Table 3.
Glucose and insulin dynamics from oral glucose tolerance test (OGTT) and frequently sampled intravenous glucose tolerance test (FSIVGTT): intervention group effects for evaluable participants (n = 100)
| Outcomesa | Control (C) (N = 30) |
Nutrition education (N) (N = 39) |
Nutrition + strength training (N+ST) (N = 31) |
Significant effectb | |||
|---|---|---|---|---|---|---|---|
| African Americans (n = 15) | Latinos (n = 15) | African Americans (n = 18) | Latinos (n = 21) | African Americans (n = 15) | Latinos (n = 16) | ||
| OGTT (3-h) | |||||||
| Fasting glucose (mg/dl) | −2.7 (3.6) | −5.3 (6.6) | −2.8 (5.9) | −0.9 (7.6) | −2.7 (4.8) | −2.5 (4.8) | – |
| 2–hglucose (mg/dl) | −6.9 (22.3) | 0.7 (20.0) | 7.9 (13.6)*** | −17.0 (26.1) | −0.1 (22.7) | −10.7 (23.6) | I×E (<0.01) |
| Fasting insulin (μU/ml) | 2.2 (6.3) | −1.0 (13.7) | −1.3 (7.5) | −2.6 (7.1) | −2.3 (6.9) | −4.0 (8.6) | – |
| 2-h Insulin (μU/ml) | −1.2 (82.7) | 35.1 (133.0) | 21.8 (55.0) | −80.9 (246.8) | −34.9 (79.3) | −34.1 (110.8) | – |
| Glucose IAUC (nmol/min/l) | 1.9 (36.1) | 22.1 (41.5) | 9.8 (31.5)*** | −19.3 (35.8) | −15.8 (29.0) | −4.1 (37.9) | I×E (0.02) |
| Insulin IAUC (nmol/min/l) | 18.5 (148.6) | −8.1 (156.5) | 33.8 (184.4) | −78.9 (127.2) | −49.1 (100.4) | −43.9 (137.3) | – |
| HOMA | 0.4 (1.7) | −1.1 (1.8) | −0.1 (1.4) | −0.6 (1.9) | −0.7 (1.5) | −1.0 (1.9) | – |
| FSIVGTT | |||||||
| SI (×10−4 min−1/μU/ml) | −0.4 (0.7) | −0.4 (1.8) | 0.1 (0.6)* | 0.3 (1.3)* | 0.0 (0.7) | −0.2 (0.9) | I (<0.01) |
| AIR (μU/ml × 10 min) | 132.3 (753.8) | 199.7 (1,433.5) | 384.3 (400.3) | 29.4 (1,153.1) | −96.8 (569.1) | −40.4 (985.3) | I×E (0.05) |
| DI (×10−4 min−1) | −468.3 (1,003.7) | 53.3 (1,344.3) | 342.8 (1,081.1)*,** | 582.9 (1,090.5)*,** | −209.1 (1,287.6) | −277.3 (1,271.9) | I (<0.01) |
| SG (% per min) | 0.0 (0.02) | 0.0 (0.04) | 0.0 (0.01) | 0.0 (0.04) | 0.0 (0.01) | 0.0 (0.02) | – |
Data are unadjusted change scores: mean (s.d.).
P-values were calculated using two-way ANCOVA. Covariates included: Tanner stage, sex, DEXA fat and lean tissue mass. AIR included SI as a covariate. While unadjusted scores are reported here for all variables, analyses were based on log scores for fasting insulin, 2-hr insulin, insulin IAUC, HOMA, SI, AIR, DI, and SG. Means differences and interactions across intervention (I) and ethnic (E) groups are significantly different from one another using Bonferroni multiple comparisons (P < 0.05).
Denotes significantly different from C group at (P < 0.05).
Denotes significantly different from N+ST group at (P < 0.05).
Denotes significant intervention by ethnicity interaction at P < 0.05.
AIR, acute insulin response to glucose; DI, disposition index; HOMA, homeostasis model assessment; IAUC, incremental areas under the curve; SG, glucose effectiveness; SI, insulin sensitivity.