Risk of cholecystectomy in morbidly obese patients after bariatric surgery in Taiwan

[New Progress in Longitudinal Research on the Risk Factors for Cholelithiasis]

Cholelithiasis is a common disease of the digestive system. The risk factors for cholelithiasis have been reported and summarized many times in the published literature, which primarily focused on cross-sectional studies. Due to the inherent limitations of the study design, the reported findings still need to be validated in additional longitudinal studies. Moreover, a number of new risk factors for cholelithiasis have been identified in recent years, such as bariatric surgery, hepatitis B virus infection, hepatitis C virus infection, kidney stones, colectomy, osteoporosis, etc. These new findings have not yet been included in published reviews. Herein, we reviewed the 101 cholelithiasis-associated risk factors identified through research based on longitudinal investigations, including cohort studies, randomized controlled trials, and nested case control studies. The risk factors associated with the pathogenesis of cholelithiasis were categorized as unmodifiable and modifiable factors. The unmodifiable factors consist of age, sex, race, and family history, while the modifiable factors include 37 biological environmental factors, 25 socioenvironmental factors, and 35 physiochemical environmental factors. This study provides thorough and comprehensive ideas for research concerning the pathogenesis of cholelithiasis, supplying the basis for identifying high-risk groups and formulating relevant prevention strategies.

Prevention of Gallstones After Bariatric Surgery using Ursodeoxycholic Acid: A Narrative Review of Literatures

Obesity by itself is a factor in the development of gallstone disease, and periods of weight loss after bariatric surgery further increase the risk of gallstone formation. In patients with obesity, hypersecretion of cholesterol may increase the risk of gallstone formation, which is approximately five-fold higher than that in the general population. The incidence of gallstone formation after bariatric surgery is 10-38% and often associated with a proportional increase in the risk of developing biliary complications. Routine postoperative administration of ursodeoxycholic acid (UDCA) is recommended to prevent gallstone formation. Several randomized trials have indicated that UDCA can effectively prevent gallstones and reduce the risk of cholecystectomy after bariatric procedures. The effective daily dose of UDCA in each study ranged from 500 to 1,200 mg, and it may be considered at least during the period of rapid weight loss (first 3-6 months postoperatively) to decrease the incidence of symptomatic gallstones.

Risk of anemia in morbidly obese patients after bariatric surgery in Taiwan

BACKGROUND

Bariatric surgery is one of most effective long-term treatments for morbid obesity. However, post-bariatric surgery anemia is identified as a common adverse effect and remains a challenge nowadays.

AIM

To estimate the risk of post-bariatric surgery anemia and to stratify the association between age, gender, and types of surgery.

METHODS

This study is a population-based cohort study. We conducted this nationwide study using claims data from National Health Insurance Research Database in Taiwan. There were 4373 morbidly obese patients in this study cohort.

RESULTS

Among patients who were diagnosed with morbid obesity, 2864 received bariatric surgery. All obesity-associated comorbidities decreased in the surgical group. Increasing risk of post-bariatric surgery anemia among obese patients was found by Cox proportional hazards regression [adjusted hazard ratio (HR): 2.36]. Also, we found significantly increasing cumulative incidence rate of anemia among patients receiving bariatric surgery by log-rank test. After adjusting for age and gender, the increasing incidence of post-bariatric surgery anemia was found among women (adjusted HR: 2.48), patients in the 20–29-year-old group (adjusted HR: 3.83), and patients in the 30-64-year-old group (adjusted HR: 2.37). Moreover, malabsorptive and restrictive procedures had significantly higher adjusted HRs, 3.18 and 1.55, respectively.

CONCLUSION

Bariatric surgery give rise to anemia risk among obese patients, specifically in women, young- and middle-aged patients, and patients undergoing malabsorptive procedures in our population-based cohort study in Taiwan.