Table 4.

Hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between serum cysteine concentration and risk of oesophageal squamous cell carcinoma and gastric cardia adenocarcinoma in the Linxian General Population Nutrition Intervention Trial cohort.

Group	Continuous‡			Quartile
				Q1	Q2		Q3		Q4
	HR	95% CI	P	Ref	HR	95% CI	HR	95% CI	HR	95% CI	Ptrend§
Oesophageal Squamous Cell Carcinoma
Age & sex-adjusted	0.87	0.81, 0.94	0.00027	1.00	1.01	0.77, 1.34	0.70	0.52, 0.93	0.73	0.55, 0.96	0.011
Fully adjusted*	0.86	0.79, 0.93	0.00016	1.00	0.96	0.69, 1.34	0.61	0.44, 0.86	0.70	0.51, 0.98	0.0064
Gastric Cardia Adenocarcinoma
Age & sex-adjusted	0.85	0.76, 0.94	0.00093	1.00	1.06	0.70, 1.62	0.96	0.64, 1.45	0.70	0.46, 1.06	0.060
Fully adjusted*	0.81	0.73, 0.90	<0.0001	1.00	0.95	0.61, 1.48	0.77	0.50, 1.19	0.59	0.38, 0.91	0.0081

^*Fully adjusted HRs and 95% CIs in were calculated using models stratified on age and sex, with additional adjustment for continuous age variables within each stratum, cigarette smoking, alcohol drinking, BMI, serum creatinine and serum creatinine squared

^‡Continuous HRs are scaled to 19 nmol/mL, which is one half of the inter-quartile range in the population distribution (75^th percentile – 25^th percentile ÷ 2)

^§P for trend comes from a model where quartile of cysteine was entered as an ordinal variable