Serum Irisin Level Is Positively Associated with Bone Mineral Density in Patients on Maintenance Hemodialysis

Table 2

Correlation of lumbar BMD levels and clinical variables by simple regression or multivariable linear regression analyses among the 80 hemodialysis patients.

Variables	Lumbar BMD (g/cm^2)
	Simple regression		Multivariable regression
	r		Beta	Adjusted R^2 change
Female	−0.430	<0.001	−0.353	0.134	<0.001
Diabetes mellitus	0.164	0.146	—	—	—
Hypertension	0.162	0.152	—	—	—
Age (years)	−0.268	0.016	—	—	—
Log-HD duration (months)	−0.054	0.631	—	—	—
Body mass index (kg/m^2)	0.332	0.003	—	—	—
Systolic blood pressure (mmHg)	0.208	0.064	—	—	—
Diastolic blood pressure (mmHg)	0.200	0.075	—	—	—
Log-albumin (mg/dL)	0.022	0,848	—	—	—
Blood urea nitrogen (mg/dL)	0.035	0.757	—	—	—
Creatinine (mg/dL)	0.297	0.007	—	—	—
Alkaline phosphatase (U/L)	−0.294	0.008	−0.176	0.022	0.049
Total calcium (mg/dL)	−0.022	0.849	—	—	—
Phosphorus (mg/dL)	0.149	0.188	—	—	—
Intact parathyroid hormone (pg/mL)	−0.137	0.244	—	—	—
Log-irisin (ng/mL)	0.517	<0.001	0.450	0.258	<0.001
Urea reduction rate	−0.271	0.015	—	—	—
Kt/V (Gotch)	−0.268	0.016	—	—	—

Data of HD duration, albumin, and irisin showed skewed distribution and therefore were log-transformed before analysis. Analysis of data was done using the univariate linear regression analyses or multivariate stepwise linear regression analysis (adapted factors were female, age, body mass index, creatinine, alkaline phosphatase, urea reduction rate, Kt/V, and log-irisin). HD, hemodialysis; Kt/V, fractional clearance index for urea. was considered statistically significant.