Rezaeian Shahab, Moghimbeigi Abbas, Esmailnasab Nader
Department of Epidemiology, School of Health, Shiraz University of Medical Sciences, Shiraz, IR Iran.
Research Center for Health Sciences, Department of Epidemiology and Biostatistics, School of Public Health, Hamadan University of Medical Sciences, Hamadan, IR Iran.
Int J Endocrinol Metab. 2014 Apr 1;12(2):e13946. doi: 10.5812/ijem.13946. eCollection 2014 Apr.
Several studies have demonstrated an increased risk of congenital hypothyroidism (CH) in girls in comparison to boys.
The aim of this study was to determine the potential interactions that are able to change the effect of gender on congenital hypothyroidism.
We conducted a matched 1:4 case-control study in Hamadan Province, western of Iran, from 2005 to 2011. Based on screening program data, neonates with TSH ≥ 10 mU/L and T4 ≤ 6.4 μg/dL were considered as congenital hypothyroidism (Cases). Cases and controls were matched regarding the year and place of birth. Data was analyzed using two different approaches including propensity score and multiple conditional logistic regression model.
A total of 277 cases and 1036 controls were included in the study. Girls accounted for 57.4% of the cases and 51.2% of controls (P = 0.065). Based on the multiple conditional logistic regressions, only the interaction of gender (girl) and birth season (summer) increased the likelihood of CH significantly (OR = 3.09; 95% CI: 1.09-8.74; P = 0.034). On the other hand, the ORs of the interaction of gender and all other factors (except for birth season) were not statistically significant in CH.
Birth season might act as an interaction that is able to increase the risk of CH in girls. Accordingly, awareness of the birth season could help policymakers who plan preventive programs to reduce the false negative results among neonates, especially girls.
多项研究表明，与男孩相比，女孩患先天性甲状腺功能减退症（CH）的风险更高。
本研究旨在确定可能改变性别对先天性甲状腺功能减退症影响的潜在相互作用。
2005年至2011年，我们在伊朗西部的哈马丹省进行了一项1:4匹配病例对照研究。根据筛查项目数据，促甲状腺激素（TSH）≥10 mU/L且甲状腺素（T4）≤6.4 μg/dL的新生儿被视为先天性甲状腺功能减退症患者（病例组）。病例组和对照组在出生年份和地点方面进行了匹配。数据采用倾向得分和多重条件逻辑回归模型两种不同方法进行分析。
本研究共纳入277例病例和1036例对照。女孩占病例组的57.4%，对照组的51.2%（P = 0.065）。基于多重条件逻辑回归分析，只有性别（女孩）与出生季节（夏季）的相互作用显著增加了患先天性甲状腺功能减退症的可能性（比值比[OR]=3.09；95%置信区间[CI]：1.09 - 8.74；P = 0.034）。另一方面，在先天性甲状腺功能减退症中，性别与所有其他因素（出生季节除外）的相互作用的OR值无统计学意义。
出生季节可能是一种能够增加女孩患先天性甲状腺功能减退症风险的相互作用因素。因此，了解出生季节有助于计划预防项目的政策制定者减少新生儿尤其是女孩中的假阴性结果。
