Glucose Abnormalities in Hypothyroidism

Abstract

It is classically known that thyroid hormones excess or hyperthyroidism induce hyperglycemia. However, thyroid hormone deficiency or hypothyroidism can also induce glucose abnormalities through the development of abdominal obesity and insulin resistance. The aim of our study was to assess the frequency and predictive factors of glucose abnormalities during hypothyroidism. In this retrospective study, we included 425 patients (383 F/42 M) presenting with primary hypothyroidism. We investigated the presence of hyperglycemia, either fasting (≥100 mg/dl) and/or at 2 hours after an oral glucose tolerance test with 75 grams of glucose (≥140 mg/dl). Hyperglycemia was found in 37.6%. Subjects with hyperglycemia were older than those with normoglycemia (54.4±1.08 vs. 45.7±0.8 years), their Body Mass Index (BMI) was higher (31.5±0.53 vs. 28.7±0.37 kg/m 2 ), they had higher blood pressure (54.3% vs. 21.5%) and a family history of diabetes (36.2% vs. 29.8%). We conclude that glucose abnormalities are frequent in hypothyroidism and are developed mostly in patients with risk factors for insulin resistance such as age, high blood pressure and a positive family history of type 2 diabetes.