Table 5.

Multivariate proportional mortality hazard ratios (HRs) by body mass index (BMI) and fitness category in study participants

Fitness categorya	No. of subjects	No. (%) of deaths	P trendb	HR (95% CI)c	P value
BMI < 18.5 (kg/m2)
Low fitness	84	29 (34.5)	0.018	3.34 (2.13–5.24)	0.000
Moderate fitness	63	15 (23.8)		2.67 (1.54–4.73)	0.001
High fitness	68	12 (17.6)		2.17 (1.18–4.01)	0.013
BMI 18.5–24.9 (kg/m2)
Low fitness	763	115 (15.1)	0.000	1.61 (1.19–2.18)	0.002
Moderate fitness	823	102 (12.4)		1.54 (1.14–2.07)	0.005
High fitness	885	76 (8.6)		1 (reference)	–
BMI 25.0–29.9 (kg/m2)
Low fitness	436	59 (13.5)	0.010	1.66 (1.17–2.36)	0.005
Moderate fitness	414	40 (9.7)		1.22 (0.83–1.80)	0.315
High fitness	340	27 (7.9)		0.92 (0.59–1.43)	0.697
BMI ≥ 30.0 (kg/m2)
Low fitness	55	6 (10.9)	0.874	1.65 (0.71–3.84)	0.242
Moderate fitness	39	2 (5.1)		0.78 (0.19–3.19)	0.730
High fitness	30	4 (13.3)		1.53 (0.56–4.22)	0.407

BMI body mass index, CI confidence interval

^aFitness was assessed with a 6-m walk test. Fitness tertiles: 1st, walking speed < 0.88 m/s (low fitness); 2nd, walking speed 0.88– < 1.05 m/s (moderate fitness); 3 rd, walking speed ≥ 1.05 m/s (high fitness)

^b P values for trend were obtained by using chi-square test (linear-by-linear association)

^cAdjusted for age, sex, medical history (diabetes, stroke, hypertension, myocardial infarction, angina, and congestive heart failure), current smoking, and CVD medications (ACE inhibitor, aspirin, beta blocker, calcium channel blocker, and statin)