Genetic link claims type 1 diabetes increases risk of hypothyroidism
August 23, 2022
1 minute read
Disclosures: The authors report no relevant financial information.
Data from a Mendelian randomization analysis indicated a causal association between type 1 diabetes and hypothyroidism, leading researchers to recommend that people with type 1 diabetes undergo regular thyroid function tests .
“Our results were based on multiple Mendelian randomization methods, and there was consistency in the estimates of causal effects, indicating that the results are compelling,” Fuzhong Xue, PhDassociate director and professor in the department of epidemiology and biostatistics at Shandong University School of Public Health in Shandong, China, and colleagues wrote.
The researchers selected independent type 1 diabetes-related single nucleotide polymorphisms with genome-wide significance as instrumental variables from a large genome-wide association study of type 1 diabetes and analyzed with summary statistics on the genome-wide significance of hypothyroidism from the ThyroidOmics Consortium. They used the inverse variance weighted (IVW) method as the main analysis. Methods to confirm the results included Mendelian (MR)-Egger randomization, weighted median method, MR-Robust, and others.
The results revealed that type 1 diabetes was positively, causally associated with hypothyroidism (IVW OR = 1.083; 95% CI, 1.046-1.122; P P = 0.295).
Additionally, an independent validation set confirmed the causal association (IVW OR = 1.099; 95% CI, 1.018-1.186; P = 0.017). Various MRI methods revealed the robustness of the results, whereas data from reverse MRI analysis failed to support reverse causation (P > .05), according to the researchers.
“We have demonstrated that type 1 diabetes is an important risk factor for hypothyroidism, and there is a reasonable biological explanation,” the researchers wrote. “Therefore, patients with type 1 diabetes are recommended to have thyroid function tests performed regularly, to minimize the risk of undiagnosed hypothyroidism in young patients with type 1 diabetes.”