Effects of different metabolic states and surgical models on glucose metabolism and secretion of ileal L-cell peptides: results from the HIPER-1 study

AIM

To compare the impact of four surgical procedures (mini-gastric bypass, sleeve gastrectomy, ileal transposition and transit bipartition) vs medical management on gut peptide secretion, β-cell function and resolution of hyperglycaemia in people with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A mixed-meal tolerance test was administered 6-24 months after each surgical procedure (mini-gastric bypass, sleeve gastrectomy, ileal transposition and transit bipartition; n=30 in each group) and the results were compared with those obtained in matched lean (n=30) and obese (n=30) people with type 2 diabetes undergoing medical management.

RESULTS

Participants in the mini-gastric bypass and ileal transposition groups had a greater increase in plasma glucose concentration after the mixed-meal tolerance test than those in the sleeve gastrectomy and transit bipartition groups. Participants in the mini-gastric bypass group exhibited the greatest increase in the incremental area under the curve of plasma glucose concentration above baseline (P<0.0001). Insulin sensitivity was similar across surgical groups, and statistically greater in participants in the surgical groups than in obese participants in the non-surgical group (P<0.0001). β-cell responsiveness to glucose was greater in participants in the sleeve gastrectomy and transit bipartition groups than in the mini-gastric bypass and ileal transposition groups (P<0.001) despite a smaller incremental increase above baseline in the area under the plasma glucagon-like peptide-1 concentration curve relative to ileal transposition. Postoperative β-cell function was the strongest predictor of hyperglycaemia resolution.

CONCLUSIONS

The present study showed that the level of β-cell function after bariatric surgery is the strongest predictor of hyperglycaemia resolution. The study also demonstrates a disconnect between postprandial GLP-1 levels and β-cell function among the studied surgical procedures.

Commissioning guidance for weight assessment and management in adults and children with severe complex obesity

The challenge of managing the epidemic of patients with severe and complex obesity disease in secondary care is largely unmet. In England, the National Institute of Health and Care Excellence and the National Health Service England have published guidance on the provision of specialist (non-surgical) weight management services. We have undertaken a systematic review of 'what evidence exists for what should happen in/commissioning of: primary or secondary care weight assessment and management clinics in patients needing specialist care for severe and complex obesity?' using an accredited methodology to produce a model for organization of multidisciplinary team clinics that could be developed in every healthcare system, as an update to a previous review. Additions to the previous guidance were multidisciplinary team pathways for children/adolescent patients and their transition to adult care, anaesthetic assessment and recommendations for ongoing shared care with general practitioners, as a chronic disease management pathway.

Norepinephrine transporter expression is inversely associated with glycaemic indices: a pilot study in metabolically diverse persons with overweight and obesity

Objective

The objective of this study was to examine the cross‐sectional relationship between the expression of norepinephrine transporter (NET), the protein responsible for neuronal uptake‐1, and indices of glycaemia and hyperinsulinaemia, in overweight and obese individuals.

Methods

Thirteen non‐medicated, non‐smoking subjects, aged 58 ± 1 years (mean ± standard error of the mean), body mass index (BMI) 31.4 ± 1.0 kg m⁻², with wide‐ranging plasma glucose and haemoglobin A1c (HbA1c, range 5.1% to 6.5%) participated. They underwent forearm vein biopsy to access sympathetic nerves for the quantification of NET by Western blot, oral glucose tolerance test (OGTT), euglycaemic hyperinsulinaemic clamp, echocardiography and assessments of whole‐body norepinephrine kinetics and muscle sympathetic nerve activity.

Results

Norepinephrine transporter expression was inversely associated with fasting plasma glucose (r = −0.62, P = 0.02), glucose area under the curve during OGTT (AUC_0–120, r = −0.65, P = 0.02) and HbA1c (r = −0.67, P = 0.01), and positively associated with steady‐state glucose utilization during euglycaemic clamp (r = 0.58, P = 0.04). Moreover, NET expression was inversely related to left ventricular posterior wall dimensions (r = −0.64, P = 0.02) and heart rate (r = −0.55, P = 0.05). Indices of hyperinsulinaemia were not associated with NET expression. In stepwise linear regression analysis adjusted for age, body mass index and blood pressure, HbA1c was an independent inverse predictor of NET expression, explaining 45% of its variance.

Conclusions

Hyperglycaemia is associated with reduced peripheral NET expression. Further studies are required to identify the direction of causality.

Weigh Forward: a clinical audit of weight management in Australian general practice

Weigh Forward was a prospective clinical audit, aimed to assess the use and efficacy of 12-week weight management program in general practice. Twenty-eight practitioners participated in the audit, with a total of 258 patients observed. Of these, 147 (57%) were retained to 24 weeks. Practices were asked to implement a structured 12-week weight loss program, and encouraged to utilize relevant weight management guidelines as necessary. Patients were followed up regularly, and comprehensively assessed at baseline, 12 and 24 weeks. Evaluations were made of patient weight loss, practitioner willingness to utilize available weight loss interventions, practitioner set weight loss goals and the appropriateness of such goals. Overall, the 57% of completing patients lost an average of 6.1% ± 0.5% body weight, with 27.2% losing ≥10% body weight. Practitioners were hesitant to intensify treatment, and those with comorbidities were less likely (odds ratio 1.8; 95% CI 1.4-2.4) to receive intensified treatment than those without. Practitioners also tended to set high weight loss goals, with a mean goal of 17.3% body-weight loss. The clinically significant mean weight loss demonstrates that practitioners are able to generate meaningful weight loss in primary care settings, however, could benefit from increased use of available interventions.

Neuroendocrine adaptations to bariatric surgery

The global epidemic of obesity and its related disease in combination with robust physiological defence of intentional weight loss generates a pressing need for effective weight loss therapies. Bariatric surgery, which works very effectively at delivering substantial sustained weight loss, has been an enigma with respect to mechanism of action. Naive concepts of restriction and malabsorption do not explain the efficacy of the most commonly used bariatric procedures. This century has seen increased interest in unravelling the mystery of the mechanisms underlying surgery associated weight loss with a focus on integrative gastrointestinal (GI) physiology, gut-brain signalling, and beyond weight loss effects on metabolism. GI interventions, some very minor, can alter GI wall stretch and pressure receptors; a range of GI hormones affecting hunger and satiety; bile acid metabolism and signalling; the characteristics of GI microbiome; portal vein nutrient sensing; and circulating concentrations of amino acids. Understanding the mechanisms involved should present targets for less invasive effective therapies.

Fat-free mass loss generated with weight loss in overweight and obese adults: What may we expect?

There is concern that intentional weight loss may generate excessive loss of fat-free mass (FFM). Idealists target minimal loss of FFM, while others consider that FFM loss of up to 25% of weight loss is acceptable. In a cross-sectional study of 275 weight-stable, overweight or obese adults, we used whole-body dual-energy X-ray absorptiometry to measure FFM. A range of models was used to estimate the expected ΔFFM/Δweight ratio required to attain the body composition of a weight-stable individual at a lower body mass index (BMI). Higher BMI was associated linearly with higher FFM in men and women. Proportional ΔFFM/Δweight was influenced by sex, BMI and age. Direct scatter plot analysis, quadratic curve fit modelling and linear FFM-BMI modelling provided similar estimates for each model of ΔFFM/Δweight ratio, with 40% for men and 33% for women. These results show that the 25% rule is inappropriate and our estimates are higher than those generally reported after intentional weight loss indicating favourable preservation of FFM.

Control of type 2 diabetes after 1 year of laparoscopic adjustable gastric banding in the helping evaluate reduction in obesity (HERO) study

AIMS

The 5-year, open-label, prospective, observational helping evaluate reduction in obesity (HERO) study (N = 1106) examines efficacy and safety of the LAP-BAND AP(®) laparoscopic adjustable gastric band (LAGB) in obese patients. This interim analysis assessed the control of type 2 diabetes (T2D), 1 year after the implantation of the LAGB.

METHODS

Baseline T2D was defined by chart review or use of antidiabetic medications or haemoglobin A1c (HbA1c) ≥ 7.0%. Control of T2D at 1 year was defined as A1c <7.0% (with or without antidiabetic medications).

RESULTS

After 1 year, 187 of 273 patients with T2D at baseline had adequate data available to assess T2D status, of which 135 patients (72.2%) achieved target control of T2D compared with 42.8% control rate at baseline. Independent predictors of achieving target control at 1 year included the following: (i) shorter diabetes duration odds ratio (OR) 0.914 [95% confidence interval (CI), 0.839, 0.995, p = 0.038], (ii) not using insulin therapy OR 0.16 (95% CI, 0.06, 0.47, p < 0.001) and (iii) greater mean % weight loss OR 1.176 (95% CI, 1.093, 1.266, p < 0.001). Patients using insulin at baseline were 84% less likely to achieve control of T2D after 1 year; each additional year of diabetes at baseline reduced the likelihood of good control by 9%; and each 1% of weight loss increases the likelihood of good control by 18%. Rates of device-related adverse events and reoperations were low and were not significantly different between patients with and without baseline T2D at 1 year.

CONCLUSIONS

Greater % weight loss, not using insulin therapy, and shorter disease duration predicted increased likelihood of target control of T2D, 1 year after implantation of the LAGB.

Severe obesity and diabetes self-care attitudes, behaviours and burden: implications for weight management from a matched case-controlled study. Results from Diabetes MILES--Australia

AIMS

To investigate whether diabetes self-care attitudes, behaviours and perceived burden, particularly related to weight management, diet and physical activity, differ between adults with Type 2 diabetes who are severely obese and matched non-severely obese control subjects.

METHODS

The 1795 respondents to the Diabetes MILES--Australia national survey had Type 2 diabetes and reported height and weight data, enabling BMI calculation: 530 (30%) were severely obese (BMI ≥ 35 kg/m(2); median BMI = 41.6 kg/m(2)) and these were matched with 530 control subjects (BMI < 35 kg/m(2); median BMI = 28.2 kg/m(2)). Diabetes self-care behaviours, attitudes and burden were measured with the Diabetes Self-Care Inventory-Revised. Within-group and between-group trends were examined.

RESULTS

The group with BMI ≥ 35 kg/m(2) was less likely to achieve healthy diet and exercise targets, placed less importance on diet and exercise recommendations, and found the burden of diet and exercise recommendations to be greater than the group with BMI < 35 kg/m(2). The group with BMI ≥ 35 kg/m(2) was more likely to be actively trying to lose weight, but found weight control a greater burden. These issues accentuated with increasing obesity and were greatest in those with BMI > 45 kg/m(2). There were no between-group differences in other aspects of diabetes self-care: self-monitoring of blood glucose, use of medications and smoking. Moderate-to-severe symptoms of depression were independently associated with reduced likelihood of healthy diet and physical activity, and with greater burden associated with diet, physical activity and weight management.

CONCLUSIONS

Severely obese people with diabetes demonstrated self-care attitudes, behaviours and burdens that infer barriers to weight loss. However, other important diabetes self-care behaviours are supported equally by severely obese and non-severely obese individuals.

Fat mass is a predictor of incident foot pain

OBJECTIVE

Foot pain is a common complaint in adults. Increased BMI and fat mass have been linked only to foot pain prevalence. Therefore, a longitudinal study to examine the relationship between body composition and incident foot pain over 3 years was conducted.

DESIGN AND METHODS

Sixty-one community dwelling participants from a previous study of musculoskeletal health, who did not have foot pain at study inception in 2008, were invited to take part in this follow-up study in 2011. Current foot pain was determined using the Manchester Foot Pain and Disability Index, and body composition was measured using dual X-ray absorptiometry at study baseline.

RESULTS

Of the 51 respondents (84% response rate, 37 females and 14 males), there were 11 who developed foot pain. BMI ranged from underweight to morbidly obese (17-44 kg/m2), mean 27.0 ± 6.0 kg/m2. Incident foot pain was positively associated with both fat mass (odds ratio [OR] 1.11, 95% confidence interval [CI] 1.03-1.20) and fat-mass index (OR 1.28, 95% CI 1.04-1.57) in multivariate analysis.

CONCLUSIONS

Fat mass is a predictor of incident foot pain. This study supports the notion that incident foot pain in overweight individuals is associated with fat mass rather than body mass alone.

Gastric bypass in Type 2 diabetes with BMI < 30: weight and weight loss have a major influence on outcomes

AIM

To assess factors influencing glycaemic control following gastric bypass surgery in patients with Type 2 diabetes and BMI< 30 kg/m(2) .

METHODS

Prospective longitudinal study of 103 patients with inadequate glycaemic control who underwent gastric bypass surgery at Soonchunhyang University, Seoul, Korea (n = 66) and Min-Sheng General Hospital, Taipei, Taiwan (n = 37). Procedures were performed August 2009 to January 2011. Key outcome measures were excellent glycaemic control of Type 2 diabetes defined as HbA1c < 42 mmol/mol (≤6%); inadequate response defined as HbA1c > 53 mmol/mol (> 7%). Analysis was conducted using binary logistic regression, and cut-points obtained from receiver operator characteristics.

RESULTS

Excellent glycaemic control was achieved in 31 (30%) at 1 year. Diabetes duration of < 7 years and BMI > 27 kg/m(2) provided independent predictors and useful cut-points. Likelihood of excellent glycaemic control for an individual could be estimated using loge (Odds) = -6.7 + (0.26 × BMI) + (-1.2 × diabetes duration). Baseline BMI of < 27 kg/m(2) and baseline C-peptide of < 2.0ng/ml, best predicted a poor glycaemic response. In those with favourable baseline characteristics percentage weight loss (%WL) had a dominant influence on glycaemic outcomes. Baseline C-peptide (> 2.4 ng/ml) and subsequent percentage weight loss (> 16%) were associated with excellent glycaemic control. Higher BMI was associated with greater percentage weight loss.

CONCLUSION

In patients with Type 2 diabetes and BMI < 30 kg/m(2) , glycaemic response to gastric bypass is predicted by higher baseline BMI, shorter disease duration and higher fasting C-peptide. Post-surgery weight loss has a dominant effect. Baseline BMI and weight loss have a major influence on outcomes.

Bariatric surgery: an IDF statement for obese Type 2 diabetes

The International Diabetes Federation Taskforce on Epidemiology and Prevention of Diabetes convened a consensus working group of diabetologists, endocrinologists, surgeons and public health experts to review the appropriate role of surgery and other gastrointestinal interventions in the treatment and prevention of Type 2 diabetes. The specific goals were: to develop practical recommendations for clinicians on patient selection; to identify barriers to surgical access and suggest interventions for health policy changes that ensure equitable access to surgery when indicated; and to identify priorities for research. Bariatric surgery can significantly improve glycaemic control in severely obese patients with Type 2 diabetes. It is an effective, safe and cost-effective therapy for obese Type 2 diabetes. Surgery can be considered an appropriate treatment for people with Type 2 diabetes and obesity not achieving recommended treatment targets with medical therapies, especially in the presence of other major co-morbidities. The procedures must be performed within accepted guidelines and require appropriate multidisciplinary assessment for the procedure, comprehensive patient education and ongoing care, as well as safe and standardized surgical procedures. National guidelines for bariatric surgery need to be developed for people with Type 2 diabetes and a BMI of 35 kg/m² or more.

The effects of dietary weight loss with or without exercise training on liver enzymes in obese metabolic syndrome subjects

AIM

Insulin resistance and visceral adiposity are predisposing factors for fatty liver disease. The main objectives of this study were (i) to compare the effects of caloric restriction (CR) alone or together with moderate-intensity aerobic exercise training (CR+EX) on liver enzymes, a surrogate marker of liver injury, in obese metabolic syndrome (MetS) subjects and (ii) to identify anthropometric, metabolic, cardiovascular and dietary predictors of changes in liver enzymes.

METHODS

Sedentary men and women (n = 63), aged 55 ± 6 (s.d.) years with body mass index 32.7 ± 4.1 kg/m(2) and confirmed MetS, were randomized to 12-week CR, CR+EX or no treatment (Control).

RESULTS

Weight loss averaged 7.6% in the CR and 9.1% in the CR+EX group (time effect, p < 0.001; group effect, p = 0.11); insulin sensitivity improved by 49 and 45%, respectively (both p < 0.001). Fitness (maximal oxygen consumption) increased by 19% in the CR+EX group only (p < 0.001). Alanine aminotransferase (ALT) levels decreased by 20% in the CR and 24% in the CR+EX group (time effect, both p < 0.001; group effect, p = 0.68); corresponding values for γ-glutamyltransferase (GGT) were -28 and -33%, respectively (time effect, both p < 0.001; group effect, p = 0.28). Reduction in abdominal fat mass (measured by DXA from L1 to L4) independently predicted ΔALT (r = 0.42, p = 0.005) and ΔGGT (r = 0.55, p < 0.001), whereas change in dietary saturated fat intake was independently associated with ΔALT (r = 0.35, p = 0.03).

CONCLUSIONS

Reductions in central adiposity and saturated fat intake are key drivers of improvement in liver enzymes during lifestyle interventions. Exercise training did not confer significant incremental benefits in this study.

Impact of laparoscopic adjustable gastric banding on type 2 diabetes

Bariatric surgery is becoming an accepted option for obese people with type 2 diabetes. Our aim was to assess the impact of laparoscopic adjustable gastric banding (LAGB) through a systematic review of the literature. Data was sourced from Scopus, MEDLINE and EMBASE published from 2000 through May 2011, and five unpublished studies that were performed by industry for regulatory approval were also included. Studies were selected on the basis that they provide some detail of diabetes status before and after LAGB. There were 35 studies meeting the inclusion criteria. There was considerable heterogeneity in study design, sample size, length of follow-up, attrition rates and classification of diabetes status. Weight loss was progressive over the first 2 years with a weighted average of 47% excess weight loss at 2 years. Remission or improvement in diabetes varied from 53% to 70% over different time periods. Results were broadly consistent, demonstrating clinically relevant improvements in diabetes outcomes with sustained weight loss in obese people with type 2 diabetes following LAGB surgery. However, there were significant shortcomings in the reviewed literature with few high-quality studies, inconsistent reporting of diabetes outcomes and high attrition rates. Long-term studies that address these limitations are needed.

Impact of laparoscopic adjustable gastric banding on type 2 diabetes

Bariatric surgery is becoming an accepted option for obese people with type 2 diabetes. Our aim was to assess the impact of laparoscopic adjustable gastric banding (LAGB) through a systematic review of the literature. Data was sourced from Scopus, MEDLINE and EMBASE published from 2000 through May 2011, and five unpublished studies that were performed by industry for regulatory approval were also included. Studies were selected on the basis that they provide some detail of diabetes status before and after LAGB. There were 35 studies meeting the inclusion criteria. There was considerable heterogeneity in study design, sample size, length of follow-up, attrition rates and classification of diabetes status. Weight loss was progressive over the first 2 years with a weighted average of 47% excess weight loss at 2 years. Remission or improvement in diabetes varied from 53% to 70% over different time periods. Results were broadly consistent, demonstrating clinically relevant improvements in diabetes outcomes with sustained weight loss in obese people with type 2 diabetes following LAGB surgery. However, there were significant shortcomings in the reviewed literature with few high-quality studies, inconsistent reporting of diabetes outcomes and high attrition rates. Long-term studies that address these limitations are needed.

Bariatric surgery: an IDF statement for obese Type 2 diabetes

The International Diabetes Federation Taskforce on Epidemiology and Prevention of Diabetes convened a consensus working group of diabetologists, endocrinologists, surgeons and public health experts to review the appropriate role of surgery and other gastrointestinal interventions in the treatment and prevention of Type 2 diabetes. The specific goals were: to develop practical recommendations for clinicians on patient selection; to identify barriers to surgical access and suggest interventions for health policy changes that ensure equitable access to surgery when indicated; and to identify priorities for research. Bariatric surgery can significantly improve glycaemic control in severely obese patients with Type 2 diabetes. It is an effective, safe and cost-effective therapy for obese Type 2 diabetes. Surgery can be considered an appropriate treatment for people with Type 2 diabetes and obesity not achieving recommended treatment targets with medical therapies, especially in the presence of other major co-morbidities. The procedures must be performed within accepted guidelines and require appropriate multidisciplinary assessment for the procedure, comprehensive patient education and ongoing care, as well as safe and standardized surgical procedures. National guidelines for bariatric surgery need to be developed for people with Type 2 diabetes and a BMI of 35 kg/m(2) or more.

Bariatric surgery: an IDF statement for obese Type 2 diabetes

The International Diabetes Federation Taskforce on Epidemiology and Prevention of Diabetes convened a consensus working group of diabetologists, endocrinologists, surgeons and public health experts to review the appropriate role of surgery and other gastrointestinal interventions in the treatment and prevention of Type 2 diabetes. The specific goals were: to develop practical recommendations for clinicians on patient selection; to identify barriers to surgical access and suggest interventions for health policy changes that ensure equitable access to surgery when indicated; and to identify priorities for research. Bariatric surgery can significantly improve glycaemic control in severely obese patients with Type 2 diabetes. It is an effective, safe and cost-effective therapy for obese Type 2 diabetes. Surgery can be considered an appropriate treatment for people with Type 2 diabetes and obesity not achieving recommended treatment targets with medical therapies, especially in the presence of other major co-morbidities. The procedures must be performed within accepted guidelines and require appropriate multidisciplinary assessment for the procedure, comprehensive patient education and ongoing care, as well as safe and standardized surgical procedures. National guidelines for bariatric surgery need to be developed for people with Type 2 diabetes and a BMI of 35 kg/m(2) or more.

X-ray microspectroscopy and chemical reactions in soil microsites

Soils provide long-term storage of environmental contaminants, which helps to protect water and air quality and diminishes negative impacts of contaminants on human and ecosystem health. Characterizing solid-phase chemical species in highly complex matrices is essential for developing principles that can be broadly applied to the wide range of notoriously heterogeneous soils occurring at the earth's surface. In the context of historical developments in soil analytical techniques, we describe applications of bulk-sample and spatially resolved synchrotron X-ray absorption spectroscopy (XAS) for characterizing chemical species of contaminants in soils, and for determining the uniqueness of trace-element reactivity in different soil microsites. Spatially resolved X-ray techniques provide opportunities for following chemical changes within soil microsites that serve as highly localized chemical micro- (or nano-)reactors of unique composition. An example of this microreactor concept is shown for micro-X-ray absorption near edge structure analysis of metal sulfide oxidation in a contaminated soil. One research challenge is to use information and principles developed from microscale soil chemistry for predicting macroscale and field-scale behavior of soil contaminants.

Bleeding complications in skin cancer surgery are associated with warfarin but not aspirin therapy

BACKGROUND

The aim was to identify risk factors for postoperative bleeding following skin cancer surgery.

METHODS

This was a prospective study of 5950 skin lesions excised in 2394 patients. No patient stopped taking aspirin or warfarin unless the international normalized ratio (INR) exceeded 3.0.

RESULTS

The rate of postoperative bleeding was 0.7 per cent overall and 2.5 per cent in the 320 patients taking warfarin. The rate of bleeding was 1.0 per cent for skin flap repairs, 0.4 per cent for simple excision and closure, and 5.0 per cent for skin grafts. Diabetic patients and smokers were not at increased risk of bleeding. There were four independent factors for bleeding: age 67 years or older (odds ratio (OR) 4.7 (95 per cent confidence interval 1.8 to 12.2); P = 0.002), warfarin therapy (OR 2.9 (1.4 to 6.3); P = 0.006), surgery on or around the ear (OR 2.6 (1.2 to 5.7); P = 0.012) and closure with a skin flap or graft (OR 2.7 (1.4 to 5.3); P = 0.004). Aspirin therapy was not an independent risk factor for bleeding.

CONCLUSION

Most postoperative bleeds were inconvenient but not life threatening, unlike the potential risk of thromboembolism after stopping warfarin or aspirin. There was no case for discontinuing aspirin before skin surgery, but the INR should be monitored in patients taking warfarin.

Night eating syndrome and nocturnal snacking: association with obesity, binge eating and psychological distress

OBJECTIVE

Night eating syndrome (NES) is characterized by a time-delayed pattern of eating relative to sleep, where most food is consumed in the evening and night. This study aimed to investigate the clinical significance of NES and nocturnal snacking by exploring the relationship between NES and (1) obesity, (2) binge eating disorder (BED) and (3) psychological distress.

SUBJECTS

One hundred and eighty bariatric surgery candidates, 93 members of a non-surgical weight loss support group and 158 general community respondents (81 males/350 females, mean age: 45.8+/-13.3 years, mean body mass index (BMI): 34.8+/-10.8 and BMI range: 17.7-66.7).

METHODS

NES diagnosis required within the previous 3 months: (1) no appetite for breakfast, (2) consumption of > or =50% of daily energy after 1900 hours and (3) sleep difficulties > or =3 nights/week. Nocturnal snacking (awakening to eat) was recorded. Validated questionnaires assessed BED, symptoms of depression, appearance dissatisfaction (AD) and mental health-related quality of life (MHQoL). NES and binge eating (BE) (> or =1 episode/week) were confirmed by interview.

RESULTS

NES criteria were met by 11.1% of the total cohort. Across all groups, BE (P=0.001), BMI (P=0.003) and male gender (P=0.013) explained 10% of NES variance. Individuals with co-morbid NES and BE reported similarly elevated psychological distress as other binge eaters. NES alone was not associated with psychological distress. Those with NES who consumed nocturnal snacks reported poorer MHQoL (P=0.007) and greater depressive symptoms (P=0.039) and hunger (P=0.013) than others with NES. Low MHQoL (P=0.007) and male gender (P=0.022) explained 27% of the variance in the nocturnal snacking group.

DISCUSSION

In this study, NES was positively associated with BMI, BE and male gender. Elevated psychological distress was only apparent in those who consumed nocturnal snacks. Further characterization and understanding of the clinical significance of NES and nocturnal snacking is required.

Changes in fat-free mass during significant weight loss: a systematic review

OBJECTIVE

To identify the proportion of weight lost as fat-free mass (FFM) by various weight loss interventions.

METHODS

Medline and Embase were systematically searched for reliable measurements of FFM before and after weight loss of >10 kg and eligible data were pooled. In a fixed effect model of % FFM loss/weight loss (%FFML), linear regression analysis was used to determine the influence of degree of caloric restriction, exercise, magnitude of weight loss, initial body mass index (BMI) and type of surgery.

RESULTS

Data were included from 26 cohorts treated with dietary and behavioral interventions and 29 cohorts of bariatric surgery patients. The degree of caloric restriction was positively associated with %FFML (r (2)=0.31, P=0.006) and in three randomized controlled trials exercise was shown to decrease %FFML. Compared with laparoscopic adjustable gastric banding (LAGB), biliopancreatic diversion (BPD) and roux en Y gastric bypass (RYGB) caused greater log(e) (natural log) %FFML (r (2)=0.453, P<0.001). Differences in log(e) %FFML between surgical procedures were independent of initial BMI and magnitude of weight loss.

CONCLUSIONS

The degree of caloric restriction, exercise and rate of weight loss influence the proportion of weight lost as FFM after non-surgical interventions. For surgical interventions, BPD and RYGB result in greater %FFML than LAGB.

Randomized clinical trial of the effect of applying ointment to surgical wounds before occlusive dressing

BACKGROUND

A blinded randomized clinical trial was undertaken to evaluate the effect of applying ointment to a wound before occlusive dressing, in comparison with no ointment or sterile paraffin.

METHODS

Some 778 patients with 1801 surgical wounds following excision of skin lesions were enrolled in the trial. No ointment was placed on 510 sutured wounds of 247 patients, paraffin ointment was put on 729 wounds (269 patients) and mupirocin ointment on 562 wounds (262 patients). Wound infection, scar, haemorrhage, dehiscence and other complications were assessed at suture removal. At 6-9 months after surgery, patients were surveyed to assess the wounds, with a response rate of 74.0 per cent.

RESULTS

There were no significant differences in outcome for all endpoints evaluated. The infection rate was 1.4 per cent with no ointment, 1.6 per cent for paraffin and 2.3 per cent for mupirocin (P = 0.490). Total complication rates were 3.5, 4.7 and 4.8 per cent for no ointment, paraffin and mupirocin respectively (P = 0.590). Some 10.9, 10.3 and 8.2 per cent of patients respectively had a neutral or negative perception of their wounds at 6-9 months after surgery (P = 0.650). There was no difference in postoperative pain, degree of inconvenience or overall level of satisfaction with treatment.

CONCLUSION

Putting ointment on a surgical wound before occlusive dressing does not benefit the patient. In view of the risk of antibiotic resistance, mupirocin ointment is not indicated for clean surgical wounds.

Polysomnography before and after weight loss in obese patients with severe sleep apnea

OBJECTIVE

While obstructive sleep apnea (OSA) is strongly related to obesity, few studies have examined polysomnographic (PSG) changes with major weight loss. We examined the effect of weight loss following laparoscopic adjustable gastric banding (LAGB) on the PSG changes in patients with severe OSA. In addition, we studied daytime sleepiness, the metabolic syndrome and quality of life (QOL).

METHODS

A prospective study was conducted of 25 severely obese patients (17 men, eight women) with paired diagnostic PSG, biochemical and questionnaire studies, the first prior to LAGB and the second at least 1 y later. Subjects with a baseline apnea-hypopnea index (AHI) >25/h were included.

RESULTS

Subject baseline age was 44.7 y, weight 154 kg and body mass index 52.7 kg/m(2). The second PSG study was conducted 17.7+/-10 (range 12-42) months after surgery and mean percentage of excess loss and weight loss were 50.1+/-15% (range 24-80%) and 44.9+/-22 kg (range 18-103 kg), respectively. There was a significant fall in AHI from 61.6+/-34 to 13.4+/-13, improved sleep architecture with increased REM and stage III and IV sleep, daytime sleepiness, as measured by Epworth Sleepiness Scale, of 13+/-7.0 to 3.8+/-3.0, and fewer patients requiring nasal continuous positive airways pressure (CPAP). There were also major improvements in the metabolic syndrome, QOL, body image and fewer symptoms of depression (P<0.05 for all).

CONCLUSION

Weight loss provides major improvement or resolution of OSA and CPAP requirements. It also reduces daytime sleepiness, and improves the metabolic syndrome and QOL. LAGB placement should be considered a broadly effective therapy for sleep apnea in the severely obese patient.

Body composition changes following laparoscopic gastric banding for morbid obesity

Most reports of outcome following obesity surgery report weight and co-morbidity changes only. We studied body composition changes in 17 adult patients (15 F, 2 M, age 43+/-2 years, range 28-58 years), with morbid obesity (initial BMI 40.4+/-4.9 kg/m(2), range 34.7-48.8) who were managed surgically by laparoscopically inserting an adjustable gastric band. Body composition was studied before and after surgery (mean interval of 909+/-51 days, range 441-1155 days) using anthropometry (abdominal circumference, AC, sum of four skinfold thicknesses, SFSUM), whole-body potassium counting (TBK), in vivo neutron activation analysis total body nitrogen (TBProtein) and whole-body dual-energy ray absorptiometry (total body percent fat TBF%, and total body bone mineral density TBBMD). Weight loss over the study period was 23.4+/-2.5 kg. ( p<0.0003) with an AC reduction of 20.0+/-4.5 cm ( p<0.008). Both SFSUM and TBF% were significantly reduced ( p<0.02 and p<0.0005 respectively). Both TBK and TBProtein after normalization for sex and height, were significantly ( p<0.0054 and p<0.001 respectively) reduced, but the ratio of loss of fat mass to fat-free mass, at 4.4:1 was usual for weight loss, and there was no significant changes in the ratio of potassium to protein. TBBMD, after normalization relative to a young same sex adult, was not significantly changed. In this group of patients, most of the substantial weight loss over a 2- to 3-year period was due to loss of fat mass, with relatively less reduction in the components of fat-free mass. Adjustable laparoscopic gastric banding induces fat loss without significant other deleterious effects on body composition.

Improvements in insulin sensitivity and beta-cell function (HOMA) with weight loss in the severely obese. Homeostatic model assessment

AIMS

To examine the effect of weight loss on insulin sensitivity and beta-cell function in severely obese subjects of varying glycaemic control.

PATIENTS AND METHODS

Subjects were 254 (F:M 209:45) patients having adjustable gastric banding for severe obesity, with paired biochemical data from before operation and at 1-year follow up. The homeostatic model assessment method was used to calculate insulin sensitivity (HOMA%S) and beta-cell function (HOMA%B). Subjects were grouped by diabetic status and by pre-weight loss HbA1c.

RESULTS

Initial mean (sd) weight and body mass index were 128 (26) kg and 46.2 (7.7) kg/m2, respectively, and at 1-year were 101 (22) kg and 36.4 (6.7) kg/m2. The percentage of excess weight lost (%EWL) was 44.3 (14)%. HOMA%S improved from 37.5 (16)% presurgery to 62 (25)% (P < 0.001). %EWL was the only predictor of HOMA%S improvement (r = 0.28, P < 0.001). Subjects with normal fasting glucose, impaired fasting glucose and Type 2 diabetes had a fall, no change and increase in HOMA%B, respectively. The improvement in HOMA%B in subjects with diabetes (n = 39) was inversely related to the time with diabetes (r = -0.36, P = 0.02). In non-diabetic subjects the HOMA%S-HOMA%B relationship was favourably altered with weight loss, so that for any given HOMA%S there was an increase in HOMA%B (f = 11.8, P = 0.001). This improvement in HOMA%B was positively related to %EWL (r = 0.25, P = 0.019).

DISCUSSION

There are beneficial changes in both insulin sensitivity and beta-cell function with weight loss. Modern laparoscopic obesity surgery may have an important early role in the management of Type 2 diabetes in obese subjects.

Molecular configurations and orientations of hydrazine between structural layers of kaolinite

Hydrazine is one of the most commonly used entraining agents to penetrate kaolinite, yet the mechanism of intercalation of kaolinite by hydrazine is still in debate. The objectives of this study are to investigate the possible molecular configurations and orientations of hydrazine in the interlayer of kaolinite and the configuration changes induced by water molecules. Water molecules increased the intercalation rate and caused the expansion of the intercalation complex from 0.96 to 1.03 nm. The kinetic effect was likely the result of breaking the self-associations of hydrazine molecules and releasing more "free" hydrazine molecules for the intercalation. H-bonding caused large red shifts of the inner surface OH stretching bands from 3695 to 3626 cm(-1) in the 0.96-nm kaolinite hydrazine intercalation (KHI) complex and to 3570 and 3463 cm(-1) in the 1.03-nm KHI complex. The NH stretching bands of the hydrazine molecules in the KHI complexes became sharper and blue-shifted more than 20 cm(-1) compared with the free liquids. The symmetric NH vibrations at 3365 and 3310 cm(-1), and the NN vibration at 1092 cm(-1) became infrared inactive in the 0.96-nm KHI complex. The frequency of the SiO bands of the kaolinite in the 1.03-nm KHI complex was slightly lower than in the 0.96-nm KHI complex (5 cm(-1) shift). These IR band changes implied that hydrazine molecules have different configurations in the complexes: hydrazine molecules had an eclipsed form in the interlayer of the 0.96-nm KHI complex. The eclipsed configuration has a dipole moment of 3.31 D, which is higher than the gauche form (1.83-1.90 D). The molecule was oriented with the NN bond parallel or nearly parallel to the (001) surface of the mineral and the four H atoms of each hydrazine molecule reacted with the basal siloxane surface. When a suitable amount of water was present, it promoted the configuration change of the hydrazine molecules from the eclipsed form to the common gauche form. This gauche form was stabilized by transforming to a more polarized NH3NH tautomer structure (5.4 D). To promote an optimal interaction between hydrazine and the mineral surface, the NN bond of the hydrazine was tilted about 30 degrees from the (001) plane and caused the intercalation complex to expand from 0.96 to 1.03 nm. The eclipsed form and the tautomer were stabilized by the asymmetric interlayer environment of kaolinite. The two proposed models and reaction mechanisms match the high dipole moment requirement as found for other entraining agents. Further investigation is needed to confirm the exact configuration of hydrazine molecules and whether or not the tautomer exists.

Reduced plasma homocysteine in obese red wine consumers: a potential contributor to reduced cardiovascular risk status

BACKGROUND

Moderate alcohol consumption is associated with improved vascular risk profile and decreased mortality in the middle aged. An elevated homocysteine concentration is an independent risk factor for cardiovascular disease.

OBJECTIVE

To examine the relationship between alcohol consumption and homocysteine concentrations in severely obese patients (body mass index (BMI)>35).

DESIGN

A careful alcohol history was obtained from 350 (male:female 1:5) consecutive patients as part of preoperative assessment for surgical treatment of obesity. Data were obtained concerning amount, frequency, timing and type of alcohol consumption. Fasting homocysteine, serum folate and vitamin B(12) concentrations were measured. Differences between groups were assessed using Student t-test, and ANOVA. Linear regression was used to assess factors influencing homocysteine concentration.

RESULTS

There is a U-shaped relationship between alcohol consumption and homocysteine concentrations, with light to moderate consumption being associated with lower concentrations. Those consuming <100 g/week (n=165) of alcohol had geometric mean (95% CI of mean) serum homocysteine concentrations of 8.5 (8.2-8.9) micromol/l compared with 9.5 (9.1-9.9) micromol/l for non or rare consumers (n=153; P=0.001). The lower concentrations of homocysteine in regular consumers were associated with higher folate concentrations of 9.4 (8.6-10.2) ng/ml when compared with non-consumers 7.5 (7.1-7.8) ng/ml (P=0.001). Red wine consumers (n=42) had lower fasting concentrations of homocysteine 7.8 (7.5-8.1) micromol/l compared with 153 non-consumers 9.4 (9.0-9.8) micromol/l (P<0.001), 82 beer and spirit consumers 9.0 (8.4-9.7) micromol/l (P=0.005) and 73 white wine consumers 8.8 (8.2-9.4 micromol/l (P=0.013). Red wine consumption was an independent predictor for lower homocysteine concentrations.

CONCLUSION

Mild to moderate alcohol consumption, especially red wine consumption, in obese subjects is associated with lower fasting homocysteine concentrations. This may reduce cardiovascular risk and help explain the 'French paradox'.

Effect of Structural Stress on the Intercalation Rate of Kaolinite

Particle size in kaolinite intercalation showed an inverse reactivity trend compared with most chemical reactions: finer particles had lower reactivity and some of the fine particles cannot be intercalated. Although this phenomenon was noted in the early 1960s and several hypotheses have been reported, there is no widely accepted theory about the unusual particle size response in the intercalation. We propose that structural stress is a controlling factor in the intercalation and the stress contributes to the higher reactivity of the coarser particles. In this study, we checked the structural deformation spectroscopically and indirectly proved the structural stress hypothesis. A Georgia kaolinite was separated into nine size fractions and their intercalations by hydrazine monohydrate and potassium acetate were investigated with X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) analyses. The apical Si-O band of kaolinite at 1115 cm(-1) shifted to 1124 cm(-1) when the mineral was intercalated to 1.03 nm by hydrazine monohydrate, and its strong pleochroic properties became much weaker. Similar reduction in pleochroism was observed on the surface OH bands of kaolinite after intercalation. Both the bending vibrations of the inner OH group at 914 cm(-1) and of the surface OH group at 937 cm(-1) shifted to 903 cm(-1) after intercalation by hydrazine. A new band for the inner OH group appeared at 3611 cm(-1) during the deintercalation of the 1.03 nm hydrazine kaolinite complex. Pleochroism change in the apical Si-O band suggested the tetrahedra had increased tilt with respect to the (001) plane. The tilt of the Si-O apical bond could occur only if the octahedra had also undergone structural rearrangement during intercalation. These changes in the octahedral and tetrahedral sheets represent some change in the manner of compensation for the structural misfit of the tetrahedral sheet and octahedral sheet. As the lateral dimensions of a kaolinite particle increases, the cumulative degree of misfit increases. Intercalation breaks the hydrogen bonds between layers and allows for the structure to reduce the accumulated stress in some other manner. The reversed size effect on intercalation probably was not caused by crystallinity differences as reported in the literature, because the Hinckley and Lietard crystallinity indices of the four clay fractions were very close to each other. Impurities, such as dickite- or nacrite-like phases are not significant in the studied sample as suggested by the XRD and IR results, they are not the main reasons for the lower reactivity of the finer particles.

Echinococcus granulosus: regulation of leukocyte growth by living protoscoleces from horses, sheep, and cattle

To determine whether living hydatid tissue can, like hydatid fluid, regulate leukocyte growth, T-cell, B-cell, and macrophage lines were cocultured with protoscoleces of Echinococcus granulosus and their growth was compared with that of control cultures by thymidine uptake estimates and chemiluminescent assays of cell number. Protoscoleces supported mitosis of IL-1-deprived D10 T cells, but did not increase D10 count. The action of protoscoleces was affected by the species and organ of their origin and the length of time in culture. Unusually marked mitotic reaction, unaffected by parasite age and origin, was recorded in the B-cell line, BSM, also without commensurate count increase, indicating that induced mitosis resulted in cell loss. It is concluded that protoscoleces can induce mitosis in B and T cells of particular lineages and that this is a potential means of producing the pathological proliferation and depletion of B- and T-cell areas which characterize local reaction to hydatids.

Quality of life after lap-band placement: influence of time, weight loss, and comorbidities

OBJECTIVE

To assess the quality of life (QOL) in severely obese subjects before and after Lap-Band gastric restrictive surgery and identify factors that may influence change.

RESEARCH METHODS AND PROCEDURES

All patients, over a 3-year period, attending for preoperative assessment (n = 459) or annual review after surgery (n = 641) have completed the Short Form-36 (SF-36) health survey. Eight domain and physical component summary (PCS) and mental component summary (MCS) scores were calculated. Scores were analyzed in groups based on time after surgery and compared with community normal (CN) values. Paired preoperative and 1-year scores (n = 218) data were used to find predictors of QOL change.

RESULTS

All preoperative mean scores (n = 459) were lower than CN values, with greater impairment in the PCS (36.8 +/- 9.5 vs. CN: 51.3 +/- 8.3, p < 0.001) than in the MCS (45.7 +/- 8.2 vs. CN: 48.8 +/- 9.5, p < 0.001) scores. After 1 year, scores were closer to CN scores (PCS: 52.4 +/- 8.2 and MCS: 48.4 +/- 7.7), and these remained closer for 4 years. Preoperative obesity comorbidity, especially physical disability, was the best predictor of poor preoperative SF-36 scores and of improvement in scores at 1 year. The percentage of excess weight loss at 1 year (46 +/- 16%) was of little predictive value of improved QOL.

DISCUSSION

Severely obese subjects have poor health-related QOL as measured by the SF-36 health survey. Lap-Band surgery for this group has provided a dramatic and sustained improvement in all measures of the SF-36. Improvement is greater in those with greater preoperative disability, and the extent of weight loss is not a good predictor of improved QOL.

Pregnancy after Lap-Band surgery: management of the band to achieve healthy weight outcomes

BACKGROUND

Severely obese women have higher obstetric risks and poorer neonatal outcomes. Weight loss reduces obstetric risk. The introduction of a laparoscopically-placed adjustable gastric band, a safe and effective method of weight loss, has given us the ability and responsibility to adjust the band in relation to pregnancy.

OBJECTIVE

Our aim was to devise a safe management plan to achieve healthy maternal weight gain (Institute of Medicine 1990) during pregnancy.

METHODS

In a cohort group of 650 patients to have a Lap-Band placement for severe obesity, we have reviewed the management of the band and pregnancy outcomes of all women (n=20) to complete a pregnancy (n=22) with a band in-situ.

RESULTS

All 22 pregnancies were singleton, with no primary caesarean sections (3 for recurring indications). The mean maternal weight gain was 8.3 kg compared with 15.2 kg for the 15 previous pregnancies of women in this group (p<0.05). There was no difference in birth weights. Obstetric complications were minimal, and there were no premature or low birth weight infants. 11 of 15 subjects with active management of the band achieved a maternal weight gain within the advised range compared with only 2 of 7 prior to this.

CONCLUSION

The ability to adjust gastric restriction allows optimal control of maternal weight change in pregnancy and should help avoid the risks of excessive weight change.

Nonalcoholic fatty liver disease: predictors of nonalcoholic steatohepatitis and liver fibrosis in the severely obese

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) is common in severely obese subjects and can progress to cirrhosis and liver failure. Predicting advanced or progressive disease may help in selecting patients for liver biopsy and assist the development of therapeutic options.

METHODS

Liver biopsies were taken at laparoscopic obesity surgery in 105 consecutive patients. The clinical and biochemical variables were analyzed for correlation with specific histologic features.

RESULTS

Twenty-six patients (25%) were found to have nonalcoholic steatohepatitis (NASH), and 11 (42%) of these had advanced fibrosis. A raised index of insulin resistance (odds ratio [OR] 9.3, 95% confidence interval [CI] 3.4-26), systemic hypertension (OR 5.2, 95% CI 2.0-13.5), and raised alanine aminotransferase (OR 8.6, 95% CI 3.1-23.5) were independent predictors of NASH. A combination of 2 or 3 of these predictors allows a sensitivity of 0.8 and specificity of 0.89 for NASH. Alcohol consumption was associated with a reduction in NASH (OR 0.35, 95% CI 0.12-1.00) and diabetes (OR 0.18, 95% CI 0.047-0.67).

CONCLUSION

Insulin resistance and systemic hypertension, features of the metabolic syndrome, are independently associated with advanced forms of NAFLD. Moderate alcohol consumption seems to reduce the risk of NAFLD in the severely obese, possibly by reducing insulin resistance.

A disparity between conventional lipid and insulin resistance markers at body mass index levels greater than 34 kg/m(2)

OBJECTIVE

The aim of this study was to examine changes in lipid profile and markers of insulin resistance with increasing body mass index (BMI) in the range 34-77 kg/m(2). In addition we compare the lipid profiles of severely obese patients with those of the Australian community.

SUBJECTS AND METHODS

A total of 572 patients (85% F, 15% M) were assessed prior to gastric restrictive surgery. Conventional lipid profiles and markers of insulin resistance were measured. Lipids were compared with the Australian National Heart Foundation 1989 study (control group).

RESULT

There was no difference in mean total cholesterol levels between the obese group (5.52 mmol/l) and the control group (5.47 mmol/l). The mean total cholesterol levels in the obese group fell with increasing BMI (r=-0.13, P<0.01). Obese subjects had elevated fasting triglyceride levels 1.96 mmol/l (control group, 1.12 mmol/l, P<0.001), but levels did not change with increasing BMI (r=0.0, NS). HDL-C levels were lower, 1.21 mmol/l (control group 1.44 mmol/l, P<0.001), and decreased with increasing BMI (r=-0.20, P<0.01). LDL-C levels were lower in obese men (3.65 mmol/l vs control group 4.17 mmol/l, P<0.01) but not women and levels fell with increasing BMI (r=-0.15, P<0.05). For the obese group, markers of insulin resistance (fasting plasma glucose, HbA1c, fasting plasma insulin and C-peptide) all rose significantly with increasing BMI.

CONCLUSION

Raised total cholesterol is not a co-morbidity of severe obesity. There is a disparity between the conventional lipid measures and insulin resistance measures of the metabolic syndrome with increasing BMI. Conventional lipid measures may be poor indicators of dyslipidaemic risk in the severely obese.

Mitosis and differentiation in T-cells under cytotoxic action of Echinococcus granulosus hydatid fluid

In the T-cell line, D10, thymidine uptake was used to measure the proportion of cells in S-phase, and the MTT assay to measure the number of viable cells. The effect of Echinococcus granulosus hydatid fluid (HF) on the lymphocytes was assayed in 3-day cultures of the T-cell line, D10, in increasing concentrations of HF. Apparent cytotoxic effects of HF were recorded as a log-linear decline in S-phase activity, which was reduced by the presence of IL-1, IL-2, or a combination of the two. In the presence of IL-2, however, mitogenic treatment with concanavalin A increased the cytotoxic effect in 3-day cultures, while in day-2 cultures, HF itself showed mitogenic effect. HF-induced decline in S-phase activity was not matched by a parallel decline in viable cells, suggesting that the apparent cytotoxicity of HF could result from cell-cycle arrest. Depending on its origin, HF enhanced membrane expression of CD25 and CD38 on human peripheral blood lymphoblasts, and diminished that of CD28. Taken together, these changes suggest that HF can induce T-cell mitosis and reduce co-stimulation with subsequent T-cell anergy or apoptosis.

Pre-operative predictors of weight loss at 1-year after Lap-Band surgery

BACKGROUND

The authors studied a range of preoperative factors for their predictive value of effectiveness of Lap-Band placement, using the percentage of excess weight loss at 1-year as the outcome measure (%EWL1).

METHODS

All factors were measured and recorded prior to surgery. Factors included: patient demographics, family, medical and weight history. Laboratory measures and the responses to the SF-36 Health Survey were also assessed. Factors were assessed for correlation with %EWL1.

RESULTS

The group (N=440, F:M 383:57) had mean age 40.0+/-9.5 years, weight of 126+/-25 kg, and BMI 45.6+/-7.5 kg/m2 pre-operatively. At 1-year follow-up, the group had mean weight 97.6< or =20 kg, BMI 35.6 = 6.3 kg/m2, and %EWL1 45.8< or =17%. Increasing age (R= -0.13, p<0.01) and preoperative BMI (R=-0.22, p<0.001) were significantly associated with less %EWL1 and all other factors were controlled for these before assessing significance. Important factors associated with a lower %EWL1 included: hyperinsulinemia (R=-0.36, p<0.001), insulin resistance (R=-0.33, p<0.001) and disease associated with insulin resistance, poor physical ability, pain, and poor general health responses to the SF-36 Health Survey. Patients who consumed alcohol regularly had a better rate of weight loss (R= 0.23, p<0.005). Factors that had no influence included gender, a history of mental illness and measures of mental health, previous bariatric surgery, and a history of many medical conditions associated with obesity.

CONCLUSION

Important physical factors have been found to influence the rate of weight loss. Those with increased age, pain, physical disability and insulin resistance have a great deal to gain from weight loss. Although this study has identified factors that are associated with less weight loss, we have not found any factor that predicts an unacceptably low weight loss and thus provides a contraindication to Lap-Band placement. The findings of this study allow us to set more realistic goals for the rate of weight loss in specified sub-groups of our patients.

Elevated homocysteine levels with weight loss after Lap-Band surgery: higher folate and vitamin B12 levels required to maintain homocysteine level

OBJECTIVE

To investigate homocysteine levels and their relationship with serum folate and vitamin B12 concentrations with weight loss after the Lap-Band form of gastric restrictive surgery, with the view to minimizing risk.

METHODS

We measured levels of fasting plasma homocysteine (tHcy), folate (serum and RBC) and vitamin B12 in two groups. The study group was 293 consecutive patients at 12 (n=192) or 24 (n=101) months review after surgery. The controls were 244 consecutive patients presenting for this surgery.

RESULTS

The group losing weight had higher geometric mean tHcy levels: 10.4 (95% CI, 9.8-10.8) micromol/l compared with 9.2 (95% CI, 8.9-9.7) in controls (P<0.001). This occurred with higher folate levels and unchanged vitamin B12 levels. Levels of folate and B12 together explained 35% (r (2)) of the homocysteine variance in the weight loss group compared with only 9% (r (2)) in controls (P<0.001). Those taking regular multivitamin supplements had lower tHcy levels: 9.6 (9.1-10.0) micromol/l vs 12.3 (11.4-13.3) in those not taking supplements (P<0.001). A low normal plateau of tHcy levels occurred at levels of folate >15 ng/l and B12)600 ng/ml. A curvilinear relationship exists between these cofactors and tHcy levels, with the dose-response relationship shifted to the right in the weight loss group.

CONCLUSION

This study shows elevated tHcy levels with weight loss, without lower serum folate or vitamin B(12) levels. There is an altered dose-response relationship with higher serum B(12) and folate levels required to maintain recommended tHcy levels. Patients losing weight have significant health benefits; however, they may be at greater risk of vascular events or fetal abnormality in association with raised tHcy levels. Multivitamin supplementation is effective in lowering tHcy levels.

Sleep disturbance and obesity: changes following surgically induced weight loss

BACKGROUND

Obesity causes sleep disturbance and is the most significant risk factor for sleep apnea. Only surgical methods provide substantial sustained weight loss for most severely obese subjects.

OBJECTIVE

To study sleep disturbance in patients undergoing laparoscopic adjustable gastric banding with a commercially available product (Lap-Band).

METHODS

In this study, 313 consecutive patients with severe obesity (body mass index [calculated as weight in kilograms divided by the square of height in meters] >35) completed a preoperative sleep questionnaire and clinical assessment. One hundred twenty-three patients completed the same assessment 12 months after surgery. The characteristics of sleep disturbance and changes in responses to weight loss have been assessed.

RESULTS

There was a high prevalence of significantly disturbed sleep in men (59%) and women (45%), with women less likely to have had their sleep disturbance investigated. Observed sleep apnea was more common in men, but daytime sleepiness was not affected by sex. Waist circumference was the best clinical measure predicting observed sleep apnea (R = 0.36; P<.001). The group lost an average of 48% (SD, 16%) of excess weight by 12 months. There was a significant improvement in the responses to all questions at follow-up, with habitual snoring reduced to 14% (preoperative value, 82%), observed sleep apnea to 2% (preoperative value, 33%), abnormal daytime sleepiness to 4% (preoperative value, 39%), and poor sleep quality to 2% (preoperative value, 39%) (P<.001 for all).

CONCLUSIONS

Obesity-related sleep disorders improve markedly with weight loss. Sustainable weight loss should be a primary aim in the management of severely obese patients with significant sleep disturbance, including sleep apnea. Low-risk laparoscopic obesity surgery should be considered for selected patients with this important comorbidity.

Growth kinetics of leukocyte cell lines cultured with hydatid fluid of Echinococcus granulosus equinus

Oxidation of 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and tritiated thymidine uptake were used to measure, respectively, the viable cell count and the S-phase activity of D10, B9, A20 and p388d leukocytic cell lines cultured in the presence of varying concentrations of fluid from fertile and infertile hydatid cysts of Echinococcus granulosus equinus. Exposure to hydatid fluid raised or lowered the entry of D10 cells into S-phase depending on the concentration of the fluid and of the supporting cytokines. Enlargement of the S-phase population was unaccompanied by increase in viable count indicating that the mitotic cycles induced by hydatid products were not completed. A similar conclusion was reached in respect of the p388d monocytic line, and both changes appear consistent with those occurring in histopathology in vivo. By contrast, the main effect on B9 and A20 B cells was inhibition of entry into S-phase.

Echinococcus granulosus: assays for hydatid immunoregulatory factors using established lymphoid cell lines

Mitosis, mitochondrial metabolic rate and proliferation were measured in established lymphoid cell lines exposed to chromatographic fractions of equine Echinococcus granulosus hydatid fluid. In several cell lines, one or more of the three parameters were modified by the exposure. As an assay for potential immunoregulatory activity, the method was simple and repeatable. The following novel observations were made: (1) Mitotic reaction was found among lines of T-cell, B-cell and macrophage origin; (2) mitosis was accompanied by proliferation in the B-cell lines, B9 and A20, and in the macrophage lines, HL-60 and P388d. With mitotically responsive T-cells, proliferation was slight in CTLL-2 and absent in D10, implying cell-cycle modification; (3) mitotic responsiveness tended to occur in cell lines with mature characteristics; (4) among cytokine-dependent cell lines, hydatid fluid FPLC fraction 1 mimicked IL-1 and several fractions mimicked IL-2 and IL-6 in the maintenance of mitosis; and (5) there was significant statistical interaction between the influences of mammalian cytokines and hydatid fluid fractions, implying that the propensity of antigenically unprimed lymphoid cells to be regulated by E. granulosus is conditioned by cytokine activity.

Anaemia, diarrhoea and opportunistic infections in Fell ponies

This report summarises clinical and pathological observations on Fell pony foals with a range of signs that included ill thrift, anaemia, respiratory infection, glossal hyperkeratosis and diarrhoea. Some of the foals had normochromic, normocytic anaemia and some had low levels of plasma proteins, including immunoglobulin G. Antibiotic and supportive treatment was ineffective and all affected foals died or were killed on humane grounds. Postmortem examination of 12 foals and tissues from 2 other foals revealed a range of lesions that included glossal hyperkeratosis, typhlocolitis, intestinal cryptosporidiosis, granulomatous enteritis, proliferative and necrotising bronchiolitis consistent with adenovirus infection; lesions similar to those in the respiratory tract were present in the salivary gland and pancreas of individual foals. Lymphoid tissue was judged to be smaller than expected. These observations suggest the possibility of opportunistic infections secondary to some form of undefined immunocompromised state.

Gastroesophageal reflux in obesity: the effect of lap-band placement

BACKGROUND

Gastroesophageal reflux disease (GERD) is a common condition which is often aggravated by morbid obesity. Lap-Band surgery provides effective weight loss in the morbidly obese. There have been several reports that gastric banding causes or aggravates reflux. The aim of this study was to evaluate the effect of Lap-Band placement on GERD.

METHODS

All patients with a significant history of GERD who had a Lap-Band inserted over a 2-year period were evaluated postoperatively to assess any change in impact on reflux. Resolution required absence of reflux symptoms and no anti-reflux drug therapy.

RESULTS

There were 48 (16%) of 274 consecutive patients with a significant history of reflux esophagitis requiring regular therapy preoperatively. The median age was 39 (range 23-58) and M:F ratio was 5:43. We confirm a high prevalence of GERD in patients with morbid obesity: 17% with symptoms requiring regular therapy (Community Norm 7%). Total resolution of all reflux symptoms occurred in 36 (76%) patients, improvement in 7 (14%), no change in 3 (6%), and aggravation of symptoms in 2 (4%). Patients with severe and moderate symptoms had similar improvement. Resolution or improvement was reported soon after surgery.

CONCLUSION

Rapid and major improvement in symptoms of GERD occurs after Lap-Band placement. The placement of the band probably acts directly to reduce reflux. This result contrasts with reports which have found gastric banding causes or aggravates GERD.

Marked improvement in asthma after Lap-Band surgery for morbid obesity

BACKGROUND

Asthma and morbid obesity are common chronic conditions that may be related. Laparoscopic banding provides effective weight control of morbid obesity. The aim of this study was to evaluate the prevalence of asthma in the morbidly obese and the changes in asthma after laparoscopic adjustable gastric banding (LAGB) (Lap-Band) surgery for morbid obesity.

METHODS

Asthma was assessed preoperatively in all patients presenting for LAGB. 32 consecutive asthmatic patients were followed up clinically and by a standard questionnaire at least 12 months after surgery, and any change in asthma impact was recorded.

RESULTS

The prevalence of the doctors' diagnosis of asthma was 24.6% (73 of 296 consecutive patients). This was significantly higher than the prevalence in the Australian community of 12% to 13% (P < 0.001). The 32 patients who were followed up had a mean body weight of 125.2 kg and a body mass index (BMI) of 45.7 kg/m2 prior to operation, and a weight of 89.3 kg (BMI 32.9 kg/m2) at follow-up. All 32 patients recorded a lower asthma score postoperatively. There were significant improvements in all aspects of asthma assessed. These included severity, daily impact, medications needed, hospitalization, sleep, and exercise. The mean preoperative scaled asthma score was 44.5 +/- 16. There was a highly significant reduction at follow-up to a mean value of 14.3 +/- 11 (P < 0.001).

CONCLUSIONS

There is a high prevalence of asthma in morbidly obese adults, and major reductions in asthma severity occur after Lap-Band(r) surgery and weight loss. Mechanisms other than direct weight loss appear to play a part in this improvement. Prevention of gastroesophageal reflux may be an important factor.

Effect of transportation and weaning on humoral immune responses of calves

Transportation exposes cattle to stress and results in increased morbidity and mortality. An investigation was made of the effects of transport and another important stressor, weaning, on the immune function of calves by determining humoral immune responses to keyhole limpet haemocyanin (KLH). In a 2 x 2 factorial designed experiment, suckled calves were either (1) weaned at housing (day 0) and not transported, (2) weaned at housing and transported, (3) weaned while still at pasture nine to 13 days prior to housing and not transported or (4) weaned at pasture and transported. All calves were immunized with KLH at housing (day 0) and serum samples were collected subsequently to determine class and subclass anti-KLH antibody responses (IgG1, IgG2, IgA and IgM) by direct ELISA. Increased anti-KLH IgG1 and IgG2 concentrations were shown in calves that were weaned prior to housing and transported on day 10 (P < 0.05 and P < 0.01 respectively). Transported calves had increased IgG1 concentrations on day 20 (P < 0.05) compared with calves that were not transported. However, calves weaned at housing and not transported had increased IgA and IgM responses on day 30 compared with the other groups of calves (P < 0.05). This study shows that transportation and weaning affect the humoral immune responses of suckler calves and that the effects persist for several weeks. However, the effects of the treatments were not consistent for all antibody classes measured.

Immunological activities of a lymphocyte mitogen isolated from coenurus fluid of Taenia multiceps (Cestoda)

The purification of a mitogen from Taenia multiceps coenurus fluid has been previously reported. In the present study, this activity, which was independent of endotoxin, stimulated the expression of lymphocyte IL-2 and Fc receptors, enhanced mitotic response to phylohaemogglutinin and concanavalin A and antagonised the previously described suppressive effects of the macrophage modifying fraction of coenurus fluid. The mitogen also increased peritoneal macrophage count and viability, Fc receptor expression and Fc receptor-mediated phagocytosis. The mitogenic activity could be destroyed by a combination of protease and amylase, but not by either enzyme alone. It is suggested that the mitogen forms part of a homeostatic mechanism for the preservation of a balanced host-parasite relationship.

Echinococcosis

Hydatids, the intermediate stages, or metacestodes, of the tapeworm genus, Echinococcus, present a major immunological problem; they survive, grow and metastasize in immunized hosts which are protected against reinfection and possess effector mechanisms capable of killing the parasite. Explanations for this state of concomitant immunity have been made from investigations of avoidance strategies, genetics and quantitative hydatid growth. The latter study suggests that the host-parasite relationship is sustained as a dynamic equilibrium between parasite growth and acquired immunity, the balance being subject to mutual regulation and including the possibility of spontaneous rejection of the parasite. Two immunoregulatory, or cytokine-like, factors have been detected in hydatids of Echinococcus spp. One appears to be a mediator of the previously reported mitogenic effects of hydatids. Recent evidence has linked these effects to generation of T-suppressor populations. The second factor interferes with the interaction of macrophages and T-cells, mimics the effect of metacestode infection in impairing the accessory action of macrophages in lymphoproliferative responses, and is suppressive for rosette-forming cell responses against third-party antigens. It is suggested that these factors form part of a primary homeostatic mechanism regulating hydatid growth and immunity.