Table 1.
Participants’ Baseline Characteristics According to Baseline Selenium Levels Measured in Nail Samples.
| Means (SD) by Selenium Quartile Groups* | ||||||
|---|---|---|---|---|---|---|
| Baseline Characteristics | Total n=140 | Q1(low) n=35 | Q2 n=35 | Q3 n=35 | Q4(high) n=35 | P-value |
| Selenium level, mg/kg | 0.41(0.2) | 0.19(0.03) | 0.34(0.04) | 0.45(0.03) | 0.67(0.1) | <0.001 |
| Age | 69.35(4.1) | 68.70(3.3) | 69.68(4.9) | 69.08(3.6) | 69.96(4.1) | 0.409 |
| Male, % | 49.2 | 54.0 | 56.0 | 50.0 | 36.7 | 0.21 |
| Body Mass Index, kg/m2 | 22.94(3.6) | 22.04(2.7) | 21.92(3.2) | 23.38(3.5) | 24.44(4.5) | 0.001 |
| Systolic blood pressure, mmHg | 143.21(24.2) | 133.21(19.7) | 141.54(20.6) | 148.3(27.3) | 149.9(24.1) | 0.002 |
| Diastolic blood pressure, mmHg | 83.03(12.34) | 79.98(10.84) | 83.48(12.49) | 84.56(13.79) | 84.12(11.89) | 0.236 |
| life-long residency, % | 55.3 | 60.0 | 50.0 | 52.0 | 59.2 | 0.674 |
| Alcohol, % | 46.2 | 60.0 | 42.0 | 46.0 | 36.7 | 0.179 |
| Smoking, % | 50.8 | 23.8 | 25.7 | 28.7 | 21.8 | 0.592 |
| Self-reported history of, % | ||||||
| Diabetes | 4.0 | 4.0 | 4.0 | 6.0 | 2.0 | 0.800 |
| Hypertension | 15.6 | 10.0 | 8.0 | 20.0 | 24.5 | 0.07 |
| Stroke | 1.0 | 0 | 0 | 0 | 4.1 | 0.103 |
| Heart Attack | 3.5 | 6.0 | 2.0 | 4.0 | 2.0 | 0.66 |
| Cholesterol, mmol/L | 4.00(0.8) | 3.99(.7) | 3.68(.6) | 3.87(.7) | 4.24(.7) | 0.004 |
| HDL, mmol/L | 1.15(0.3) | 1.30(.3) | 1.13(.2) | 1.08(.2) | 1.13(.3) | 0.02 |
| Triglyceride, mmol/L | 1.11(0.3) | 1.2(.7) | .96(.3) | 1.11(8) | 1.09(.6) | 0.356 |
*
Range of baseline selenium levels is lower than 0.245 mg/kg in the lowest quartile (Q1), from 0.246 to 0.407 mg/kg in Q2, from 0.408 to 0.523 in Q3, and higher than 0.523 mg/kg in the highest quartile (Q4).