In the Journals

Thyroid disease triggered earlier use of insulin in type 2 diabetes

In patients with type 2 diabetes, those with comorbid thyroid disease may have an earlier need for insulin treatment, according to recent findings.

“Our retrospective study suggests an interaction of thyroid diseases with metabolic control in type 2 diabetes, resulting in an earlier need of insulin treatment,” the researchers wrote. “Patients with compensated as well as newly diagnosed thyroid disorders required significantly earlier insulin therapy compared to patients without thyroid diseases at the time of diabetes onset. These findings confirm that diabetes patients with thyroid comorbidity need more endocrine attention.”

Researchers evaluated 1,957 patients with type 2 diabetes who were seen at the department of endocrinology and diabetes at the University Hospital in Frankfurt, Germany. The study population consisted of 843 women and 1,114 men. In 534 (27.3%) of the patients, a thyroid condition had also been diagnosed. Of the patients with coexisting type 2 diabetes and thyroid disease, 202 were men (37.8%) and 333 were women (62.2%). Conversely, among diabetes without thyroid disease, there was a significantly higher percentage of men compared with women (64.1% men, 35.9% women; P<.001).
Patients with type 2 diabetes and coexisting thyroid disease who were on an insulin regimen (n=328) were asked about the sequence of the two diagnoses.

The researchers found that in 70.7% of insulin-treated type 2 diabetes/coexisting thyroid disease patients, thyroid disease diagnosis was made after diabetes onset, whereas 24.5% of patients were diagnosed with thyroid disease first, and 4.8% were diagnosed with both conditions in the same year. Patients whose thyroid disease preceded type 2 diabetes onset needed insulin therapy significantly earlier (median insulin-free interval, 2.5 years) vs. those for whom diabetes onset preceded thyroid disease (median insulin-free interval, 8 years; P<.001). There was a clear negative association between age at diabetes onset and the period of insulin freedom (P<.001), with older patients requiring earlier insulin treatment.

Disclosure: The researchers report no relevant financial disclosures.