. 2010 Jun 1;103(1):90–93. doi: 10.1038/sj.bjc.6605719

Table 4. Hazard ratio for breast cancer risk in relation to level of serum GGT (adjusted by age, age at first birth/nulliparity, age at menarche, height and weight).

	All
	HR (95% CI)	P-value
N (cases)	1803 (96)

GGT in quartiles
Q1 (⩽8.0 IU l⁻¹)	1.00	0.011
Q2 (8.1–11.0 IU l⁻¹)	1.55 (0.81, 2.97)
Q3 (11.1–14.0 IU l⁻¹)	2.41 (1.33, 4.35)
Q4 (>14.0 IU l⁻¹)	2.17 (1.19, 3.93)

GGT by median value
Below median (11.0 IU l⁻¹)	1.00	0.004
Above median	1.88 (1.23, 2.87)

GGT by normal range
In normal range (⩽40 IU l⁻¹)	1.00	0.003
Above normal range	2.50 (1.36, 4.60)

Abbreviation: CI=confidence interval; HR=hazard ratio; GGT=γ-glutamyl transferase; Q1, first quartile; Q2, second quartile; Q3, third quartile; Q4, fourth quartile. Values in bold type represent significant P-values (P<0.05)