/mL after BPD). Discussion: Our study demonstrates that the mechanisms involved in ghrelin and GH secretion after the secretagogue stimulus (GHRH/arginine) are consistent with patterns observed in other populations.     

Salivary cortisol in low dose (1 microg) ACTH test in healthy women: comparison with serum cortisol

To date, a single report has appeared on the use of salivary cortisol for adrenal function testing with a low dose ACTH, although 1 microg has become preferred as a more physiological stimulus than the commonly used 250 microg ACTH test. Our present study was aimed to obtain physiological data on changes of free salivary cortisol after 1 microg ACTH stimulation. This approach was compared with the common method based on the changes of total serum cortisol. Intravenous, low-dose ACTH test was performed in 15 healthy women (aged 22-40 years) with normal body weight, not using hormonal contraceptives, in the follicular phase of the menstrual cycle. Blood and saliva for determination of cortisol were collected before ACTH administration and 30 and 60 min after ACTH administration. Basal concentration of salivary cortisol (mean +/- S.E.M., 15.9+/-1.96 nmol/l) increased after 1 microg ACTH to 29.1+/-2.01 nmol/l after 30 min, and to 27.4+/-2.15 nmol/l after 60 min. The differences between basal and stimulated values were highly significant (p<0.0001). The values of salivary cortisol displayed very little interindividual variability (p<0.04) in contrast to total serum cortisol values (p<0.0001) A comparison of areas under the curve (AUC) related to initial values indicated significantly higher AUC values for salivary cortisol than for total serum cortisol (1.89+/-0.88 vs. 1.22+/-0.19, p<0.01). Correlation analysis of serum and salivary cortisol levels showed a borderline relationship between basal levels (r=0.5183, p=0.0525); correlations after stimulation were not significant. Low-dose ACTH administration appeared as a sufficient stimulus for increasing salivary cortisol to a range considered as a normal adrenal functional reserve.     

Novel treatments for complications after bariatric surgery

Bariatric surgery has been considered one of best treatments for obesity. As every surgical procedure—and any medical intervention, it is not exempt of complications, among which leaks, strictures, acute hemorrhages and fistulae highlight. Leaks are more common in the gastro-jejunal anastomosis (GJA) in the case of Roux-en-y Gastric Bypass (RYGB), while in Sleeve Gastrectomy (LSG) they locate in the stapler line. Stenosis can be seen in the gastro-jejunostomy in the RYGB and in the gastric tube in case of the LSG. For each of these complications, many innovative solutions have been developed, including new surgical devices. In spite of promising good results, evidence regarding utility and safeness of these technologies is still scarce. Self-expandable endoscopic stents have been used to treat leaks, with an overall success rate of 80–90 % and a migration rate of 15–35 %. The bear trap-like over-the-scope (Ovesco) clips have been used to treat GI hemorrhages, leaks and even fistulae, with a 70–80 % success rate, although more endoscopic sessions may be needed. Overstitch, an endosurgical suture devices, have been used to treat leaks, fistulae and perforations. Overall, technical success achievement approaches to 90 %, while clinical success ranges from 80 to 90 %, except for leaks closure, where a lower success rate has been observed. Despite of all of these advances, early diagnosis and treatment remains the main strategy to achieve success. In summary, novel therapies for complication management can be very useful, though further studies with larger series are still needed in order to confirm their efficacy and safeness.     

Short-term psychological outcomes in severely obese adolescents after bariatric surgery

Bariatric surgery is suggested as a treatment option for severely obese adolescents. Because adolescence is characterized by intense psychosocial adjustment and development, it is important to study the effect of this procedure on adolescents' psychological health. This study examined baseline status and short-term changes in anxiety, depression, anger, disruptive behavior, and self-concept in 37 adolescents (mean age 16.6 ± 1.3). Participants completed the Beck Youth Inventories (BYI) at inclusion and (on average) 4 months after undergoing Roux-en-Y gastric bypass (RYGB). Internalizing (anxiety and depression) and externalizing (anger and disruptive behavior) symptoms were higher at baseline than gender-specific norms. One fifth had a very low self-concept. Four months after surgery, the adolescents showed significantly fewer symptoms of anxiety and depression and significantly improved self-concept from baseline. Anger and disruptive behavior showed no significant changes. An analysis of clinically meaningful changes was conducted, and besides the overall positive outcome, 16% (n = 6) of the adolescents had deteriorated on two or more inventories in BYI shortly after surgery. This impaired group did not show any specific features at inclusion. The results indicate the importance of psychological monitoring immediately after bariatric surgery and the need for additional psychosocial support to be available for vulnerable sub-groups of adolescents. Further studies with larger samples are necessary to identify characteristics predictive of short-term adverse psychological outcomes in adolescents after bariatric surgery.     

Seasonal variation of body weight loss after bariatric surgery

Seasonal variations have been described in humans in several variables such as sleep, mood, appetite, food preferences, or body weight. We hypothesized that these variations could also influence the decrease in body weight rate in patients submitted to body weight loss interventions. Thus, here we tested the variations of weight loss according to the time of the year the surgery took place in a group patients (n = 1322) submitted to bariatric surgery in the Hospital Universitari de la Vall d’Hebron in Barcelona (geographical coordinates: 41°25?41″N 2°8?32″E). For the analysis, the percentage of total body weight loss (%TWL), excess body weight loss (%EWL) and percentage of body mass index loss (%BMIL) were calculated at 3 (n = 1255), 6 (n = 1172), 9 (n = 1002), and 12 months (n = 1076) after surgery. For %EWL and %BMIL a statistically significant seasonal variation was detected when the variables were calculated at 3 months, but not at the other times, with more weight loss in summer-fall. However, seasonal variations were not detected for %TWL (p = 0.09). The mean amplitude of the seasonal rhythm for %EWL was of 1.8%, while for the rhythm of %BMIL was 0.7%. Moreover, a second peak was detected in January–February modulating the seasonal rhythm of the two variables. Results confirm seasonal variations in humans and indicate that short term responses to weight loss can be modulated by the time of year.     

Salivary testosterone and cortisol responses in professional rugby players after four resistance exercise protocols

The acute response of free salivary testosterone (T) and cortisol (C) concentrations to four resistance exercise (RE) protocols in 23 elite men rugby players was investigated. We hypothesized that hormonal responses would differ among individuals after four distinct RE protocols: four sets of 10 repetitions (reps) at 70% of 1 repetition maximum (1RM) with 2 minutes' rest between sets (4 x 10-70%); three sets of five reps at 85% 1RM with 3 minutes' rest (3 x 5-85%); five sets of 15 reps at 55% 1RM with 1 minute's rest (5 x 15-55%); and three sets of five reps at 40% 1RM with 3 minutes' rest (3 x 5-40%). Each athlete completed each of the four RE protocols in a random order on separate days. T and C concentrations were measured before exercise (PRE), immediately after exercise (POST), and 30 minutes post exercise (30 POST). Each protocol consisted of four exercises: bench press, leg press, seated row, and squats. Pooled T data did not change as a result of RE, whereas C declined significantly. Individual athletes differed in their T response to each of the protocols, a difference that was masked when examining the pooled group data. When individual data were retrospectively tabulated according to the protocol in which each athlete showed the highest T response, a significant protocol-dependent T increase for all individuals was revealed. Therefore, RE induced significant individual, protocol-dependent hormonal changes lasting up to 30 minutes after exercise. These individual responses may have important ramifications for modulating adaptation to RE and could explain the variability often observed in studies of hormonal response to RE.     

Salivary cortisol concentration after high-intensity interval exercise: Time of day and chronotype effect

Due to personal and working necessities, the time for exercise is often short, and scheduled early in the morning or late in the afternoon. Cortisol plays a central role in the physiological and behavioral response to a physical challenge and can be considered as an index of exercise stress. Therefore, the aim of this study was to evaluate the influence of the circadian phenotype classification on salivary cortisol concentration in relation to an acute session of high-intensity interval exercise (HIIE) performed at different times of the day. Based on the morningness–eveningness questionnaire, 12 M-types (N = 12; age 21 ± 2 years; height 179 ± 5 cm; body mass 74 ± 12 kg, weekly training volume 8 ± 1 hours) and 11 E-types (N = 11; age 21 ± 2 years; height 181 ± 11 cm; body mass 76 ± 11 kg, weekly training volume 7 ± 2 hours) were enrolled in a randomized crossover study. All subjects underwent measurements of salivary cortisol secretion before (PRE), immediately after (POST), and 15 min (+15 min), 30 min (+30 min), 45 min (+45 min) and 60 min (+60 min) after the completion of both morning (08.00 am) and evening (08.00 p.m.) high-intensity interval exercise. Two-way analysis of variance with Tuckey’s multiple comparisons test showed significant increments over PRE-cortisol concentrations in POSTcondition both in the morning (4.88 ± 1.19 ng · mL^?1 vs 6.60 ± 1.86 ng · mL^?1, +26.1%, P < 0.0001, d > 0.8) and in the evening (1.56 ± 0.48 ng · mL^?1 vs 2.34 ± 0.37, +33.4%, P = 0.034, d > 0.6) exercise in all the 23 subject that performed the morning and the evening HIIE. In addition, during morning exercise, significant differences in cortisol concentration between M-types and E-types at POST (5.49 ± 0.98 ng · mL^?1 versus 8.44 ± 1.08 ng · mL^?1, +35%, P < 0.0001, d > 0.8), +15 min (4.52 ± 0.42 ng · mL^?1 versus 6.61 ± 0.62 ng · mL^?1, +31.6%, P < 0.0001, d > 0.8), +30 min (4.10 ± 1.44 ng · mL^?1 versus 6.21 ± 1.60 ng · mL^?1, +34.0%, P < 0.0001, d = 0.7), + 45 min (3.78 ± 0.55 ng · mL^?1 versus 5.80 ± 0.72 ng · mL^?1, +34.9%, P < 0.0001, d = 0.7), and + 60 min condition(3.53 ± 0.45 ng · mL^?1 versus 5.78 ± 1.13 ng · mL^?1, 38.9%, P = 0.0008, d = 0.7) were noted. No statistical significant differences between M-types and E-types during evening HIIE on post-exercise cortisol concentration were detected. E-types showed a higher morning peak of salivary cortisol respect to M-types when performing a HIIE early in the morning and produced higher salivary cortisol concentrations after the cessation of the exercise. Practical applications suggest that it is increasingly important for the exercise professionals to identify the compatibility between time of day for exercising and chronotype to find the individual’s favorable circadian time to perform a HIIE.     

Seasonal variations of changes in lipid and glucidic variables after bariatric surgery

Seasonality is a phenomenon that is characterized by changes over the year in sleep, mood, behaviour, appetite and body weight. In humans, seasonal variations have been found in certain variables, such as lipid variables and body mass index. We hypothesize that this rhythm could influence the expected variation of the levels of biochemical variables in cases of body weight loss. Thus, the goal of this study was to observe whether the time of year in which bariatric surgery (BS) took place modulated the changes in several variables related to glucidic and lipid metabolism. Blood samples were obtained from 24 women and 10 men before BS and 1 and 3 months after BS. We calculated the percentage of variation that occurred for each individual and for each variable as a function of the time of the year. Data were adjusted to a 12-month period sinusoidal curve, with significance being set at p < 0.05. The results showed that almost all of the studied variables changed due to the BS according to a seasonal rhythm. Most of the variables showed a decrease that was most prominent in winter. In the cases of body mass index (BMI), adrenocorticotropin hormone (ACTH), and cortisol, the highest variation occurred in winter. Insulin and cholesterol in high-density lipoproteins (cHLD) variations were higher in springtime. Glucose variation showed a decrease after surgery with acrophase in summer-fall and plasminogen activator inhibitor-1 (PAI-1) and homeostatic model assessment-insulin resistance (HOMA-IR) in spring-summer. Ghrelin levels showed increases with a rhythm of variation with an acrophase in summer-fall. The seasonal rhythm found in this study fits nearly with the inverse of the endogenous circannual rhythm of the variables studied. The time of the year when the highest variation takes place is related to the circannual rhythm of the variable. The results agree with the manifestation of seasonal rhythm in human biochemical variables, which are reflected in the responses to weight loss after BS.     

Salivary cortisol and social status among Dominican men

Studies of nonhuman primates indicate that social subordinance associates with chronic elevated cortisol, but this finding has not been replicated among humans. This topic was examined in a study of 31 healthy adult male Dominican villagers ages 17 to 49 years. Each subject's mean cortisol level was calculated using multiple time-standardized salivary cortisol samples (minimum = 6, mean = 14. 8 samples per subject) determined by radioimmunoassay. Semistructured ethnographic interviews were used to collect several measures of social status. Data were analyzed with a backward stepwise multivariate linear regression model. Partial regression statistics revealed four significant associations with cortisol: (i) men with reputations for illicit social behavior had higher cortisol; (ii) men who reported more frequent distressed mood had higher cortisol; (iii) men rated as less trustworthy, agreeable, influential, and helpful by their peers had higher cortisol; and (iv) men whose fathers were absent as a childhood caretaker had higher cortisol. No associations were found between cortisol and (a) a composite of educational attainment, income, and material wealth; (b) frequency of tobacco consumption; (c) frequency of perceived social stressors; or (d) a composite of number of children and dependents.     

Endothelial activation markers and their key regulators after restrictive bariatric surgery

Objective: Increased plasma levels of endothelial activation markers in obese subjects reflect the positive association between cardiovascular diseases and obesity. The pro‐inflammatory state associated with obesity is thought to play a major role in endothelial cell activation in severely obese individuals. Previous studies demonstrated that long‐term weight loss after bariatric surgery is accompanied by a decreased proinflammatory state. However, little is known about the long‐term effects of bariatric surgery on endothelial cell activation. Research Methods and Procedures: Plasma levels of soluble intercellular adhesion molecule‐1 (sICAM‐1), soluble endothelial selectin (sE‐selectin), and soluble vascular cell adhesion molecule‐1 (sVCAM‐1), all markers of endothelial cell activation, and of their regulators adiponectin and resistin were measured at different time‐points postoperatively in 26 consecutive patients who underwent restrictive surgery, with a follow‐up of 2 years. Results: During the first 6 months after bariatric surgery, sE‐selectin levels decreased. Despite substantial weight loss, sICAM‐1 and sVCAM‐1 plasma levels did not decrease significantly. After 24 months, sICAM‐1 levels were significantly decreased, whereas sE‐selectin levels were further decreased. However, sVCAM‐1 levels remained elevated. Adiponectin levels did not change significantly during the first 6 months after bariatric surgery, whereas resistin levels increased. After 24 months, adiponectin levels were similar to normal‐weight controls, but resistin levels remained high. Discussion: Reductions in plasma levels of different markers of endothelial activation after bariatric surgery show different temporal patterns, suggesting that distinct mechanisms are involved in their regulation. Although not all endothelial activation markers normalize after bariatric surgery, our findings suggest that bariatric surgery can reduce endothelial activation in the long term.     

Salivary and plasma cortisol response to adrenocorticotropin administration in pigs

Two experiments were conducted to determine the responsiveness of salivary and plasma cortisol to acute (i.v.), depot (i.m.) and chronic (repeated i.m.) adrenocorticotropin (ACTH) administration in swine. In Experiment 1, barrows (castrated pigs) were assigned to one of three injection treatments: (1) saline i.m. (SHAM1, n=2); (2) 0.75 IU/kg BW ACTH in saline i.v. (ACUTE, n=2); (3) 2.25 IU/kg BW ACTH in gel i.m. (DEPOT, n=3). Total cortisol concentrations were determined for concurrent saliva and blood samples. Correlations between salivary and plasma cortisol within treatments were: SHAM1, r=0.60; ACUTE, r=0.58; DEPOT, r=0.79. In Experiment 2, barrows were assigned to one of two injection treatments: (1) gel i.m. (SHAM2, n=3); (2) 2.25 IU/kg BW ACTH in gel i.m. (CHRONIC, n=4). The injections occurred every 6 h for a total of eight injections. Concurrent saliva and blood samples were obtained every 3 h for 72 h followed by an increasing sampling interval until day 6. Overall correlations between salivary and plasma cortisol were: SHAM2, r=0.30 and CHRONIC, r=0.61. Experiment 1 found that the relationship between salivary and plasma cortisol was stronger during longer (DEPOT) than shorter (ACUTE) ACTH stimulation. Experiment 2 found a strong relationship between the two measurements during chronic ACTH stimulation, but that relationship weakened after ACTH stimulation ceased.