Table 3.
Changes in Serum Biochemical Levels, Metabolic Factors, and Quality of Life from Baseline to 96 Weeks.*
| Variable | Change from Baseline | P Value† | |||
|---|---|---|---|---|---|
| Placebo (N = 74) |
Vitamin E (N = 78) |
Pioglitazone (N = 70) |
Vitamin E vs. Placebo |
Pioglitazone vs. Placebo |
|
| Serum enzymes and bilirubin | |||||
| Alanine aminotransferase (U/liter) | −20.1 | −37.0 | −40.8 | 0.001 | <0.001 |
| Aspartate aminotransferase (U/liter) | −3.8 | −21.3 | −20.4 | <0.001 | <0.001 |
| γ-Glutamyltransferase (U/liter) | −4.0 | −14.0 | −21.1 | 0.003 | <0.001 |
| Alkaline phosphatase (U/liter) | −3.8 | −9.3 | −12.0 | 0.008 | 0.004 |
| Total bilirubin (mg/dl) | 0.06 | 0.04 | −0.04 | 0.56 | 0.07 |
| Lipids | |||||
| Triglycerides (mg/dl) | −6.7 | −0.6 | −19.8 | 0.45 | 0.16 |
| Cholesterol (mg/dl) | |||||
| Total | −9.6 | −13.6 | −11.4 | 0.25 | 0.50 |
| High-density lipoprotein | −1.9 | −0.9 | 1.1 | 0.51 | 0.008 |
| Low-density lipoprotein | −5.8 | −12.0 | −8.1 | 0.07 | 0.26 |
| Metabolic factors | |||||
| Fasting serum glucose (mg/dl) | 1.8 | 1.8 | −3.1 | 0.81 | 0.006 |
| Insulin resistance‡ | 0.4 | 0.4 | −0.7 | 0.80 | 0.03 |
| Weight (kg) | 0.7 | 0.4 | 4.7 | 0.65 | <0.001 |
| Body-mass index | 0.4 | 0.1 | 1.8 | 0.50 | <0.001 |
| Waist circumference (cm) | 0.2 | −0.4 | 3.3 | 0.53 | 0.06 |
| Body composition (% fat) | 0 | 0.4 | 2.7 | 0.50 | <0.001 |
| Quality of life§ | |||||
| SF-36 score, physical component | −0.3 | 0.4 | −0.9 | 0.45 | 0.93 |
| SF-36 score, mental component | 0.4 | −0.5 | −1.9 | 0.76 | 0.23 |
The numbers of subjects listed for the three study groups are the numbers for whom data on alanine aminotransferase levels were available. The total numbers of subjects included in the analyses of other variables ranged from 212 to 223. The change from baseline is the value at 96 weeks minus the baseline value. To convert the values for bilirubin to micromoles per liter, multiply by 17.1. To convert the values for triglycerides to millimoles per liter, multiply by 0.01129. To convert the values for cholesterol to millimoles per liter, multiply by 0.02586. To convert the values for glucose to millimoles per liter, multiply by 0.05551.
P values were calculated with the use of analysis-of-covariance models, regressing change from baseline to 96 weeks on treatment group and baseline value of the outcome measure.
The homeostasis model assessment for insulin resistance (HOMA-IR) was used to calculate insulin resistance, according to the following formula: (milligrams of glucose per deciliter × microunits of insulin per milliliter) ÷ 405. Diabetes developed in four subjects assigned to the vitamin E group, and these subjects were not given an oral glucose-tolerance test at 96 weeks. Their HOMA-IR values at 96 weeks were imputed as the 95th percentile value at baseline. Analyses were performed with the use of ranks owing to asymmetry in the distribution of change in HOMA-IR values.
Scores on the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) were standardized to the 1998 U.S. general population with a mean (±SD) of 50±10.