Table 3.

Subgroup analyses stratified by gender

	Model 1, β (95% CI, P)	Model 2, β (95% CI, P)	Model 3, β (95% CI, P)
Male
Non-arthritis	Reference	Reference	Reference
Osteoarthritis or degenerative arthritis	0.045 (0.026, 0.065) < 0.0001	0.053 (0.034, 0.072) < 0.0001	0.047 (0.028, 0.066) < 0.0001
Rheumatoid arthritis	0.010 (− 0.016, 0.036) 0.4569	0.021 (− 0.005, 0.046) 0.1139	0.023 (− 0.003, 0.048) 0.0776
Female
Non-arthritis	Reference	Reference	Reference
Osteoarthritis or degenerative arthritis	− 0.012 (− 0.026, 0.003) 0.1158	0.005 (− 0.010, 0.020) 0.4922	0.007 (− 0.008, 0.021) 0.3526
Rheumatoid arthritis	− 0.010 (− 0.034, 0.013) 0.3941	0.001 (− 0.022, 0.024) 0.9418	0.008 (− 0.015, 0.031) 0.5157

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