Analysis of risk factors for gallbladder polyp formation - A retrospective study based on serial ultrasounds

Retrospective Study of the Prevalence and Associated Factors of Gallbladder Polyps among Residents of Two Korean Cities

Background/Aims: Well-known risk factors for gallbladder polyps include metabolic syndrome, age, and dyslipidemia. Jeju Island is approximately 80 km from the Korean peninsula and is divided into two administrative regions (Jeju City and Seogwipo City), with Mount Halla intervening in the center. Jeju City has higher employment and birth rates than Seogwipo City. Age and alcohol consumption differ between the two regions, and these factors may affect the prevalence of gallbladder polyps (GBPs). Therefore, we investigated the prevalence of GBPs and compared various factors, including alcohol consumption habits and age, associated with GBPs among residents in the two regions. Methods: This study included 21,734 residents who visited the Health Screening and Promotion Center of Jeju National University Hospital between January 2009 and December 2019. We investigated the prevalence and associated factors of GBPs among residents of Jeju City and Seogwipo City. Results: The prevalence of GBPs in Jeju City and Seogwipo City was 9.8% and 8.9% (p = 0.043), respectively. The mean age and rate of high-risk alcohol intake were higher in Seogwipo City. The mean body mass index and levels of fasting blood glucose, total cholesterol, low-density lipoprotein cholesterol, aspartate aminotransferase, gamma-glutamyl transferase, and alkaline phosphatase were lower in Jeju City. Conclusions: This study demonstrated a significant difference in GBP prevalence between the two regions of Jeju Island. Age and alcohol consumption might contribute to this difference; however, further prospective cohort studies are warranted to confirm our findings.

Longitudinal Ultrasound Assessment of Changes in Size and Number of Incidentally Detected Gallbladder Polyps

BACKGROUND. Previous European multisociety guidelines recommend routine follow-up imaging of gallbladder polyps (including polyps < 6 mm in patients without risk factors) and cholecystectomy for polyp size changes of 2 mm or more. OBJECTIVE. The purpose of this study was to assess longitudinal changes in the number and size of gallbladder polyps on serial ultrasound examinations. METHODS. This retrospective study included patients who underwent at least one ultrasound examination between January 1, 2010, and December 31, 2020 (as part of a hepatocellular carcinoma screening and surveillance program) that showed a gallbladder polyp. Number of polyps and size of largest polyp were recorded based primarily on review of examination reports. Longitudinal changes on serial examinations were summarized. Pathologic findings from cholecystectomy were reviewed. RESULTS. Among 9683 patients, 759 (8%) had at least one ultrasound examination showing a polyp. Of these, 434 patients (248 men, 186 women; mean age, 50.6 years) had multiple examinations (range, 2-19 examinations; mean, 4.8 examinations per patient; mean interval between first and last examinations, 3.6 ± 3.1 [SD] years; maximum interval, 11.0 years). Among these 434 patients, 257 had one polyp, 40 had two polyps, and 137 had more than two polyps. Polyp size was 6 mm or less in 368 patients, 7-9 mm in 52 patients, and 10 mm or more in 14 patients. Number of polyps increased in 9% of patients, decreased in 14%, both increased and decreased on serial examinations in 22%, and showed no change in 55%. Polyp size increased in 10% of patients, decreased in 16%, both increased and decreased on serial examinations in 18%, and showed no change in 56%. In 9% of patients, gallbladder polyps were not detected on follow-up imaging; in 6% of patients, gallbladder polyps were not detected on a follow-up examination but were then detected on later studies. No gallbladder carcinoma was identified in 19 patients who underwent cholecystectomy. CONCLUSION. Gallbladder polyps fluctuate in size, number, and visibility over serial examinations. Using a 2-mm threshold for growth, 10% increased in size. No carcinoma was identified. CLINICAL IMPACT. European multisociety guidelines that propose surveillance of essentially all polyps and a 2-mm size change as the basis for cholecystectomy are likely too conservative for clinical application.

Risk factors for cholesterol polyp formation in the gallbladder are closely related to lipid metabolism

Background

The purpose of this study was to assess the risk factors for cholesterol polyp formation in the gallbladder.

Methods

This was a multicenter retrospective study based on pathology. From January 2016 to December 2019, patients who underwent cholecystectomy and non-polyp participants confirmed by continuous ultrasound follow-ups were reviewed. Patients in the cholesterol polyp group were recruited from three high-volume centers with a diagnosis of pathologically confirmed cholesterol polyps larger than 10 mm. Population characteristics and medical data were collected within 24 h of admission before surgery. The non-polyp group included participants from the hospital physical examination center database. They had at least two ultrasound examinations with an interval longer than 180 days. Data from the final follow-up of the non-polyp group were analyzed. The risk factors for cholesterol polyp formation were analyzed by comparing the two groups.

Results

A total of 4714 participants were recruited, including 376 cholesterol polyp patients and 4338 non-polyp participants. In univariate analysis, clinical risk factors for cholesterol polyps were age, male sex, higher body mass index (BMI), higher low-density lipoprotein (LDL), lower high-density lipoprotein (HDL), and higher aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. In multivariate logistic analysis, independent risk factors were age > 50 years (odds ratio [OR] = 3.02, 95% confidence interval [CI] 2.33–3.91, P < 0.001], LDL > 2.89 mmol/L (OR = 1.38, 95% CI 1.08–1.78, P = 0.011), lower HDL (OR = 1.78 95% CI 1.32–2.44, P < 0.001), AST > 40 IU/L (OR = 3.55, 95% CI 2.07–6.07, P < 0.001), and BMI > 25 kg/m ² (OR = 1.32, 95% CI 1.01–1.72, P = 0.037).

Conclusions

Age, LDL, HDL, AST, and BMI are strong risk factors for cholesterol polyp formation. Older overweight patients with polyps, accompanied by abnormal lipid levels, are at high risk for cholesterol polyps.