Table 2.
Baseline values and mean changes for primary and secondary characteristics following 6-month vitamin D intervention
| Placebo (n = 75a) | Vitamin D (n = 57a) | P-value between groups¶ | Adjusted P-value between groups# | |||||
|---|---|---|---|---|---|---|---|---|
| Baselineb | Changed | p-value within group‖ | Baselineb | Changed | P-value within group‖ | |||
| Weight (kg) | 91.3 ± 18.9 | − 0.57 (− 1.53, 0.39) | 0.24 | 86.3 ± 19.6 | 0.16 (− 0.73, 1.06) | 0.71 | 0.28 | − |
| BMI (kg/m2) | 32.0 ± 5.9 | − 0.19 (− 0.51, 0.13) | 0.24 | 30.0 ± 6.2 | 0.05 (− 0.25, 0.35) | 0.75 | 0.30 | − |
| Waist Circumference (cm) | 103.8 ± 12.6 | − 0.16 (− 1.08, 0.76) | 0.73 | 101.5 ± 11.0 | − 0.39 (− 1.25, 0.47) | 0.37 | 0.73 | − |
| HbA1c (%) | 5.9 ± 0.22 | 0.007 (− 0.10, 0.11) | 0.90 | 5.9 ± 0.19 | − 0.04 (− 0.12, 0.05) | 0.37 | 0.54 | − |
| HbA1c (mmol/mol) | 41.3 ± 2.37 | 0.075 (− 1.07,1.22) | 0.90 | 40.9 ± 2.02 | − 0.40 (− 1.31,0.50) | 0.37 | 0.54 | − |
| SBP (mmHg) | 129.3 ± 15.5 | − 5.04 (− 8.27, − 1.81) | 0.003 | 127.4 ± 12.8 | −6.59 (− 10.44, − 2.74) | 0.001 | 0.54 | − |
| DBP (mmHg) | 76.6 ± 12.0 | − 0.84 (− 3.08, 1.40) | 0.46 | 75.9 ± 9.9 | − 4.87 (− 8.10, − 1.64) | 0.004 | 0.036 | − |
| RBC (× 106 uL) | 5.2 ± 0.51 | − 0.08 (− 0.15, − 0.007) | 0.03 | 5.2 ± 0.58 | − 0.09 (− 0.19, 0.008) | 0.07 | 0.84 | − |
| Hemoglobin (g/dL) | 14.5 ± 1.4 | − 0.17 (− 0.34, − 0.004) | 0.045 | 14.4 ± 1.4 | 0.16 (− 0.89, 1.22) | 0.76 | 0.49 | − |
| Hematocrit (%) | 44.0 (42.0, 45.7)c | 0.0 (− 1.4, 1.6) | 0.46 | 43.2 (41.4, 45.8) | −1.0 (− 2.4, 1.4) | 0.15 | 0.07 | − |
| Total Cholesterol (mmol/L) | 5.1 ± 0.95 | − 0.08 (− 0.25, 0.09) | 0.37 | 5.3 ± 0.86 | − 0.32 (− 0.58, − 0.06) | 0.02 | 0.11 | − |
| HDL (mmol/L) | 1.1 ± 0.23 | − 0.04 (− 0.07, − 0.01) | 0.005 | 1.1 ± 0.26 | 0.03 (− 0.08, 0.14) | 0.58 | 0.15 | − |
| LDL (mmol/L) | 3.4 ± 0.86 | − 0.08 (− 0.29, 0.12) | 0.42 | 3.4 ± 0.80 | − 0.15 (− 0.37, 0.06) | 0.16 | 0.65 | − |
| Triglyceride (mmol/L) | 1.5 ± 0.74 | 0.16 (− 0.10, 0.43) | 0.23 | 1.6 ± 0.84 | 0.16 (− 0.31, 0.63) | 0.49 | 0.99 | − |
| 25 (OH) D (ng/ml) | 17.0 ± 4.6 | − 0.88 (− 2.20, 0.44) | 0.19 | 14.9 ± 4.3 | 19.4 (16.4, 22.5) | < 0.001 | < 0.001 | − |
| PTH (pg/ml) | 57.4 ± 28.3 | 7.7 (− 0.56, 15.9) | 0.07 | 58.2 ± 19.4 | − 3.1 (− 9.4, 3.1) | 0.32 | 0.045 | − |
| Serum Calcium (mmol/L) | 2.25 ± 1.1 | 0.51 (− 0.16, 1.2) | 0.13 | 1.99 ± 1.3 | 0.70 (0.06, 1.3) | 0.03 | 0.67 | − |
| Creatinine (Umol/L) | 74.2 ± 11.3 | − 4.1 (− 7.1, − 1.1) | 0.008 | 73.0 ± 17.1 | 0.53 (− 4.6, 5.7) | 0.84 | 0.11 | − |
| CPK (U/L) | 118.5 (83.5, 201.0)c | − 4.5 (− 32.8, 14.2) | 0.36 | 124.5 (83.7, 185.7) | −2.0 (− 18.0, 15.0) | 0.55 | 0.79 | − |
| C-peptide (U/L) | 2.1 (1.7, 3.1)c | 0.18 (− 0.13, 0.59) | 0.007 | 2.4 (1.9, 3.1) | 0.15 (−0.29, 0.71) | 0.12 | 0.84 | − |
| SGOT (U/L) | 21.0 (18.3, 26.8)c | −2.0 (− 7.0, 1.0) | 0.011 | 22.0 (17.8, 27.3) | −3.0 (− 5.0, 2.0) | 0.062 | 0.88 | − |
| SGPT (U/L) | 26.0 (19.0, 36.8)c | −3.0 (−9.0, 1.0) | < 0.001 | 29.0 (19.0, 42.0) | −3.0 (− 12.0, 3.0) | 0.018 | 0.88 | − |
| ALP (U/L) | 73.7 ± 19.6 | 3.4 (−0.24, 7.0) | 0.07 | 73.8 ± 17.7 | −6.1 (− 10.1, −2.0) | 0.004 | 0.001 | − |
| Bilirubin (umol/L) | 9.05 (7.2, 14.0)c | −0.75 (−2.4, 2.0) | 0.699 | 11.3 (9.7, 15.0) | −1.85 (−5.2, 1.2) | 0.006 | 0.039 | − |
| Mean FPG (mmol/L) | 6.3 ± 0.73 | 0.13 (−0.08, 0.35) | 0.22 | 6.1 ± 0.63 | 0.30 (−0.09, 0.68) | 0.13 | 0.41 | 0.434 |
| 2 h PCG (mmol/L) | 9.3 ± 2.9 | 1.09 (0.44, 1.7) | 0.001 | 9.2 ± 2.4 | 1.15 (0.44, 1.9) | 0.002 | 0.90 | 0.768 |
| Mean FPI (μU/ml) | 9.8 ± 6.1 | 0.64 (−1.4, 2.7) | 0.54 | 9.8 ± 5.0 | − 1.4 (−2.6, −0.19) | 0.024 | 0.11 | 0.137 |
| 2 h PCI (μU/mL) | 64.9 (38.5, 138.3)c | 1.2 (−30.0, 19.2) | 0.717 | 98.6 (70.1, 180.3) | −23.3 (−70.9, 14.2) | 0.06 | 0.22 | 0.882 |
| Matsuda Index | 2.9 (1.7, 4.1)c | 0.21 (−0.84, 0.95) | 0.731 | 2.2 (1.7, 3.4) | 0.08 (−0.54, 0.99) | 0.455 | 0.82 | 0.750 |
| HOMA-IR | 2.5 (1.7, 3.7)c | 0.06 (−0.77, 0.86) | 0.746 | 2.4 (1.5, 3.4) | −0.05 (− 0.94, 0.44) | 0.455 | 0.45 | 0.326 |
| HOMA- β | 65.9 ± 44.3 | −0.38 (−11.7, 11.0) | 0.947 | 71.9 ± 36.8 | −18.6 (−30.4, −6.8) | 0.003 | 0.027 | 0.011 |
| Disposition index | 0.069 (0.034, 0.094) | 0.0017 (−0.05, 0.013) | 0.534 | 0.072 (0.05, 0.14) | −0.0087 (− 0.041, 0.022) | 0.140 | 0.93 | 0.997 |
| Insulinogenic index | 0.58 (0.33, 0.98) | −0.054 (− 0.40, 0.15) | 0.25 | 0.63 (0.45, 1.06) | −0.17 (− 0.30, 0.17) | 0.018 | 0.79 | 0.586 |
Abbreviations: BMI Body mass index, FPI Fasting plasma insulin, SBP Systolic blood pressure, DBP Diastolic blood pressure, RBC Red blood cells, PTH Parathyroid hormone, CPK Creatine phosphokinase, AST Aspartate aminotransferase, ALT Alanine aminotransferase, ALP Alkaline phosphatase, FPG Fasting plasma glucose, FPI Fasting plasma insulin, 2 h PCG 2 h post-challenge glucose, 2 h PCI 2 h post-challenge insulin, HOMA-IR Homeostatic model of assessment - insulin resistance
‖ Data are analyzed by paired sample t-test or Wilcoxon signed rank test where appropriate (level of significance P ≤ 0.05)
¶ Data are analyzed by independent sample t-test (level of significance P ≤ 0.05)
# Data are analyzed by ANCOVA using a general linear model and change values for each respective outcome with age, baseline BMI, gender and ethnicity as covariates
a Initial sample size; the sample size was reduced for some variables due to missing values
b Data are presented as mean ± SD
c Data represented by median and inter-quartile range, Mann-Whitney U-test was used to compare median of the differences
d Mean change; 95% CI or IQR where appropriate in parentheses