Silva Luísa Silveira da, Menezes Ana Maria Baptista, Barros Fernando C, Wehrmeister Fernando C, Silva Helen Denise Gonçalves da, Horta Bernardo Lessa
Universidade Federal de Pelotas, Pelotas, Brasil.
Universidade Católica de Pelotas, Pelotas, Brasil.
Cad Saude Publica. 2024 Mar 11;40(3):e00085523. doi: 10.1590/0102-311XPT085523. eCollection 2024.
This study assessed the association of birth weight, gestational age, and intrauterine growth with bone mineral density (BMD) at 22 and 30 years of age in the 1982 and 1993 birth cohorts in Pelotas, Rio Grande do Sul State, Brazil. BMD was measured by dual-energy X-ray absorptiometry (DXA) and the association was assessed using analysis of variance. Multiple linear regression was used to control for confounding factors: sex; household income at birth; maternal smoking during pregnancy; maternal schooling; maternal ethnicity/skin color; and pre-pregnancy body mass index. The study tested whether body fat in adulthood was a mediator of the association analyzed, using the G-computation Formula. A total of 6,803 participants from the 1982 and 1993 cohorts were evaluated at 30 and 22 years of age, respectively. Birth weight was associated with BMD at all sites, with a greater difference at the femoral neck. Individuals born weighing less than 2,000g had on average -0.036g/cm2 (95%CI: -0.064; -0.008) of BMD in the femoral neck than individuals weighing more than 3,500g. Individuals with an intrauterine growth z-score at least 1.28 standard deviation below the mean had an average of -0.013g/cm2 (95%CI: -0.024; -0.002) of BMD in the lumbar spine compared with individuals with an above-average z-score. The mediation analysis showed that body fat in adulthood did not mediate the association. Birth conditions have been associated with BMD in adulthood and the identification of early factors related to bone loss is essential due to the demographic inversion that has been taking place in low- and middle-income countries.
本研究评估了巴西南里奥格兰德州佩洛塔斯1982年和1993年出生队列中出生体重、胎龄和宫内生长与22岁和30岁时骨密度（BMD）之间的关联。采用双能X线吸收法（DXA）测量骨密度，并使用方差分析评估这种关联。采用多元线性回归来控制混杂因素：性别；出生时家庭收入；孕期母亲吸烟情况；母亲受教育程度；母亲种族/肤色；以及孕前体重指数。该研究使用G计算法检验成年期体脂是否为所分析关联的中介因素。分别对1982年和1993年队列中的6803名参与者在30岁和22岁时进行了评估。出生体重与所有部位的骨密度均有关联，在股骨颈处差异更大。出生体重低于2000g的个体，其股骨颈骨密度平均比出生体重超过3500g的个体低-0.036g/cm²（95%CI：-0.064；-0.008）。与z评分高于平均水平的个体相比，宫内生长z评分至少低于平均值1.28个标准差的个体，其腰椎骨密度平均低-0.013g/cm²（95%CI：-0.024；-0.002）。中介分析表明，成年期体脂并非该关联的中介因素。出生状况与成年期骨密度有关联，鉴于低收入和中等收入国家正在发生的人口结构转变，识别与骨质流失相关的早期因素至关重要。
