Table 1.

Characteristics of participants with complete data at both 18th and 22th-year follow-ups compared with those participants with missing data, loss of follow-up or death, stratified by sex

Variables	Men			Women
	Mean or median (SD or p25-p75); %			Mean or median (SD or p25-p75); %
	Participants included	Participants excluded1	p-value	Participants included	Participants excluded1	p-value
	N = 1408	N = 1195		N = 1560	N = 1085
Perinatal
Maternal education (years)	N = 1406	N = 1193	0.183a	N = 1557	N = 1085	0.003a
0–4	25.3	29.2		26.7	32.0
5–8	47.6	45.3		46.4	45.2
9–11	18.6	17.5		19.0	14.5
≥12	8.5	8.0		7.9	8.3
Family income (MMW)	N = 1388	N = 1159	0.039a	N = 1528	N = 970	0.272a
≤1	17.9	20.6		17.3	20.3
1.1–3	42.4	42.3		41.6	40.6
3.1–6	24.4	20.2		24.9	23.5
>6	15.3	16.9		16.2	15.6
Gestational age (weeks)	N = 1391	N = 1159	0.321a	N = 1539	N = 1050	0.002a
<34	1.2	2.0		1.2	2.9
34–36	6.2	6.4		7.8	6.7
37–40	75.8	76.1		77.2	79.3
>40	16.8	15.5		13.8	11.1
Maternal nutritional status (BMI)	N = 1366	N = 1155	0.182a	N = 1530	N = 1046	0.237a
Low weight	10.4	9.1		8.0	7.8
Adequate	67.3	69.7		67.6	71.3
Overweight	17.9	15.7		19.4	16.5
Obese	4.4	5.5		5.0	4.4
Birth weight (grams)	N = 1407	N = 1188	0.017a	N = 1559	N = 1078	< 0.001a
<2500	7.5	10.1		10.9	10.6
2500–2999	22.5	19.2		26.1	33.4
3000–3999	64.0	63.3		59.2	53.6
≥4000	6.0	7.4		3.8	2.4
Length at birth (centimeters)	N = 1395	N = 1165	0.901b	N = 1548	N = 1054	0.029b
	49.1 (2.3)	49.1 (2.6)		48.5 (2.3)	48.3 (2.3)
15 years
Skin color	N = 1345	N = 765	0.108a	N = 1540	N = 673	0.597a
White	63.0	66.5		63.4	64.6
Black, brown or other	37.0	33.5		36.6	35.4
18 years
Smoking habit	N = 1408	N = 606	0.015a	N = 1560	N = 531	0.005a
No	86.0	81.7		88.2	83.2
Yes	14.0	18.3		11.8	16.8
Total physical activity (min/week)	N = 1406	N = 602	0.203c	N = 1559	N = 528	0.966c
	630.0 (300.0 1110.0)	592.5 (260.0; 1140.0)		270.0 (110.0; 600.0)	280.0 (120.0; 600.0)
Total calcium consumption (mg)	N = 1406	N = 587	0.282c	N = 1559	N = 517	0.656c
	674.8 (488.9; 939.4)	670.6 (479.5; 897.8)		638.1 (449.3; 922.1)	660.2 (477.4; 891.4)
Lean mass index (kg/m2)	N = 1408	N = 493	0.281b	N = 1560	N = 390	0.002b
	18.0 (1.5)	18.0 (1.7)		14.0 (1.4)	14.3 (1.6)
Fat mass index (kg/m2)	N = 1408	N = 493	0.012b	N = 1560	N = 390	< 0.001b
	4.1 (2.9)	4.5 (3.5)		8.3 (3.5)	9.0 (3.9)
Body mass index (kg/m2)	N = 1408	N = 570	< 0.001b	N = 1560	N = 449	< 0.001b
	23.0 (3.6)	24.2 (5.5)		23.2 (4.4)	24.6 (5.8)
22 years
Lean mass index (kg/m2)	N = 1408	N = 133	0.185b	N = 1560	N = 217	< 0.001b
	18.2 (1.7)	18.0 (2.0)		14.3 (1.7)	14.8 (1.9)
Fat mass index (kg/m2)	N = 1408	N = 133	0.571b	N = 1560	N = 217	< 0.001b
	5.5 (3.4)	5.7 (4.0)		9.8 (4.1)	11.0 (5.0)
Body mass index (kg/m2)	N = 1408	N = 279	< 0.001b	N = 1560	N = 315	< 0.001b
	24.7 (4.2)	26.2 (6.7)		25.1 (5.3)	27.3 (7.3)
Whole body BMD (g/cm2)	N = 1408	N = 139	0.041b	N = 1560	N = 221	0.532b
	1.3 (0.1)	1.2 (0.1)		1.2 (0.1)	1.2 (0.1)
Lumbar spine BMD (g/cm2)	N = 1408	N = 164	0.542b	N = 1560	N = 220	0.886b
	1.2 (0.1)	1.2 (0.2)		1.2 (0.1)	1.2 (0.1)
Femoral neck BMD (g/cm2)	N = 1408	N = 164	0.187b	N = 1560	N = 220	0.355b
	1.2 (0.2)	1.2 (0.2)		1.0 (0.1)	1.0 (0.1)
Outcome changes (Δ) at 18–22 years*
Whole body BMD change (g/cm2)	N = 1408	N = 12	0.174c	N = 1560	N = 10	0.241c
	0.04 (0.02; 0.07)	0.04 (0.01; 0.05)		0.02 (0.01; 0.04)	0.04 (0.02; 0.06)
Lumbar spine BMD change (g/cm2)	N = 1406	N = 62	0.514c	N = 1558	N = 32	0.980c
	0.06 (0.02; 0.10)	0.05 (0.01; 0.09)		0.04 (0.01; 0.07)	0.04 (0.01; 0.07)
Femoral neck BMD change (g/cm2)	N = 1407	N = 59	0.486c	N = 1547	N = 43	0.412c
	0.01 (−0.05; 0.06)	0.02 (−0.04; 0.07)		0.01 (−0.03; 0.05)	0.02 (−0.02; 0.10)

N Number of observations, SD standard deviation, % percentage, MMW monthly minimum wages, BMI body mass index, BMD bone mineral density (g/m²)

*Changes in measurement of BMD at 22y – at 18y

¹Participants excluded from the analyses due to loss of follow-up or missing data;

^aP value refers to Chi-squared heterogeneity test;

^bP value refers to Student’s t-test;

^cP value refers to Wilcoxon Rank Sum Test

The 1993 Pelotas Birth Cohort, Brazil