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Effect of Bariatric Surgery on the Metabolic Syndrome: A Population-Based, Long-term Controlled Study


      To assess the effect of weight loss by bariatric surgery on the prevalence of the metabolic syndrome (MetS) and to examine predictors of MetS resolution.


      We performed a population-based, retrospective study of patients evaluated for bariatric surgery between January 1, 1990, and December 31, 2003, who had MetS as defined by the American Heart Association/National Heart, Lung, and Blood Institute (increased triglycerides, low high-density lipoprotein, increased blood pressure, increased fasting glucose, and a measure of obesity). Of these patients, 180 underwent Roux-en-Y gastric bypass, and 157 were assessed in a weight-reduction program but did not undergo surgery. We determined the change in MetS prevalence and used logistic regression models to determine predictors of MetS resolution. Mean follow-up was 3.4 years.


      In the surgical group, all MetS components improved, and medication use decreased. Nonsurgical patients showed improvements in high-density lipoprotein cholesterol levels. After bariatric surgery, the number of patients with MetS decreased from 156 (87%) of 180 patients to 53 (29%); of the 157 nonsurgical patients, MetS prevalence decreased from 133 patients (85%) to 117 (75%). A relative risk reduction of 0.59 (95% confidence interval [CI], 0.48-0.67; P<.001) was observed in patients who underwent bariatric surgery and had MetS at follow-up. The number needed to treat with surgery to resolve 1 case of MetS was 2.1. Results were similar after excluding patients with diabetes or cardiovascular disease or after using diagnostic criteria other than body mass index for MetS. Significant predictors of MetS resolution included a 5% loss in excess weight (odds ratio, 1.26; 95% CI, 1.19-1.34; P<.001) and diabetes mellitus (odds ratio, 0.32; 95% CI, 0.15-0.68; P=.003).


      Roux-en-Y gastric bypass induces considerable and persistent improvement in MetS prevalence. Our results suggest that reversibility of MetS depends more on the amount of excess weight lost than on other parameters.
      ACEI (angiotensin-converting enzyme inhibitor), AHA (American Heart Association), ARB (angiotensin receptor blocker), ATP (Adult Treatment Panel), BMI (body mass index), CI (confidence interval), CV (cardiovascular), HDL-C (high-density lipoprotein cholesterol), MetS (metabolic syndrome), NHLBI (National Heart, Lung, and Blood Institute), RYGB (Roux-en-Y gastric bypass), TG (triglyceride)
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        • Grundy SM
        • Cleeman JI
        • Daniels SR
        • et al.
        Diagnosis and management of the metabolic syndrome: an American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement [published corrections appear in Circulation. 2005;112 (17):e297 and 2005;112 (17): e298].
        Circulation. 2005 Oct 25; 112 (Epub 2005 Sep 12.): 2735-2752
        • Ford ES
        Prevalence of the metabolic syndrome defined by the International Diabetes Federation among adults in the U.S.
        Diabetes Care. 2005; 28: 2745-2749
        • Ford ES
        • Giles WH
        • Dietz WH
        Prevalence of the metabolic syndrome among US adults: findings from the third National Health and Nutrition Examination Survey.
        JAMA. 2002; 287: 356-359
        • Gami AS
        • Witt BJ
        • Howard DE
        • et al.
        Metabolic syndrome and risk of incident cardiovascular events and death: a systematic review and meta-analysis of longitudinal studies.
        J Am Coll Cardiol. 2007; 49 (Epub 2007 Jan 12.): 403-414
        • Einhorn D
        • Reaven GM
        • Cobin RH
        • et al.
        American College of Endocrinology position statement on the insulin resistance syndrome.
        Endocr Pract. 2003; 9: 237-252
        • Dansinger ML
        • Gleason JA
        • Griffith JL
        • Selker HP
        • Schaefer EJ
        Comparison of the Atkins, Ornish, Weight Watchers, and Zone diets for weight loss and heart disease risk reduction: a randomized trial.
        JAMA. 2005; 293: 43-53
        • Ekelund U
        • Brage S
        • Franks PW
        • Hennings S
        • Emms S
        • Wareham NJ
        Physical activity energy expenditure predicts progression toward the metabolic syndrome independently of aerobic fitness in middle-aged healthy Caucasians: the Medical Research Council Ely Study.
        Diabetes Care. 2005; 28: 1195-1200
      1. Florez H, Tremposa M, Orchard TJ, et al. Diabetes Prevention Program Research Group. Metabolic Syndrome increases diabetes risk in IGT subjects: Effects across Diabetes Prevention Program Interventions [abstract 1299-P]. Presented at: American Diabetes Association 67th Scientific Session. Chicago, IL; 2007.

        • Burnet DL
        • Elliott LD
        • Quinn MT
        • Plaut AJ
        • Schwartz MA
        • Chin MH
        Preventing diabetes in the clinical setting.
        J Gen Intern Med. 2006; 21: 84-93
        • National Institutes of Health
        Gastrointestinal surgery for severe obesity: Consensus Development Conference Panel.
        Ann Intern Med. 1991; 115: 956-961
        • Sjostrom L
        • Lindroos AK
        • Peltonen M
        • Swedish Obese Subjects Study Scientific Group
        • et al.
        Lifestyle, diabetes, and cardiovascular risk factors 10 years after bariatric surgery.
        N Engl J Med. 2004; 351: 2683-2693
        • Melton III, LJ
        History of the Rochester Epidemiology Project.
        Mayo Clin Proc. 1996; 71: 266-274
        • Robinson JD
        • Lupkiewicz SM
        • Palenik L
        • Lopez LM
        • Ariet M
        Determination of ideal body weight for drug dosage calculations.
        Am J Hosp Pharm. 1983; 40: 1016-1019
        • Okosun IS
        • Chandra KM
        • Boev A
        • et al.
        Abdominal adiposity in U.S. adults: prevalence and trends, 1960-2000.
        Prev Med. 2004; 39: 197-206
        • Ballantyne GH
        • Svahn J
        • Capella RF
        • et al.
        Predictors of prolonged hospital stay following open and laparoscopic gastric bypass for morbid obesity: body mass index, length of surgery, sleep apnea, asthma, and the metabolic syndrome.
        Obes Surg. 2004; 14: 1042-1050
        • Scopinaro N
        • Papadia F
        • Marinari G
        • Camerini G
        • Adami G
        Long-term control of type 2 diabetes mellitus and the other major components of the metabolic syndrome after biliopancreatic diversion in patients with BMI < 35 kg/m2.
        Obes Surg. 2007; 17: 185-192
        • Gazzaruso C
        • Giordanetti S
        • La Manna A
        • et al.
        Weight loss after Swedish Adjustable Gastric Banding: relationships to insulin resistance and metabolic syndrome.
        Obes Surg. 2002; 12: 841-845
        • Coppini LZ
        • Bertevello PL
        • Gama-Rodrigues J
        • Waitzberg DL
        Changes in insulin sensitivity in morbidly obese patients with or without metabolic syndrome after gastric bypass.
        Obes Surg. 2006; 16: 1520-1525
        • Alexandrides TK
        • Skroubis G
        • Kalfarentzos F
        Resolution of diabetes mellitus and metabolic syndrome following Roux-en-Y gastric bypass and a variant of biliopancreatic diversion in patients with morbid obesity.
        Obes Surg. 2007; 17: 176-184
        • Madan AK
        • Orth W
        • Ternovits CA
        • Tichansky DS
        Metabolic syndrome: yet another co-morbidity gastric bypass helps cure.
        Surg Obes Relat Dis. 2006; 2: 48-51
        • Mattar SG
        • Velcu LM
        • Rabinovitz M
        • et al.
        Surgically-induced weight loss significantly improves nonalcoholic fatty liver disease and the metabolic syndrome.
        Ann Surg. 2005; 242: 610-617
        • Morinigo R
        • Casamitjana R
        • Delgado S
        • et al.
        Insulin resistance, inflammation, and the metabolic syndrome following Roux-en-Y gastric bypass surgery in severely obese subjects.
        Diabetes Care. 2007 Jul; 30 (Epub 2007 Apr 27.): 1906-1908
        • Vogel JA
        • Franklin BA
        • Zalesin KC
        • et al.
        Reduction in predicted coronary heart disease risk after substantial weight reduction after bariatric surgery.
        Am J Cardiol. 2007 Jan 15; 99 (Epub 2006 Nov 16.): 222-226
        • Torquati A
        • Wright K
        • Melvin W
        • Richards W
        Effect of gastric bypass operation on Framingham and actual risk of cardiovascular events in class II to III obesity.
        J Am Coll Surg. 2007; 204: 776-782
        • Batsis JA
        • Romero-Corral A
        • Collazo-Clavell ML
        • et al.
        Effect of weight loss on predicted cardiovascular risk: change in cardiac risk after bariatric surgery.
        Obesity (Silver Spring). 2007; 15: 772-784
        • Omalu BI
        • Ives DG
        • Buhari AM
        • et al.
        Death rates and causes of death after bariatric surgery for Pennsylvania residents, 1995 to 2004.
        Arch Surg. 2007; 142: 923-928
        • Flum DR
        • Dellinger EP
        Impact of gastric bypass operation on survival: a population-based analysis.
        J Am Coll Surg. 2004; 199: 543-551
        • Christou NV
        • Sampalis JS
        • Liberman M
        • et al.
        Surgery decreases long-term mortality, morbidity, and health care use in morbidly obese patients.
        Ann Surg. 2004; 240: 416-423
        • Adams TD
        • Gress RE
        • Smith SC
        • et al.
        Long-term mortality after gastric bypass surgery.
        N Engl J Med. 2007; 357: 753-761
        • Sjostrom L
        • Narbro K
        • Sjostrom CD
        • Swedish Obese Subjects Study
        • et al.
        Effects of bariatric surgery on mortality in Swedish obese subjects.
        N Engl J Med. 2007; 357: 741-752
        • Carey DG
        • Pliego GJ
        • Raymond RL
        Body composition and metabolic changes following bariatric surgery: effects on fat mass, lean mass and basal metabolic rate: six months to one-year follow-up.
        Obes Surg. 2006; 16: 1602-1608
        • Eckel RH
        • Barouch WW
        • Ershow AG
        Report of the National Heart, Lung, and Blood Institute-National Institute of Diabetes and Digestive and Kidney Diseases Working Group on the pathophysiology of obesity-associated cardiovascular disease.
        Circulation. 2002; 105: 2923-2928