Table 4.

Severe physical impairment^* in relation to change in BMI class from age 18 years to late life among postmenopausal women (n 76 016), Women’s Health Initiative Observational Study

	Model 1		Model 2		Model 3		Model 4
	OR	95 % CI	OR	95 % CI	OR	95 % CI	OR	95 % CI
Underweight BMI at 18 years
Staying underweight	Reference		Reference		Reference		Reference
Becoming normal weight	0·83	0·65, 1·06	0·88	0·67, 1·14	0·85	0·64, 1·13	0·94	0·69, 1·28
Becoming overweight/obese	1·96	1·53, 2·51	1·61	1·23, 2·11	1·40	1·05, 1·86	1·52	1·11, 2·09
Normal weight BMI at 18 years
Staying normal weight	Reference		Reference		Reference		Reference
Becoming underweight	1·69	1·40, 2·04	1·38	1·12, 1·69	1·29	1·03, 1·62	1·35	1·06, 1·71
Becoming overweight/obese	2·71	1·68, 2·00	2·12	2·00, 2·24	1·93	1·81, 2·06	1·97	1·84, 2·11
Overweight and obese BMI at 18 years
Staying overweight/obese	Reference		Reference		Reference		Reference
Becoming normal weight	0·37	0·29, 0·47	0·51	0·39, 0·66	0·55	0·42, 0·73	0·52	0·39, 0·71

Model 1 adjusted for demographic factors including age at baseline, race/ethnicity, marital status, income, education, occupation and living status.

Model 2 adjusted for model 1 covariates and behavioural factors including smoking status, alcohol intake, current physical activity, physical activity during youth, total daily energy intake and self-reported health.

Model 3 adjusted for model 2 covariates and medical factors including history of CHD, congestive heart failure, stroke, diabetes, hypertension, arthritis, cancer, chronic obstructive pulmonary disease, any fracture, falls in the last 12 months, depression, age at menopause and number of term pregnancies.

Model 4 adjusted for model 3 covariates and medications including contraception, hormone therapy, glucocorticosteroids, psychotropic drugs, beta-blockers, anticonvulsants and anti-migraine drugs.

^*Severe physical impairment defined as score of less than 60 on the Physical Functioning subscale of the Rand thirty-six-item Short-Form Health Survey.