Table 2.
Association between change in lifestyle factor (categorical1 and continuous2) and glycemic outcomes, by sex and visit3
| A. Association with HbA1c | N | HbA1c Month 6 | HbA1c Δ 6-0 | P-value | N | HbA1c Month 24 | HbA1c Δ 24-0 | P-value |
|---|---|---|---|---|---|---|---|---|
| PWC-170 (m/min) | ||||||||
| Female | ||||||||
|
| ||||||||
| Worsened (Δ <−1) | 64 | 6.0 (0.8) | 0.1 (0.7) | p=ns | 47 | 6.0 (0.9) | 0.4 (0.7) | p=0.01 |
| No change | 105 | 6.1 (1.0) | 0.1 (0.8) | 53 | 5.9 (0.7) | 0.0 (0.6)b | ||
| Improved (Δ >1) (S) | 62 | 5.9 (1.2) | 0.1 (1.0) | 27 | 6.4 (1.8) | 0.7 (1.8)b | ||
| Continuous Δ | β (SE) = −0.019 (0.027) | p=ns | β (SE) = 0.018 (0.039) | p=ns | ||||
|
| ||||||||
| Male | ||||||||
|
| ||||||||
| Worsened (Δ <−1) | 34 | 6.2 (0.9) | 0.4 (0.6)a,c | p=0.001 | 34 | 6.2 (1.3) | 0.5 (1.3)a | p=0.01 |
| No change | 54 | 5.9 (0.8) | −0.1 (0.4)c | 23 | 6.0 (0.9) | 0.2 (0.8) | ||
| Improved (Δ >1) (S) | 50 | 5.7 (0.7) | −0.1 (0.6)a | 21 | 5.6 (0.6) | −0.2 (0.5)a | ||
| Continuous Δ | β (SE) = −0.040 (0.017) | p=0.02 | β (SE) = −0.097 (0.042) | p=0.02 | ||||
|
| ||||||||
| Saturated fat (% of energy/day) | ||||||||
| Female | ||||||||
|
| ||||||||
| Worsened (Δ>1.3) | 109 | 6.2 (1.1) | 0.2 (0.9) | p=ns | 55 | 6.2 (0.9) | 0.5 (0.9)a,c | p=0.01 |
| No change | 100 | 6.0 (1.1) | 0.1 (0.9) | 60 | 6.0 (0.9) | 0.2 (0.8)c | ||
| Improved (Δ< −1.5) (S) | 98 | 6.1 (0.9) | 0.1 (0.8) | 80 | 5.9 (0.8) | 0.1 (0.7)a | ||
| Continuous Δ | β (SE) = 0.012 (0.014) | p=ns | β (SE) = 0.023 (0.015) | p=ns | ||||
|
| ||||||||
| Male | ||||||||
|
| ||||||||
| Worsened (Δ>1.3) | 51 | 6.0 (0.8) | 0.1 (0.5) | p=ns | 27 | 6.0 (0.8) | 0.1 (0.7) | p=ns |
| No change | 61 | 5.9 (1.0) | 0.1 (0.7) | 37 | 6.1 (1.0) | 0.1 (0.8) | ||
| Improved (Δ< −1.5) (S) | 62 | 5.9 (0.9) | −0.0 (0.7) | 38 | 5.9 (1.2) | 0.1 (1.0) | ||
| Continuous Δ | β (SE) = 0.019 (0.014) | p=ns | β (SE) = 0.014 (0.021) | p=ns | ||||
|
| ||||||||
| Fiber (g/day) | ||||||||
| Female | ||||||||
|
| ||||||||
| Worsened (Δ< −2) | 100 | 6.2 (0.9) | 0.2 (0.7) | p=ns | 67 | 6.3 (0.9) | 0.4 (0.9)a,c | p=0.007 |
| No change | 109 | 6.1 (1.1) | 0.1 (0.9) | 58 | 6.0 (0.8) | 0.2 (0.8)c | ||
| Improved (Δ>1.5) (S) | 98 | 6.0 (1.1) | 0.2 (0.9) | 70 | 5.8 (0.8) | 0.1 (0.7)a | ||
| Continuous Δ | β (SE) = −0.007 (0.010) | p=ns | β (SE) = −0.030 (0.011) | p=0.008 | ||||
|
| ||||||||
| Male | ||||||||
|
| ||||||||
| Worsened (Δ< −2) | 60 | 6.0 (0.9) | 0.1 (0.7) | p=ns | 32 | 5.7 (0.6) | 0.0 (0.7) | p=ns |
| No change | 52 | 5.9 (0.9) | 0.0 (0.5) | 25 | 5.9 (0.9) | 0.3 (0.6) | ||
| Improved (Δ>1.5) (S) | 62 | 6.0 (0.9) | 0.1 (0.7) | 45 | 6.1 (0.9) | 0.2 (0.8) | ||
| Continuous Δ | β (SE) = −0.004 (0.009) | p=ns | β (SE) = 0.014 (0.012) | p=ns | ||||
| B. Association with Glycemic Failure | N | % Failed after Month 6 | P-value |
|---|---|---|---|
| PWC-170 (m/min) | |||
| Female | |||
|
| |||
| Worsened (Δ <−1) | 64 | 34% | p=ns |
| No change | 105 | 43% | |
| Improved (Δ >1) (S) | 62 | 29% | |
| Continuous Δ | OR = 1.0 (0.9=1.2) | p=ns | |
|
| |||
| Male | |||
|
| |||
| Worsened (Δ <−1) | 34 | 62%a,c | p=0.007 |
| No change | 54 | 43%c | |
| Improved (Δ >1) (S) | 50 | 26%a | |
| Continuous Δ | OR = 0.8 (0.7–0.9) | p=0.04 | |
|
| |||
| Sweetened beverages (servings/day) | |||
| Female | |||
|
| |||
| Worsened or stayed at >0 | 114 | 42% | p=ns |
| Improved or stayed at 0 (S) | 193 | 34% | |
| Continuous Δ | OR = 1.2 (0.9–1.5) | p=ns | |
|
| |||
| Male | |||
|
| |||
| Worsened or stayed at >0 | 60 | 52% | p=ns |
| Improved or stayed at 0 (S) | 114 | 39% | |
| Continuous Δ | OR = 1.6 (1.1–2.5) | p=0.04 | |
In part A, mean (SD) HbA1c values and change from baseline by sex and visit are shown. In part B, percents of participants who failed to control glycemia on the randomized treatment assignment after 6 months are given. Tests were performed to examine differences in glycemic outcome across categories of change in the lifestyle factor. Lifestyle change categories indicating a beneficial change are labeled with ‘(S)’. If the overall test was significant, pairwise comparisons were performed and significance was denoted by the superscripts (a) comparing worsened vs improved, (b) comparing no change vs improved, and (c) comparing worsened vs no change.
In part A, slope (β) and standard error (SE) represent a change in HbA1c per 1 unit increase in the lifestyle factor (i.e., a positive slope means HbA1c increases as lifestyle factor increases, whereas a negative slope means HbA1c decrease as lifestyle factor increases). In part B, odds ratio (OR) and 95% confidence interval give the risk of glycemic failure; OR<1 indicates greater fitness is protective and OR>1 indicates that more sweetened beverages increases risk of failure.
Only lifestyle factors with significant results are shown; all models were adjusted for the following standard set of covariates: baseline HbA1c, treatment group, age at baseline, and medication adherence. Italic bold values indicate significant associations (p<0.05).