Table 2: Weighted mean values and the regression coefficients with standard errors (SEs) for C-reactive protein, red blood cell distribution width, and platelet-to-lymphocyte ratio by serum parathyroid hormone (PTH) levels among the United States adults aged at least 20 years, NHANES 2003–2006.

Mean (SE)Regression coefficient (SE)
Model 1Model 2Model 3Model 4

C-reactive protein (mg/dL)
 PTH group (pg/mL)
  6–390.47 (0.01)0000
  40–590.47 (0.02)0.021 (0.044)0.041 (0.044)0.089 (0.040)0.088 (0.038)
  60–990.55 (0.02)0.162 (0.032)0.195 (0.034)0.189 (0.035)0.183 (0.037)
  100–14910.75 (0.07)0.339 (0.068)0.363 (0.066)0.194 (0.065)0.175 (0.068)
   value for trend<0.001<0.001<0.001<0.001
 Continuous PTH0.085 (0.031)0.109 (0.031)0.139 (0.029)0.138 (0.031)
   value0.0110.001<0.001<0.001
Red blood cell distribution width (%)
 PTH group (pg/mL)
  6–3912.72 (0.02)0000
  40–5912.87 (0.02)0.069 (0.022)0.087 (0.022)0.106 (0.020)0.057 (0.022)
  60–9913.16 (0.04)0.320 (0.039)0.337 (0.040)0.332 (0.038)0.239 (0.040)
  100–149113.68 (0.08)0.770 (0.085)0.757 (0.087)0.667 (0.086)0.504 (0.084)
   value for trend<0.001<0.001<0.001<0.001
 Continuous PTH0.299 (0.032)0.315 (0.032)0.322 (0.032)0.231 (0.031)
   value<0.001<0.001<0.001<0.001
Platelet-to-lymphocyte ratio
 PTH group (pg/mL)
  6–39138.0 (1.2)0000
  40–59139.0 (1.1)−0.752 (1.171)−1.674 (1.226)−1.007 (1.253)−0.480 (1.324)
  60–99142.6 (1.0)1.778 (1.200)0.399 (1.238)0.713 (1.336)1.059 (1.565)
  100–1491153.9 (3.9)11.7462 (3.603)9.641 (3.542)9.353 (3.770)7.454 (4.271)
   value for trend0.0040.1140.0850.190
 Continuous PTH3.183 (0.962)1.679 (1.030)2.193 (1.086)2.444 (1.416)
   value0.0020.1140.0520.095

Linear regression analyses were conducted using serum PTH as both categorical and continuous variable. Model 1: adjusted for age and sex; Model 2: adjusted for age, sex, race/ethnicity, smoking status, and glycohemoglobin levels (continuous); Model 3: adjusted for variables in Model 2 plus albumin, triglycerides, and high-density lipoprotein levels (all continuous); Model 4: adjusted for variables in Model 3 plus corrected total calcium, 25-hydroxyvitamin D, and estimated glomerular filtration rate (all continuous).