Table 4.

Multiple linear regression model coefficients for maximum PTHa

Independent Variables Coefficient (SEM) P Value
Demographic parameters
black race 295.7 (32.9) <0.001
age (yr) -4.11 (1.1) 0.002
male -69.6 (32.7) 0.033
Laboratory parameters
phosphorus (mg/dl) 53.8 (8.1) <0.001
calcium (mg/dl) 55.8 (19.7) 0.005
albumin 50.6 (39.0) 0.196
aluminum 0.12 (1.01) 0.905
Other parameters
interdialytic weight gain 8.4 (12.0) 0.485
diabetes mellitus -158.9 (34.1) <0.001
  • a The regression coefficients show the estimated change in maximum PTH (pg/ml) per unit change in each predictor, after accounting for other variables. Therefore, on average the maximum PTH level is 295.7 pg/ml higher in blacks than whites, 158.9 pg/ml lower in diabetic than nondiabetic patients, and 69.6 pg/ml lower in males than females. Furthermore, the maximum PTH level decreased by 4.1 pg/ml for each additional year of age, and increased by 53.8 pg/ml for every 1 mg/dl increase in serum phosphorous.