Insulin Sensitivity and Beta-Cell Function in Graves' Disease and Their Changes with the Carbimazole-Induced Euthyroid State.

BACKGROUND AND OBJECTIVE: Thyroid hormones play an important role in intermediate metabolism, and abnormal glucose tolerance is often observed in patients with hyperthyroidism. Several pathogenic mechanisms have been proposed as contributors. However, there is no conclusive evidence in the existing literature regarding the predominant underlying pathophysiology. Our objective was to determine the changes in insulin resistance parameters and beta-cell function in patients with Graves' disease following restoration of a euthyroid state. METHODOLOGY: This was an observational study with a before-after study design. Forty-five treatment-naïve adults with Graves' diseases were included and 36 completed the study. An oral glucose tolerance test was performed at baseline and after 3 months of achieving a stable euthyroid state to assess glucose tolerance, insulin sensitivity, and beta-cell function. All patients were treated with antithyroid medication. The outcome measures studied were the Homeostasis Model Assessment-2 Insulin Resistance (HOMA2-IR), Matsuda index, and Insulin Secretion-Sensitivity Index (ISSI)-2. RESULTS: Two-thirds of the patients had abnormal glucose tolerance at baseline. Among those with abnormal glucose tolerance at baseline, 34.7% had persistent abnormality during follow-up. During follow-up, no significant change was noted in the indices of insulin resistance. Patients with abnormal glucose tolerance had a significantly lower ISSI-2 index at baseline and it improved after achieving a euthyroid state. CONCLUSIONS: Abnormal glucose tolerance is a significant metabolic consequence in patients with Graves' disease. Decreased beta-cell function was observed among those with abnormal glucose tolerance and it improved during follow-up. In a proportion of patients, abnormal glucose tolerance persisted after 3 months, emphasizing the need for continued follow-up.

An unusual cause of pulmonary calcification.

Metastatic pulmonary calcification (MPC) is an uncommon entity resulting from abnormalities in calcium-phosphorus homoeostasis. Most cases reported in the literature are among patients with chronic kidney disease receiving haemodialysis. Primary hyperparathyroidism is a relatively common condition affecting calcium homoeostasis, in which MPC can rarely occur. We report the case of one such patient who presented with severe hypercalcaemia and features of interstitial lung disease. Radiographic imaging was normal and the diagnosis was clinched by diffuse pulmonary uptake in 99mTechnetium-methylene diphosphate scan.

Osteoporosis and malignancy: a dicey combination.

Osteoporosis is the most common metabolic bone disorder worldwide, especially in women. Postmenopausal status is the most common risk factor for osteoporosis in elderly women. The operational diagnosis of osteoporosis is usually made with the help of central dual energy X-ray absorptiometry scan. Clinically, osteoporosis is suspected in the background of one or more fractures of the hip, vertebra, proximal humerus or pelvis in the absence of local disease or high-energy trauma. Serious underlying illness can present with vertebral fractures and can be missed if other clues from clinical examination and investigations are overlooked. We report a case emphasising this aspect.

Puzzling thyroid function test.

A 13-½-year-old boy was referred to the Department of Endocrinology as a case of thyrotoxicosis for initiation of antithyroid medication. His chief complaint was a swelling in front of the neck, which was incidentally noted by his mother 2 weeks prior to presentation. He denied any history of symptoms suggestive of hyperthyroidism or ophthalmological involvement. His physical examination was unremarkable except for a grade 2 goitre. Thyroid function test revealed elevated free triiodothyronine and tetraiodothyronine in the face of an unsuppressed thyroid-stimulating hormone level. Technetium-99 uptake scan showed increased uptake indicating enhanced thyroid activity. However, he was clinically euthyroid. This raised the possibility of resistance to thyroid hormones, which was confirmed by documenting similar thyroid function test abnormalities in other members of his family and genetic testing. The family was reassured of the benign nature of the condition.