Demographic and clinical characteristics
A total of 227 patients with PLA were enrolled in this retrospective study. As shown in Table 1, the average age of total patients was 56 years (range: 11-84 years), and 135 (59.47%) of them were male. Among them, 66 (29.07%) patients had a history of smoking, 43 (18.94%) patients had alcohol drinking history. 43 (18.94%) and 8 (3.52%) patients had hypertension and cirrhosis, respectively. Most patients had a normal (60.79%) or low-grade fever temperature (34.80%) at admission, and the medium time for temperature normalization was 6.39 (range: 0-40). leucocytes abnormally increased in 119 patients (52.42%) on the first day of admission. In this cohort, the number of abscess was mainly single (75.77%). The maximum diameter of the abscess in 132 patients (58.15%) was between 5 and 10 cm, and followed by small abscess in 75 cases (33.04%). In 137 (60.35%) patients, the abscess was located in the right liver lobe, 34 (14.98%) in the left, and 41 (18.06%) in the both. Gas formation were observed in 45 patients (19.82%). In Table 2, 116 blood cultures were collected and 28 patients (24.14%) were positive. There was no significant difference in positive proportion between two groups. Based on pus culture from 148 cases, 98 patients (66.22%) showed positive growth. Among the positive patients, 114 patients (85.07%) were Gram-negative bacteria, 18 (13.43%) were Gram-positive bacteria, and 2 (1.49%) were Candida spp. infections. Klebsiella pneumonia and Escherichia coli in the Gram-negative organisms were the two most common bacteria in this study, accounting for 57.46% and 17.91%, respectively. In the Gram-positive organisms, Streptococcus spp. (6.72%) was the most pathogens cultured. It was documented that pleural and celiac effusion were the most common complications (18.41%, and 7.58%, respectively, Table 3). 136 (59.91%) patients received percutaneous drainage, 28 (12.33%) underwent surgical drainage, and the rest 63 (27.75%) were administrated conservative treatment. 125 (55.07%) patients presented combined antibiotic use. All patients showed outcomes with cured or improved and no patient died during hospital stay. The average costs of total patients was 4096 dollars.
Associations between Diabetes Mellitus and patients characteristics
In this study, 227 patients were divided into two groups based on DM. The Non-DM group included 166 (73.13%) patients and the DM group included 61 (26.87%) patients, with an average diabetes duration time of 5.5 years (range: 0.2-30 years). There was no significant difference in gender, age, the body temperature at admission, abscess number, size, site, and gas forming between the two groups (Table 1). However, patients in DM group exhibited more hypertension but lower leucocytes counts (P<0.001, and P=0.007, respectively). Interestingly, the use of steroid hormone (34.43% vs. 21.69%) and immune response enhancer (39.34% vs. 10.84%) were significantly higher in PLA patients with DM than in the non-DM group (P<0.05). Although the infection of Gram-negative and –positive in this study were similar between the two groups, patients in DM group had higher Candida spp. infection than that of in Non-DM group (P=0.052, Table 2). In Table 3, no significant difference had been found in complications, intravenous antibiotics use, outcomes, hospital stay, total costs and reoccurrence in three months between the two groups. While the choice of treatments were different between the two groups (P=0.024). Percutaneous drainage was mainly adopted in patients without DM (64.46%), while percutaneous drainage and conservative treatment were mainly performed in patients with DM (47.54% and 40.98%).
Effect of Diabetes Mellitus on short-term survival in liver abscess patients
During the follow-up period, 24 (10.57%) died within six months and 14 (6.17%) were diagnosed with PLA recurrence within three months after discharge. The PLA patients with DM had a lower six-month survival than that of in Non-DM group (81.97% vs. 92.17%, P=0.027) and no significant difference had been found with reoccurrence rate between the two groups (P=0.164, Table 3). To explore risk factors independently associated with short-term survival after hospitalization in PLA patients, univariable and multivariable analysis were made. Univariate variables with P<0.10 were further analyzed with multivariate model. As shown in Table 4, diabetes mellitus (OR: 0.097, 95% CI: 0.018-0.526, P=0.007) was the only independent risk factor for six-month survival after discharge. Other factors including age >60 years, gender, cirrhosis, biliary tract infection, abscess number and size, gas forming, Escherichia coli infection, and treatments methods were not found to be independent risk factors. The Kaplan-Meier curve of six-month survival after discharge was further estimated with regard to DM in Figure 1. It was found that PLA patients with DM had worse short-term survival than those in Non-DM group (Log-Rank test, P=0.021).
Subgroups analysis in PLA patients with DM
Abnormal glycaemia level in the DM group was considered to be a potent risk factor of short-term survival in PLA patients, which was further investigated in subgroups. All the patients were classified into two subgroups according to the HbA1C level. The clinical characteristics, laboratory results, abscess information, treatments and outcomes were compared between the two subgroups in Table 5. No difference was presented between the two subgroups in age, gender, diabetes duration time, underlying conditions, diabetic vascular diseases, laboratory tests, abscess characteristics, medicine use, outcomes, and hospital stay, etc. However, there was an obvious difference in the selection of treatments between the two subgroups (P=0.027). Percutaneous drainage was mainly performed in patients with poor-control of glycaemia (60.53%) and conservative treatment was mainly adopted in patients with good-control of glycaemia (60.87%). Besides, combined intravenous antibiotic showed a higher proportion in poor-control group (71.05%, P=0.033). Although there was no significant difference, total hospitalization costs and relapsed PLA within three months after discharge showed an obvious increase in the poor-control group compared to good-control group (6,037 vs. 3,154 dollars, 13.16% vs. 4.35%, respectively). Kaplan-Meier curve with different glycaemia levels in terms of six-month survival was shown in Figure 2. No difference was unfolded between the two groups in Kaplan-Meier plots (Log-Rank test, P=0.218).