Table II.

Hazard ratios (95% CIs) for early menopause by level of physical activity: Nurses’ Health Study II (1989–2011)^a

	n Cases	Age-adjusted	MV1a	MV2b
		HR (95% CI)	HR (95% CI)	HR (95% CI)
Physical activity, 1989 (MET h/week)
<3	437	1	1	1
3 – <9	648	0.98 (0.87, 1.10)	1.00 (0.88, 1.13)	1.00 (0.88, 1.13)
9 – <18	574	0.94 (0.83, 1.06)	0.97 (0.85, 1.10)	0.96 (0.85, 1.09)
18 – <27	363	0.94 (0.81, 1.08)	0.97 (0.84, 1.11)	0.96 (0.83, 1.10)
27 – <42	336	0.97 (0.84, 1.12)	1.01 (0.87, 1.16)	0.99 (0.86, 1.14)
≥42	418	0.92 (0.81, 1.06)	0.94 (0.82, 1.08)	0.92 (0.81, 1.06)
P-trend		0.34	0.42	0.24
Physical activity, updated (MET h/week)
<3	515	1	1	1
3 – <9	795	1.01 (0.90, 1.12)	1.03 (0.92, 1.16)	1.03 (0.92, 1.15)
9 – <18	438	0.94 (0.82, 1.07)	0.98 (0.86, 1.12)	0.97 (0.84, 1.10)
18 – <27	284	1.02 (0.88, 1.19)	1.07 (0.92, 1.24)	1.05 (0.90, 1.22)
27 – <42	241	0.98 (0.83, 1.14)	1.01 (0.86, 1.19)	0.99 (0.84, 1.16)
≥42	234	0.91 (0.78, 1.07)	0.94 (0.80, 1.11)	0.91 (0.77, 1.07)
P-trend		0.26	0.41	0.21
Physical activity, cumulative average (MET h/week)
<3	308	1	1	1
3 – <9	634	0.93 (0.81, 1.06)	0.94 (0.82, 1.08)	0.94 (0.82, 1.08)
9 – <18	667	0.90 (0.79, 1.04)	0.94 (0.82, 1.07)	0.93 (0.81, 1.07)
18 – <27	466	1.03 (0.89, 1.19)	1.06 (0.91, 1.22)	1.04 (0.90, 1.21)
27 – <42	358	0.92 (0.79, 1.08)	0.95 (0.81, 1.11)	0.93 (0.80, 1.09)
≥42	348	0.89 (0.76, 1.04)	0.91 (0.78, 1.07)	0.89 (0.76, 1.04)
P-trend		0.42	0.53	0.26

^aMultivariable (MV) model adjusted for age (continuous, months), pack-years of smoking (0–10, 11–20 or ≥21), age at menarche (continuous), parity (nulliparous, 1–2, or ≥3), breastfeeding duration (in months; continuous), oral contraceptive use (never/past/current), % of calories from vegetable protein (quintiles), alcohol intake (<10, ≥10 g/day), and intake of vitamin D from dairy source (quintiles).

^bMV model additionally adjusted for BMI (<18.5, 18.5–<25, 25–<30 or ≥30 kg/m²).