Association of serum high-density lipoprotein cholesterol with new-onset cholelithiasis

Objective To investigate the influence of serum high-density lipoprotein cholesterol (HDL-C) level on new-onset cholelithiasis. Methods A prospective cohort study was conducted. The physical examination data of 87 891 on-the-job and retired workers in Kailuan Group were collected from July 2006 to December 2015 and were included in the statistical analysis. A one-way analysis of variance was used for comparison of normally distributed continuous data between multiple groups, the Kruskal-Wallis H test was used for comparison of continuous data with skewed distribution between multiple groups, and the chi-square test was used for comparison of categorical data between groups. The subjects were divided into four groups according to HDL-C quartiles, and the incidence density of cholelithiasis was calculated for each group. The life-table method was used to calculate the cumulative incidence rate of cholelithiasis in each group, the log-rank test was used for comparison between groups, and the Cox regression model was used to analyze the influence of HDL-C level on new-onset cholelithiasis. Results There were significant differences between the four groups in sex, age, body mass index, low-density lipoprotein cholesterol, HDL-C, fasting blood glucose, high-sensitivity C-reactive protein, triglyceride, total cholesterol, hypertension, diabetes, drinking, smoking, and physical exercise (all P < 0. 05) . During the mean follow-up time of 8. 19 ± 0. 85 years, a total of 2881 cases of new-onset cholelithiasis were observed, and the incidence density of cholelithiasis in the four groups was 4. 36 per 1000 person-years, 3. 81 per 1000 person-years, 3. 96 per 1000 person-years, and 3. 90 per 1000 person-years, respectively. The cumulative incidence rates in the four groups were 6. 49%, 6. 01%, 6. 36%, and 6. 16%, respectively, and the log-rank test showed a significant difference between groups (χ2= 25. 34, P < 0. 05) . In the Cox proportional hazards regression model, after the adjustment for possible confounding factors, the results showed that compared with the first quartile group of HDL-C, the second, third, and fourth quartile groups had hazard ratios (95% confidence interval) for gallstone disease of 0. 84 (0. 75-0. 93) , 0. 86 (0. 78-0. 96) , and 0. 78 (0. 70-0. 86) , respectively (P for trend < 0. 05) . Conclusion A high serum level of HDL-C is an independent protective factor against new-onset chole-lithiasis, and the risk of cholelithiasis decreases with the increase in HDL-C.