Table 3

Adjusted geometric means of HbA1c according to combined categories of bilirubin and coffee consumption*
Low bilirubin† High bilirubin†
Sex Coffee (cups/day) n Geometric mean n Geometric mean
Men < 1 877 5.16 (5.12–5.21) 1034 5.08 (5.05–5.12)
1–3 1077 5.13 (5.09–5.16) 959 5.04 (5.01–5.08)
≥ 4 359 5.16 (5.10–5.23) 186 5.18 (5.10–5.27)
Trend‡ P = 0.74 P = 0.55
Women < 1 1125 5.14 (5.12–5.17) 1498 5.06 (5.04–5.08)
1–3 1503 5.11 (5.09–5.13) 1578 5.06 (5.04–5.08)
≥ 4 282 5.09 (5.04–5.14) 256 5.02 (4.97–5.07)
Trend‡ P = 0.04 P = 0.37

In parentheses are 95% confidence intervals of geometric means. Interaction P values were 0.43 in men and 0.37 in women.

* Adjusted for age, smoking, alcohol intake and body mass index by analysis of covariance.

† Low: < 0.6 mg/dL in men and < 0.5 mg/dL in women; high: ≥ 0.6 mg/dL in men and ≥ 0.5 mg/dL in women.

‡ Ordinal values were assigned to coffee categories.

Wang et al.

Wang et al. BMC Endocrine Disorders 2012 12:24   doi:10.1186/1472-6823-12-24

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