Associations between superoxide dismutase, malondialdehyde and all-cause mortality in older adults: a community-based cohort study

Table 2 Association between superoxide dismutase activity and all-cause mortality in women and men

	HR [95% CI] for all-cause mortality
	Unadjusted model	Basic model ^a	Fully adjusted model ^b
Women
No. of participants	1034	1034	822
No. of events	537	537	407
No. of person years	3521.9	3521.9	2925.3
Risk at each 10 U/mL increase in SOD activity	0.96 [0.88, 1.05]	0.84[0.77, 0.92] ***	0.82[0.74, 0.92] **
Risk by quintiles
Quintile 1	1.00(reference)	1.00(reference)	1.00(reference)
Quintile 2	0.93[0.70, 1.22]	0.81[0.61, 1.07]	0.73 [0.53, 1.02]
Quintile 3	0.90 [0.68, 1.19]	0.61 [0.46, 0.81]**	0.52 [0.38, 0.72]***
Quintile 4	0.87 [0.66, 1.13]	0.60 [0.45, 0.79]***	0.53 [0.39, 0.73]***
Quintile 5	0.79 [0.61, 1.03]	0.54 [0.41, 0.71]***	0.48 [0.35, 0.66]***
P-trend	0.07	< 0.001	< 0.001
Men
No. of participants	818	818	683
No. of events	319	319	249
No. of person years	3160.9	3160.9	2715.9
Risk at each 10 U/mL increase in SOD	1.05 [0.94, 1.17]	0.97 [0.86, 1.08]	0.99 [0.86, 1.14]
Risk by quintiles
Quintile 1	1.00(reference)	1.00(reference)	1.00(reference)
Quintile 2	1.25 [0.90, 1.72]	1.17 [0.84, 1.61]	1.13 [0.77, 1.68]
Quintile 3	1.24 [0.89, 1.71]	1.16 [0.84, 1.61]	1.11 [0.75, 1.66]
Quintile 4	1.02 [0.71, 1.46]	0.74 [0.52, 1.06]	0.74 [0.48, 1.14]
Quintile 5	1.30 [0.90, 1.86]	1.10 [0.77, 1.58]	1.14 [0.74, 1.76]
P-trend	0.40	0.90	0.64

HR: hazard ratio; CI: confidence interval; SOD: superoxide dismutase
a. Basic model: adjusted for age (continuous), and residence (urban or rural);
b. Fully adjusted model: additionally adjusted for frequent vegetable consumption (yes or no), frequent fruit consumption (yes or no), frequent meat consumption (yes or not), frequent physical exercise (yes or no), smoking (current smoker, non-current smoker), alcohol drinking (current drinker, non-current drinker), hypertension (yes or no), body mass index (continuous), glucose (< 7 mmol/L or > =7 mmol/L), total cholesterol (< 6.2 mmol/L, > = 6.2 mmol/L), triglycerides(< 2.3 mmol/L or > =2.3 mmol/L), malondialdehyde (continuous)
* P < 0.05; **P < 0.01; *** P < 0.001

ISSN: 1471-2318