Table 5.

Coefficients between clinical characteristics, biochemical characteristics, and bone mineral density after multiple linear regression analysis in males and females

Characteristic	Male (n = 2,100)			Female (n = 2,401)
	Femur neck BMD	Total femur BMD	Lumbar spine BMD	Femur neck BMD	Total femur BMD	Lumbar spine BMD
Age, yr	–0.00285a	–0.00259a	–0.00005	–0.00638a	–0.00665a	–0.00595a
Body mass index, kg/m2	0.00967	0.01030	0.00202	0.00096	–0.00202	–0.00052
Total FFMI, kg/m2	0.00895	0.01439	0.02249	0.01456b	0.02474b	0.02110
Body fat, %	–0.00111	–0.00064	0.00369	0.00134	0.00301	0.00346
Smoking amount, pack-yr	0.00007	–0.00002	–0.00030	–0.00574	–0.00099	–0.00036
Exercise	0.00263	0.00475	–0.01493	0.00224	0.00435	0.00287
PTH, mg/mL	–0.00014	–0.00019	–0.00020	–0.00019b	–0.00023b	0.00017
25(OH)D, ng/mL	–0.00019	–0.00014	–0.00074	–0.00019	–0.00024	–0.00058
Ca intake, mg/dL	0.00003b	0.00003b	0.00003b	0.000003	0.000009	0.000011
P intake, mg/dL	0.00002b	0.00001	0.000004	0.000008	0.000003	0.000006
ALP, mg/dL	–0.00024a	–0.00026a	–0.00029a	–0.00014a	–0.00020a	–0.00026a
Airway obstruction
None	-	-	-	-	-	-
Mild	0.00223	0.01493	0.00854	0.00093	0.00857	0.01500
Moderate to severe	0.00768	0.00964	0.02127	–0.00851	–0.01130	0.00436

Regression models were adjusted for age, body mass index, FFMI, body fat percentage, smoking amount, serum 25(OH)D, PTH, ALP, daily calcium intake, daily phosphorus intake, exercise, and severity of airway obstruction.

BMD, bone mineral density; FFMI, fat free mass index; PTH, parathyroid hormone; 25(OH)D, 25-hydroxyvitamin D; ALP, alkaline phosphatase.

^ap < 0.001.

^bp < 0.05.