Table 3.

Mean and confidence interval of the body composition variables at 18 years in the 1993 Pelotas birth cohort according to categories of age at menarche

Variables at 18 years	Age at Menarche (years)						P-value
	≤11		12–13		≥14
	N	Mean	N	Mean	N	Mean
		(95 % CI)		(95 % CI)		(95 % CI)
Waist circumference (cm)	550	76.0	1037	73.7	408	70.9	<0.0001*
		(75.1; 76.9)		(73.2; 74.3)		(70.1; 71.7)
Fat mass index (kg/m2)	530	9.40	1008	8.43	402	7.19	<0.0001*
		(9.08; 9.72)		(8.22; 8.65)		(6.89; 7.49)
Fat-free mass index (kg/m2)	530	15.12	1008	15.00	402	14.75	0.0009*
		(15.00; 15.25)		(14.90; 15.09)		(14.62; 14.88)
BMI (kg/m2)	550	24.8	1036	23.5	408	21.9	0.0001*
		(24.4; 25.2)		(23.2; 23.8)		(21.6; 22.3)
Overweight (%)	203	36.9	303	29.3	72	17.7	<0.001*
		(32.9; 41.0)		(26.5; 32.0)		(13.9; 21.4)

Abbreviation BMI body mass index, CI confidence interval

*Linear trend test