Effects of bariatric surgery on serum uric acid in people with obesity with or without hyperuricaemia and gout: a retrospective analysis

Machine learning analysis of lab tests to predict bariatric readmissions

The purpose of this study was to develop a machine learning model for predicting 30-day readmission after bariatric surgery based on laboratory tests. Data were collected from patients who underwent bariatric surgery between 2018 and 2023. Laboratory test indicators from the preoperative stage, one day postoperatively, and three days postoperatively were analyzed. Least absolute shrinkage and selection operator regression was used to select the most relevant features. Models constructed included support vector machine (SVM), generalized linear model, multi-layer perceptron, random forest, and extreme gradient boosting. Model performance was evaluated and compared using the area under the receiver operating characteristic curve (AUROC). A total of 1262 patients were included, of which 7.69% of cases were readmitted. The SVM model achieved the highest AUROC (0.784; 95% CI 0.696-0.872), outperforming other models. This suggests that machine learning models based on laboratory test data can effectively identify patients at high risk of readmission after bariatric surgery.

Benefits of uric acid-lowering medication after bariatric surgery in patients with gout

BACKGROUND/PURPOSE

Patients with gout are at risk for increased serum uric acid (SUA) levels and gout attacks in the short term after undergoing bariatric surgery, and the purpose of this study was to evaluate the benefits of short-term treatment with uric acid-lowering medication after bariatric surgery for the control of gout attacks and SUA levels in patients with gout.

METHODS

71 patients who underwent SG from January 2020 to December 2022 were prospectively included. These patients were diagnosed with hyperuricemia before surgery and had a history of gout attacks. Patients were classified into a drug-treatment group (DTG, n = 32) and a non-drug-treatment group (NDTG, n = 39) according to whether they took uric acid-lowering medication after surgery. Changes in the number of gout attacks, body mass index (BMI), and SUA levels at 1 week, 1 month, 3 months, and 6 months after bariatric surgery were measured in both groups.

RESULTS

In the DTG, 22 patients (68.8%) experienced an increase in SUA within 1 week, 3 patients (9.4%) had an acute attack of gout within the first month, and no patients had a gout attack thereafter. In the NDTG, 35 patients (89.7%) experienced an increase in SUA within 1 week, 7 patients (17.9%) had an acute gout attack within the first month, and 4 patients (10.3%) experienced gout attacks between month 1 and month 3 postoperatively. Both groups were free of gout attacks between the 3rd and 6th postoperative month and showed a significant decrease in SUA and BMI by the sixth month.

CONCLUSION

In patients with gout, continued use of uric acid-lowering medication after bariatric surgery is beneficial in reducing the number of gout attacks and the risk of rising SUA.

Changes in Serum Urate Levels after Bariatric Surgery in Patients with Obesity: An Observational Study

BACKGROUND

Obesity is a risk factor for hyperuricemia and gout, while weight reduction can reduce urate levels. The aim of this study was to examine the effect of bariatric surgery on longitudinal serum urate levels.

METHODS

We performed a retrospective observational study of 283 patients who had undergone bariatric surgery [237 (83.7%) gastric bypass, 34 (12.0%) sleeve gastrectomy and 12 (4.2%) gastric banding] and were followed up for 2 years. The results shown represent mean (standard deviation).

RESULTS

Bariatric surgery was associated with significant reduction in serum urate from baseline level of 0.343 (0.086) mmol/L to 0.296 (0.076) mmol/L (p < 0.001) at 12 months and 0.286 (0.073) mmol/L (p < 0.001) at 24 months, including in men and women, and in patients with or without diabetes. Patients with elevated urate levels at baseline, who comprised 27.2% of the total cohort, achieved reduction in levels by 4 months.

CONCLUSION

Bariatric surgery leads to significant reduction in serum urate levels at 12 and 24 months. This could reduce incidence of gout and need for prophylactic medication(s).

Bariatric Surgery and Its Metabolic Echo Effect on Serum Uric Acid Levels

Bariatric surgery (BS) has been a significant means of reducing weight in obese individuals. The metabolic changes after bariatric surgery are crucial as they extend its advantages beyond weight loss. As its name implies, "metabolic surgery" also addresses obesity-related metabolic concerns. Bariatric surgery has always been associated with lessened serum uric acid (SUA) levels. In this review, we examined current studies to understand how surgical therapies impact serum uric acid levels. Strongly minded on the extent and timing of changes in the level of serum uric acid after bariatric surgeries. We conducted a comprehensive search for relevant current studies in PubMed, Google Scholar, JAMA, and the Cochrane Library until February 1, 2024. We aimed to analyze the metabolic advantages of bariatric surgery, focusing on its function in treating hyperuricemia and lowering the risk of associated disorders. Our review elaborates on factors contributing to decreased serum uric acid levels after bariatric surgery, such as alterations in renal function, insulin sensitivity, and inflammatory markers.

Inflammatory and metabolic markers and comorbidities remission following sleeve gastrectomy: A single center one-year cohort study

BACKGROUND AND AIM

Obesity is a global concern with several health-related complications. Bariatric surgeries are major treatment options in patients with obesity and other comorbidities. This study aims to investigate the effects of sleeve gastrectomy on metabolic indexes, hyperechogenic liver changes, inflammatory state, diabetes, and other obesity-related comorbidities remission after the sleeve gastrectomy.

METHODS

This prospective study was conducted on patients with obesity candidates for laparoscopic sleeve gastrectomy. Patients were followed for one year after the surgery. Comorbidities, metabolic and inflammatory parameters were assessed before and one- year after the surgery.

RESULTS

137 patients (16 males, 44 in the DM group) underwent sleeve gastrectomy. One year after the study, obesity-related comorbidities improved significantly; diabetes had complete remission in 22.7% and partial remission in 63.6% of patients. Hyper-cholesterolemia, hyper-triglyceridemia, and hyper-uricemia also improved in 45.6%, 91.2%, and 69% of the patients. Metabolic syndrome indexes improved in 17.5% of the patients. Also, the prevalence of hyperechogenic changes in the liver has declined from 21% before the surgery to 1.5% after that. Based on logistic regression analysis, increased levels of HbA1C reduced the chance of diabetes remission by 0.9%. In comparison, every unit of increased BMI before the surgery improved the case of diabetes remission by 16%.

CONCLUSION

Laparoscopic sleeve gastrectomy is a safe and effective treatment option in patients with obesity and diabetes. Laparoscopic sleeve gastrectomy alleviates BMI and insulin resistance and effectively improves other obesity-related comorbidities such as Hypercholesterolemia, hyper-triglyceridemia, hyper-uricemia, and hyperechogenic changes of the liver. HbA1C and BMI before the surgery are notable predictors of diabetes remission within the first year after the surgery.

Risk Prediction for the Development of Hyperuricemia: Model Development Using an Occupational Health Examination Dataset

OBJECTIVE

Hyperuricemia has become the second most common metabolic disease in China after diabetes, and the disease burden is not optimistic.

METHODS

We used the method of retrospective cohort studies, a baseline survey completed from January to September 2017, and a follow-up survey completed from March to September 2019. A group of 2992 steelworkers was used as the study population. Three models of Logistic regression, CNN, and XG Boost were established to predict HUA incidence in steelworkers, respectively. The predictive effects of the three models were evaluated in terms of discrimination, calibration, and clinical applicability.

RESULTS

The training set results show that the accuracy of the Logistic regression, CNN, and XG Boost models was 84.4, 86.8, and 86.6, sensitivity was 68.4, 72.3, and 81.5, specificity was 82.0, 85.7, and 86.8, the area under the ROC curve was 0.734, 0.724, and 0.806, and Brier score was 0.121, 0.194, and 0.095, respectively. The XG Boost model effect evaluation index was better than the other two models, and similar results were obtained in the validation set. In terms of clinical applicability, the XG Boost model had higher clinical applicability than the Logistic regression and CNN models.

CONCLUSION

The prediction effect of the XG Boost model was better than the CNN and Logistic regression models and was suitable for the prediction of HUA onset risk in steelworkers.

The Impact of Obesity Surgery on Serum Uric Acid in People With Severe Obesity: A Retrospective Study

Studies indicate an association between hyperuricemia (HUA) and metabolic syndrome risk factors. On the other hand, obesity is a major modifiable and independent risk factor for HUA and gout. However, evidence concerning the effects of bariatric surgery on serum uric acid levels is limited and not completely clarified. This retrospective study was carried out with 41 patients who underwent sleeve gastrectomy (n = 26) and Roux-en-Y gastric bypass (n = 15) from September 2019 to October 2021. Anthropometric, clinical, and biochemical data, including uric acid blood urea nitrogen and creatinine fasting blood sugar (FBS), serum triglyceride (TG), and serum cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), were measured preoperatively and postoperative 3, 6 and 12 months. From baseline to 6 and 12 months, bariatric surgery resulted in a significant decrease in serum uric acid of patients with severe obesity (p < 0.001). The decreases in serum FBS, TG, and cholesterol of patients were significant during 6 and 12 months of follow-up (p < 0.05). However, the HDL increase of patients was not statistically significant in 6 and 12 months (p > 0.05). Besides, although patients' serum level of LDL decreased significantly during the 6 months of follow-up (p = 0.007), it was not significant after 12 months (p = 0.092). Bariatric surgery significantly reduces serum uric acid levels. Therefore, it may be an effective supplementary therapy for lowering serum uric acid concentrations in morbidly obese patients.

Effectiveness of Fecal Microbiota Transplantation for Weight Loss in Patients With Obesity Undergoing Bariatric Surgery: A Randomized Clinical Trial

IMPORTANCE

Severe obesity is a major health concern. However, a few patients remain resistant to bariatric surgery and other treatments. Animal studies suggest that weight may be altered by fecal microbiota transplantation (FMT) from a lean donor.

OBJECTIVE

To determine whether FMT from a lean donor reduces body weight and further improves the results of bariatric surgery.

DESIGN, SETTING, AND PARTICIPANTS

This double-blinded, placebo-controlled, multicenter, randomized clinical trial was conducted in 2018 to 2021 among adult individuals with severe obesity treated at 2 bariatric surgery centers in Finland and included 18 months of follow-up. Patients eligible for bariatric surgery were recruited for the study. Data were analyzed from March 2021 to May 2022.

INTERVENTIONS

FMT from a lean donor or from the patient (autologous placebo) was administered by gastroscopy into the duodenum. Bariatric surgery was performed 6 months after the baseline intervention using laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG).

MAIN OUTCOMES AND MEASURES

The main outcome was weight reduction measured as the percentage of total weight loss (TWL).

RESULTS

Forty-one patients were recruited to participate in the study and were included in the final analysis (29 women [71.1%]; mean [SD] age, 48.7 [8.7] years; mean [SD] body mass index, 42.5 [6.0]). A total of 21 patients received FMT from a lean donor, and 20 received an autologous placebo. Six months after FMT, 34 patients underwent LRYGB and 4 underwent LSG. Thirty-four patients (82.9%) attended the last visit 18 months after the baseline visit. The percentage of TWL at 6 months was 4.8% (95% CI, 2.7% to 7.0%; P < .001) in the FMT group and 4.6% (95% CI, 1.5% to 7.6%; P = .006) in the placebo group, but no difference was observed between the groups. At 18 months from the baseline (ie, 12 months after surgery), the percentage of TWL was 25.3% (95% CI, 19.5 to 31.1; P < .001) in the FMT group and 25.2% (95% CI, 20.2 to 30.3; P < .001) in the placebo group; however, no difference was observed between the groups.

CONCLUSIONS AND RELEVANCE

FMT did not affect presurgical and postsurgical weight loss. Further studies are needed to elucidate the possible role of FMT in obesity.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03391817.

Racial and Sex Disparities in Gout Prevalence Among US Adults

IMPORTANCE

Emerging data suggest gout and hyperuricemia may now be more frequent among Black adults in the US than White adults, especially Black women. However, national-level, sex-specific general population data on racial differences in gout prevalence and potential socioclinical risk factors are lacking.

OBJECTIVE

To identify sex-specific factors driving disparities between Black and White adults in contemporary gout prevalence in the US general population.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional analysis used nationally representative, decadal survey data from successive cycles of the National Health and Nutrition Examination Survey from 2007 to 2016. Data were analyzed from November 1, 2019, through May 31, 2021. Participants included US adults self-reporting Black or White race.

EXPOSURES

Self-reported race, excess body mass index, chronic kidney disease (CKD; defined as estimated glomerular filtration rate <60 mL/min/1.73 m2, according to latest equations without race coefficient), poverty, poor-quality diet, low educational level, alcohol consumption, and diuretic use.

MAIN OUTCOMES AND MEASURES

Race- and sex-specific prevalence of physician- or clinician-diagnosed gout and hyperuricemia and their differences before and after adjusting for potential socioclinical risk factors.

RESULTS

A total of 18 693 participants were included in the analysis, consisting of 3304 Black women (mean [SD] age, 44.8 [0.4] years), 6195 White women (mean [SD] age, 49.8 [0.3] years), 3085 Black men (mean [SD] age, 43.6 [0.5] years]), and 6109 White men (mean [SD] age, 48.2 [0.3] years). Age-standardized prevalence of gout was 3.5% (95% CI, 2.7%-4.3%) in Black women and 2.0% (95% CI, 1.5%-2.5%) in White women (age-adjusted odds ratio [OR], 1.81 [95% CI, 1.29-2.53]); prevalence was 7.0% (95% CI, 6.2%-7.9%) in Black men and 5.4% (95% CI, 4.7%-6.2%) in White men (age-adjusted OR, 1.26 [95% CI, 1.02-1.55]). These associations attenuated after adjusting for poverty, diet, body mass index, and CKD among women and for diet and CKD among men but became null after adjusting for all risk factors (ORs, 1.05 [95% CI, 0.67-1.65] among women and 1.05 [95% CI, 0.80-1.35] among men). Hyperuricemia end point findings were similar.

CONCLUSIONS AND RELEVANCE

In this nationally representative race- and sex-specific cross-sectional study of US adults, gout was more prevalent in adults self-reporting Black race during a recent 10-year period compared with their White counterparts. These racial differences may be explained by sex-specific differences in diet and social determinants of health and clinical factors. Culturally informed efforts focusing on these factors could reduce current gout-related disparities.

Gouty arthritis and kidney function outcomes and serum uric acid level variations in obese patients following bariatric surgery

Background

Obesity is an independent risk factor for chronic kidney disease (CKD) and is the strongest known modifiable risk factor for hyperuricemia and gout. We aimed to discover the outcome of serum uric acid (SUA), gouty arthritis, and kidney function in obese patients after bariatric surgery and possible links with BMI variations.

Methods

Retrospective study has been performed in National Hospital in Riyadh, KSA, between Jan. 2018 to Jan. 2020. We studied only 98 patients who met our inclusion criteria. Patients followed-up at 1 month (for gouty attack only) postoperative, 3 months postoperative, and 6 months postoperative for body mass index (BMI), serum creatinine, dipstick urinalysis, SUA, and estimated glomerular filtration rate (eGFR). Radiological studies, medical history, follow up radiological studies, and clinical follow up were obtained from the hospital data system.

Results

A total of 98 patients with mean eGFR were 90.65 ± 29.34 ml/min/1.73 m2, mean SUA 5.56 ± 1.84 mg/dl, and mean BMI was 45.28 ± 7.25 kg/m2, at surgery. Mean BMI had decreased significantly to 38.52 ± 6.05 kg/m2 at 3 months and to 34.61 ± 5.35 kg/m2 at 6 months (P < 0.001). The mean GFR had improved significantly (99.14 ± 23.32 ml/min/1.73 m2) at 6 months (P < 0.001). Interestingly, proteinuria had resolved in 17 patients out of 23 patients at 6 months. Number of gouty attacks was decreased during the first month post-surgery (P < 0.001). SUA level was significantly decreased (4.32 ± 1.27 mg/dl) (P < 0.001). SUA showed significant negative correlations with eGFR at 3 months and positively significant correlations with BMI at 3 and 6 months. By multinomial logistic regression, BMI and initial eGFR were the independent predictive variables for the outcome of eGFR at 6 months, while male gender and initial SUA were the independent predictive variables on the outcome of SUA at 6 months. Postoperatively in gouty arthritis patients, the number of joints affected, patient global VAS assessment, and number of gouty attacks were significantly reduced (P < 0.001).

Conclusion

Bariatric surgery has been associated with reduction of BMI and subsequently reduction of SUA levels, gouty attacks, and improvement of eGFR.

Role of diet in hyperuricemia and gout

BACKGROUND

Gout is the most common form of inflammatory arthritis, affecting 41 million adults worldwide. The global burden of gout has been increasing over the last three decades, yet its management remains suboptimal. The primary aim of this manuscript is to review the impact of various diets such as the DASH, Mediterranean, and low purine diets; weight loss; and individual foods, including alcohol, caffeine, cherry, dairy, high-fructose corn syrup, omega-3 fatty acids, and vitamin C on hyperuricemia and clinical gout outcomes such as flares and tophi.

CONCLUSION

Few studies to date have specifically evaluated the effect of various dietary approaches on hyperuricemia among people with gout and on gout-specific outcomes. Overall, the dietary factors appear to have a small effect on serum urate levels, and their impact on the long-term clinical course of gout is uncertain. Limited evidence suggests that avoidance of certain foods and beverages may decrease the frequency of gout flares. Weight loss may be beneficial for prevention as well as treatment of gout. Urate-lowering therapy remains the mainstay of therapy, with diet and dietary factors studied to date playing a limited role in the definitive management of gout.

Metabolic surgery in China: present and future

Obesity and its related complications comprise a serious public health problem worldwide, and obesity is increasing in China. Metabolic surgery is a new type of treatment with unique advantages in weight loss and obesity-related metabolic complications. The pathogenesis of obesity is complex and not yet fully understood. Here, we review the current efficacy and safety of metabolic surgery, as well as recent progress in mechanistic studies and surgical procedures in China. The exciting and rapid advances in this field provide new opportunities for patients with obesity and strike a balance between long-term effectiveness and safety.

Dietary and Lifestyle-Centered Approach in Gout Care and Prevention

PURPOSE OF REVIEW

We aim to provide a comprehensive review of the available literature to inform dietary recommendations for patients with gout and hyperuricemia that have the potential to simultaneously lower serum urate and reduce gout morbidity while addressing gout's cardiometabolic comorbidities holistically.

RECENT FINDINGS

The global burden of gout is rising worldwide, particularly in developed nations as well as in women. Patients with gout are often recommended to follow a low-purine (i.e., low-protein) diet to avoid purine-loading. However, such an approach may lead to increased consumption of unhealthy carbohydrates and fats, which in turn contributes to metabolic syndrome and subsequently raises serum urate levels and leads to adverse cardiovascular outcomes. On the other hand, several well-established diets for cardiometabolic health, such as the Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets, in combination with weight loss for those who are overweight or obese, also have beneficial effects on relevant gout endpoints. It is important to recognize not only the direct effect of diet on hyperuricemia and gout, but its mediated effect through obesity and insulin resistance. Thus, several preeminent healthy dietary patterns that have proven benefits in cardiometabolic health have the power to holistically address not only gout morbidity but also its associated comorbidities that lead to premature mortality among patients with gout.