Table 3.

Adjusted RRs for quartile levels of creatinine-adjusted melatonin (ng/mg of creatinine) for all breast cancer combined and for ER+ breast cancer only

CasesControlsRR (95% CI)PtrendRRa (95% CI)Ptrend
All cases
 Q1 (<6.69)581271.0 (ref.)0.411.0 (ref.)0.27
 Q2 [6.69–12.81)601301.02 (0.66–1.56)1.07 (0.67–1.71)
 Q3 [12.81–22.18)741291.26 (0.82–1.94)1.26 (0.79–2.01)
 Q4 (≥22.18)661291.13 (0.73–1.75)1.25 (0.78–2.02)
ER+ cases
 Q1 (<6.69)48891.0 (ref.)0.841.0 (ref.)0.80
 Q2 [6.69–12.81)40900.83 (0.55–1.38)0.82 (0.48–1.42)
 Q3 [12.81–22.18)47870.99 (0.58–1.69)0.93 (0.53–1.65)
 Q4 (≥22.18)41850.89 (0.53–1.51)0.88 (0.50–1.56)

Abbreviation: RR, relative risk.

  • aAdjusted for body mass index, education, and bilateral oophorectomy.