Low birth weight and intrauterine growth restriction and their relationship with handgrip strength in adolescents.

OBJECTIVE: To analyze the association between low birth weight (LBW) and intrauterine growth restriction (IUGR) with handgrip strength (HGS) in adolescents. METHODS: Birth cohort study from São Luís, Maranhão, Brazil, conducted between 1997 and 1998. The Jamar Plus+ dynamometer was used to measure HGS during the second follow-up. Birth weight was assessed from information from the participants' hospital records. LBW was defined as a birth weight <2500 g, while IUGR was defined as a Kramer's index <0.85. The associations of LBW and IUGR with HGS were estimated using linear regression models. The directed acyclic graph (DAG) was used to identify the variables for adjustment. RESULTS: We evaluated 544 individuals who participated in the baseline and second follow-up, and 279 who participated in the first and second follow-ups. In crude and adjusted analyses, LBW was not associated with HGS. However, in the crude analysis, male adolescents with IUGR had lower HGS (β: -4.17; 95%CI -7.67; -0.66) compared with those without IUGR. In the adjusted analysis, the association was maintained, with male adolescents with IUGR showing a reduction of 4.36 kgf (β -4.36; 95%CI -7.88; -0.85) in HGS compared with those without IUGR. There was no association between IUGR and HGS in females. CONCLUSIONS: LBW was not associated with HGS. However, male adolescents with IUGR had lower HGS.