Subgroup analyses and sensitivity analyses for clinical characteristics and study quality
| GFR | Proteinuria | |||||||
|---|---|---|---|---|---|---|---|---|
| Subgroups | Number of comparisons | Mean difference (95% CI) | I2 (%) | p Value* | Number of comparisons | Mean difference (95% CI) | I2 (%) | p Value* |
| BMI | ||||||||
| Overweight or obese (BMI ≥25) | 6 | 6.51 (0.29 to 12.73) | 89 | 0.57 | 8 | 0.58 (−0.13 to 1.28) | 87 | <0.0001 |
| Healthy weight (BMI <25) | 3 | 0.82 (−11.12 to 12.76) | 89 | 3 | −0.01 (−0.91 to 0.90) | 82 | ||
| Unknown | 4 | 9.50 (−1.66 to 20.67) | 96 | 4 | −1.64 (−2.27 to −1.01) | 50 | ||
| Type of diabetes | ||||||||
| T1DM | 6 | 6.73 (−1.45 to 14.91) | 94 | 0.05 | 6 | −1.02 (−1.79 to −0.25) | 81 | 0.002 |
| T2DM | 5 | 8.63 (−0.24 to 17.50) | 87 | 6 | 0.88 (0.11 to 1.64) | 88 | ||
| Mixed | 2 | 0.19 (−0.43 to 0.80) | 0 | 3 | −0.48 (−1.57 to 0.61) | 84 | ||
| Nephropathy stage | ||||||||
| Normoalbuminuria or mix of normoalbuminuria and microalbuminuria | 2 | 1.81 (−1.91 to 5.53) | 0 | 0.03 | 3 | 1.83 (0.63 to 3.03) | 86 | 0.001 |
| Microalbuminuria | 2 | 2.96 (−18.41 to 24.32) | 95 | 3 | −0.33 (−0.84 to 0.18) | 32 | ||
| Mix of microalbuminuria and macroalbuminuria | 2 | −2.18 (−8.94 to 4.58) | 0 | 1 | −1.04 (−2.15 to 0.06) | – | ||
| Macroalbuminuria | 7 | 9.05 (4.30 to 13.81) | 95 | 8 | −0.69 (−1.45 to 0.07) | 89 | ||
| Intervention period | ||||||||
| Short (6–23 months)† | 7 | 10.52 (3.69 to 17.35) | 92 | 0.06 | 8 | −0.18 (−1.27 to 0.91) | 92 | 0.89 |
| Long (≥24 months) | 6 | 1.33 (−5.56 to 8.23) | 92 | 7 | −0.09 (−0.78 to 0.60) | 90 | ||
| Overall risk of bias | ||||||||
| High (risk score 4–8) | 5 | 3.01 (−5.92 to 11.94) | 85 | 0.50 | 6 | −0.16 (−1.04 to 0.71) | 91 | 0.95 |
| Low (risk score 1–3) | 8 | 6.37 (2.58 to 10.16) | 92 | 9 | −0.12 (−0.96 to 0.71) | 91 | ||
| Diet compliance: | ||||||||
| Fair (APIR <0.9) | 9 | 8.92 (2.75 to 15.09) | 94 | 0.006 | 10 | −0.42 (−1.32 to 0.48) | 91 | 0.1 |
| Poor (APIR ≥0.9) | 4 | 0.03 (−1.49 to 1.56) | 0 | 5 | 0.43 (−0.06 to 0.93) | 76 | ||
| Measurement index of proteinuria | ||||||||
| Proteinuria (g/24 h) | – | – | – | – | 4 | −0.71 (−1.99 to 0.57) | 94 | <0.00001 |
| Albuminuria (mg/24 h) | – | – | – | 7 | 0.26 (−0.33 to 0.85) | 80 | ||
| Albuminuria (μg/min) | – | – | – | 3 | −1.30 (−2.39 to −0.22) | 67 | ||
| Albumin/Cre ratio (mg/mmol) | – | – | – | 1 | 2.94 (1.99 to 3.88) | – | ||
| Sensitivity analysis | ||||||||
| Excluding a subgroup of normoalbuminuria with separate data | 12 | 6.31 (2.47 to 10.15) | 92 | 14 | −0.26 (−0.88 to 0.36) | 91 | ||
| Excluding studies including normoalbuminuria | 11 | 6.52 (2.52 to 10.52) | 93 | 12 | −0.62 (−1.15 to −0.09) | 84 | ||
*p Value for subgroup difference.
†Short intervention period was 3–23 months for proteinuria.
APIR, actual protein intake ratio; BMI, body mass index; Cre ratio, creatine ratio; GFR, glomerular filtration rate; T1DM, type 1 diabetes mellitus; T2DM, type 2 diabetes mellitus.