Table 5

Incidence of retinal microaneurysm and ischaemic findings† with relation to job title or six year internal exposure level

Exposure index§IncidenceOdds ratio‡
Exposure duration prior to the study (y)TTCA (mg/g creatinine)CS2 (ppm)Non-exposed workersCS2 exposed workersAge adjustedAge + other possible confounders adjusted
†Defined as Minnesota codes I, IV1–3, V1–3 or receiving treatment for ischaemia.
‡OR for the non-exposed group was 1.0 as the referent.
¶Adjusted for age, BMI, education level, smoking status, alcohol drinking, shift work, coronary prone behaviour pattern, systolic blood pressure, and HDL cholesterol at baseline.
§Geometric mean (SD).
*p<0.05 compared to the non-exposed group by multiple logistic regression analysis, in which age, body mass index, education level, smoking status, alcohol intake, shift work, coronary prone behaviour pattern, systolic blood pressure, and HDL cholesterol at baseline and exposure variable were included as covariates.
Retinal microaneurysm
Entire group10.7 (2.3)1.5 (1.9)4.8 (1.8)11/219 (5.0%)17/184 (9.2%)2.0 (0.9–4.4)2.2 (1.0–5.1)
By job title at baseline
    Other than spinning/refining9.9 (2.2)0.9 (1.8)2.8 (1.8)5/51 (9.8%)2.2 (0.7–6.6)3.2 (0.9–10.3)
    Spinning or refining11.0 (2.3)1.9 (1.8)5.9 (1.6)12/133 (9.0%)1.9 (0.8–4.6)1.9 (0.8–4.8)
By internal exposure level for 1992–98
    Low11.1 (2.2)0.6 (1.4)2.4 (1.7)3/45 (6.7%)1.4 (0.4–5.3)1.9 (0.5–7.4)
    Mid–low12.1 (2.0)1.3 (1.2)4.4 (1.6)5/46 (10.9%)2.5 (0.8–7.5)2.8 (0.9–8.9)
    Mid–high12.1 (2.5)1.9 (1.1)5.9 (1.3)2/46 (4.3%)0.9 (0.2–4.2)0.5 (0.1–4.3)
    High8.3 (2.3)3.5 (1.3)8.3 (1.3)7/46 (15.2%)3.7 (1.2–10.6)*3.8 (1.2–11.4)*
Ischaemic findings
Entire group10.8 (2.3)1.6 (1.9)5.0 (1.8)21/329 (6.4%)30/254 (11.8%)2.1 (1.2–3.8)*2.1 (1.1–4.0)*
By job title at baseline
    Other than spinning/refining10.6 (2.2)0.9 (1.8)3.0 (1.8)8/74 (10.8%)2.0 (0.8–4.8)2.1 (0.9–5.4)
    Spinning or refining10.9 (2.3)2.0 (1.8)6.1 (1.7)22/180 (12.2%)2.1 (1.1–4.0)*2.1 (1.1–4.1)*
By internal exposure level for 1992–98
    Low10.9 (2.2)0.6 (1.5)2.4 (1.7)8/63 (12.7%)2.2 (0.9–5.4)2.3 (0.9–5.6)
    Mid–low12.4 (2.0)1.3 (1.2)4.6 (1.5)4/63 (6.3%)1.1 (0.4–3.4)1.0 (0.3–3.1)
    Mid–high11.9 (2.3)2.1 (1.1)6.4 (1.4)6/65 (9.2%)1.5 (0.6–3.9)1.6 (0.6–4.4)
    High8.6 (2.5)3.6 (1.3)8.7 (1.3)12/63 (19.0%)3.9 (1.8–8.7)*4.2 (1.8–9.7)*