Table 2.
Clinical variables according to coffee consumption status (i.e., none vs. former vs. current consumers) and lifetime intensity of coffee consumption (i.e., mean daily cups per day groups).
| Variable | Category | Non- consumers (0 cups/day) (N = 34) | Lifetime intensity in former coffee consumers | Lifetime intensity in current coffee consumers | Comparisons ( p -values) | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1–3 cups/day* (N = 12) | 4–8 cups/day* (N = 10) | 1–3 cups/day* (N = 138) | 4–8 cups/day* (N = 41) | 1–3 vs. 4–8 cups/day among former- consumers | 1–3 vs. 4–8 cups/day among current consumers | Former consumers vs. non- consumers | Current consumers vs. non- consumers | |||
| Country—N (%) | Italy | 23 (67.6) | 9 (75.0) | 9 (90.0) | 120 (87.0) | 39 (95.1) | 0.594 | 0.171 | 0.309 | 0.003 |
| Moldova/ Romania | 11 (32.4) | 3 (25.0) | 1 (10.0) | 18 (13.0) | 2 (4.9) | |||||
| Gender—N (%) | Males | 18 (52.9) | 7 (58.3) | 6 (60.0) | 86 (62.3) | 26 (63.4) | 1.000 | 1.000 | 0.785 | 0.339 |
| Females | 16 (47.1) | 5 (41.7) | 4 (40.0) | 52 (37.7) | 15 (36.6) | |||||
| BMI at interview—N(%) | <18.5 | 5 (14.7) | 1 (8.3) | 2 (20.0) | 7 (5.1) | 0 (0.0) | 0.427 | 0.116 | 1.000 | 0.057 |
| 18.5–24.9 | 15 (44.1) | 7 (58.3) | 3 (30.0) | 76 (55.1) | 18 (43.9) | |||||
| ≥25 | 14 (41.2) | 4 (33.3) | 5 (50.0) | 55 (39.9) | 23 (56.1) | |||||
| Age at interview (years) | Mean ± SD | 64.3 ± 11.3 | 64.6 ± 12.4 | 58.9 ± 10.1 | 62.5 ± 11.3 | 60.9 ± 9.3 | 0.227 | 0.415 | 0.403 | 0.232 |
| Age at onset (years) | Mean ± SD | 60.5 ± 12.6 | 60.8 ± 15.8 | 56.1 ± 9.3 | 60.6 ± 12.0 | 57.8 ± 9.1 | 0.348 | 0.190 | 0.521 | 0.562 |
| Diagnostic delay (years)# | Median (range) | 0.8 [0.1–15.8] |
1.0 [0.3–4.3] |
0.6 [0.3–1.8] |
0.9 [0.1–5.0] |
0.9 [0.1–9.3] |
0.077 | 0.614 | 0.920 | 0.977 |
| Education (years) | Mean ± SD | 9.4 ± 4.5 | 12.2 ± 4.7 | 9.4 ± 3.9 | 10.3 ± 4.1 | 11.1 ± 5.2 | 0.142 | 0.290 | 0.236 | 0.105 |
| Age at start coffee consuming (years) | Mean ± SD | — | 22.8 ± 12.2 | 20.0 ± 8.5 | 22.1 ± 9.1 | 18.1 ± 5.5 | 0.459 | 0.010 | — | — |
| Duration of coffee consumption (years) | Mean ± SD | — | 39.8 ± 18.3 | 37.0 ± 13.9 | 40.4 ± 13.8 | 42.8 ± 10.5 | 0.634 | 0.318 | — | — |
| Coffee load (cup-years)#, § | Median (range) | — | 84.9 [4.0–119.9] |
159.9 [60.0–303.8] |
81.9 [2.0–119.9] |
187.9 [77.9–341.8] |
<0.001 | <0.001 | — | — |
| Coffee intensity at interview—N (%) | 1–3 cups/day | — | — | — | 132 (96.4) | 24 (60.0) | – | <0.001 | — | — |
| 4–8 cups/day | 5 (3.6) | 16 (40.0) | ||||||||
| ΔFS# | Median (range) | 0.6 [0.1–5.3] |
0.6 [0.1–1.5] |
1.1 [0.1–2.4] |
0.6 [0.0–4.3] |
0.4 [0.1–3.4] |
0.267 | 0.646 | 0.746 | 0.716 |
Patients who consumed decaffeinated coffee were excluded from the analysis.
Missing values were excluded from the analysis and percentages were computed out of the total number of observations. SD, standard deviation; p-values from ANOVA models or Fisher exact test for continuous and categorical variables, respectively.
log-transformed variable was used in the ANOVA model.
The cup-years is the unit for measuring the amount a person has consumed over a long period of time and it was computed by dividing the cumulative lifetime exposure load by 365.25 units.
Lifetime intensity of coffee consumption was computed as the weighted mean of the number of cups consumed per day at different age periods, with weights equal to the duration of coffee consumption within each age period. Coffee intensity at the interview is the number of cups/day drunk at the time of the interview.