Department of Oral and Maxillofacial Surgery, Jiangyin People's Hospital Affiliated to Nantong University, Jiangyin, China.
Department of Cardiology, Jiangyin People's Hospital Affiliated to Nantong University, Jiangyin, China.
J Oral Rehabil. 2024 Feb;51(2):278-286. doi: 10.1111/joor.13607. Epub 2023 Oct 13.
Previous studies investigated the associations between obesity and temporomandibular disorders (TMDs), but the evidence for the causal inferences was unclear.
We aimed to investigate the causal link between life course adiposity and TMDs.
Mendelian randomization (MR) studies were performed using genetic instruments for birth weight (BW) (N = 261 932), childhood body mass index (BMI) (N = 39 620), childhood body size (N = 454 718), adult BMI (N = 99 998), body fat percentage (N = 454 633) and TMDs (N = 211 023). We assessed the overall effect of each life course adiposity factor via inverse-variance weighted (IVW), weighted median, and MR-Egger methods and performed extensive sensitivity analyses. Additionally, multivariable MR was conducted to evaluate the direct and indirect effects of childhood BMI on TMDs while accounting for BW and adult BMI, and vice versa.
Univariable MR analyses revealed a causal effect of low childhood adiposity on an increased risk of TMDs (childhood BMI: IVW OR: 0.65, 95% CI: 0.54-0.78, p < .001; childhood body size: IVW OR: 0.56, 95% CI: 0.43-0.73, p < .001). No causal association existed between genetically predicted BW, adult BMI, or body fat percentage and TMDs. In the multivariable MR analyses, the effects of childhood BMI on TMDs occurrence remained significant and direct, even after adjusting for BW and adult BMI (multivariable IVW OR: 0.78, 95% CI: 0.61-0.99, p = .048). No pleiotropy and heterogeneity were detected (p > .05).
Low childhood BMI might causally increase the risk of TMDs through a direct pathway.
先前的研究调查了肥胖与颞下颌关节紊乱（TMD）之间的关联，但因果推断的证据并不明确。
我们旨在研究生命历程肥胖与 TMD 之间的因果关系。
使用出生体重（BW）（N=261932）、儿童期体重指数（BMI）（N=39620）、儿童期体型（N=454718）、成人 BMI（N=99998）、体脂肪百分比（N=454633）和 TMD（N=211023）的遗传工具进行孟德尔随机化（MR）研究。我们通过逆方差加权（IVW）、加权中位数和 MR-Egger 方法评估每个生命历程肥胖因素的总体效应，并进行了广泛的敏感性分析。此外，进行了多变量 MR 分析，以评估儿童 BMI 对 TMD 的直接和间接影响，同时考虑到 BW 和成人 BMI，反之亦然。
单变量 MR 分析表明，儿童时期低肥胖与 TMD 风险增加有关（儿童 BMI：IVW OR：0.65，95%CI：0.54-0.78，p<.001；儿童体型：IVW OR：0.56，95%CI：0.43-0.73，p<.001）。遗传预测的 BW、成人 BMI 或体脂肪百分比与 TMD 之间不存在因果关系。在多变量 MR 分析中，即使在调整 BW 和成人 BMI 后，儿童 BMI 对 TMD 发生的影响仍然显著且直接（多变量 IVW OR：0.78，95%CI：0.61-0.99，p=0.048）。未检测到 pleiotropy 和异质性（p>.05）。
儿童时期 BMI 较低可能通过直接途径导致 TMD 的风险增加。
