Predictive value of metabolic syndrome on new-onset cholelithiasis

Abstract

Objective To investigate the predictive value of metabolic syndrome (MS) on new-onset cholelithiasis. Methods The retrospective cohort study was conducted. The data of 89 553 subjects who participated health examination at the Kailuan General Hospital Affiliated to the North China University of Science and Technology, Kailuan Linxi Hospital, Kailuan Zhaogezhuang Hospital, Kailuan Tangjiazhuang Hospital, Kailuan Fan′gezhuang Hospital, Kailuan Lyujiatuo Hospital, Kailuan Jinggezhuang Hospital, Kailuan Linnancang Hospital, Kailuan Qianjiaying Hospital, Kailuan Majiagou Hospital and Kailuan Branch Hospital from June 2006 to December 2015 were collected. According to the diagnostic criteria of MS published by International Diabetes Federation, all the patients were divided into 4 groups, including 70 657 without MS in the normal group, 14 075 corresponded with 3 diagnostic criteria of MS in the MS-3 group, 4 556 corresponded with 4 diagnostic criteria of MS in the MS-4 group and 265 corresponded with 5 diagnostic criteria of MS in the MS-5 group.Health examinations were applied to all subjects by the fixed team of doctors at the same place. Epidemiological investigation, anthropometric parameters and biochemical indicators were collected. Observation indicators: (1) comparisons of clinical characteristics among the 4 groups; (2) incidence of cholelithiasis in the 4 groups; (3) risk factors analysis affecting new-onset cholelithiasis. Measurement data with normal distribution were represented as ±s and comparisons among groups were analyzed using the one-way ANOVA. Pairwise comparison and homogeneity of variance were done using the LSD test. Heterogeneity of variance was done using the Dunnett′s T3 test. Measurement data with skewed distribution were described as M (Q) and comparisons among groups were analyzed using the nonparametric Kruskal-Wallis test. Comparisons of count data were analyzed by the chi-square test. The incidence of cholelithiasis in the 4 groups were calculated by the Kaplan-Meier method and comparisons of incidence were done by the Log-rank test. The COX proportional hazards model was used to analyze the hazard ratios (HR) and 95% confidence interval (95%CI) of MS on new-onset cholelithiasis. Results (1) Comparisons of clinical characteristics among the 4 groups: age, sex (male), systolic blood pressure (SBP), diastolic blood pressure(DBP), waistline, triglyceride(TG), total cholesterol (TC), high density lipoprotein-cholesterol (HDL-C), fasting blood glucose, BMI, cases with hypertension, diabetes, drinking, smoking and physical exercise were (50±12)years, 52 895, (127±20)mmHg (1 mmHg=0.133 kPa), (81±11)mmHg, (85±9)cm, 1.14 mmol/L (range, 0.83-1.56 mmol/L), (4.9±1.1)mmol/L, (1.56±0.39)mmol/L, (5.2±1.3)mmol/L, (24.5±3.3)kg/m2, 24 016, 7 696, 11 636, 20 689, 10 245 in the normal group and (54±11)years, 12 905, (142±19)mmHg, (90±11)mmHg, (94±8)cm, 2.08 mmol/L (range, 1.51-3.04 mmol/L), (5.1±1.3)mmol/L, (1.50±0.42)mmol/L, (6.3±2.1)mmol/L, (27.1±3.2)kg/m2, 10 031, 5 737, 3 090, 4 762, 2 353 in the MS-3 group and (54±10)years, 4 556, (146±19)mmHg, (92±11)mmHg, (97±7)cm, 2.57 mmol/L (range, 2.03-3.80 mmol/L), (5.2±1.4)mmol/L, (1.44±0.45)mmol/L, (7.2±2.4)mmol/L, (28.1±3.1)kg/m2, 3 696, 2 971, 1 091, 1 699, 867 in the MS-4 group and (56±11)years, 265, (146±17)mmHg, (92±11)mmHg, (98±6)cm, 2.60 mmol/L (range, 2.06-3.91 mmol/L), (4.9±1.1)mmol/L, (0.86±0.14)mmol/L, (7.7±2.9)mmol/L, (28.7±2.9)kg/m2, 221, 196, 62, 93, 78 in the MS-5 group, respectively, with statistically significant differences among the 4 groups (F=481.40, χ2=3 359.07, F=3 551.06, 3 280.16, 5 915.20, χ2=18 358.71, F=211.30, 473.42, 4 168.34, 3 909.75, χ2=9 829.51, 14 449.74, 375.78, 225.14, 145.73, P<0.05). (2) Incidence of cholelithiasis in the 4 groups: 89 553 subjects were observed for (8.0±1.1)years, and 4 313 had new-onset cholelithiasis with a cumulative incidence of 4.8%. The cumulative incidences of cholelithiasis in the normal, MS-3, MS-4 and MS-5 groups were respectively 4.5%, 5.6%, 6.3% and 13.2%, with a statistically significant difference among the 4 groups (χ2=89.96, P<0.05). There were statistically significant differences in the cumulative incidences of cholelithiasis among the normal, MS-3, MS-4 and MS-5 groups (χ2=28.56, 29.25, 43.48, 17.13, 35.75, 16.82, P<0.05). (3) Risk factors analysis affecting new-onset cholelithiasis: results of COX proportional hazards model showed that hazard of the new-onset cholelithiasis in the normal group was increased compared with that in the MS-3, MS-4 and MS-5 groups with adjustment for sex, age, high-sensitivity C-reactive protein, smoking, drinking and physical exercise (HR=1.16, 1.33, 2.68, 95%CI: 1.07-1.26, 1.17-1.51, 1.92-3.74, P<0.05). Conclusion MS is an independent risk factor of new-onset cholelithiasis, and the increased incidence risk of new-onset cholelithiasis is consistent with subjects corresponded with diagnostic criteria of MS. Key words: Cholelithiasis; Metabolic syndrome; Incidence