Obesity in adults: a clinical practice guideline

Obesity is a complex chronic disease in which abnormal or excess body fat (adiposity) impairs health, increases the risk of long-term medical complications and reduces lifespan.1 Epidemiologic studies define obesity using the body mass index (BMI; weight/height2), which can stratify obesity-related health risks at the population level. Obesity is operationally defined as a BMI exceeding 30 kg/m2 and is subclassified into class 1 (30­34.9), class 2 (35­39.9) and class 3 (≥ 40). At the population level, health complications from excess body fat increase as BMI increases.2 At the individual level, complications occur because of excess adiposity, location and distribution of adiposity and many other factors, including environmental, genetic, biologic and socioeconomic factors.

Nutrient Status 9 Years After Biliopancreatic Diversion with Duodenal Switch (BPD/DS): an Observational Study.

BACKGROUND: Since biliopancreatic diversion with duodenal switch (BPD/DS) produces hypoabsorption, evaluation of long-term nutrient changes is appropriate. METHODS: Measurements of micronutrients, trace elements, PTH, iron studies, and protein were completed for consented patients at baseline prior to surgery and at yearly intervals. The patients were advised and supplements were adjusted by blood studies with compliance checks. Independent t tests and ANOVAs compared changes between cross-sectional cohorts based on follow-up time from surgery. A p value of 0.05 was considered significant. RESULTS: Between 1999 and 2010, 284 patients had BPD/DS. At baseline, nutrient analysis was available for only 190 patients (70% women), age 42.7 ± 10.0 years, BMI 53.0 ± 11.9 kg/m2; at year 1, 189 were available; at year 3, 193; at year 5, 132; at year 7, 98; and at year 9, 68. Gender distribution was not significantly different between cohorts. Baseline vitamin D was low and PTH high. All of the patients took some supplements. Fat-soluble vitamins remained low. Protein deficiency appeared at year 3 and increased to 30% at year 9. Baseline zinc was normal, but at year 5, 45% were low. Over time, hematocrit was low for 40% and hemoglobin for 46%. Iron deficiency continued through year 9, more marked in males. Calcium deficiency increased from year 3 and remained steady. Half of the patients had abnormal PTH at baseline, and the percentage increased over time. Twenty percent had abnormal baseline magnesium values. Magnesium fluctuated during observation. CONCLUSIONS: Major deficits in nutrient status occurred and persisted after surgery although supplementation was prescribed. Interventions are mandated to avoid nutrient deficiency.

Evaluation of nutrient status after laparoscopic sleeve gastrectomy 1, 3, and 5 years after surgery.

BACKGROUND: Laparoscopic sleeve gastrectomy evolved as a primary bariatric procedure with little information on its nutritional effects. Our objective was to assess the longer term micronutrient and vitamin status after laparoscopic sleeve gastrectomy at a university hospital. METHODS: Measurements of ferritin, iron, total iron binding capacity, hemoglobin, hematocrit, parathyroid hormone, albumin, calcium, magnesium, phosphorus, zinc, folate, and vitamins A, B1, B12, and D were obtained at baseline and 1, 3, and 5 years after surgery. Two-sample t tests with multiple adjusted comparisons and Fisher's exact test were used to determine deficiency. RESULTS: A total of 82 patients (67% women), with a mean age of 46.4 years and a baseline body mass index 55.7 kg/m2 were included in the present study (35 at 1, 27 at 3, and 30 at 5 years postoperatively). The percentage of excess body mass index loss was 58.5% at year 1 in 35 patients, 63.1% at year 3 in 27 patients, and 46.1% at year 5 in 30 patients. The parathyroid hormone level decreased from 75.0 to 49.6 ng/mL in year 1 to 40.7 ng/mL in year 3. The year 5 levels increased to 99.6 ng/mL. The mean vitamin D level increased from 23.6 ng/mL to 35.0, 32.1 and 34.8 at years 1, 3, and 5 (P = .05 for baseline to year 1). The vitamin D level was less than normal in 42% of the patients at year 5. After normalization from baseline, by year 5, parathyroid hormone had increased in 58.3% of patients. At year 5, vitamin B1 was less than normal in 30.8% of patients, and hemoglobin and hematocrit were less than normal in for 28.6% and 25% of patients, respectively. Finally, 28.9% of patients reported taking supplements in year 1, 42.9% in year 3, and 63.3% in year 5. The other variables were not significantly different. CONCLUSIONS: Laparoscopic sleeve gastrectomy resulted in health improvements through year 3. At year 5, the nutrient levels had reverted toward the baseline values. These observations provide focus for necessary clinical monitoring.

Increased PTH and 1.25(OH)(2)D levels associated with increased markers of bone turnover following bariatric surgery.

The objective of this study was to characterize changes in metabolic bone parameters following bariatric surgery. Seventy-three obese adult patients who underwent either gastric banding (GB), Roux-en-Y gastric bypass (RYGB), or biliopancreatic diversion with duodenal switch (BPD/DS) were followed prospectively for 18 months postoperatively. Changes in the calcium-vitamin D axis (25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D (1,25(OH)(2)D), calcium, parathyroid hormone (PTH)), markers of bone formation (osteocalcin, bone-specific alkaline phosphatase) and resorption (urinary N-telopeptide (NTx)), as well as bone mineral density (BMD) were assessed at 3-month intervals during this time period. Bariatric surgery resulted in significant and progressive weight loss over 18 months. With supplementation, 25OHD levels increased 65.3% (P < 0.0001) by 3 months, but leveled off and decreased <30 ng/ml by 18 months. PTH initially decreased 21.4% (P = 0.01) at 3 months, but later approached presurgery levels. 1,25(OH)(2)D increased significantly starting at month 12 (50.3% increase from baseline, P = 0.008), and was positively associated with PTH (r = 0.82, P = 0.0001). When stratified by surgery type, median PTH and 1,25(OH)(2)D levels were higher following combined restrictive and malabsorptive operations (RYGB and BPD/DS) compared to GB. Bone formation/resorption markers were increased by 3 months (P < 0.05) and remained elevated through 18 months. Radial BMD decreased 3.5% by month 18, but this change was not significant (P = 0.23). Our findings show that after transient improvement, preoperative vitamin D insufficiency and secondary hyperparathyroidism persisted following surgery despite supplementation. Postoperative secondary hyperparathyroidism was associated with increased 1,25(OH)(2)D levels and increased bone turnover markers.

Micronutrient deficiencies after laparoscopic gastric bypass: recommendations.

BACKGROUND: The aim of this study was to evaluate the changes of micronutrients in patients with morbid obesity after laparoscopic Roux-en-Y gastric bypass surgery (LRYGBP). METHODS: We retrospectively reviewed 121 patients diagnosed with morbid obesity who undertook LRYGBP and evaluated the serum iron (Fe), calcium (Ca), zinc (Zn), selenium (Se), vitamin A (VitA), 25-hydroxy vitamin D3 (VitD), vitamin B(12) (VitB(12)), and parathormone (PTH) measured at 6, 12, and 24 months after LRYGBP. RESULTS: During a follow-up period of 69 months (June 1999 to February 2005), a cohort of 121 patients, 40 men and 81 women, underwent LRYGBP, a mean age of 46 years (range 22-67). The mean body mass index (BMI) before LRYGBP was 47.00 +/- 7.15 kg/m(2) (range 30.65-76.60 kg/m(2)). After 6 months of the surgery, the mean BMI was 33.79 +/- 6.06 kg/m(2) (range 21.70-52.76 kg/m(2)). The mean BMI decreased (P < 0.001) 6 months after the surgery. Within the following 2 years, the serum Fe, Ca, Zn, Se, VitA, VitD, and VitB(12) had normalized. The serum Zn, Se, and VitA of some patients decreased but were nearly normal. In contrast, serum PTH remained continuously at a higher level than normal. CONCLUSIONS: This study confirms that LRYGBP is a reliable and safe weight loss method for the patients suffering from morbid obesity. After surgery, serum Ca, Zn, and Se metabolisms and PTH levels are altered in these patients. Therefore, multi-vitamin and mineral supplementation are strongly recommended in all patients after LRYGBP.

Laparoscopic Roux-en-Y gastric bypass for morbid obesity:Follow-up results in 121 patients / 中国微创外科杂志

Objective To summarize the changes of nutrition and metabolism after laparoscopic Roux-en-Y gastric bypass surgery (LRYGBP) in the treatment of morbid obesity. Methods LRYGBP was performed in 121 patients with morbid obesity (male, 40 patients; femal, 81 patients). The body mass index (BMI) was measured 1 month before and 6 months after the operation. A comparative analysis was conducted on serum levels of ferrum (Fe), calcium (Ca), zincum (Zn), selenium (Se), vitamin A (VitA), vitamin D (VitD), vitamin B_ 12 (VitB_ 12 ), and parathyroid hormone (PTH) at 6, 12, and 24 months after operation. Results The BMI was declined from 47.00?7.15 kg/m~2 preoperatively to 33.79?6.06 kg/m~2 postoperatively, with a decrease of 0.26~42.58 kg/m~2 (13.21?5.47 kg/m~2) (t=26.103, P=0.001). The postoperative serum levels of Fe, Ca, Zn, Se, VitA, VitD, and VitB_ 12 were all within the normal limits. However, the levels of Zn, Se, and VitA were lower than the normal in 19.5% (17/87), 22.7% (20/88), and 3.7% (28/83) of patients at 6 months after operation, and in 6.0% (2/30), 11.5% (3/26), and 17.2% (5/29) of patients at 2 years after operation, respectively. The serum PTH levels were 11~161 pg/ml (66?34 pg/ml), 24~154 pg/ml (72?34 pg/ml), and 21~194 pg/ml (75?40 pg/ml) at 6, 12, and 24 months after operation, respectively (normal limits, 9~44 pg/ml). Conclusions Laparoscopic Roux-en-Y gastric bypass surgery is a reliable and safe option for patients with morbid obesity. The serum levels of calcium, zinc, selenium, and PTH will be influenced following the surgery. Supplementation of multi-vitamins and mineral substances should be strongly advised in all patients.