Jarl S. Torgerson

Effects of bariatric surgery on cancer incidence in obese patients in Sweden (Swedish Obese Subjects Study): a prospective, controlled intervention trial

BACKGROUND Obesity is a risk factor for cancer. Intentional weight loss in the obese might protect against malignancy, but evidence is limited. To our knowledge, the Swedish Obese Subjects (SOS) study is the first intervention trial in the obese population to provide prospective, controlled cancer-incidence data. METHODS The SOS study started in 1987 and involved 2010 obese patients (body-mass index [BMI] >or=34 kg/m(2) in men, and >or=38 kg/m(2) in women) who underwent bariatric surgery and 2037 contemporaneously matched obese controls, who received conventional treatment. While the main endpoint of SOS was overall mortality, the main outcome of this exploratory report was cancer incidence until Dec 31, 2005. Cancer follow-up rate was 99.9% and the median follow-up time was 10.9 years (range 0-18.1 years). FINDINGS Bariatric surgery resulted in a sustained mean weight reduction of 19.9 kg (SD 15.6 kg) over 10 years, whereas the mean weight change in controls was a gain of 1.3 kg (SD 13.7 kg). The number of first-time cancers after inclusion was lower in the surgery group (n=117) than in the control group (n=169; HR 0.67, 95% CI 0.53-0.85, p=0.0009). The sex-treatment interaction p value was 0.054. In women, the number of first-time cancers after inclusion was lower in the surgery group (n=79) than in the control group (n=130; HR 0.58, 0.44-0.77; p=0.0001), whereas there was no effect of surgery in men (38 in the surgery group vs 39 in the control group; HR 0.97, 0.62-1.52; p=0.90). Similar results were obtained after exclusion of all cancer cases during the first 3 years of the intervention. INTERPRETATION Bariatric surgery was associated with reduced cancer incidence in obese women but not in obese men. FUNDING Swedish Research Council, Swedish Foundation for Strategic Research, Swedish Federal Government under the LUA/ALF agreement, Hoffmann La Roche, Cederoths, AstraZeneca, Sanofi-Aventis, Ethicon Endosurgery.

Snacking frequency in relation to energy intake and food choices in obese men and women compared to a reference population.

OBJECTIVE:To investigate snacking frequency in relation to energy intake and food choices, taking physical activity into account, in obese vs reference men and women.DESIGN:Cross-sectional, descriptive study.SUBJECTS:In total, 4259 obese, middle-aged subjects (1891 men and 2368 women) from the baseline examination of the XENDOS study and 1092 subjects (505 men and 587 women) from the SOS reference study were included.MEASUREMENTS:A meal pattern questionnaire describing habitual intake occasions (main meals, light meals/breakfast, snacks, drink-only), a dietary questionnaire describing habitual energy and macronutrient intake and a questionnaire assessing physical activity at work and during leisure time were used.RESULTS:The obese group consumed snacks more frequently compared to the reference group (P<0.001) and women more frequently than men (P<0.001). Energy intake increased with increasing snacking frequency, irrespective of physical activity. Statistically significant differences in trends were found for cakes/cookies, candies/chocolate and desserts for the relation between energy intake and snacking frequency, where energy intake increased more by snacking frequency in obese subjects than in reference subjects.CONCLUSION:Obese subjects were more frequent snackers than reference subjects and women were more frequent snackers than men. Snacks were positively related to energy intake, irrespective of physical activity. Sweet, fatty food groups were associated with snacking and contributed considerably to energy intake. Snacking needs to be considered in obesity treatment, prevention and general dietary recommendations.

Musculoskeletal pain in the obese: a comparison with a general population and long-term changes after conventional and surgical obesity treatment.

Obesity is associated with musculoskeletal pain and osteoarthritis. This study compares the prevalence of work‐restricting musculoskeletal pain in an obese and a general population and investigates changes in the incidence of and recovery from musculoskeletal pain after bariatric surgery or conventional obesity treatment. A random sample of 1135 subjects from a general population was compared with 6328 obese subjects in the Swedish obese subjects (SOS) study. For the obese subjects, information about musculoskeletal pain was also collected 2 and 6 years after obesity surgery or the start of non‐surgical treatment. In both sexes, self‐reported work‐restricting pain in the neck and back area and in the hip, knee and ankle joints was more common in the obese subjects than in the general population (odds ratios (ORs) ranging from 1.7 to 9.9, P<0.001). Operated obese women had a lower incidence of work‐restricting pain in the knee and ankle joints compared with the conventionally treated control group over 2 and 6 years (ORs 0.51–0.71). Among subjects reporting symptoms at baseline, the recovery rate for pain in the knee and ankle joints in men and pain in the neck and back and in the hip, knee and ankle joints in women improved in the surgical group compared with the control group after 2 years (ORs 1.4–4.8). Obese subjects have more problems with work‐restricting musculoskeletal pain than the general population. Surgical obesity treatment reduces the long‐term risk of developing work‐restricting musculoskeletal pain and increases the likelihood of recovering from such pain.

Psychosocial functioning in the obese before and after weight reduction: construct validity and responsiveness of the Obesity-related Problems scale.

OBJECTIVE: The Obesity-related Problems scale (OP) is a self-assessment module developed to measure the impacts of obesity on psychosocial functioning. Our principal aim was to evaluate the construct validity and responsiveness of the OP scale. Our specific aims were to test: (1) the psychometric performance of OP; (2) if OP scores differed by gender and weight category; (3) if OP scores are inversely related to mental well-being; (4) if weight reduction in the obese is accompanied by improvements in psychosocial functioning (OP).SUBJECTS: Four samples were used: 6863 subjects in the SOS cross-sectional study; 2128 in the SOS intervention study; 1017 nonobese in the SOS reference study; and 3305 obese subjects in the XENDOS study.MEASUREMENTS: Psychosocial functioning was measured by OP. Overall mood was measured by MACL. Anxiety and depression symptoms were measured by HAD.RESULTS: Psychometric testing provided strong support for the construct validity of OP. Factor analysis confirmed the homogeneity of the construct and multitrait/multi-item scaling analysis demonstrated strong item-convergent/discriminant validity. Reliability coefficients were high and floor and ceiling effects were small. Psychometric results were cross-validated and replicated in subgroups by gender, age and body mass index (BMI). As expected, large differences in OP were observed between obese and nonobese (P<0.0001). Obese women reported more weight-related psychosocial problems than obese men (P<0.0001). Psychosocial disturbances (OP) among the obese were significantly related to poor mood (MACL; P<0.0001) and anxiety and depression symptoms (HAD; P<0.0001). Change in OP over time was strongly correlated with weight loss (P<0.0001). A distinct dose–response effect between weight reduction and improvements in OP was demonstrated. Scores on psychosocial functioning (OP) and mental well-being (MACL, HAD) in nonobese (BMI<30) surgical patients at 4-y follow-up were equal to scores observed in nonobese reference subjects (NS).CONCLUSION: OP is a psychometrically valid obesity-specific measure suitable for evaluating HRQL effects of obesity interventions. The negative impact of obesity on psychosocial functioning is considerable and disturbances are connected with poor mental well-being. Weight reduction in the obese is followed by improvements in both psychosocial functioning and mental well-being.

Gallstones, gallbladder disease, and pancreatitis: cross-sectional and 2-year data from the Swedish Obese Subjects (SOS) and SOS reference studies.

OBJECTIVES:Obesity and weight loss have been associated with gallstone disease. There is also an association between gallstones and pancreatitis. We investigated cross-sectional relationships between body mass index (BMI), body fat distribution, and prevalence of gallstones, gallbladder disease, and pancreatitis in men and women. Furthermore, 2-yr incidences of these disorders were examined in relation to changes in weight and body fat distribution after surgical and conventional obesity treatment.METHODS:Self-administered questionnaires were used to assess biliary and pancreatic disease. In the cross-sectional investigation, 6328 obese patients and 1135 randomly selected reference individuals were used. Longitudinally, 1422 operated and 1260 conventionally treated patients were examined.RESULTS:Obese subjects had significantly higher prevalence of cholelithiasis, cholecystitis, cholecystectomies, and pancreatitis as compared with the reference population. In women, BMI and waist–hip ratio (WHR) were independently related to an increased biliary disease prevalence. In men, only BMI was independently associated with biliary disease. Compared with conventional treatment, obesity surgery significantly increased the incidence of cholelithiasis, cholecystitis, and cholecystectomies in men. There was no incidence difference among women. In both genders, weight loss, but not change in WHR, was related to an increased incidence of biliary disease.CONCLUSIONS:This study showed an increased prevalence of gallstones, gallbladder disease, and pancreatitis in the obese. Biliary disease was related to BMI and WHR in women, but only to BMI in men. Weight loss, but not change in WHR, increased the risk of biliary disease in both genders.

Severe obesity and personality: a comparative controlled study of personality traits

OBJECTIVE: The primary purpose was to assess personality trait differences between the severely obese seeking treatment and a mainly non-obese reference group. We also investigated gender differences and differences between obese patients and obese not seeking treatment.METHOD: Personality traits were assessed using 7 of 15 scales from the Karolinska Scales of Personality (KSP): Somatic Anxiety, Muscular Tension, Psychastenia, Psychic Anxiety, Monotony Avoidance, Impulsiveness, and Irritability. Patients from the Swedish Obese Subjects (SOS) intervention study (n=3270, ages 37–57, 71% women) and the SOS reference study (n=1135, 54% women) completed the survey. Data presented in this study were gathered prior to treatment. Significance tests and effects sizes were calculated.RESULTS: Although statistically significant differences were found between obese patients and reference subjects on nearly all personality traits, effect sizes were at most moderate. Of the three scales with moderate effects sizes, differences on Somatic Anxiety and Psychastenia could be traced to items tapping condition-specific symptoms, e.g., problems with sweating and breathing as indicators of Somatic Anxiety. Moderate differences on the Impulsiveness scale (men alone) could not be explained by item composition. Further, the obese patients differed from obese in the reference group, and both obese and reference women reported significantly higher levels on Somatic Anxiety, Muscular Tension and Psychic Anxiety compared to men (effect size: small).CONCLUSIONS: Our results provided no evidence of a general obese personality profile, instead considerable heterogeneity in personality traits was observed across our obese samples (treatment seekers vs non-seekers, men vs women) and generally only small differences were noted compared to a reference study population. Further research is needed to investigate if the somewhat elevated levels of Impulsiveness, particularly among male obese patients, is affected by weight loss. When assessing personality traits in diseased groups consideration should be given to possible confounding from, e.g., somatic symptoms.

A dietary and behavioural programme for the treatment of obesity. A 4‐year clinical trial and a long‐term posttreatment follow‐up

Abstract.  Lantz H, Peltonen M, Ågren L, Torgerson JS (Sahlgrenska University Hospital, Göteborg, Sweden). A dietary and behavioural programme for the treatment of obesity. A 4‐year clinical trial and a long‐term posttreatment follow‐up. J Intern Med 2003; 254: 272–279.

A comparative controlled study of personality in severe obesity: a 2-y follow-up after intervention

OBJECTIVE: The primary purpose was to examine 2-y effects of weight change on personality traits in severely obese subjects treated conventionally or surgically. We also assessed differences between the severely obese patients and a primarily normal-weight reference group.METHOD: Personality traits were assessed using 7 of 15 scales from the Karolinska Scales of Personality (KSP): Somatic Anxiety, Muscular Tension, Psychasthenia, Psychic Anxiety, Monotony Avoidance, Impulsiveness, and Irritability. A total of 1380 surgical candidates, 1241 conventionally treated patients and 1135 subjects from the SOS (Swedish Obese Subjects) reference study, representing the general population, completed the KSP. Data presented in this study were gathered twice from the patients (prior to treatment and after 2 y) and once from the reference subjects. Significance tests and effect sizes (ES) were calculated.RESULTS: At baseline, the obese were characterised as more anxiety prone, impulsive, irritable and less monotony avoiding than the reference group; surgery patients more so than the conventionally treated. At follow-up, it was found that anxiety proneness decreased and Monotony Avoidance increased with increasing weight loss. The conventionally treated were, on average, weight stable and, hence, only a small decrease was noted regarding Somatic Anxiety. The surgery group lost on average 28 kg, and differences between surgically treated and the reference group decreased on all scales except Impulsiveness, which remained unchanged. The largest improvement was in relation to Psychasthenia.CONCLUSIONS: Weight reduction maintained for 2 y was associated with changes on practically all personality traits in proportion to the magnitude of weight loss. In particular, Psychasthenia seemed to be alleviated, while Impulsiveness was unaffected.

Effects on body weight of strict or liberal adherence to an initial period of VLCD treatment. A randomised, one-year clinical trial of obese subjects

OBJECTIVES: To examine the impact on early and late weight loss of three different, initial very low calorie diet (VLCD) approaches in a one-year obesity treatment program.DESIGN: Randomised clinical trial.SUBJECTS: 121 obese subjects, aged 21–60 y, BMI ≥30.0 kg/m2.INTERVENTIONS: The VLCD-strict group was prescribed a strict outpatient VLCD for 16 weeks, followed by a 36-week hypocaloric diet. The VLCD-mw group received the same treatment, but were hospitalised in a metabolic ward for the initial week. The VLCD-plus group was allowed two small meals weekly, but received otherwise the same recommendations as the VLCD-strict group.RESULTS: After 16 weeks, there was no difference in weight loss between the treatment groups in the intent-to-treat population, while among completers, the weight loss was about 7 kg larger in the VLCD-strict group compared to the VLCD-plus group (P<0.05). At one year, these groups differed by approximately 4 kg, both according to intention-to-treat and among completers (P<0.05, both differences). These differences were more prominent among females. The weight reduction in the VLCD-mw group was generally not superior to the VLCD-strict group.CONCLUSIONS: In the short-term, strict VLCD only reduced weight better than a liberal VLCD approach among completers. However, after one year, a strict VLCD regimen seemed beneficial compared to a liberal VLCD for all patients. There was no extra weight loss if the VLCD period was initiated on a metabolic ward.

Intermittent versus on-demand use of a very low calorie diet: a randomized 2-year clinical trial

Abstract.  Lantz H, Peltonen M, Ågren L, Torgerson JS (Sahlgrenska University Hospital, Göteborg, Sweden). Intermittent versus on‐demand use of a very low calorie diet: a randomized 2‐year clinical trial. J Intern Med 2003; 253: 463–471.