Haematological parameters and serum trace elements in "healthy" and "unhealthy" morbidly obese patients before and after gastric bypass

Change in Mineral Status After Bariatric Surgery: a Meta-analysis

BACKGROUND

The risk of protein and vitamin deficiencies after bariatric surgery has been well studied, but the change in mineral status has not gotten enough attention. This study aimed to perform a meta-analysis regarding the change in mineral levels after bariatric surgery and the prevalence of postoperative mineral deficiency, with subgroup analyses of different surgical procedures, study regions, and follow-up time.

METHODS

CENTRAL, PubMed, and EMBASE were searched for related articles. Meta-analysis, subgroup analysis, and sensitivity analysis were performed if necessary.

RESULTS

A total of 107 articles with 47,432 patients were included. The most severe mineral deficiency after bariatric surgery was iron (20.1%), followed by zinc (18.3%), copper (14.4%), chlorine (12.2%), phosphorus (7.5%), and calcium (7.4%). Serum concentrations of potassium, sodium, selenium, manganese, and molybdenum showed no significant change before and after surgery. Subgroup analyses revealed that SG had fewer deficiencies in serum iron, calcium, zinc, magnesium, phosphorus, copper, and selenium than RYGB. OAGB showed a higher incidence of serum iron and zinc deficiencies than RYGB. Studies conducted in different regions also found various mineral statuses after surgery. Studies with follow-up ≥ 5 years had a lower prevalence of zinc, copper, and selenium deficiencies than follow-up < 5 years.

CONCLUSION

A high deficiency rate of serum iron, zinc, copper, chlorine, phosphorus, and calcium was seen after bariatric surgery. The difference in surgical procedures, study regions, and follow-up time may affect postoperative mineral status; more targeted mineral supplement programs are needed considering these influencing factors.

Impact of Short-Term Weight Loss on Hemostasis and Thrombosis after Bariatric Surgery

Introduction

Obesity causes thrombophilia and many coagulation problems related to slowing the capillary flow. We aimed to evaluate rapid weight loss outcomes in the early period after bariatric surgery on the coagulation system. Materials and Method. A prospective study enrolled 28 patients with a BMI > 40 kg/m2 who underwent bariatric surgery. Preoperative and postoperative (first and third months) demographic criteria-such as age, gender, weight, height, and alcohol and tobacco use, and biochemical parameters such as PLT, PT, aPTT, INR, bleeding time, coagulation time, fibrinogen, D-dimer, albumin, calcium, ionized calcium, vitamin D, and PTH-were analyzed.

Results

We found that both bleeding and thrombotic parameters increase in early-slowing surgery. The first-month platelet levels were significantly different from the preoperative values (p < 0.001). The prothrombin time in the first (p < 0.001) and third months (p < 0.009) was also comparable. The PTT in the first month was higher than in the preoperative period (p < 0.011). INR in the first month (p < 0.001) was higher than that in the preoperative period and the third month (p = 0.007) value was higher than in the first month. In terms of fibrinogen levels, all parameters indicated statistical significance within each other; preoperative to the first month (p < 0.001), the first month to the third month (p < 0.016). Third-month D-dimer levels were lower than the first month's values (p = 0.032).

Conclusion

Thromboembolic events have crucial importance in the converse scenario of haemorrhagic diathesis during the first months of bariatric surgery. Vitamin support and antithrombotic agents may be recommended in the early postoperative period.

Micronutrient status in bariatric surgery patients receiving postoperative supplementation per guidelines: Insights from a systematic review and meta-analysis of longitudinal studies

The micronutrient status and optimal monitoring schedule after bariatric surgery have not been sufficiently assessed. This systematic review and meta-analysis investigated the longitudinal changes in micronutrient status after bariatric surgery. PubMed, EMBASE, and Cochrane Library were searched for articles that measured preoperative and postoperative serum micronutrient levels in patients undergoing Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). Among guideline-adherent studies, the longitudinal changes in micronutrient status were investigated using weighted mean difference (WMD) using a random-effects model. Among the 82 included studies, the guideline adherence rates for micronutrient supplementation after bariatric surgery did not exceed 20%. In patients supplemented per guidelines, vitamin A significantly decreased after RYGB by -7.54 (95% confidence interval [CI], -10.16 to -4.92) μg/dl at 12-23 months, vitamin E decreased after RYGB by -2.35 (95% CI, -3.65 to -1.05) μg/dl at ≥24 months, and ferritin by -54.93 (95% CI, -77.19 to -32.67] μg/L at ≥24 months after SG, compared with baseline, with moderate level of evidence. Significant decreases in micronutrient levels at certain follow-up intervals in studies with supplementation per guidelines need to be considered to establish a post-bariatric micronutrient monitoring schedule for timely detection and management of micronutrient deficiencies.

Improvement in the cardiovascular profile of patients with morbid obesity following bariatric surgery: Effect on hypercoagulability

Obesity is an inflammatory state related to vascular endothelium dysfunction. It generates a biological situation of hypercoagulability increasing the risk of thrombosis. This prothrombotic condition could be improved by bariatric surgery.The main objective was to analyze the impact of bariatric surgery on cardiovascular risk factors (CVRF) associated with changes in thrombin generation and procoagulant activity of microparticles (MP).We present a prospective longitudinal study including consecutive patients candidate for bariatric surgery. We performed 3 sequential clinical visits: at inclusion, before surgery after completing the modified fasting phase, and 6 months after surgery. We analyzed CVRF, thrombin generation, and MP activity. The data analysis was performed using a logistic regression model to determine changes over time of hemostatic parameters and body mass index (BMI). McNemar test for binary variables was used to analyze the CVRF.We included 94 patients (66 women), with an average age of 45.7 ± 10.1 years. The mean BMI reduction at the end of the follow-up was 15.5 ± 4.2 kg/m2. We detected a statistically significant improvement in CVRF: hypertension, diabetes mellitus, dyslipidemia, and obstructive sleep apnea, as well as a significant reduction in thrombin generation capacity and procoagulant MP activity.Massive weight loss induced by bariatric surgery improves the cardiovascular profile, associated with a reduction in the hypercoagulable status.

Thromboelastography Values Remain Hypercoagulative 6 Months After Obesity Surgery: a Pilot Study

PURPOSE

Obesity causes a prothrombotic state and is known as a predisposing factor for thromboembolic events. In this pilot study, we assessed the impact of surgery for obesity and the subsequent weight loss on blood coagulation using traditional coagulation tests and thromboelastography (TEG).

MATERIAL AND METHODS

We studied blood samples from 18 patients receiving bariatric surgery. Besides traditional blood coagulation tests and high-sensitivity C-reactive protein (hsCRP) as a marker of inflammation, the TEG parameters reaction time (R), kinetics time (K), angle (α), maximum amplitude (MA), clot strength (G), and lysis percent at 60 min (LY60) were determined preoperatively and on the first postoperative day and 6 months after surgery.

RESULTS

Altogether, 54 samples were analyzed. The median MA (71.3 mm), G (12,403.3 d/sc), and hsCRP (3.5 mg/l) were elevated preoperatively. The median hsCRP further increased on the first day postoperatively, but declined to the normal range 6 months after surgery, while MA and G remained elevated. In traditional coagulation tests, there was an increase in median fibrinogen and D-dimer postoperatively. D-dimer normalized (0.4 mg/l) during the study period, while the fibrinogen level (4.1 g/l) remained above the upper limit of normal.

CONCLUSIONS

Measured by TEG, patients receiving bariatric surgery have hemostatic abnormalities indicating hypercoagulation at the 6-month follow-up visit, suggesting an elevated risk for thromboembolic events for at least 6 months after surgery.

Hepatic CD36 downregulation parallels steatosis improvement in morbidly obese undergoing bariatric surgery

BACKGROUND

The notion that hepatic expression of genes involved in lipid metabolism is altered in obese patients is relatively new and its relationship with hepatic steatosis and cardiometabolic alterations remains unclear.

OBJECTIVE

We assessed the impact of Roux-en-Y gastric bypass surgery (RYGB) on the expression profile of genes related to metabolic syndrome in liver biopsies from morbidly obese individuals using a custom-made, focused cDNA microarray, and assessed the relationship between the expression profile and hepatic steatosis regression.

MATERIALS AND METHODS

Plasma and liver samples were obtained from patients at baseline and 12 months after surgery. Samples were assayed for chemical and gene expression analyses, as appropriate. Gene expression profiles were assessed using custom-made, focused TaqMan low-density array cards.

RESULTS

RYGB-induced weight loss produced a favorable reduction in fat deposits, insulin resistance (estimated by homeostasis model assessment of insulin resistance (HOMA-IR)), and plasma and hepatic lipid levels. Compared with the baseline values, the gene expression levels of key targets of lipid metabolism were significantly altered: CD36 was significantly downregulated (-40%; P=0.001), whereas APOB (+27%; P=0.032) and SCARB1 (+37%; P=0.040) were upregulated in response to surgery-induced weight reduction. We also observed a favorable reduction in the expression of the PAI1 gene (-80%; P=0.007) and a significant increase in the expression of the PPARA (+60%; P=0.014) and PPARGC1 genes (+36%; P=0.015). Notably, the relative fold decrease in the expression of the CD36 gene was directly associated with a concomitant reduction in the cholesterol (Spearman's r=0.92; P=0.001) and phospholipid (Spearman's r=0.76; P=0.04) contents in this tissue.

CONCLUSIONS

For the first time, RYGB-induced weight loss was shown to promote a favorable downregulation of CD36 expression, which was proportional to a favorable reduction in the hepatic cholesterol and phospholipid contents in our morbidly obese subjects following surgery.

Diabetic and dyslipidaemic morbidly obese exhibit more liver alterations compared with healthy morbidly obese

Background & aims

To study the origin of fat excess in the livers of morbidly obese (MO) individuals, we analysed lipids and lipases in both plasma and liver and genes involved in lipid transport, or related with, in that organ.

Methods

Thirty-two MO patients were grouped according to the absence (healthy: DM − DL −) or presence of comorbidities (dyslipidemic: DM − DL +; or dyslipidemic with type 2 diabetes: DM + DL +) before and one year after gastric bypass.

Results

The livers of healthy, DL and DM patients contained more lipids (9.8, 9.5 and 13.7 times, respectively) than those of control subjects. The genes implicated in liver lipid uptake, including HL, LPL, VLDLr, and FAT/CD36, showed increased expression compared with the controls. The expression of genes involved in lipid-related processes outside of the liver, such as apoB, PPARα and PGC1α, CYP7a1 and HMGCR, was reduced in these patients compared with the controls. PAI1 and TNFα gene expression in the diabetic livers was increased compared with the other obese groups and control group. Increased steatosis and fibrosis were also noted in the MO individuals.

Conclusions

Hepatic lipid parameters in MO patients change based on their comorbidities. The gene expression and lipid levels after bariatric surgery were less prominent in the diabetic patients. Lipid receptor overexpression could enable the liver to capture circulating lipids, thus favouring the steatosis typically observed in diabetic and dyslipidaemic MO individuals.

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The criteria used to define the “metabolically healthy” obese is not applicable to morbidly obese patients.

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Virtually no studies of how bariatric surgery affects depending on comorbidities and less how affect to the liver.

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Anthropometrics, fat, lipid profile and inflammation parameters are different depending of comorbidities, not only in plasma but also in liver.

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The extent of lipases and lipids in the liver biopsies could help not only the diagnosis but also to follow the course of recovery after surgery.

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The morbidly obese individuals with diabetes and dyslipidemia have more altered metabolic profiles than the other two groups.