The link between obesity and vitamin D in bariatric patients with omega-loop gastric bypass surgery - a vitamin D supplementation trial to compare the efficacy of postoperative cholecalciferol loading (LOAD): study protocol for a randomized controlled trial

The Effect of Vitamin D Supplementation on Serum 25-Hydroxy Vitamin D in the Patients Undergoing Bariatric Surgery: a Systematic Review and Meta-Analysis of Randomized Clinical Trials

Currently, there is no consensus on the optimal vitamin D administration in bariatric patients. The present systematic review and meta-analysis were conducted to examine the effect of vitamin D supplements on serum level of 25(OH) vitamin D in the patients undergoing bariatric surgery (BS).Random model effects were used to estimate standardized mean difference (SMD) with a 95% confidence interval (CI). Nine clinical trials were included in the meta-analysis. Vitamin D supplementation in patients undergoing BS modestly improves vitamin D status (SMD, 0.53; 95% CI, 0.28, 0.77) particularly, in the dosages above 2850 IU/day and in the patients with BMI greater than 50 kg/m². Vitamin D supplementation was associated with prevention of raising of the PTH serum concentration and without impact on serum calcium levels.

Effect of one-anastomosis gastric bypass on cardiovascular risk factors in patients with vitamin D deficiency and morbid obesity: A secondary analysis

BACKGROUND AND AIMS

Bariatric patients often suffer from vitamin D (VD) deficiency, and both, morbid obesity and VD deficiency, are related to an adverse effect on cardiovascular disease (CVD) risk. Therefore, we assessed the change of known CVD risk factors and its associations during the first 12 months following one-anastomosis gastric bypass (OAGB).

METHODS AND RESULTS

In this secondary analysis, CVD risk factors, medical history and anthropometric data were assessed in fifty VD deficient (25-hydroxy-vitamin D (25(OH)D) <75 nmol/l) patients, recruited for a randomized controlled trial of VD supplementation. Based on previous results regarding bone-mass loss and the association between VD and CVD risk, the study population was divided into patients with 25(OH)D ≥50 nmol/l (adequate VD group; AVD) and into those <50 nmol/l (inadequate VD group; IVD) at 6 and 12 months (T6/12) postoperatively. In the whole cohort, substantial remission rates for hypertension (38%), diabetes (30%), and dyslipidaemia (41%) and a significant reduction in CVD risk factors were observed at T12. Changes of insulin resistance markers were associated with changes of total body fat mass (TBF%), 25(OH)D, and ferritin. Moreover, significant differences in insulin resistance markers between AVD and IVD became evident at T12.

CONCLUSION

These findings show that OAGB leads to a significant reduction in CVD risk factors and amelioration of insulin resistance markers, which might be connected to reduced TBF%, change in 25(OH)D and ferritin levels, as an indicator for subclinical inflammation, and an adequate VD status. REGISTERED AT CLINICALTRIALS.GOV: (Identifier: NCT02092376) and EudraCT (Identifier: 2013-003546-16).

Course of depressive symptomatology and its association with serum uric acid in one-anastomosis gastric bypass patients

The changes in depressive symptomatology during the first year following one-anastomosis gastric bypass (OAGB) were evaluated and its association with uric acid (sUA). Fifty patients were included in this analysis. Beck Depression Inventory (BDI) for measuring depressive symptomatology, blood samples, and anthropometric measurements were assessed before (T0), at 6 (T6), and 12 months (T12) after surgery. There was a significant reduction in BDI total score at T6 (− 5.6 (95% CI − 2.1, − 9.1) points; p = 0.001) and at T12 (− 4.3 (95% CI − 0.9, − 7.9) points; p = 0.011). BMI loss was unrelated to depressive symptomatology. Patients with moderate to severe depressive symptomatology presented lower sUA levels than patients with none or minimal to mild (p = 0.028). ROC analysis revealed that sUA levels below 5.0 at T6 and 4.5 mg/dl at T12 had a prognostic accuracy for depression severity. Furthermore, delta sUA was significantly associated with delta BMI (β = 0.473; p = 0.012) and delta waist circumference (β = 0.531; p = 0.003). These findings support an improvement in depressive symptomatology in the first year postoperatively, however, without relation to BMI loss. Patients with moderate to severe depressive symptomatology presented with lower sUA levels over time. Therefore, sUA could be useful to predict moderate to severe depressive symptomatology in patients undergoing OAGB in clinical practice.

Changes in Bone Mineral Density Following Weight Loss Induced by One-Anastomosis Gastric Bypass in Patients with Vitamin D Supplementation

BACKGROUND

Little is known about changes in bone mineral density (BMD) following weight loss after one-anastomosis gastric bypass (OAGB) and the role of serum vitamin D and its supplementation on bone metabolism. We evaluated BMD after OAGB as a function of vitamin D supplementation with respect to a minimum threshold of 25-hydroxy-vitamin-D [25(OH)D] concentration, which could prevent or decelerate an eventual bone loss.

METHODS

Fifty bariatric patients who participated in the randomized controlled trial were included in this analysis. BMD and anthropometric measurements by DXA and laboratory parameters were assessed before (T0), at 6 (T6), and 12 months (T12) after surgery.

RESULTS

OAGB resulted in a 36% total body weight loss with a decrease in body fat and an increase in lean body mass. A significant decrease in BMD was seen in lumbar spine by 7%, left hip 13%, and total body 1%, but not in forearm. Bone turnover markers increased significantly but with normal parathyroid hormone concentrations. Weight loss was not associated with changes in BMD. A serum 25(OH)D concentration > 50 nmol/l at T6 and T12 (adequate-vitamin-D-group; AVD) showed a significant lower bone loss, compared to the inadequate-vitamin-D-group (IVD; < 50 nmol/l). Lower bone loss in the left hip showed a strong correlation with higher 25(OH)D concentrations (r = 0.635, p = 0.003).

CONCLUSION

These findings support a dose effect of vitamin D supplementation on bone health and suggest that 25(OH)D concentrations need to be above 50 nmol/l at least during the first postoperative year to decelerate bone loss in patients undergoing OAGB.

CLINICAL TRIAL REGISTRY NUMBER AND WEBSITE

Clinicaltrials.gov (NCT02092376) at https://clinicaltrials.gov /. EudraCT (2013-003546-16) at https://eudract.ema.europa.eu /.

Differences in Serum Magnesium Levels in Diabetic and Non-Diabetic Patients Following One-Anastomosis Gastric Bypass

Patients with obesity and type 2 diabetes mellitus (T2DM) are regarded to have reduced serum magnesium (Mg) concentrations. We aimed to assess the changes in serum Mg concentrations at 12-month follow-up in patients, with and without T2DM, who underwent one anastomosis gastric bypass surgery. Overall, 50 patients (80% female, age 42.2 (12.5) years) with morbid obesity (mean baseline BMI 43.8 (4.3) kg/m2) were included in the analysis. Half of the included patients had T2DM diagnosed at baseline, and these patients showed lower serum Mg concentration (0.78 (0.07)) vs. 0.83 (0.05) mmol/L; p = 0.006), higher blood glucose levels (129.9 (41.3) vs. 87.6 (8.1) mg/dL; p < 0.001) as well as HbA1c concentrations (6.7 (1.4) vs. 5.3 (0.5)%; p < 0.001). During follow-up, BMI and glucose levels showed a decrease; however, serum Mg levels remained stable. At baseline 42% of patients were found to be Mg deficient, which was reduced to 33% at six months and to 30% at 12 months follow-up. Moreover, patients with T2DM had an odds ratio of 9.5 (95% CI = 3.0-29.7; p < 0.001) for magnesium deficiency when compared to patients without T2DM. Further research into the role of Mg and its role in T2DM and other obesity-related comorbidities are needed.

Obesity, Bariatric Surgery, and Vitamin D

The high prevalence of obesity is a worldwide problem associated with multiple comorbidities, including cardiovascular diseases. Vitamin D deficiency with secondary hyperparathyroidism is common in obese individuals and can be aggravated after bariatric surgery. Moreover, there is no consensus on the optimal supplementation dose of vitamin D in postbariatric surgical patients. We present new data on the variability of 25(OH)D response to supplementation in postmenopausal obese women. It is important to recognize and treat vitamin D deficiency before bariatric surgery to avoid postoperative complications, such as metabolic bone disease with associated high fracture risk. The objective of this article is to discuss the bone metabolism consequences of vitamin D deficiency after bariatric surgery.

Vitamin D3 Loading Is Superior to Conventional Supplementation After Weight Loss Surgery in Vitamin D-Deficient Morbidly Obese Patients: a Double-Blind Randomized Placebo-Controlled Trial

Background

Bariatric patients often suffer from vitamin D deficiency (VDD), and both, morbid obesity and VDD, are related to non-alcoholic fatty liver disease. However, limited data are available regarding best strategies for treating VDD, particularly, in bariatric patients undergoing omega-loop gastric bypass (OLGB). Therefore, we examined the efficacy and safety of a forced vitamin D dosing regimen and intervention effects in liver fibrotic patients.

Methods

In this double-blind, randomized, placebo-controlled trial, 50 vitamin D-deficient patients undergoing OLGB were randomly assigned to receive, in the first month postoperatively, oral vitamin D₃ (≤3 doses of 100,000 IU; intervention group) or placebo as loading dose (control group) with subsequent maintenance dose (3420 IU/day) in both groups until 6-month visit.

Results

Compared with control group, higher increase of 25(OH)D (67.9 (21.1) vs. 55.7 nmol/L (21.1); p = 0.049) with lower prevalence of secondary hyperparathyroidism (10 vs. 24 %; p = 0.045) was observed in intervention group. No (serious) adverse events related to study medication were found. The loading dose regimen was more effective in increasing 25(OH)D in patients with significant liver fibrosis while this was not the case for conventional supplementation (placebo with maintenance dose) (71.5 (20.5) vs. 22.5 nmol/L (13.8); p = 0.022; n = 14).

Conclusions

Our findings indicate that a high vitamin D₃ loading dose, in the first month postoperatively, with subsequent maintenance dose is effective and safe in achieving higher vitamin D concentrations in OLGB patients. Unexpectedly, it is more effective in patients with significant liver fibrosis which is of potentially high clinical relevance and requires further investigation.

Electronic supplementary material

The online version of this article (doi:10.1007/s11695-016-2437-0) contains supplementary material, which is available to authorized users.

Prevalence of Liver Fibrosis and its Association with Non-invasive Fibrosis and Metabolic Markers in Morbidly Obese Patients with Vitamin D Deficiency

BACKGROUND

Morbidly obese patients are at risk for non-alcoholic fatty liver disease (NAFLD) and vitamin D deficiency (VDD). Non-alcoholic steatohepatitis (NASH) is the progressive variant of NAFLD and can advance to fibrosis, cirrhosis, and liver cancer. We aimed to examine prevalence of liver fibrosis and its non-invasive predictors in bariatric patients with VDD (<75 nmol/l).

METHODS

Baseline liver biopsy of a randomized controlled trial was performed in 46 patients with omega loop gastric bypass. Clinical, laboratory, and histological data were examined and tested with univariate and multivariable analysis.

RESULTS

In total, 80 % were females, aged 42 (SD 13) years with BMI 44 (4) kg/m(2). Twenty-six percent had diabetes mellitus (DM) and 44 % metabolic syndrome (MeS). Seventy-two percent had NASH, 11 % simple steatosis, and 17 % normal liver. In total, 30 % demonstrated significant fibrosis (F ≥ 2) with 9 % of advanced (F3) and 4 % cirrhosis (F4). Increased stages of fibrosis were primarily associated with higher levels of HOMA2-insulin resistance (IR), procollagen type I propeptide (P1NP), lower osteocalcin, albumin-corrected calcium, parathyroid hormone, vitamin D, male sex, and higher age. Other independent risk factors for advanced fibrosis were MeS (OR = 9.3 [0.99-87.5], p = 0.052) and DM (OR = 12.8 [1.2-137.4], p = 0.035). The fibrosis FIB-4 index <10.62 and NAFLD fibrosis score <-26.93 had a negative predictive value of 100 and 96 %, respectively.

CONCLUSIONS

Liver fibrosis is frequent in morbidly obese patients with concurrent DM and/or MeS. Increased serum levels of IR, P1NP, lower osteocalcin, and VDD are clinically relevant predictors of fibrosis. Consequently, we suggest that patients with preoperative presence of these markers are at increased risk for liver fibrosis and should be monitored closely.