Table 1.
Changes in Fasting Biochemistry in CR and Upon RF
| Mean (SEM) | Baseline | CR | RF |
P Values for Overall Comparison |
|||
|---|---|---|---|---|---|---|---|
| Overall | BL-CR | CR-RF | BL-RF | ||||
| Caloric intake, kcal/d | 2255 (53) | 226 (5) | 4552 (324) | <0.0001 | <0.001 | <0.001 | <0.001 |
| Glucose metabolisma | |||||||
| Glucose, mmol/L | 4.74 (0.12) | 3.48 (0.08) | 4.70 (0.11) | <0.0001 | <0.001 | <0.001 | 1.00 |
| Insulin, pmol/L | 44.6 (7.7) | 14.6 (2.6) | 87.6 (14.2) | <0.0001 | <0.001 | <0.001 | <0.001 |
| Glucagon, pg/mL | 24.8 (2.7) | 74.7 (11.6) | 38.2 (4.2) | 0.0001 | <0.001 | <0.001 | 0.01 |
| 3-OH butyrate, µmol/L | 101.8 (7.8) | 1763 (258) | 93.7 (7.4) | <0.0001 | <0.001 | <0.001 | 1.00 |
| Leptin, ng/mL | 3.26 (0.81) | 0.66 (0.19) | 4.55 (1.34) | <0.0001 | <0.001 | <0.001 | 0.22 |
| Lipid metabolismb | |||||||
| Total cholesterol, mmol/L | 4.11 (0.34) | 4.30 (0.29) | 3.73 (0.27) | 0.0009 | 0.18 | <0.001 | 0.006 |
| Triglycerides, mmol/L | 1.31 (0.11) | 1.24 (0.10) | 1.52 (0.14) | 0.10 | |||
| Thyroid functionc | |||||||
| TSH, mU/L | 1.34 (0.18) | 1.14 (0.19) | 2.00 (0.29) | 0.006 | 0.20 | 0.001 | 0.04 |
| Free T4, pmol/L | 13.93 (0.35) | 14.80 (0.51) | 14.94 (0.47) | 0.03 | 0.07 | 1.00 | 0.03 |
| Free T3, pmol/L | 5.02 (0.19) | 3.92 (0.17) | 4.65 (0.28) | 0.001 | <0.001 | 0.002 | 0.12 |
| Steroidsc | |||||||
| Testosterone, nmol/L | 18.51 (2.10) | 17.05 (2.52) | 15.27 (2.12) | 0.10 | |||
| DHEAS, µg/dL | 312.2 (43.8) | 347.1 (39.9) | 298.6 (49.7) | 0.10 | |||
Data are presented as mean (SEM). We tested the correlation of biochemistry assay concentrations with levels measured by metabolomics; the Pearson correlation ranged between ρ = 0.87 and ρ = 0.95 (for glucose, 3-OH butyrate and DHEAS) but was lower for cholesterol (ρ = 0.70; the metabolomics platform measures free cholesterol, whereas the standard clinical assay measures total cholesterol) and free T4 (ρ = 0.50).
Abbreviations: 3-OH butyrate, 3-hydroxybutyrate; BL, baseline; TSH, thyroid-stimulating hormone.
To convert glucose values to milligrams per deciliter, multiply by 18. To convert 3-OH butyrate values to milligrams per deciliter, divide by 96.09. Reference ranges for insulin: 0 to 60 pmol/L; 3-OH butyrate: 20 to 270 µmol/L.
To convert lipid values to milligrams per deciliter, multiply by 38.7 for total cholesterol and 88.5 for triglycerides.
Reference ranges for TSH: 0.35 to 5.5 mU/L; free T4: 10.0 to 19.8 pmol/L; free T3: 3.5 to 6.5 pmol/L; testosterone: 8.0 to 29.0 nmol/L; DHEAS: 161.2 to 561.6 µg/dL.