Table 1—

Distribution of potential confounders in cases and controls

ControlsCasesTotal
Total507 (49.3)521 (50.7)1028
Body mass index
 <20 kg·m−251 (10.1)52 (10.0)103 (10.0)
 20–25 kg·m−2270 (53.3)238 (45.7)508 (49.4)
 25–30 kg·m−2135 (26.6)156 (29.9)291 (28.3)
 ≥30 kg·m−251 (10.1)73 (14.0)124 (12.1)
Male sex239 (47.1)206 (39.5)445 (43.3)
Age yrs34.7±7.4832.8±7.3733.7±7.48
Socioeconomic status
 Professional242 (47.7)186 (35.7)428 (41.6)
 Managerial29 (5.7)28 (5.4)57 (5.5)
 Skilled139 (27.4)186 (35.7)325 (31.6)
 Semi-skilled29 (5.7)29 (5.6)58 (5.6)
 Unskilled27 (5.3)39 (7.5)66 (6.4)
 Students38 (7.5)43 (8.3)81 (7.9)
Smoking
 Never-smoker139 (27.4)142 (27.3)281 (27.3)
 Exposed to environmental tobacco smoke142 (28.0)150 (28.8)292 (28.4)
 Ex-smoker93 (18.3)93 (17.9)186 (18.1)
 Current smoker133 (26.2)136 (26.1)269 (26.2)
Supplement use106 (20.9)123 (23.6)229 (22.3)
  • Data are presented as n (%) n, or mean±sd.