Lipid profile in the severely obese: changes with weight loss after lap-band surgery

The effect of loss of excess weight on the metabolic risk factors after bariatric surgery in morbidly and super-obese patients

BACKGROUND

Changes in metabolic risk factors such as dyslipidemia and hyperinsulinemia as well as levels of sex hormones and leptin were studied in morbidly obese (MO) and super-obese (SO) patients during excess weight loss (EWL), separately in males and females.

METHODS

In this prospective clinical intervention study, 431 patients were included (361 females and 70 males). There were 217 patients with MO (BMI 40-49.9 kg/m2) and 214 patients with SO (BMI > or =50 kg/m2). All patients underwent restrictive bariatric operations. Metabolic parameters (lipids, insulin, leptin, hepatic transaminases, uric acid, and sex hormones) were measured before obesity surgery and at defined postoperative points of EWL (25%, 50%, 75% and 100%).

RESULTS

Successful weight reduction of 25% EWL was achieved by 94% of patients at 2 months. With this moderate EWL, most of the patients already improved their risk profile considerably, including normalization of insulin levels. Additional EWL led to a further amelioration of risk profile in all patients, including normalization of triglyceride levels. Male MO and SO patients had a worse metabolic situation preoperatively and a greater benefit after weight loss. Even though SO patients did not lose as much excess weight as MO patients, they did profit comparably.

CONCLUSION

Bariatric surgery is a valuable tool not only to reduce excess weight in severely obese patients but also to improve the metabolic risk profile within a short time-frame. This benefit is most pronounced in high-risk males.

Short-term outcome in the first 10 morbidly obese adolescent patients in the FDA-approved trial for laparoscopic adjustable gastric banding

BACKGROUND

We received the LAP-BAND Investigational Device Exemption (IDE) from the US Food and Drug Administration in December 2004 to conduct a prospective longitudinal trial examining the safety and efficacy of laparoscopic adjustable gastric banding (LAGB) in morbidly obese adolescents ages 14 to 17 years.

OBJECTIVES

To report the short-term results of LAGB in the first 10 adolescents with complete 9 months of follow-up.

PATIENTS AND METHODS

Baseline characteristics and outcome data were analyzed in 10 patients enrolled between March 2005 and February 2006.

RESULTS

All of the patients were girls. Their mean body mass index (+/-SD) was 50 +/- 13 kg/m, and excess weight was 171 +/- 79 pounds. Comorbidities included depression (3 patients), sleep apnea (3), hypertension (6), dyslipidemia (7), insulin resistance (9), metabolic syndrome (9), and steatohepatitis (in 4 of 5 patients with liver biopsy). Operative time was 45 +/- 9 minutes, and discharges were within 23 hours of surgery. Band-related complications were as follows: 2 dehydration, 1 pouch dilation, and 1 port revision. All of the patients lost weight, with a 9-month excess weight loss of 30% +/- 16% (range 14%-57%). Hypertension and the metabolic syndrome were resolved in 100% of patients (P = 0.04) and 80% of the patients (P = 0.01), respectively, along with significant improvement in the Pediatric Quality of Life and Beck Depression Inventory scores and a trend toward improvement in high-density lipoprotein cholesterol abnormalities (P = 0.08).

CONCLUSIONS

At short-term follow-up, weight loss occurred with minimal complications, leading to early resolution of major obesity-related comorbidities. Continued evaluation of the long-term safety and efficacy of LAGB as a surgical adjunct to a comprehensive obesity treatment program is warranted.

Effect of Weight Loss following Bariatric Surgery on Myocardial Dispersion of Repolarization in Morbidly Obese Patients

BACKGROUND

Weight-stable obese subjects have an increased risk of arrhythmias and sudden death, even in the absence of cardiac dysfunction, and the risk of sudden cardiac death (SCD) with increasing weight is seen in both genders. The mechanism of unexplained deaths in obese patients is still unclear and may be related to ventricular repolarization abnormalities. The aim of this study is to determine the effect of severe obesity on spatial and transmural ventricular repolarization and to clarify the influence of bariatric surgery with a consequent substantial weight loss on arrhythmogenic substrate in the morbidly obese population.

METHODS

For the study, we enrolled 100 severely obese patients; 50 age-matched non-obese healthy subjects were also recruited as controls. All subjects underwent conventional 12-lead electrocardiography for analysis of spatial and transmural ventricular repolarization assessed by corrected QT dispersion (QTc-d), corrected JT dispersion (JTc-d) and transmural dispersion of repolarization, (TDR). All subjects underwent bariatric surgery and were resubmitted to electrocardiographic, biochemical and anthropometric examination 12 months postoperatively.

RESULTS

Severely obese patients had greater values in QTc-d, JTc-d and TDR than the normal-weight controls. Bariatric surgery reduced significantly the QTc-d value, JTc-d value and TDR value. There was a significant correlation between decrease of heterogeneity of repolarization indexes (QTd, JTd and TDR) and bariatric surgery-induced weight loss.

CONCLUSIONS

In severely obese patients, surgically-induced weight loss is associated with significant decrease in the heterogeneity of ventricular repolarization. The reduction of spatial (QTc-d, JTc-d) and transmural dispersion of repolarization (TDR) may be of clinical significance, by reducing the risk of potentially fatal arrhythmias in morbidly obese subjects.

Short- and long-term results of laparoscopic gastric banding for morbid obesity

BACKGROUND

Today, gastric banding has become a common bariatric procedure. Weight loss can be excellent, but is not sufficient in a significant proportion of patients. Few long-term studies have been published. We present our results after up to 9 years of follow-up.

MATERIALS AND METHODS

One hundred twenty-seven patients (1997-2004) were analyzed retrospectively after laparoscopic gastric banding (perigastric technique: n = 60; pars flaccida technique: n = 67) in terms of preoperative characteristics, weight loss, comorbidities, short- and long-term complications, and quality of life.

RESULTS

Median follow-up was 63 months (range 2-104). Incidence of postoperative complications were: gastric perforation in 3.1%, band erosion in 3.1%, band or port leak in 2.3%, port infection in 5.3%, port dislocation in 6.9%, and pouch dilatation in 16.9%. Total number of patients requiring reoperation was 34 (26.7%) [perigastric technique n = 23 (38.8%) versus pars flaccida technique n = 11 (16%), p = 0.039]. Mean excess body weight loss (%) was 50.6%. Most patients reported an increase in quality of life after surgery.

CONCLUSIONS

Gastric banding is effective for achieving weight loss and improving comorbidity in obese patients. Obviously, gastric banding can be performed more safely with the pars flaccida technique, although the complication rate remains relatively high. Nevertheless, based on adequate patient selection, gastric banding should still be considered a valuable therapeutic option in bariatric surgery.

The effect of laparoscopic gastric bypass surgery on dyslipidemia in severely obese patients

BACKGROUND

Dyslipidemia is common in the morbidly obese population. Lipid parameters typically improve after bariatric surgery, but the effects have been inconsistent and may depend on the surgical procedure performed. If bariatric surgery consistently improves dyslipidemia, there may be associated cost savings in lipid-modifying medications.

METHODS

Patients undergoing laparoscopic Roux-en-Y gastric bypass surgery (RYGB) for morbid obesity had lipid analyses performed preoperatively and 1 and 2 years postoperatively. The number of lipid-modifying medications taken was documented by an electronic medical record review.

RESULTS

A total of 168 patients were enrolled. Of these, 96 patients had preoperative and 1-year postoperative data and 18 had preoperative and 2-year postoperative data. In the 1-year cohort, total cholesterol (TC) decreased by 12.5%, low-density lipoprotein cholesterol (LDL) decreased by 19.4%, high-density lipoprotein cholesterol (HDL) increased by 23.2%, triglycerides (TG) decreased by 41.2%, and the percentage of dyslipidemic patients decreased from 82.3% to 28.1% (P < .001 for all). In the 2-year cohort, TC decreased by 7.2% (P = .036), LDL decreased by 21.7% (P < .001), HDL increased by 40.3% (P < .001), TG decreased by 27.3% (P = .015), and the percentage of dyslipidemic patients decreased from 94.4% to 27.8% (P < .001). In the 1-year cohort, 26.0% of patients were taking lipid-modifying medications preoperatively, compared with 14.6% postoperatively (P = .049).

CONCLUSIONS

Laparoscopic RYGB improved all lipid parameters studied and decreased the percentage of dyslipidemic patients. Furthermore, fewer patients were taking lipid-modifying medications postoperatively, suggesting a substantial medication cost savings over time.

Resolution of hyperlipidemia after laparoscopic Roux-en-Y gastric bypass

BACKGROUND

Hyperlipidemia is an established risk factor for development of coronary artery disease. The aim of our study was to examine the changes in serum lipid profiles of morbidly obese patients complicated by hyperlipidemia, who underwent laparoscopic gastric bypass.

STUDY DESIGN

We retrospectively reviewed the charts of 95 morbidly obese patients with documented hyperlipidemia who underwent laparoscopic gastric bypass. Mean duration of hyperlipidemia was 44+/- 56 months. Hyperlipidemia was defined as an elevated level of triglycerides (> 150 mg/dL) or total cholesterol (> 200 mg/dL). Changes in lipid profile of a subset of patients with subnormal levels of high-density lipoprotein cholesterol (<or= 40 mg/dL), high levels of low-density lipoprotein cholesterol (> 130 mg/dL), and very-low-density lipoprotein cholesterol (> 40 mg/dL) were also examined. Fasting lipid profiles were measured preoperatively and at 3-month intervals.

RESULTS

There were 68 women (72%) with a mean age of 43 +/- 10 years. Mean body mass index was 47+/- 5 kg/m2. Mean percentage of excess body weight loss at 12 months postoperatively was 66%. One year after gastric bypass, mean total cholesterol levels decreased by 16%; triglyceride levels decreased by 63%; low-density lipoprotein cholesterol levels decreased by 31%; very-low-density lipoprotein cholesterol decreased by 74%; total cholesterol/high-density lipoprotein cholesterol risk ratio decreased by 60%, and high-density lipoprotein cholesterol levels increased by 39%. Also, within 1 year, 23 of 28 (82%) patients requiring lipid-lowering medications preoperatively were able to discontinue their medications.

CONCLUSIONS

Weight loss after laparoscopic gastric bypass substantially improves lipid profiles in morbidly obese patients who have hyperlipidemia. Improvement in lipid profiles was observed as early as 3 months postoperatively and was sustained at 1 year. Improvement of lipid profiles after laparoscopic gastric bypass can reduce health risks associated with high levels of atherogenic lipoproteins.

A model of long-term metabolic progression of type 2 diabetes mellitus for evaluating treatment strategies

AIM

To develop a novel metabolic computer model of the natural lifetime progression of type 2 diabetes that generates dynamic risk factor trajectories consistent with prespecified lifetime therapeutic strategies, in order to enhance the long-term economic and outcome modelling of type 2 diabetes and its complications.

METHODS

The main model drivers of progressive disease were changes in insulin sensitivity and islet beta-cell function derived from an analysis of follow-up results from the Belfast Diet Study. These were related to clinical measures through an adaptation of the homeostasis model assessment. Established causal relationships estimating body mass index, lipids and blood pressure from measures of glycaemia and plasma insulin were calibrated using Third National Health and Nutrition Examination Survey (USA) data, standardizing for age, sex, ethnicity and smoking. The effects of individual interventions were calibrated using published trial evidence, in line with the current understanding of the main modes of action of each agent.

RESULTS

A comparison of the effects of common therapies using the model showed both similarities and differences. Large improvements in glycaemic control from lifestyle modifications, further enhanced by oral glucose-lowering drugs or insulin, were reproduced. Projections comparing lifetime therapeutic strategies suggest that simple guidelines may not always be valid.

CONCLUSION

This novel mathematical model using evidence from the long-term natural history of type 2 diabetes is able to project the expected effects of various antihyperglycaemic therapies. Coupled with an economic model, this metabolic model may provide a mechanism for healthcare professionals and policymakers to evaluate different long-term strategies for the management of type 2 diabetes.

Obesity, weight loss and bariatric surgery

Obesity is shaping up to be the major health care problem and one of the most frequent causes of preventable death in Western countries in the 21st century. Bariatric surgery is the only current treatment that has been shown to achieve major and durable weight loss. Major weight loss in the severely obese leads to total or partial control of a wide range of common and serious diseases, such as diabetes, heart disease and hypertension. Laparoscopic adjustable gastric banding is the most common type of obesity surgery performed in Australia. It is effective, relatively safe and minimally invasive. The blocks to broader application of bariatric surgery should be identified and resolved.

Sustained weight loss in obese subjects has benefits that are independent of attained weight

OBJECTIVE

To explore the hypothesis that sustained weight loss in severely obese patients may have benefits that are independent of their attained BMI.

RESEARCH METHODS AND PROCEDURES

We conducted a comparison of two weight-stable groups with BMI in the 30 to 35 kg/m(2) range. Subjects (n = 79) were selected obese patients 3 years after laparoscopic adjustable gastric band surgery, and controls (n = 79) were obese patients seeking weight loss therapy. Subjects were selected in a de-identified manner from our database to best match the control group. A range of clinical, biochemical, and questionnaire measures were obtained to assess obesity-related health status

RESULTS

Subjects maintained a mean weight loss of 32.8 +/- 18 kg after surgery. The weight loss subjects had significantly lower fasting plasma glucose, insulin, and triglyceride concentrations, along with higher high-density lipoprotein-cholesterol levels and better indirect measures of insulin sensitivity when compared with controls (p < 0.05 for all). In addition, aminotransferase levels, neutrophil counts, and globulin levels were also significantly lower in weight loss subjects. All differences in laboratory variables remained significant after controlling for BMI. The subjects also reported better health-related quality of life, fewer symptoms of depression, and greater satisfaction with their appearance than controls.

DISCUSSION

These findings suggest that the post-weight loss state conveys benefits that are greater than predicted by the attained BMI. These findings may have important implications regarding the expectations of weight loss therapy, and mechanisms for this effect should be carefully sought.

Nutrient deficiencies secondary to bariatric surgery

PURPOSE OF REVIEW

The number of adolescent and adult patients submitting to bariatric surgery is increasing rapidly around the world. This review describes the literature published in the last few years concerning nutritional deficiencies after bariatric surgery as well as their etiology, incidence, treatment and prevention.

RECENT FINDINGS

Although bariatric surgery was first introduced in the 1950s, safe and successful surgical management has progressed over the last two decades and longer post-surgical follow-up data are now available. Most of the patients undergoing malabsorptive procedures will develop some nutritional deficiency, justifying mineral and multivitamin supplementation to all postoperatively. Nutrient deficiency is proportional to the length of absorptive area and to the percentage of weight loss. Low levels of iron, vitamin B12, vitamin D and calcium are predominant after Roux-en-Y gastric bypass. Protein and fat-soluble vitamin deficiencies are mainly detected after biliopancreatic diversion. Thiamine deficiency is common in patients with frequent vomiting. As the incidence of these deficiencies progresses with time, the patients should be monitored frequently and regularly to prevent malnutrition.

SUMMARY

Nutritional deficiencies can be prevented if a multidisciplinary team regularly assists the patient. Malnutrition is generally reverted with nutrient supplementation, once it is promptly diagnosed. Especial attention should be given to adolescents, mainly girls at reproductive age who have a substantial risk of developing iron deficiency. Future studies are necessary to detect nutrient abnormalities after new procedures and to evaluate the safety of bariatric surgery in younger obese patients.