Martin Thurnheer

Hedonic hunger is increased in severely obese patients and is reduced after gastric bypass surgery

BACKGROUNDnOvereating as a pathogenetic hallmark of obesity may be promoted by an increase in hedonic hunger, ie, the drive to eat palatable foods in the absence of energy need. Gastric bypass surgery, which effectively reduces severe obesity, might also affect hedonic hunger.nnnOBJECTIVEnThe objective was to assess hedonic hunger in severely obese patients with and without a history of gastric bypass surgery.nnnDESIGNnSeverely obese patients who had not undergone gastric bypass surgery (n = 123), gastric bypass patients (n = 136), and nonobese control subjects (n = 110) were examined with the Power of Food Scale (PFS)--a questionnaire that reliably measures an individuals motivation to consume highly palatable foods.nnnRESULTSnCompared with nonobese control subjects, severely obese patients achieved markedly higher aggregated PFS scores and subdomain scores related to generally available as well as physically present foods (all P < 0.001). On the aggregated score as well in those 2 subdomains, gastric bypass patients scored significantly lower than did non-gastric bypass obese patients (all P < 0.001) and did not differ significantly from the nonobese control group (P > 0.2). In contrast, in the PFS domain concerning food tasted, gastric bypass patients had significantly lower scores than did the nonobese control subjects (P = 0.04) and the severely obese patients (P = 0.008), both of whom did not differ significantly in this measure (P = 0.90).nnnCONCLUSIONnIn comparison with nonobese control subjects, severely obese patients display a marked increase in hedonic hunger that is not observed in patients who have undergone gastric bypass surgery, suggesting that the operation normalizes excessive appetite for palatable foods, which may be an important pathophysiologic feature of severe obesity.

Concomitant Cholecystectomy During Laparoscopic Roux-en-Y Gastric Bypass in Obese Patients Is Not Justified: A Meta-Analysis

While LRYGB has become a cornerstone in the surgical treatment of morbidly obese patients, concomitant cholecystectomy during LRYGB remains a matter of debate. The aim of this meta-analysis was to estimate the rate and morbidity of subsequent cholecystectomy after laparoscopic Roux-en-Y gastric bypass (LRYGB) in obese patients. A meta-analysis was performed analyzing the rate and morbidity of subsequent cholecystectomy in patients who underwent LRYGB without concomitant cholecystectomy. Thirteen studies met the inclusion criteria. The rate of subsequent cholecystectomy was 6.8xa0% (95 % CI, 5.0–8.7xa0%) based on 6,048 obese patients who underwent LRYGB without concomitant cholecystectomy. The rate of subsequent cholecystectomy due to biliary colic or gallbladder dyskinesia was 5.3xa0%; due to cholecystitis, 1.0xa0%; choledocholithiasis, 0.2xa0%; and biliary pancreatitis, 0.2xa0%. The mortality after subsequent cholecystectomy was 0xa0% (95 % CI, 0–0.1xa0%). The surgery-related complication rate after subsequent cholecystectomy was 1.8xa0% (95xa0% CI, 0.7–3.4xa0%) resulting in a risk of 0.1xa0% (95xa0% CI, 0.03–0.3xa0%) to suffer from a cholecystectomy-related complication in patients undergoing LRYGB without concomitant cholecystectomy. A prophylactic concomitant cholecystectomy during LRYGB should be avoided in patients without cholelithiasis and exclusively be performed in patients with symptomatic biliary disease.

Roux-en Y Gastric Bypass Surgery Reduces Hedonic Hunger and Improves Dietary Habits in Severely Obese Subjects

BackgroundMany obese subjects suffer from an increased hedonic drive to consume palatable foods, i.e., hedonic hunger, and often show unfavorable dietary habits. Here, we investigated changes in the hedonic hunger and dietary habits after Roux-en-Y gastric bypass (RYGB) surgery.MethodsForty-four severely obese patients were examined before and on average 15.9u2009±u20090.9xa0months after RYGB surgery with the Power of Food Scale (PFS), a questionnaire that reliably measures an individual’s motivation to consume highly palatable foods but not actual consumptive behavior. Dietary habits were assessed by a food frequency questionnaire.ResultsAfter the RYGB procedure, patients showed markedly lower aggregated PFS scores and sub-domain scores related to generally available, physically present, as well as tasted foods than before the surgery (all Pu2009<u20090.001). Changes in dietary habits after the surgery were characterized by a more frequent consumption of poultry, fish, eggs, and cooked vegetables (Pu2009<u20090.008) and a less frequent consumption of chocolate (Pu2009<u20090.048), cakes/biscuits/cookies (Pu2009=u20090.09), and fruit juice/soft drinks (Pu2009=u20090.08).ConclusionsData show a marked reduction of the hedonic drive to consume palatable food and beneficial changes in dietary habits characterized by an increased intake of protein-rich foods and vegetables and a reduced consumption of sugar-containing snacks and beverages after RYGB surgery. Based on these findings, it can be speculated that the reduction of the hedonic drive to consume palatable foods induced by RYGB surgery helps severely obese patients to establish healthier dietary habits.

C-Reactive Protein 2 Days After Laparoscopic Gastric Bypass Surgery Reliably Indicates Leaks and Moderately Predicts Morbidity

BackgroundThe aim of the present study was to evaluate whether serum C-reactive protein (CRP) is a useful predictor of early post-operative complications, particularly of intestinal leaks after laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery.MethodsThe present study was a retrospective analysis of a prospectively maintained database with 809 patients who underwent LRYGB from 2002 until 2011. For 410 of these patients, at least one CRP measurement within the first seven post-operative days was available. The diagnostic value was determined by the area under the curve (AUC) of the receiver operating characteristic (ROC) curve.ResultsForty-nine of 410 patients (12.0xa0%; 95xa0% confidence intervals [95xa0% CI], 9.2–15.5xa0%) developed surgery-related complications. Leaks occurred in 17 patients (4.1xa0%; 95xa0% CI, 2.6–6.5xa0%) at a median of 5xa0days after surgery. CRP levels 2xa0days after surgery showed the highest diagnostic value for post-operative complications (AUC, 0.74; 95xa0% CI, 0.60–0.89). Sensitivity was 0.53 (95xa0% CI, 0.31–0.74) and specificity was 0.91 (95xa0% CI, 0.79–0.96) on day 2 (cutoff level, 229xa0mg/l). The sensitivity for intestinal leaks was 1.00 (95xa0% CI, 0.51–1.00).ConclusionCRP on post-operative day 2 is a valuable predictor of post-operative complications, in particular intestinal leaks. Radiological imaging studies for intestinal leaks could be restricted to patients with CRP values exceeding 229xa0mg/l.

Seasonal Variation in the Deficiency of 25-Hydroxyvitamin D3 in Mildly to Extremely Obese Subjects.

BackgroundVitamin D deficiency is a common finding in obese subjects even before any bariatric operation. However, most previous studies reporting on high rates of vitamin D deficiency in obese subjects have not systematically controlled for seasonal variations. Furthermore, the existence of seasonal variation in serum 25-hydroxyvitamin D3 levels has not been well documented in obese subjects so far.MethodsSerum 25-hydroxyvitamin D3 levels were measured in 248 obese subjects (body mass index: range, 30.1–68.9xa0kg/m2). Fat mass was determined using standard bioelectrical impedance analysis.ResultsSerum 25-hydroxyvitamin D3 levels decreased with the increasing body mass index and fat mass (both Pu2009<u20090.001) and showed a marked variation across the seasons of the year (Pu2009<u20090.001), which was not affected by the degree of obesity. According to the variation in absolute levels, the prevalence of vitamin D deficiency (<50xa0nmol/l) was 3.8-fold higher during winter than during summer (91.2% vs. 24.3%; Pu2009<u20090.001).ConclusionData show a marked seasonal variation in absolute serum 25-hydroxyvitamin D3 concentrations and prevalence of vitamin D deficiency in subjects with mild to extreme obesity. Considering the increasing number of studies reporting on vitamin D deficiency in obesity, the present finding points to season as a crucial factor that should not be neglected when assessing serum levels of this vitamin in obese subjects.

Is Routine Cholecystectomy Justified in Severely Obese Patients Undergoing a Laparoscopic Roux-en-Y Gastric Bypass Procedure? A Comparative Cohort Study

BackgroundThe aim of the present study was to evaluate the risks and benefits of concurrent prophylactic cholecystectomy (CPC) during laparoscopic Roux-en-Y gastric bypass (LRYGB).MethodsFrom December 2000 to November 2006, CPC during LRYGB was only performed in the presence of gallbladder pathology (nu2009=u2009140). Beginning in December 2006, CPC was performed during all LRYGB procedures (nu2009=u2009134). Exclusion criteria were open bypass procedure, previous bariatric surgery other than gastric banding, and previous cholecystectomy (CCE) or necessary concurrent CCE due to gallbladder pathology.ResultsDuring a median follow-up of 3.1xa0years, 26 (18.6%; 95% CI, 12.9–25.9%) of 140 patients without CPC subsequently required a CCE, leading to a gallbladder disease-free survival rate at 5xa0years of 77.4% (95% CI, 67.3–87.6%). Multivariate analysis identified a distal LRYGB and excess weight loss of >75% at 2xa0years to be significant risk factors for the development of biliary complications while a preoperative BMIu2009>u200950xa0m2/kg was protective. In the second series, prophylactic CCE was not associated with prolonged hospitalization or operative time. The postoperative complications were not related to the CPC.ConclusionsThe present data indicate that a substantial number of patients develop gallbladder complications after LRYGB. Furthermore, CPC can safely be performed during LRYGB. Based on these findings, CPC should be considered a reasonable approach in severely obese patients undergoing LRYGB.

Copper deficiency after gastric bypass surgery.

after adjusting by log-transformed age and BMI. Similarly, the quantitative trait diastolic arterial blood pressure was significantly associated with the variant (P < 0.023): homozygous CC: 74.2 ± 0.6, heterozygous CT: 76.2 ± 0.7 and homozygous TT: 78.1 ± 1.7 mm Hg. In summary, the findings of Lieb et al. can also be generalized to Argentinean population, as an example of replication in a different group of European descent. However, these results do not exclude other possible effects of the variants of the FAAH on metabolic syndrome–related phenotypes, for instance arterial blood pressure or plasma triglycerides. These data, which need to be confirmed in larger samples, may be of interest because the use of FAAH as a therapeutic target in hypertension is under evaluation not only because of the potential beneficial effect of endocannabinoid-related drugs on arterial blood pressure but also on the development of the hypertensive cardiac hypertrophy (2,3).

Poor prediction of resting energy expenditure in obese women by established equations.

The objective of the study was to evaluate the accuracy of established prediction equations that calculate resting energy expenditure (REE) in obese women. This was a cross-sectional study. In 273 mildly to severely obese women (age, 41.7 +/- 13.2 years; body mass index, 42.8 +/- 7.0 kg/m(2)), REE was measured by indirect calorimetry (mREE), along with fat mass (FM) and fat-free mass (FFM) by bioelectrical impedance analysis. Eleven established equations were used to predict REE (pREE), with 9 equations basing on the anthropometric parameters body weight and height and 2 equations including body composition parameters (FM, FFM). All equations provided pREE values that significantly correlated with mREE (r > 0.66, P < .001), although 8 equations systematically underestimated mREE (P < .05). Of note, even the best equation was not able to accurately predict mREE with a deviation of less than +/-10% in more than 70% of the tested women. Furthermore, equations using body composition data were not superior in predicting REE as compared with equations exclusively including anthropometric variables. Multiple linear regression analyses revealed 2 new equations--one including body weight and age and another including FM, FFM, and age--that explained 56.9% and 57.2%, respectively, of variance in mREE. However, when these 2 new equations were applied to an independent sample of 33 obese women, they also provided an accurate prediction (+/-10%) of mREE in only 56.7% and 60.6%, respectively, of the women. Data show that an accurate prediction of REE is not feasible using established equations in obese women. Equations that include body composition parameters as assessed by bioelectrical impedance analysis do not increase the accuracy of prediction. Based on our results, we conclude that calculating REE by standard prediction equations does not represent a reliable alternative to indirect calorimetry for the assessment of REE in obese women.

Basal Serum Prolactin Levels in Obesity—Unrelated to Parameters of the Metabolic Syndrome and Unchanged After Massive Weight Loss

BackgroundProlactin (PRL) has been proposed to play an important role in the pathophysiology of obesity. To further elucidate the relationship between PRL and obesity-related metabolic disturbances, we performed a large cross-sectional study and also reassessed serum PRL levels in a subsample ~1xa0year after gastric bypass surgery.MethodsIn the cross-sectional part of the study, we assessed basal serum PRL levels in 344 obese subjects (68% women; BMI mean ± SD, 44.3u2009±u20096.6xa0kg/m2; range 27.0–67.0xa0kg/m2) along with measurements of glucose, insulin, C-peptide, triglycerides, total cholesterol, LDL-cholesterol, HDL-cholesterol, high sensitive (hs) C-reactive protein, and fat mass assessed by bioelectrical impedance analysis. In 38 patients, we reassessed PRL levels ~1xa0year after they have undergone a gastric bypass operation.ResultsWomen displayed higher basal PRL levels than men (9.0u2009±u20094.8 vs. 7.9u2009±u20093.6xa0μg/l, Pu2009=u20090.03). Basal PRL levels were neither significantly correlated with the BMI of the subjects (ru2009=u2009−0.05, Pu2009=u20090.77) nor with any other of the assessed variables (all ru2009<u20090.16, Pu2009>u20090.06) even after adjusting for the influence of sex. After massive surgically induced weight loss that on average almost approached 50xa0kg, basal serum PRL levels remained completely unchanged (before vs. after, 9.1u2009±u20096.0 vs. 9.2u2009±u20094.6xa0μg/l, Pu2009=u20090.86). However, preoperative PRL levels significantly correlated with that assessed after the operation (ru2009=u20090.47; Pu2009=u20090.005).ConclusionsIn contrast to our expectation, we could detect neither any significant association between basal PRL levels and the degree of obesity or related metabolic disturbances nor any systematic changes in basal concentrations of the hormone after massive weight loss. In sum, our data do not support the notion of a major role of PRL in the pathophysiology of obesity.

The Hedonic Drive to Consume Palatable Foods Appears to be Lower in Gastric Band Carriers than in Severely Obese Patients Who Have Not Undergone a Bariatric Surgery

BackgroundWe have recently shown that severely obese patients display a markedly enhanced drive to consume palatable food, and that this hedonic hunger is reduced after gastric bypass surgery. Adjustable gastric banding is another frequently performed bariatric operation with unknown effects on hedonic hunger motivation. Here, we compared the level of hedonic hunger in patients who have undergone a gastric banding with that in severely obese patients who have not undergone a bariatric operation and nonobese controls.MethodsIn a cross-sectional case–control study, 116 gastric banding patients, 138 severely obese patients, and 133 nonobese controls were examined with the Power of Food Scale (PFS), a questionnaire that reliably measures an individual’s motivation to consume highly palatable food.ResultsWhile the severely obese patients displayed markedly higher aggregated PFS scores and scores on the subdomain “generally available” and “physically present” food than the nonobese controls (all Pu2009<u20090.001), the gastric banding patients showed significantly lower scores on all of these variables than the obese patients (all Pu2009<u20090.001). However, the generally available food score was still higher in gastric banding patients than in the nonobese controls (Pu2009=u20090.001).ConclusionsData suggest that adjustable gastric banding may reduce the excessive appetite for palatable foods in severely obese patients. This suggestion needs to be confirmed in longitudinal studies.