Table 1. Characteristics of females by age at menarche group in ALSPAC at age 8 y and 18 y.
| Characteristic | Age at menarche among females Sample mean (SD) = 12.37 y (1.12 y) |
P-value | |||
|---|---|---|---|---|---|
| Earliest (8–11 y) N = 447 |
Intermediate (12 y) N = 722 |
Latest (13–16 y) N = 943 |
Intermediate versus earliest | Latest versus earliest | |
| Mother has no further academic education—N (%) | 249 (55.70) | 384 (53.19) | 493 (52.28) | 0.40 | 0.23 |
| After puberty onset (age 18 y assessment) | |||||
| Body mass index (kg/m2)—mean (SD) | 24.39 (4.73) | 23.15 (4.30) | 22.04 (3.67) | 6.76 × 10−06 | 4.53 × 10−20 |
| Fat mass index (kg/m2)—mean (SD) | 9.06 (3.76) | 8.08 (3.32) | 7.21 (3.04) | 7.85 × 10−06 | 4.70 × 10−19 |
| Systolic blood pressure (mm Hg)—mean (SD) | 111.07 (8.19) | 110.23 (7.84) | 109.23 (7.58) | 0.09 | 7.70 × 10−05 |
| Diastolic blood pressure (mm Hg)—mean (SD) | 66.30 (6.22) | 64.97 (6.20) | 64.34 (5.76) | 4.42 × 10−04 | 3.19 × 10−08 |
| Triglycerides (mmol/l)—mean (SD) | 0.93 (0.32) | 0.92 (0.31) | 0.92 (0.31) | 0.54 | 0.60 |
| HDL cholesterol (mmol/l)—mean (SD) | 1.47 (0.23) | 1.49 (0.23) | 1.50 (0.23) | 0.22 | 0.05 |
| LDL cholesterol (mmol/l)—mean (SD) | 1.12 (0.35) | 1.14 (0.35) | 1.16 (0.36) | 0.39 | 0.15 |
| Total cholesterol (mmol/l)—mean (SD) | 3.71 (0.65) | 3.76 (0.65) | 3.80 (0.68) | 0.30 | 0.08 |
| Glucose (mmol/l)—mean (SD) | 4.06 (0.36) | 4.04 (0.31) | 4.05 (0.41) | 0.42 | 0.68 |
| Glycoprotein acetyls (mmol/l)—mean (SD) | 1.26 (0.15) | 1.24 (0.13) | 1.24 (0.13) | 0.11 | 0.06 |
| Before puberty onset (age 8 y assessment) | |||||
| Body mass index (kg/m2)—mean (SD) | 17.21 (2.32) | 16.42 (2.13) | 15.71 (1.72) | 6.03 × 10−08 | 4.41 × 10−29 |
| Fat mass index (kg/m2)—mean (SD) | 5.91 (2.32) | 5.01 (2.26) | 4.26 (2.02) | 2.68 × 10−09 | 1.47 × 10−31 |
| Systolic blood pressure (mm Hg)—mean (SD) | 100.88 (9.93) | 99.02 (9.18) | 97.73 (8.72) | 0.003 | 1.25 × 10−07 |
| Diastolic blood pressure (mm Hg)—mean (SD) | 57.79 (6.67) | 57.07 (6.56) | 56.29 (6.34) | 0.09 | 2.21 × 10−04 |
| Triglycerides (mmol/l)—mean (SD) | 1.09 (0.42) | 1.09 (0.36) | 1.06 (0.36) | 0.98 | 0.27 |
| HDL cholesterol (mmol/l)—mean (SD) | 1.45 (0.21) | 1.48 (0.19) | 1.50 (0.20) | 0.02 | 0.001 |
| LDL cholesterol (mmol/l)—mean (SD) | 1.23 (0.31) | 1.29 (0.36) | 1.27 (0.32) | 0.03 | 0.09 |
| Total cholesterol (mmol/l)—mean (SD) | 3.94 (0.58) | 4.04 (0.62) | 4.02 (0.59) | 0.04 | 0.06 |
| Glucose (mmol/l)—mean (SD) | 4.17 (0.51) | 4.14 (0.47) | 4.11 (0.51) | 0.40 | 0.14 |
| Glycoprotein acetyls (mmol/l)—mean (SD) | 1.27 (0.14) | 1.25 (0.13) | 1.23 (0.14) | 0.06 | 0.001 |
Sample sizes vary as participants described are those with data on age at menarche, covariates, at least 1 adiposity trait, and at least 1 cardiometabolic trait. Age at menarche was self-reported rounded down to the nearest whole year; the mean value was calculated from these values. ‘No further academic education’ defined as highest level of education attained being Certificate of Secondary Education, vocational, or O level (not A level or degree).
HDL, high-density lipoprotein; LDL, low-density lipoprotein.