Table 3. Univariable meta-regression results (R2 and p-values) and pooled RR for diabetes and impaired glucose tolerance in study subgroups.
| Factor and subgroup | RR per year later age at menarche | Early versus later (Ref) menarche | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Not adiposity adjusted | Adiposity adjusted | Not adiposity adjusted | Adiposity adjusted | |||||||||||||
| N | RR (95% CI) | p-Valuea | R2 (%) | N | RR (95% CI) | p-Valuea | R2 (%) | N | RR (95% CI) | p-Valuea | R2 (%) | N | RR (95% CI) | p-Valuea | R2 (%) | |
| Ethnicity | 53.7 | 99.63 | 37.9 | 16.3 | ||||||||||||
| Asian | 3 | 0.95 (0.92, 0.97) | 2 | 0.98 (0.97, 0.99) | 11 | 1.33 (1.06, 1.69) | 9 | 1.23 (1.02, 1.49) | ||||||||
| White | 5 | 0.88 (0.86, 0.90) | 0.002 | 6 | 0.95 (0.92, 0.98) | 0.001 | 5 | 1.72 (1.61, 1.83) | 0.013 | 5 | 1.27 (1.18, 1.36) | 0.290 | ||||
| Multi-ethnic | 3 | 0.91 (0.87, 0.96) | 0.154 | 4 | 0.98 (0.96, 1.00) | 0.871 | 7 | 1.30 (1.18, 1.42) | 0.743 | 7 | 1.11 (1.02, 1.20) | 0.472 | ||||
| Study average AAM, yearsb | 33.3 | 0 | 38 | 18.9 | ||||||||||||
| <13.5 | 5 | 0.89 (0.86, 0.91) | 6 | 0.96 (0.93, 0.98) | 8 | 1.59 (1.45, 1.75) | 7 | 1.26 (1.19, 1.34) | ||||||||
| ≥13.5 | 2 | 0.92 (0.85, 1.01) | 0.154 | 2 | 0.94 (0.86, 1.03) | 0.719 | 8 | 1.36 (1.17, 1.58) | 0.036 | 6 | 1.27 (1.03, 1.55) | 0.820 | ||||
| p-Value for linear trendc | <0.001 | 0.400 | 0.014 | 0.677 | ||||||||||||
N is the number of estimates; R2 (%) is the percent of heterogeneity explained.
aThe reference category in meta-regression models is the first subgroup in each factor.
bStudies that did not report the information were excluded.
cUsing study average AAM as a continuous variable.
AAM, age at menarche; RR, relative risk.