Table 1.
Demographic and clinical characteristics of the total study population and a subset consisting of patients without gallstones before surgery who received a postoperative ultrasound
| Study population (n = 959) | Subset (n = 669) | |
|---|---|---|
| Preoperative | ||
| Age – years | 45.1 ± 11.1 | 44.8 ± 11.3 |
| Female gender – n (%) | 766 (80) | 519 (78) |
| Ethnicity – n (%) | ||
| - Dutch | 734 (77) | 499 (75) |
| - Surinamese | 55 (6) | 45 (7) |
| - Dutch Caribbean | 28 (3) | 21 (3) |
| - Moroccan | 18 (2) | 14 (2) |
| - Turkish | 16 (2) | 11 (2) |
| - Other | 49 (5) | 40 (6) |
| - Multiple | 59 (6) | 39 (6) |
| Weight at surgery – kg | 116.0 ± 18.0 | 115.7 ± 18.3 |
| Body mass index at surgery – kg/m2 | 40.2 ± 4.7 | 40.1 ± 4.8 |
| Hypertension – n (%) | 468 (49) | 311 (46) |
| Dyslipidemia – n (%) | 301 (31) | 208 (31) |
| Type 2 diabetes – n (%) | 156 (16) | 111 (17) |
| Pain syndrome – n (%) | 81 (8) | 61 (9) |
| Asymptomatic gallstones before surgery – n (%) | 186 (19) | NA |
| Type of surgery – n (%) | ||
| - RYGB | 881 (92) | 611 (91) |
| - Sleeve gastrectomy | 78 (8) | 58 (9) |
| Statin use – n (%) | 164 (17) | 122 (18) |
| - Low intensity | 26 (3) | 21 (3) |
| - Moderate intensity | 85 (9) | 64 (10) |
| - High intensity | 53 (6) | 37 (6) |
| Postoperative | ||
| Assigned to UDCA – n (%) | 475 (50) | 331 (50) |
| %TWL at 6 months* – percent | 23.0 ± 5.4 | 23.0 ± 5.4 |
| %TWL at 12 months* – percent | 29.4 ± 7.4 | 29.4 ± 7.5 |
| %TWL at 24 months* – percent | 29.4 ± 8.9 | 29.4 ± 9.2 |
Plus-minus values are means ± standard deviations. N, number; RYGB, Roux-en-Y gastric bypass; UDCA, ursodeoxycholic acid; TWL, total weight loss. *In the study population, data on weight was missing in 9 patients at 6 months, in 8 patients at 12 months, and in 5 patients at 24 months. In the subset, data on weight was missing in 1 patient at 6 and 12 months