Table 1.
Demographic information of participants.
| Characteristics | Total Participants | ||
|---|---|---|---|
| GERD | Control | Standardized Difference | |
| Total number | |||
| Age (years old) (n, %) | 0.00 | ||
| 40–44 | 746 (4.46) | 2984 (4.46) | |
| 45–49 | 3393 (20.26) | 13,572 (20.26) | |
| 50–54 | 2964 (17.70) | 11,856 (17.70) | |
| 55–59 | 2373 (14.17) | 9492 (14.17) | |
| 60–64 | 2107 (12.58) | 8428 (12.58) | |
| 65–69 | 2239 (13.37) | 8956 (13.37) | |
| 70–74 | 1697 (10.13) | 6788 (10.13) | |
| 75–79 | 877 (5.24) | 3508 (5.24) | |
| 80–84 | 329 (1.96) | 1316 (1.96) | |
| 85+ | 19 (0.11) | 76 (0.11) | |
| Sex (n, %) | 0.00 | ||
| Male | 7908 (47.23) | 31,632 (47.23) | |
| Female | 8836 (52.77) | 35,344 (52.77) | |
| Income (n, %) | 0.00 | ||
| 1 (lowest) | 2732 (16.32) | 10,928 (16.32) | |
| 2 | 2369 (14.15) | 9476 (14.15) | |
| 3 | 2640 (15.77) | 10,560 (15.77) | |
| 4 | 3537 (21.12) | 14,148 (21.12) | |
| 5 (highest) | 5466 (32.64) | 21,864 (32.64) | |
| Region of residence (n, %) | 0.00 | ||
| Urban | 6942 (41.46) | 27,768 (41.46) | |
| Rural | 9802 (58.54) | 39,208 (58.54) | |
| Obesity † (n, %) | 0.08 | ||
| Underweight | 452 (2.70) | 1861 (2.78) | |
| Normal | 6230 (37.21) | 24,112 (36.00) | |
| Overweight | 4560 (27.23) | 17,789 (26.56) | |
| Obese I | 5072 (30.29) | 21,105 (31.51) | |
| Obese II | 430 (2.57) | 2109 (3.15) | |
| Smoking status (n, %) | 0.06 | ||
| Nonsmoker | 12,187 (72.78) | 48,072 (71.77) | |
| Past smoker | 1426 (8.52) | 5098 (7.61) | |
| Current smoker | 3131 (18.70) | 13,806 (20.61) | |
| Alcohol consumption (n, %) | 0.02 | ||
| <1 time a week | 12,733 (76.05) | 50,249 (75.03) | |
| ≥1 time a week | 4011 (23.95) | 16,727 (24.97) | |
| Systolic blood pressure (mean, SD) | 126.28 (17.29) | 128.16 (18.33) | 0.11 |
| Diastolic blood pressure (mean, SD) | 78.36 (10.95) | 79.50 (11.44) | 0.10 |
| Fasting blood glucose (mean, SD) | 97.59 (28.17) | 98.81 (30.75) | 0.04 |
| Total cholesterol (mean, SD) | 199.43 (38.13) | 199.79 (37.89) | 0.01 |
| CCI score (mean, SD) | 1.22 (1.88) | 1.05 (1.75) | 0.10 |
| Periodontitis (n, %) | 13,251 (79.14) | 52,626 (78.57) | 0.01 |
Abbreviations: GERD, gastroesophageal reflux disease; CCI, Charlson Comorbidity Index; SD, standard deviation. † Obesity (BMI, body mass index, kg/m2) was categorized as <18.5 (underweight), ≥18.5 to <23 (normal), ≥23 to <25 (overweight), ≥25 to <30 (obese I), and ≥30 (obese II).