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Table 1 Characteristics of the female population in the 1982 (N: 1637) and 1993 (N: 2033) Pelotas birth cohorts, Brazilc

From: Impact of the age at menarche on body composition in adulthood: results from two birth cohort studies

Variables Age at Menarche (years)
≤11 12–13 ≥14 ≤11 12–13 ≥14
1982 1993
N (%) or Mean (SD)
Gestational age (w)a
 ≤37 35 (10.9) 96 (13.6) 39 (14.1) 71 (14.3) 158 (17.1) 71 (20.3)
 38–39 125 (39.1) 272 (38.4) 97 (35.2) 177 (35.6) 307 (33.2) 109 (31.1)
 ≥40 160 (50.0) 340 (48.0) 140 (50.7) 249 (50.1) 459 (49.7) 170 (48.6)
Birth weight (g)a
 <2500 37 (9.2) 75 (8.6) 27 (7.5) 58 (10.6) 103 (10.0) 57 (14.0)
 2500–2999 118 (29.2) 263 (30.1) 111 (31.0) 140 (25.4) 322 (31.1) 120 (29.4)
 3000–3499 145 (35.9) 316 (36.2) 138 (38.6) 236 (42.9) 380 (36.7) 157 (38.5)
 ≥3500 104 (25.7) 220 (25.1) 82 (22.9) 116 (21.0) 230 (22.2) 74 (18.1)
Skin colora
 White 290 (71.6) 666 (76.2) 275 (76.8) 355 (65.9) 653 (64.9) 264 (65.5)
 Non-white 115 (28.4) 208 (23.8) 83 (23.2) 184 (34.1) 353 (35.1) 139 (34.5)
WH z-score at 4 yb 0.70 (0.99) 0.47 (0.95) 0.38 (0.92) - - -
BMI z-score at 11 yb - - - 0.74 (1.08) 0.24 (1.20) −0.26 (1.22)
Age at Menarche (y)a 405 (24.7) 874 (53.4) 358 (21.9) 550 (27.6) 1037 (52.0) 408 (20.5)
Age at Menarche (y)b 10.5 (0.8) 12.4 (0.5) 14.5 (0.8) 10.6 (0.7) 12.4 (0.5) 14.4 (0.7)
BMI (kg/m2)a
 <25 123 (30.6) 440 (50.6) 202 (56.4) 347 (63.1) 732 (70.7) 336 (82.4)
 25–29.9 129 (32.1) 250 (28.7) 87 (24.3) 117 (21.3) 199 (19.2) 60 (14.7)
 ≥30 150 (37.3) 180 (20.7) 69 (19.3) 86 (15.6) 104 (10.1) 12 (2.9)
WC (cm)b 84.8 (12.9) 79.9 (11.6) 78.4 (11.3) 76.0 (10.7) 73.7 (9.6) 70.9 (7.9)
AVFLT (cm)b 5.29 (1.91) 4.87 (1.65) 4.74 (1.41) - - -
FMI (kg/m2)b 12.5 (4.7) 10.3 (4.1) 9.7 (4.2) 9.4 (3.8) 8.4 (3.5) 7.2 (3.0)
FFMI (kg/m2)b 16.4 (2.2) 15.7 (1.7) 15.6 (1.7) 15.1 (1.5) 15.0 (1.5) 14.8 (1.3)
  1. Abbreviation: SD standard deviation, w weeks, g grams, WH weight for height z-score at 4 years, y years, BMI body mass index, WC waist circumference, AVFLT abdominal visceral fat layer thickness, FMI fat mass index, FFMI fat-free mass index
  2. aN (%); bMean (SD) cThe total number of women per variable may not add up to 1637 (1982) or 2033 (1993) due to missing data