Table 2.
Associations between lifestyle factors and frequent gastroesophageal reflux symptoms among women
| External control comparison
|
Monozygotic co-twin control comparison
|
||||||
|---|---|---|---|---|---|---|---|
| Control
(n) |
Case
(n) |
Univariate a OR (95%CI) c |
Adjusted b OR (95%CI) c |
Univariate d OR (95%CI) c |
Adjusted b OR (95%CI) c |
Pe Value |
|
| BMI f | |||||||
| <20 | 3432 | 638 | 0.78 (0.69-0.88) | 0.81 (0.71-0.92) | 0.77 (0.51-1.17) | 0.76 (0.46-1.26) | |
| 20-22.4 | 3644 | 754 | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | |
| 22.5-24.9 | 1939 | 412 | 1.16 (1.02-1.33) | 1.25 (1.06-1.46) | 1.19 (0.73-1.92) | 1.38 (0.75-2.54) | |
| 25-29.9 | 1058 | 249 | 1.38 (1.17-1.62) | 1.46 (1.19-1.80) | 1.42 (0.67-2.97) | 1.89 (0.72-5.01) | |
| ≥30 | 154 | 33 | 1.27 (0.86-1.87) | 1.59 (1.00-2.54) | 0.91 (0.14-6.11) | 1.71 (0.20-14.6) | 0.9863 |
| P value for trend | <0.0001 | <0.0001 | 0.1303 | 0.0825 | 0.5718 | ||
| Ever smoking | |||||||
| no | 5671 | 1014 | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | |
| Yes | 4578 | 1063 | 1.23 (1.11-1.35) | 1.18 (1.05-1.32) | 0.92 (0.61-1.38) | 1.08 (0.66-1.74) | 0.7166 |
| cigarettes equivalent /day | |||||||
| 1-9 | 1900 | 386 | 1.09 (0.96-1.24) | 1.12 (0.97-1.30) | 0.75 (0.47-1.22) | 0.82 (0.45-1.48) | |
| 10-19 | 1968 | 478 | 1.27 (1.13-1.44) | 1.16 (1.01-1.34) | 1.04 (0.61-1.74) | 1.32 (0.71-2.44) | |
| ≥20 | 621 | 178 | 1.51 (1.26-1.81) | 1.37 (1.12-1.68) | 1.03 (0.54-1.97) | 1.10 (0.49-2.45) | 0.5234 |
| P value for trend | <0.0001 | 0.0027 | 0.9590 | 0.6390 | 0.7896 | ||
| Alcohol | |||||||
| No | 4714 | 1000 | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | |
| Yes | 6567 | 1324 | 0.97 (0.89-1.07) | 1.01 (0.89-1.13) | 0.77 (0.55-1.09) | 0.73 (0.45-1.19) | 0.2120 |
| absolute alcohol (grams /month) | |||||||
| 1-150 | 2127 | 409 | 1.05 (0.92-1.20) | 1.03 (0.86-1.23) | 1.03 (0.65-1.66) | 1.13 (0.58-2.17) | |
| 151-1200 | 1792 | 413 | 1.09 (0.95-1.23) | 1.21 (1.04-1.42) | 0.80 (0.51-1.27) | 0.84 (0.45-1.59) | |
| 1201 -2400 | 963 | 166 | 0.76 (0.64-0.91) | 0.80 (0.65-0.98) | 0.46 (0.25-0.83) | 0.48 (0.22-1.04) | |
| >2400 | 760 | 171 | 1.00 (0.83-1.19) | 0.96 (0.78-1.19) | 0.56 (0.28-1.11) | 0.31 (0.11-0.84) | 0.1498 |
| P value for trend | 0.3554 | 0.5331 | 0.0127 | 0.0093 | 0.0161 | ||
| Coffee (cups /day) g | |||||||
| 0 | 886 | 191 | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | |
| 1-3 | 3449 | 694 | 1.02 (0.84-1.23) | 0.92 (0.76-1.12) | 1.27 (0.65-2.50) | 1.11 (0.51-2.41) | |
| 4-6 | 3187 | 718 | 1.19 (0.98-1.45) | 1.01 (0.82-1.25) | 1.62 (0.77-3.40) | 1.40 (0.60-3.23) | |
| ≥7 | 696 | 190 | 1.45 (1.14-1.84) | 1.10 (0.85-1.43) | 1.58 (0.63-3.93) | 1.04 (0.35-3.08) | 0.7062 |
| P value for trend | 0.0002 | 0.2042 | 0.1866 | 0.5614 | 0.8126 | ||
| Physical activity at work | |||||||
| primarily sedentary | 2879 | 574 | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | |
| standing and walking | 1948 | 383 | 1.06 (0.91-1.23) | 1.03 (0.89-1.20) | 1.15 (0.71-1.87) | 1.27 (0.72-2.23) | |
| standing, lifting and carrying | 3055 | 761 | 1.34 (1.18-1.52) | 1.24 (1.09-1.42) | 1.22 (0.78-1.92) | 1.32 (0.79-2.19) | |
| physically strenuous | 148 | 38 | 1.40 (0.97-2.03) | 1.16 (0.78-1.72) | 0.88 (0.19-4.13) | 1.43 (0.18-11.2) | 0.9138 |
| P value for trend | <0.0001 | 0.0023 | 0.4409 | 0.3033 | 0.8453 | ||
| Physical activity at leisure time | |||||||
| almost no | 898 | 262 | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | |
| light | 2462 | 573 | 0.80 (0.68-0.94) | 0.83 (0.70-0.99) | 0.67 (0.37-1.20) | 0.57 (0.29-1.10) | |
| medium | 4433 | 902 | 0.70 (0.59-0.81) | 0.76 (0.65-0.89) | 0.63 (0.33-1.18) | 0.61 (0.30-1.23) | |
| much | 473 | 72 | 0.50 (0.37-0.67) | 0.56 (0.41-0.75) | 0.65 (0.24-1.79) | 0.63 (0.20-1.93) | 0.5670 |
| P value for trend | <0.0001 | 0.0001 | 0.2744 | 0.4688 | 0.7869 | ||
| Education h | |||||||
| above elementary | 5187 | 992 | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | 1.0 (reference) | |
| elementary | 4962 | 1072 | 1.17 (1.07-1.29) | 1.21 (1.08-1.35) | 1.67 (1.06-2.62) | 1.87 (1.07-3.28) | 0.1347 |
Year of birth was included in each univariate analysis.
Adjusted for year of birth, BMI (5 categories), smoking (ever or never), coffee (4 categories), physical activity at work (4 categories) and at leisure time (4 categories) and education (2 categories), wherever appropriate.
OR Odds ratio, CI confident interval.
The number of twin pairs included in analysis for each factor ranged from 416 (physical activity at work) to 522 (alcohol) due to missing data.
P value of the Wald test of comparing ORs derived from the external and MZ control multivariate analyses.
P value of the Wald test of comparing ORs derived from women and men in the external control analysis is <0.0001, and the corresponding P value for trend is <0.0001
P value of the Wald test of comparing ORs derived from women and men in the external control analysis is 0.0682, and the corresponding P value for trend is 0.0127.
P value of the Wald test of comparing ORs derived from women and men in the external control analysis is 0.0057.