Nutritional Deficiencies in Severe Obesity: a Multiethnic Asian Cohort

Comparison of Sleeve Gastrectomy with Loop Duodenojejunal Bypass Versus One Anastomosis Gastric Bypass for Type 2 Diabetes: The Role of Pylorus Preservation

BACKGROUND

One anastomosis gastric bypass (OAGB) is recognized as a standard procedure in metabolic surgery. However, concerns about postoperative bile reflux and nutritional risks are prevalent. Comparatively, sleeve gastrectomy with loop duodenojejunal bypass (SG + LoopDJB) bypasses an equivalent length of the foregut as OAGB while maintaining pyloric function. The role of pylorus function remains to be further elucidated regarding these metabolic procedures' therapeutic outcomes and side effects.

METHOD

A retrospective study was conducted in our center to compare the surgical safety and 1-year outcomes of OAGB and SG + LoopDJB regarding type 2 diabetes mellitus (T2DM) remission, weight loss, gastrointestinal disorders, and nutritional status in T2DM patients matched by gender, age, and BMI.

RESULTS

The baseline characteristics were comparable between groups. Compared with OAGB, SG + LoopDJB had longer operative time and length of stay (LOS) but similar major postoperative complications. At 1-year follow-up, OAGB has similar diabetes remission (both 91.9%), weight loss effect (28.1 ± 7.1% vs. 30.2 ± 7.0% for %TWL), and lipidemia improvement to SG + LoopDJB (P > 0.05). However, OAGB presented a higher incidence of hypoalbuminemia (11.9% vs. 2.4%, P = 0.026) but a low incidence of gastroesophageal reflux disease (GERD) symptoms (9.5% vs. 26.2%, P = 0.046) than SG + LoopDJB. There was no statistical difference regarding other gastrointestinal disorders and nutritional deficiencies between groups.

CONCLUSION

Both OAGB and SG + LoopDJB show comparable, favorable outcomes in weight loss, T2DM remission, and lipidemia improvement at the 1-year follow-up. Pylorus preservation, while increasing surgical difficulty and the risk of de novo GERD, may reduce the risk of postoperative hypoalbuminemia.

Prevalence of Micronutrient Deficiencies in Preoperative Bariatric Patients in a New Zealand Tertiary Centre

PURPOSE

A potential complication of bariatric surgery is development of nutritional deficiencies. Study aims were to assess prevalence of micronutrient deficiencies in preoperative bariatric patients and to examine for ethnic differences.

METHODS

Retrospective analysis of 573 patients that underwent bariatric surgery at Counties Manukau District Health Board was carried out. Mean preoperative levels of albumin, calcium, phosphate, folate, vitamin B12, vitamin D, magnesium, haemoglobin, haematocrit, mean cell volume, mean cell haemoglobin, ferritin, iron, and transferrin were calculated. Chi square, fisher exact test, and multiple logistic regression was used to assess for differences in prevalence of micronutrient deficiencies across ethnicities.

RESULTS

The most common micronutrient deficiency was vitamin D (30.85%). There were statistically significant differences in vitamin D deficiency across ethnicities (p < 0.0001). Asians had the highest prevalence of vitamin D deficiency (60%), followed by Pacifica (44.57%), and Māori (31.68%). Asians were more likely to have vitamin D deficiency compared to NZ/Other Europeans (OR = 14.93, p < 0.001). Vitamin D deficiency was associated with higher BMI (OR = 1.05, p = 0.008). The second most common deficiency was iron (21.1%). Asians had the highest prevalence of iron deficiency (44%), followed by Māori (27.95%), and Pacifica (19.57%) (p = 0.0064). Compared to NZ/Other Europeans, Asians (OR = 4.26) and Māori (OR = 1.78) were more likely to be iron deficient (p = 0.004). Female gender was associated with iron deficiency (OR = 2.12, p = 0.007).

CONCLUSION

Vitamin D and iron are the most common micronutrient deficiencies among preoperative bariatric patients in this cohort and ethnic differences were seen. There may be a role for preoperative supplementation in these at-risk ethnic groups.

Collaborative Prescribing Practice in Managing Patients Post-Bariatric Surgery in a Tertiary Centre in Singapore

Background: A collaborative prescribing (CP) practice model, established by the endocrinologists, pharmacists, and advanced practice nurses, aims to provide for the postoperative monitoring and medical and nutritional management of stable patients after bariatric surgery. Method: Under the CP agreement, endocrinologists refer patients who have undergone bariatric surgery with stable medical conditions to CP practitioners, comprising senior pharmacists and advanced practice nurses. CP practitioners review the patient's weight loss progress, blood test results and vitals, the sufficiency of micronutrient repletion, adherence to supplements and medications, and chronic disease control. CP practitioners can prescribe and adjust the medications and supplements, in accordance with a clinical evaluation and standard guidance. Patients who require immediate attention due to complications or red flags are referred to the primary endocrinologist for further management. Results: From 5 May 2020 to 30 September 2023, CP practitioners provided 672 consultations. At least 68% and 80% of patients achieved appropriate weight loss post-surgery during the acute and maintenance phases, respectively. Less than 10% of the patients presented with anaemia and iron deficiency, and vitamin B12, folate and vitamin D deficiency. More than 80% of patients achieved a HbA1c of less than 7%. Conclusions: The CP practice framework provides a sustainable and viable model to facilitate optimal outcomes after bariatric surgery.

Vitamin B12, folate, and homocysteine in metabolic syndrome: a systematic review and meta-analysis

Background & aims

Metabolic syndrome (MetS) is associated with life-threatening conditions. Several studies have reported an association of vitamin B12, folic acid, or homocysteine (Hcy) levels with MetS. This systematic review and meta-analysis assessed the association of vitamin B12, folic acid, and Hcy levels with MetS.

Methods

PubMed, Scopus, Embase, Ovid/Medline, and Web of Science were searched up to February 13, 2023. Cross-sectional, case-control, or cohort studies were included. A random-effects model was performed using the DerSimonian and Laird method to estimate the between-study variance. Effect measures were expressed as odds ratios (OR) with their corresponding 95% confidence intervals (95% CI). Between-study heterogeneity was evaluated using Cochran's Q test and the I2 statistic.

Results

Sixty-six articles (n = 87,988 patients) were included. Higher vitamin B12 levels were inversely associated with MetS (OR = 0.87; 95% CI: 0.81-0.93; p < 0.01; I2 = 90%). Higher Hcy levels were associated with MetS (OR = 1.19; 95% CI: 1.14-1.24; p < 0.01; I2 = 90%). Folate levels were not associated with MetS (OR = 0.83; 95% CI: 0.66-1.03; p = 0.09; I2 = 90%).

Conclusion

Higher vitamin B12 levels were inversely associated with MetS, whereas higher Hcy levels were associated with MetS. Studies assessing the pathways underlying this association are required.

A Systematic Review and Meta-Analysis of Vitamin D Status of Patients with Severe Obesity in Various Regions Worldwide

INTRODUCTION

Managing nutritional deficiencies is an essential component in the treatment of severe obesity. Vitamin D deficiency is often reported in investigations in severely obese cohorts. However, no prior study has summarized findings on this topic. Consequently, the aim of this systematic review and meta-analysis was to investigate the 25-hydroxyvitamin D [25(OH)D] status in individuals with severe obesity in different regions worldwide. We also evaluated levels of calcium, parathyroid hormone (PTH), and magnesium as secondary outcome measures.

METHODS

We searched Medline, PubMed, Scopus, the Cochrane Library, and EMBASE for relevant observational studies published in English from 2009 to October 2021. The heterogeneity index among the studies was determined using the Cochran (Q) and I2 tests. Based on the heterogeneity results, the random-effect model was applied to estimate the prevalence of vitamin D deficiency.

RESULTS

We identified 109 eligible observational studies. Overall, 59.44% of patients had vitamin D deficiency [25(OH)D <20 ng/mL], whereas 26.95% had vitamin D insufficiency [25(OH)D 20-30 ng/mL]. Moreover, the mean 25(OH)D level was 18.65 ng/mL in 96 studies. The pooled mean estimate of the serum calcium, PTH, and magnesium was 9.26 mg/dL (95% confidence interval [CI]: 9.19-9.32, I2 = 99.7%, p < 0.001), 59.24 pg/mL (95% CI: 54.98, 63.51, I2 = 99.7%, p < 0.001), and 0.91 mg/dL (95% CI: 0.84, 0.98, I2 = 100.0%, p < 0.001), respectively. The results of the subgroup analysis indicated that the mean estimates of 25(OH)D were highest in North America (21.71 ng/mL [19.69, 23.74], [I2 = 97.2%, p < 0.001]) and lowest in Southeast Asia (14.93 ng/mL [14.54, 15.33], [I2 = 0.0%, p = 0.778]).

CONCLUSION

The results obtained showed a significant prevalence of vitamin D deficiency among severely obese individuals in various geographical regions, whereas the highest and lowest mean estimates were reported for North America and Southeast Asia, respectively.

Determinants of vitamin B12 deficiency in patients with type-2 diabetes mellitus - A primary-care retrospective cohort study

BACKGROUND

Like many developed nations, the prevalence of both older people and type-2 diabetes mellitus (T2DM) in Singapore is rising. This demographic shift predisposes the population to greater risks of both frailty and its complications that can be further aggravated by vitamin B12 deficiency -a highly prevalent associated variable that is potentially modifiable. Indeed, B12 deficiency adversely impacts the neuro-cognitive, haematological, and even the immune systems; jeopardizing our aspirations for successful aging. Despite this, many patients with T2DM in primary care remain unscreened due to a lack of clear guidelines for regular B12 screening. We therefore investigated the determinants of B12 deficiency in community-dwelling patients with T2DM, with the aim of profiling patients most in need of B12-deficiency screening.

METHODS

B12 deficiency was evaluated using a retrospective cross-sectional cohort of 592 primary-care patients with T2DM, recruited from 2008 to 2011 from a Polyclinic in Singapore.

RESULTS

B12 deficiency (serum B12 < 150 pmol/L) was present in 164 (27.7%) patients and was associated with a higher "metformin daily dose" (OR = 2.79; 95% CI, 2.22-3.48, P < 0.001); "age ≥ 80 years" (OR = 2.86; 95% CI, 1.31-6.25, P = 0.008); "vegetarianism" (OR = 21.61; 95% CI, 4.47-104.44, P < 0.001); and "folate deficiency" (OR = 2.04; 95% CI, 1.27-3.28, P = 0.003). Conversely, "Prescribed B12 supplementation" was associated with a lower odds of B12 deficiency (OR = 0.37; 95% CI: 0.22-0.61, P < 0.001). The area under the receiver operating characteristic curve was 0.803 (95% CI: 0.765-0.842). "Metformin daily dose" correlated interchangeably with "Metformin 1-year cumulative dose" (r = 0.960; P < 0.01), and also associated linearly with "duration of diabetes" (B = 0.113, P < 0.0001). Independent of the duration of T2DM, 29.3% of the B12-deficient patients needed > 1 screening test before the detection of B12 deficiency.

CONCLUSIONS

Primary-care screening for B12 deficiency should be part of the annual laboratory review of patients with T2DM regardless of the duration of T2DM -especially when they are prescribed ≥ 1.5 g/day of metformin; ≥ 80 years old; vegetarian; and not prescribed B12 supplementation. Concurrent evaluation for associated folate (vitamin B9) deficiency is essential when addressing T2DM-associated B12 deficiencies. Current "Metformin daily dose" is an accurate proxy of both cumulative metformin exposure and duration of T2DM.

Current treatment landscape for obesity in Singapore

The rising prevalence of obesity in Singapore is a harbinger for a corresponding increase in obesity-related complications such as type 2 diabetes mellitus (T2DM) and coronary heart disease. Obesity is a complex disease driven by multiple factors, and hence, treatment cannot follow a 'one-size-fits-all' approach. Lifestyle modifications involving dietary interventions, physical activity and behavioural changes remain the cornerstone of obesity management. However, similar to other chronic diseases such as T2DM and hypertension, lifestyle modifications are often insufficient on their own, hence the importance of other treatment modalities including pharmacotherapy, endoscopic bariatric therapy and metabolic-bariatric surgery. Weight loss medications currently approved in Singapore include phentermine, orlistat, liraglutide and naltrexone-bupropion. In recent years, endoscopic bariatric therapies have evolved as an effective, minimally invasive and durable therapeutic option for obesity. Metabolic-bariatric surgery remains the most effective and durable treatment for patients with severe obesity, with an average weight loss of 25%-30% after one year.

Long-Term Outcomes of Iron Deficiency Before and After Bariatric Surgery: a Systematic Review and Meta-analysis

PURPOSE

This study reviews the prevalence of iron deficiency (ID) in bariatric surgery candidates and the long-term outcomes of the prevalence of ID after bariatric surgery.

MATERIALS AND METHODS

A systematic literature search and meta-analysis were performed in PubMed for articles published by August 31, 2022, including these search terms: bariatric surgery, metabolic surgery, weight loss surgery, obesity surgery, sleeve gastrectomy, gastric banding, gastric bypass, duodenal switch, duodenojejunal bypass, iron, iron deficiency, sideropenia, and hypoferritinemia. Fifty-seven studies examining a total of 26,328 patients with morbidly obese were included in this meta-analysis finally.

RESULTS

The results showed a prevalence of 17% of ID in bariatric surgery candidates and a prevalence of 14%, 17%, 26%, 34%, 23%, 38%, and 23% of ID at 1-, 2-, 3-, 4-, 5-, 8-, and 10-year follow-up after bariatric surgery, respectively. Additionally, the results showed a prevalence of 15%, 19%, 35%, 38%, 29%, 30%, and 23% of ID at 1-, 2-, 3-, 4-, 5-, 8-, and 10-year follow-up after Roux-en-Y gastric bypass, respectively; a prevalence of 12%, 12%, 15%, 31%, and 17% of ID at 1-, 2-, 3-, 4-, and 5-year follow-up after sleeve gastrectomy, respectively; and a prevalence of 19% of ID at 1-year follow-up after anastomosis gastric bypass.

CONCLUSION

As a result, preoperative evaluation and correction of ID may lead to better outcomes for bariatric surgery candidates. ID is also common in patients after bariatric procedures, especially RYGB. Long-term, even lifelong, medical and nutritional monitoring and tailored interventions are critical.

Micronutrients Deficiencies in Candidates of Bariatric Surgery: Results from a Single Institution over a 1-Year Period

BACKGROUND

Micronutrient deficiencies represent a common condition after bariatric surgery (BS). The prevalence of these nutritional disorders before BS is still debated. The aim of our study was to retrospectively evaluate the prevalence of micronutrient deficiencies in candidates for BS.

METHODS

A prospectively maintained database of our institution was searched to find all patients who underwent surgery between January and December 2021. The following data were collected: age, gender, body mass index (BMI), obesity-associated diseases, and preoperative serum levels of vitamin B12, folate, and vitamin D.

RESULTS

A total of 174 patients were included in our study. Mean age and BMI were 39.2 ± 11.4 years and 44.3 ± 7.1 kg/m², respectively. One hundred and thirty-nine patients (79.9%) had at least one preoperative micronutrient disorder, with vitamin D deficiency being the most common (116, 66.7%), followed by a deficit of folate (76, 43.7%) and vitamin B12 (10, 5.7%). Forty-seven (27%) individuals had insufficient levels of vitamin D. Comparison of deficiencies between sexes showed that vitamin B12 < 20 ng/ml was significantly more frequent in women (p = 0.03). DLP showed a mild significant effect on folate levels (p = 0.01), while the association of HNT and T2DM had a mild significant effect on vitamin B12 (p = 0.02).

CONCLUSIONS

Preoperative micronutrient deficiencies were frequently found in candidates for BS. Approximately 90% of patients had deficient or insufficient serum levels of vitamin D preoperatively. Almost half of the patients had a preoperative deficit of folate, and vitamin B12 deficiency was significantly more frequent in the female population. It is mandatory to screen all patients undergoing BS for vitamin deficiencies before surgery.

Cutaneous signs of nutritional disorders

This review article focuses on the dermatologic manifestations of selected nutrient deficiencies, including protein-energy and micronutrient-related malnutrition. The various nutrient deficiencies presented may share common features. However, distinctive cutaneous signs may prompt clinicians to consider a nutritional cause and help distinguish a nutrient deficiency from other common dermatologic conditions. The recent reemergence of forgotten nutritional deficiencies, such as scurvy and pellagra, in the context of predisposing risk factors that may uniquely affect women more than men makes this topic timely. Recognition of nutritional disorders is important because appropriate treatment may reverse cutaneous signs and prevent irreversible sequelae.

Are There Ethnic Differences in Micronutrient Deficiencies in Preoperative Bariatric Patients? A Systematic Review and Meta-analysis

The purpose of this systematic review was to determine if in patients presenting for bariatric surgery, patients of different ethnicities, have different micronutrient deficiencies preoperatively. Databases searched were PubMed, Embase, MEDLINE and Cochrane Library. A meta-analysis of prevalence of vitamin D insufficiency (<20ng/ml) was carried out using a random effects model. Twenty-eight articles were included assessing preoperative micronutrient status across different ethnic groups. The most common micronutrient assessed was vitamin D, and the most assessed ethnicity was Caucasian. African Americans had the greatest prevalence of vitamin D insufficiency when compared to other ethnicities with a pooled prevalence and 95% confidence interval of 0.80 [0.74; 0.85]. There was a significant difference in vitamin D insufficiency when compared across ethnicities (p <0.01).

Pre-operative micronutrient deficiencies in patients with severe obesity candidates for bariatric surgery

PURPOSE

In patients with obesity, micronutrient deficiencies have been reported both before and after bariatric surgery (BS). Obesity is a chronic pro-inflammatory status, and inflammation increases the risk of micronutrient malnutrition. Our objective was to assess in pre-BS patients the prevalence of micronutrient deficiencies and their correlation with blood values of C-reactive protein (CRP).

METHODS

Anthropometric data, instrumental examinations, and blood variables were centrally measured in the first 200 patients undergoing a pre-BS evaluation at the "Città della Salute e della Scienza" Hospital of Torino, starting from January 2018.

RESULTS

At least one micronutrient deficiency was present in 85.5% of pre-BS patients. Vitamin D deficiency was the most prevalent (74.5%), followed by folate (33.5%), iron (32%), calcium (13%), vitamin B12 (10%), and albumin (5.5%) deficiency. CRP values were high (> 5 mg/L) in 65% of the patients. These individuals showed increased rate of iron, folate, vitamin B12 deficiency, and a higher number of micronutrient deficiencies. In a multiple logistic regression model, increased CRP levels were significantly associated with deficiencies of vitamin B12 (OR = 5.84; 95% CI 1.25-27.2; p = 0.024), folate (OR = 4.02; 1.87-8.66; p < 0.001), and with the presence of ≥ 2 micronutrient deficiencies (OR = 2.31; 1.21-4.42; p = 0.01).

CONCLUSIONS

Micronutrient deficiencies are common in patients with severe obesity undergoing BS, especially when inflammation is present. In the presence of increased CRP values before surgery, it might be advisable to search for possible multiple micronutrient deficiencies.

Nutritional Assessment and Preparation for Adult Bariatric Surgery Candidates: Clinical Practice

Bariatric surgery (BS) has proven to be highly efficacious in the treatment of obesity and its comorbidities. However, careful patient selection is critical for its success. Thus, patients should undergo medical, behavioral, and nutritional assessment by a multidisciplinary team. From the nutritional point of view, BS candidates should undergo nutritional assessment, preparation, and education by a registered dietitian in the preoperative period. Currently, detailed specified and comprehensive information on these topics is lacking. The present narrative review aimed to summarize the available literature concerning both the preoperative nutritional assessment components and the preoperative nutritional preparation and education components of patients planning to undergo BS. Current literature indicates that proper management before BS should include a comprehensive nutritional assessment, in which it is advisable to perform a clinical interview to assess patients' medical background, weight management history, eating patterns and pathologies, oral health, physical activity habits, nutritional status, supplementation usage, BS knowledge, surgery expectations and anthropometric measurements. Nutritional preparation and educational strategies should include an individualized preoperative weight-loss nutrition program, improvement of glycemic control, micronutrients deficiencies correction, eating and lifestyle habits adaptation, physical activity initiation, and strengthening knowledge on obesity and BS. At this stage, more well-designed intervention and long-term cohort studies are needed in order to formulate uniform evidence-based nutritional guidelines for patients who plan to undergo BS, including populations at higher nutritional risk. Moreover, postoperative outcomes of presurgical nutritional intervention programs should be studied.

Associations of Bariatric Interventions With Micronutrient and Endocrine Disturbances

IMPORTANCE

Few studies have described the longitudinal trajectories of serum levels of micronutrients whose deficiencies are associated with serious sequelae following bariatric procedures, such as anemia, osteoporotic fractures, and neuropathies. Furthermore, previous studies comparing laparoscopic sleeve gastrectomy (LSG) vs Roux-en-Y gastric bypass (LRYGB) or one-anastomosis gastric bypass (OAGB) procedures may have been limited by selection and confounding biases.

OBJECTIVE

To appraise the spectrum and temporal course of micronutrient deficiencies associated with bone metabolism and erythropoiesis after LSG vs OAGB or LRYGB procedures, using the propensity score as a balancing score.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, longitudinal comparative effectiveness study was conducted at a high-volume bariatric unit in Singapore from September 1, 2008, to November 30, 2017, with a cutoff date for analysis of September 2018. Patients who underwent adjustable gastric banding, biliopancreatic diversion procedures, and intragastric balloon procedures were excluded. All other patients who underwent bariatric procedures were included. Data were analyzed from September 23 to 30, 2018.

MAIN OUTCOMES AND MEASURES

Serial assessment of 13 biochemical parameters at 12 time points for up to 5 years after bariatric procedure. Inverse probability-of-treatment weights were used to obtain estimates of the mean associations of variables assessed with the bariatric surgical interventions. Longitudinal trajectories were analyzed using mixed-effects generalized linear models to apportion the temporal variation of serum micronutrients into fixed-effects and random-effects components.

RESULTS

A total of 688 patients were included in this study, of whom 499 underwent LSG (mean [SD] age, 41.5 [11.3] years; 318 [63.7%] women) and 189 underwent OAGB or LRYGB (mean [SD] age, 48.6 [9.4] years; 112 [59.3%] women). There were no differences during follow-up among patients who underwent LSG vs those who underwent OAGB or LRYGB in intact parathyroid hormone levels (mean difference, 7.05 [95% CI, -28.67 to 42.77] pg/mL; P = .70), serum 25-hydroxyvitamin D levels (mean difference, -0.72 [95% CI, -1.56 to 0.12] ng/mL; P = .09), or phosphate levels (mean difference, 0.006 [95% CI, -0.052 to 0.064] mg/dL; P = .83). Hemoglobin levels were a mean 0.63 (95% CI, 0.41 to 0.85) g/dL higher among patients who underwent LSG compared with those who underwent OAGB or LRYGB (P < .001), despite no differences in iron concentration levels (mean difference, 1.50 [95% CI, -1.39 to 4.39] µg/dL; P = .31), total iron-binding capacity (mean difference, 4.36 [95% CI, -5.25 to 13.98] µg/dL; P = .37), or ferritin levels (mean difference, 3.0 [95% CI, -13.0 to 18.9] ng/mL; P = .71). Compared with patients who underwent LSG procedures, patients who underwent OAGB or LRYGB had higher folate levels (mean difference, 2.376 [95% CI, 1.716 to 3.036] ng/mL; P < .001) but lower serum magnesium levels (mean difference, -0.25 [95% CI, -0.35 to -0.16] mg/dL; P < .001) and zinc levels (mean difference, -7.58 [95% CI, -9.92 to -5.24] µg/dL; P < .001).

CONCLUSIONS AND RELEVANCE

These findings suggest that LSG vs OAGB or LRYGB procedures have differential associations with various micronutrient and metabolic parameters. These differences should be recognized in guidelines for postbariatric nutritional surveillance and prevention.

Nutritional Risks in Adolescents After Bariatric Surgery

BACKGROUND & AIMS

Little is known about prevalence and risk factors for nutritional deficiencies in adolescents after metabolic bariatric surgery. We performed a 5-year prospective cohort study of these.

METHODS

Adolescents who had Roux-en-Y gastric bypass (RYGB, n = 161) or vertical sleeve gastrectomy (VSG, n = 67) were enrolled at 5 tertiary-care centers from March 2007 through February 2012. The final analysis cohort included 226 participants (161 who had RYGB and 65 who had VSG). We measured serum levels of ferritin; red blood cell folate; vitamins A, D, B₁, B₁₂; and parathyroid hormone at baseline and annually for 5 years. General linear mixed models were used to examine changes over time and identify factors associated with nutritional deficiencies.

RESULTS

The participants were 75% female and 72% white, with a mean age of 16.5 ± 1.6 years and mean body mass index of 52.7 ± 9.4 kg/m² at surgery. Mean body mass index decreased 23% at 5 years, and did not differ significantly between procedures. After RYGB, but not VSG, serum concentrations of vitamin B₁₂ significantly decreased whereas serum levels of transferrin and parathyroid hormone increased. Ferritin levels decreased significantly after both procedures. Hypo-ferritinemia was observed in 2.5% of patients before RYGB and 71% at 5 y after RYGB (P < .0001), and 11% of patients before VSG and 45% 5 y after VSG (P = .002). No significant changes in serum levels of folate or vitamins A, B₁, or D were found between baseline and 5 y after either procedure. By 5 y, 59% of RYGB and 27% of VSG recipients had 2 or more nutritional deficiencies. Risk factors associated with specific deficiencies included surgery type, female sex, black race, supplementation intake, weight regain, and for females, pregnancy.

CONCLUSIONS

In a prospective study of adolescents who underwent RYGB or VSG, we observed nutritional deficiencies by 5 y after the procedures-particularly in iron and B₁₂ after RYGB. Ongoing nutrient monitoring and supplementation are recommended for all patients, but surgery type, supplementation intake, sex, and race might affect risk. (Clinical trial registration: Adolescent Bariatrics: Assessing Health Benefits and Risk [also known as Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS)], NCT00474318.).

Nutritional Deficiencies in Patients with Severe Obesity before Bariatric Surgery: What Should Be the Focus During the Preoperative Assessment?

BACKGROUND

Nutritional deficiencies are a well-recognized long-term complication following bariatric surgery. The presence of preoperative deficiencies has been shown to be predictive of postoperative deficiencies.

OBJECTIVE

The aim of the study was to investigate the prevalence of micronutrient deficiency in a large sample of patients with severe obesity preoperatively, and to determine whether such deficiencies may be related to patient's sex, body mass index, or ethnic subgroup.

DESIGN

A cross-sectional study of data collected at the time of the preoperative evaluation.

PARTICIPANTS/SETTING

Data were collected during the preoperative evaluation of 872 bariatric surgery candidates in a university hospital in Israel between 2011 and 2018. The patients were 72.9% women, with a mean age of 37.9±12.1 years and mean body mass index of 42.4±4.7 MAIN OUTCOME MEASURES: Nutritional deficiencies according to blood assays. Data on anthropometrics, comorbidities, and demographic characteristics was also collected.

STATISTICAL ANALYSES

Baseline differences between patient subgroups were analyzed using independent-samples t test, analysis of variance, or χ² test.

RESULTS

Deficiencies of vitamin D, iron, folate, vitamin B-12, elevated parathyroid hormone and low transferrin saturation were present in 75.2%, 42.6%, 28.5%, 8.5%, 35.5%, and 70% of patients, respectively. Nutritional deficiencies were significantly more common among women compared with men for iron (45.9% vs 33.5%; P=0.002), low transferrin saturation (77.7% vs 44.6%; P<0.001), vitamin D (77.5% vs 69.2%; P=0.019) and elevated parathyroid hormone level (39.5% vs 22.9%; P=0.002). Iron, transferrin saturation, and vitamin D deficiencies were more prevalent in Arab patients compared with Jewish patients: 59.6% vs 36%; P<0.001, 80.2% vs 62.8%; P=0.003, and 85.1% vs 71.6%; P<0.001, respectively. Vitamin D and iron deficiency were more common among higher body mass index subgroups (P=0.004 and P=0.040, respectively).

CONCLUSIONS

The results indicate a high prevalence of nutritional deficiencies, mainly of iron and vitamin D in bariatric surgery candidates. Patients at higher risk for nutritional deficiencies include those with higher body mass index, women, and Arabs.