Table 3. Results of factor analysis, variance components and heritability estimation.
| Factor I | Factor II | Factor III | Factor IV | ||
|---|---|---|---|---|---|
| (GERD symptoms) | (SBP/ DBP) | (WC/FPG/ TG/HDL-C) | (Fibrinogen/CRP | ||
| Factor loadings | |||||
| General well-being of GERD | 0.663 | -0.075 | 0.055 | 0.160 | |
| Acidity complaints | 0.805 | 0.125 | 0.077 | -0.017 | |
| Upper abdominal complaints | 0.838 | 0.034 | -0.085 | -0.023 | |
| Lower abdominal complaints | 0.823 | 0.020 | -0.093 | -0.012 | |
| Nausea | 0.730 | 0.032 | -0.009 | 0.012 | |
| Sleep disturbances | 0.606 | -0.070 | 0.077 | 0.083 | |
| WC | 0.014 | 0.380 | 0.545 | 0.357 | |
| SBP | 0.023 | 0.901 | 0.110 | 0.068 | |
| DBP | 0.049 | 0.906 | 0.033 | 0.032 | |
| FPG | 0.053 | 0.210 | 0.440 | 0.201 | |
| TG | -0.018 | 0.282 | 0.722 | 0.085 | |
| HDL-C | 0.050 | 0.068 | -0.837 | 0.081 | |
| Fibrinogen | -0.014 | -0.020 | -0.061 | 0.885 | |
| CRP | 0.044 | 0.147 | 0.122 | 0.844 | |
| Percentaje of variance (%) | 24.1 | 14.0 | 12.7 | 12.3 | |
| Heritability, h2 (SE) | 0.31 (0.08)* | 0.43 (0.07)* | 0.53 (0.08)* | 0.48 (0.08)* | |
All traits were treated as continuous. The GERD symptom variables were square root transformed; metabolic syndrome components and inflammation components were log10 transformed.
* Adjusted for age and sex. P-value < 1.0 x 10−6
GERD, gastroesophageal reflux disease; WC, waist circumference; SBP, systolic blood pressure; DBP, diastolic blood pressure; TG, triglycerides; HDL-C, high-density lipoprotein-cholesterol; FPG, fasting plasma glucose; CRP, C-reactive protein.