Table 1.
EPIC | HUNT2 | |||||
---|---|---|---|---|---|---|
Cases (n = 626) | Matched controls (n = 626) | p valuea | Cases (n = 112) | Matched controls (n = 112) | p valuea | |
Matched variables | ||||||
Years of follow‐up, mean (sd) | 7.0 (3.7) | – | – | 5.8 (3.2) | – | – |
Age at recruitment (years), mean (sd) | 57.7 (7.8) | 57.7 (7.8) | – | 68.0 (10.7) | 68.0 (10.6) | – |
Women, n (%) | 337 (53.9) | 337 (53.9) | – | 59 (52.7) | 59 (52.7) | – |
Residential region, n (%) | – | – | ||||
North (UK, NL, Germany, Denmark, Sweden, Norway) | 457 (73.0) | 457 (73.0) | 112 (100.0) | 112 (100.0) | ||
South (France, Italy, Spain, Greece) | 169 (27.0) | 169 (27.0) | – | – | ||
Country, n (%) | ||||||
HUNT2 cohort | – | |||||
Norway | – | – | 112 (100.0) | 112 (100.0) | ||
EPIC cohort | – | |||||
Denmark | 79 (12.6) | 79 (12.6) | – | – | ||
France | 12 (1.9) | 12 (1.9) | – | – | ||
Germany | 86 (13.7) | 86 (13.7) | – | – | ||
Greece | 36 (5.8) | 36 (5.8) | – | – | ||
Italy | 66 (10.5) | 66 (10.5) | – | – | ||
The Netherlands | 62 (9.9) | 62 (9.9) | – | – | ||
Norway | 5 (0.8) | 5 (0.8) | – | – | ||
Spain | 55 (8.8) | 55 (8.8) | – | – | ||
Sweden | 145 (23.2) | 145 (23.2) | – | – | ||
United Kingdom | 80 (12.8) | 80 (12.8) | – | – | ||
Season of blood collection, n (%) | – | – | ||||
Winter (Dec, Jan, Feb) | 134 (21.4) | 135 (21.6) | 24 (21.4) | 25 (22.3) | ||
Spring (Mar, Apr, May) | 190 (30.4) | 197 (31.5) | 26 (23.2) | 25 (22.3) | ||
Summer (Jun, Jul, Aug) | 125 (20.0) | 123 (19.7) | 19 (17.0) | 19 (17.0) | ||
Autumn (Sep, Oct, Nov) | 177 (28.3) | 171 (27.3) | 43 (38.4) | 43 (38.4) | ||
Fasting status, n (%) | – | – | ||||
<3 hrs | 253 (40.4) | 263 (42.0) | 78 (69.6) | 80 (71.4) | ||
3–6 hrs | 100 (16.0) | 97 (15.5) | 32 (28.6) | 31 (27.7) | ||
>6 hrs | 171 (27.3) | 165 (26.4) | 1 (0.9) | 1 (0.9) | ||
Use of pill/HRT/ERT at blood collection, yes, n (%) | 56 (9.0) | 56 (9.0) | – | 6 (5.4) | 6 (5.4) | – |
Characteristics | ||||||
Height (cm), mean (sd) | 167.7 (9.4) | 167.2 (9.7) | 0.20 | 166.5 (9.6) | 166.3 (8.9) | 0.87 |
Weight (kg), mean (sd) | 74.7 (13.6) | 73.4 (13.9) | 0.06 | 75.1 (13.6) | 74.3 (12.6) | 0.55 |
BMI (kg/m2), mean (sd) | 26.6 (4.2) | 26.2 (4.1) | 0.13 | 27.0 (3.9) | 26.8 (3.8) | 0.61 |
Waist circumference (cm), mean (sd) | 89.8 (12.8) | 88.3 (12.9) | 0.02 | 90.4 (11.5) | 89.3 (10.8) | 0.38 |
Hip circumference (cm), mean (sd) | 101.8 (8.6) | 101.1 (8.3) | 0.2 | 103.5 (8.8) | 102.6 (6.9) | 0.33 |
Waist–hip ratio, mean (sd) | 0.9 (0.1) | 0.9 (0.1) | 0.01 | 0.9 (0.08) | 0.9 (0.09) | 0.79 |
Education level, n (%) | 0.20 | 0.45 | ||||
Primary school or less | 278 (44.4) | 248 (39.6) | 53 (47.3) | 57 (50.9) | ||
Secondary school lower level | 142 (22.7) | 166 (26.5) | 33 (29.5) | 28 (25.0) | ||
Secondary school higher level | 73 (11.7) | 79 (12.6) | 1 (0.9) | 5 (4.5) | ||
College/University degree | 113 (18.1) | 116 (18.5) | 6 (5.4) | 13 (11.6) | ||
Smoking status, n (%) | <0.01 | 0.08 | ||||
Never | 233 (37.2) | 287 (45.9) | 40 (35.7) | 48 (42.9) | ||
Past | 183 (29.2) | 201 (32.1) | 36 (32.1) | 43 (38.4) | ||
Current | 201 (32.1) | 133 (21.3) | 26 (32.1) | 21 (18.8) | ||
Age start smoking (years), mean (sd) | 20.1 (6.5) | 20.3 (6.4) | 0.43 | 22.8 (8.5) | 21.0 (8.1) | 0.79 |
Duration of smoking (years), mean (sd) | 29.4 (12.0) | 27.4 (12.9) | 0.19 | 32.5 (14.7) | 29.6 (14.8) | 0.09 |
Time since quitting (years), mean (sd) | 16.0 (11.5) | 16.0 (10.3) | 0.16 | 18.1 (11.6) | 21.8 (13.2) | 0.74 |
Smoking dose (cig/day), mean (sd) | 15.7 (8.4) | 16.3 (8.8) | 0.35 | 10.9 (6.4) | 10.2 (6.2) | 0.16 |
Smoking habits combined, n (%) | <0.01 | 0.15 | ||||
Never | 233 (37.2) | 287 (45.9) | 40 (35.7) | 48 (42.9) | ||
Former, time since quitting >15 yrs | 87 (13.9) | 89 (14.2) | 18 (16.1) | 27 (24.1) | ||
Former, time since quitting 0–15 yrs | 90 (14.4) | 103 (16.5) | 15 (13.4) | 14 (12.5) | ||
Current, 0–15 cig/day | 97 (15.5) | 60 (9.6) | 27 (24.1) | 17 (15.2) | ||
Current, >15 cig/day | 80 (12.8) | 52 (8.3) | 7 (6.3) | 1 (0.9) | ||
Former/current, quitting/dose unknown | 30 (4.8) | 30 (4.8) | 5 (4.5) | 5 (4.5) | ||
Physical activity, n (%) | 0.53 | 0.59 | ||||
Inactive | 174 (27.8) | 184 (29.4) | 12 (10.7) | 12 (10.7) | ||
Active | 432 (69.0) | 426 (68.1) | 73 (65.2) | 80 (71.4) | ||
Diabetes, yes, n (%) | 45 (7.2) | 28 (4.5) | 0.03 | 4 (3.6) | 7 (6.3) | 0.37 |
Vitamin D status | ||||||
Serum 25(OH)D (nmol/L), mean (sd) | 60.0 (27.3) | 59.4 (27.1) | 0.57 | 70.7 (23.8) | 64.7 (20.3) | 0.05 |
Quintiles of serum 25(OH)D | 0.35 | 0.18 | ||||
Q1, n (%) | 118 (18.9) | 139 (22.2) | 9 (8.0) | 9 (8.0) | ||
Q2, n (%) | 144 (23.0) | 126 (20.1) | 13 (11.6) | 21 (18.8) | ||
Q3, n (%) | 131 (21.0) | 121 (19.3) | 26 (23.2) | 26 (23.2) | ||
Q4, n (%) | 105 (16.8) | 118 (18.9) | 23 (20.5) | 31 (27.7) | ||
Q5, n (%) | 128 (20.5) | 122 (19.5) | 41 (36.6) | 25 (22.3) | ||
Predefined cut‐points of serum 25(OH)D | 0.90 | 0.26 | ||||
≤25 nmol/L, n(%) | 33 (5.3) | 39 (6.2) | 1 (0.9) | 4 (3.6) | ||
>25 to 50 nmol/L, n (%) | 214 (34.2) | 216 (34.5) | 20 (17.9) | 21 (18.8) | ||
>50 to 75 nmol/L, n (%) | 233 (37.2) | 232 (37.1) | 46 (41.1) | 56 (50.0) | ||
>75 to 100 nmol/L, n (%) | 92 (14.7) | 90 (14.4) | 33 (29.5) | 25 (22.3) | ||
> 100 nmol/L, n (%) | 54 (8.6) | 49 (7.8) | 12 (10.7) | 6 (5.4) | ||
Dietary variables | ||||||
Alcohol (g/day)b | 6.0 (0.9–19.3) | 5.7 (1.1–17.9) | 0.64 | 1.4 (0.0–4.3) | 0.7 (0.0–2.9) | 0.13 |
Any vitamin use, n (%) | 0.36 | 0.22 | ||||
Yes | 211 (33.7) | 222 (35.5) | 12 (10.7) | 11 (9.8) | ||
No | 337 (53.8) | 323 (51.6) | 11 (9.8) | 17 (15.2) |
p Values for differences in means between cases and controls were determined by paired t test, whereas differences in categorical variables were determined by conditional logistic regression. No p values were determined for years of follow‐up, age at recruitment, sex, residential region, country, season of blood collection, fasting status, and use of pill/HRT/ERT at blood collection, because these variables were used for matching.
Median (p25–p75).