Table 5.

Associations between disease duration of arthritis and lumbar bone mineral density

Disease duration of arthritis (years)	Model 1, β (95% CI) P value	Model 2, β (95% CI) P value	Model 3, β (95% CI) P value
Osteoarthritis or degenerative arthritis	0.0005 (− 0.0021, 0.0011) 0.5312	− 0.0003 (− 0.0020, 0.0013) 0.6746	− 0.0001 (− 0.0017, 0.0015) 0.8619
Rheumatoid arthritis	0.0013 (− 0.0005, 0.0032) 0.1596	0.0013 (− 0.0005, 0.0032) 0.1649	0.0006 (− 0.0012, 0.0025) 0.4979

Adjusted for age, race, educational level, body mass index, ratio of family income to poverty, vigorous recreational activities, smoked at least 100 cigarettes in life, blood urea nitrogen, total protein, total cholesterol, alkaline phosphatase, serum uric acid, serum sodium, serum potassium, serum phosphorus, and serum calcium