Table 6. HRs^a and 95% CIs^a of all-cause mortality in 22 934 women by BMI^a category, stratified by age group.

	BMI
	<18.5	18.5–20.9	21.0–22.9	23.0–24.9	25.0–27.4	27.5–29.9	≥30.0
Total
No.	928	3518	5498	5676	4556	1929	829
Person-years	9011	34 782	55 716	57 537	46 281	19 477	8313
No. of deaths	174	371	451	415	357	159	95
Mortality rateb	19.3	10.7	8.1	7.2	7.7	8.2	11.4
Age-smoking-adjusted HRs	2.66 (2.23–3.18)	1.48 (1.28–1.70)	1.12 (0.98–1.28)	1.00 (reference)	1.07 (0.93–1.23)	1.13 (0.94–1.36)	1.59 (1.27–1.99)
Multivariate HRs1c	1.49 (1.24–1.80)	1.15 (0.99–1.33)	0.99 (0.87–1.14)	1.00 (reference)	1.03 (0.89–1.19)	1.07 (0.89–1.30)	1.33 (1.05–1.69)
Multivariate HRs2d	1.58 (1.31–1.91)	1.19 (1.03–1.38)	1.01 (0.88–1.15)	1.00 (reference)	1.00 (0.87–1.16)	1.04 (0.85–1.26)	1.24 (0.97–1.57)
Multivariate HRs3e	1.44 (1.17–1.78)	1.18 (1.01–1.38)	1.02 (0.88–1.18)	1.00 (reference)	1.06 (0.91–1.24)	1.09 (0.88–1.34)	1.37 (1.07–1.77)
40–64 y
No.	425	2135	3521	3770	2890	1227	489
Person-years	4416	21 274	35 734	38 262	29 435	12 484	4999
No. of deaths	32	92	137	128	104	49	28
Mortality rateb	7.2	4.3	3.8	3.3	3.5	3.9	5.6
Age-smoking-adjusted HRs	2.10 (1.43–3.10)	1.30 (0.99–1.70)	1.16 (0.91–1.48)	1.00 (reference)	0.99 (0.76–1.28)	1.11 (0.80–1.54)	1.59 (1.06–2.39)
Multivariate HRs1c	1.46 (0.96–2.22)	1.10 (0.82–1.47)	1.09 (0.85–1.40)	1.00 (reference)	1.00 (0.77–1.31)	1.06 (0.75–1.51)	1.47 (0.94–2.27)
Multivariate HRs2d	1.55 (1.02–2.36)	1.14 (0.85–1.52)	1.10 (0.86–1.41)	1.00 (reference)	0.98 (0.75–1.28)	1.01 (0.71–1.43)	1.38 (0.89–2.14)
Multivariate HRs3e	1.78 (1.13–2.81)	1.36 (1.00–1.86)	1.21 (0.92–1.59)	1.00 (reference)	1.02 (0.76–1.36)	0.99 (0.68–1.45)	1.32 (0.82–2.15)
65–79 y
No.	503	1383	1977	1906	1666	702	340
Person-years	4595	13 508	19 982	19 275	16 845	6994	3314
No. of deaths	142	279	314	287	253	110	67
Mortality rateb	30.9	20.7	15.7	14.9	15.0	15.7	20.2
Age-smoking-adjusted HRs	1.67 (1.37–2.05)	1.26 (1.07–1.48)	1.00 (0.85–1.17)	1.00 (reference)	1.02 (0.86–1.21)	1.07 (0.86–1.34)	1.33 (1.02–1.73)
Multivariate HRs1c	1.47 (1.19–1.82)	1.14 (0.96–1.36)	0.95 (0.81–1.12)	1.00 (reference)	1.04 (0.87–1.24)	1.07 (0.85–1.35)	1.26 (0.95–1.68)
Multivariate HRs2d	1.56 (1.26–1.93)	1.19 (1.00–1.41)	0.96 (0.82–1.13)	1.00 (reference)	1.01 (0.85–1.21)	1.04 (0.83–1.31)	1.17 (0.88–1.55)
Multivariate HRs3e	1.45 (1.15–1.83)	1.17 (0.97–1.40)	0.96 (0.81–1.15)	1.00 (reference)	1.04 (0.86–1.25)	1.07 (0.83–1.37)	1.24 (0.92–1.68)

^aHR, hazard ratio; CI, confidence interval; BMI, body mass index.

^bMortality rate was defined as number of deaths per 1000 person-years.

^cMultivariate HRs1 were adjusted for age in 5-year categories; weight change since age 20 years (loss of 10.0 kg or more, loss of 5.0–9.9 kg, change of less than ±5.0 kg, gain of 5.0–9.9 kg, or gain of 10.0 kg or more); education (junior high school or less, high school, or college/university or higher); marital status (married or unmarried); cigarette smoking (never smoker, past smoker, current smoker consuming 1–19 cigarettes per day, or current smoker consuming at least 20 cigarettes per day); alcohol drinking (never drinker, past drinker, or current drinker); time spent walking per day (less than 1 hour, or 1 hour or longer); sports and physical exercise time per week (less than 1 hour, 1–2 hours, 3–4 hours, or 5 hours or longer); history of kidney disease (yes or no); history of liver disease (yes or no).

^dMultivariate HRs2 were further adjusted for history of hypertension (yes or no) and history of diabetes (yes or no).

^eMultivariate HRs3 excluded from multivariate HRs2 the 266 women who died within the 2 years after baseline.