Table 2.

Associations of phosphorus, calcium, and calcium-phosphorus product levels at study inceptiona

CharacteristicPhosphorus (mg/dl)PCalcium (mg/dl)PCalcium-Phosphorus Product (mg2/dl2)P
Age, per 3.6 yr−0.08 (0.01)<0.0001−0.06 (0.01)<0.0001−0.84 (0.29)0.0038
Female gender0.07 (0.02)0.0007−0.26 (0.02)<0.0001−0.47 (0.67)0.4835
Black race0.13 (0.02)<0.00010.06 (0.02)0.00191.54 (0.65)0.0175
Education <12 yr−0.05 (0.03)0.10720.08 (0.03)0.01300.07 (1.06)0.9497
Cigarette smoker0.03 (0.02)0.0923<0.01 (0.02)0.81590.61 (0.64)0.3426
Hypertension0.04 (0.03)0.19130.08 (0.03)0.0055−0.83 (1.04)0.4247
Diabetes0.16 (0.11)0.1198−0.09 (0.10)0.32273.06 (3.34)0.3584
Family history of MI0.08 (0.02)0.00150.01 (0.02)0.61780.94 (0.78)0.2275
BMI, per 4.4 kg/m2−0.04 (0.01)<0.0001−0.04 (0.01)<0.0001−0.31 (0.30)0.3037
LDL cholesterol, per 30.8 mg/dl−0.02 (0.01)0.05480.05 (0.01)<0.00010.17 (0.28)0.5512
HDL cholesterol, per 13.0 mg/dl0.04 (0.01)0.00040.05 (0.01)<0.0001−0.10 (0.33)0.7617
Triglycerides, per 48.7 mg/dl0.03 (0.01)0.00110.03 (0.01)0.00140.07 (0.30)0.8168
Glucose, per 13.4 mg/dl>−0.01 (0.01)0.71990.02 (0.01)0.0257−0.15 (0.30)0.6112
SBP, per 10.8 mmHg−0.09 (0.01)<0.00010.01 (0.01)0.2413−0.81 (0.36)0.0245
DBP, per 9.6 mmHg0.04 (0.01)<0.00010.03 (0.01)0.00040.95 (0.33)0.0046
eGFR, per 30.7 units−0.01 (0.01)0.3203−0.06 (0.01)<0.0001−0.22 (0.29)0.4450
Exercise intensity score, per 303.0 units0.02 (0.01)0.01570.01 (0.01)0.12780.25 (0.29)0.3826
Phosphorus intake, per 989.1 mg/d0.02 (0.06)0.7503−0.01 (0.05)0.7795−0.20 (1.77)0.9082
Calcium intake, per 817.4 mg/d0.02 (0.03)0.58370.05 (0.03)0.0783−1.08 (0.95)0.2552
Carbohydrate intake, per 177.8 g/d−0.04 (0.02)0.01430.01 (0.02)0.4769−0.01 (0.57)0.9810
Fat intake, per 70.3 g/d0.03 (0.02)0.1835−0.02 (0.02)0.4268−1.44 (0.78)0.0645
Protein intake, per 55.9 g/d−0.04 (0.04)0.3168−0.01 (0.03)0.76202.29 (1.21)0.0594
Alcohol intake, per 20.2 g/d0.01 (0.01)0.4190−0.01 (0.01)0.1940−0.43 (0.32)0.1772
Medications (%)
    asthma<0.01 (0.01)0.99980.04 (0.06)0.4984−3.37 (2.16)0.1194
    hypertension−0.05 (0.08)0.51800.03 (0.07)0.64852.52 (2.55)0.3221
    cardiac0.26 (0.10)0.00610.02 (0.09)0.81853.72 (3.06)0.2237
    hormonal0.11 (0.06)0.09650.05 (0.06)0.4308−1.23 (2.02)0.5441
  • a Linear regression analysis was used. Reference categories for categorical variables were individuals for whom the characteristic was absent. Parameter estimates for continuous variables were computed for intervals corresponding to 1 SD of the study population. Adjustment was made for all of the variables shown in the first column. Data are expressed as parameter estimate (SE).