Salim Javeedh1, Vidya T.A.2
BACKGROUND
Thyroid disease is more common in people with diabetes mellitus than in general
population. Among thyroid disorders, subclinical hypothyroidism is more common
than the overt form. Hypothyroidism is associated with dyslipidaemia,
hypertension and cardiac disease. Subclinical hypothyroidism has also been
reported to have these features. With this background, we aimed to determine the
prevalence of subclinical thyroid disorder and its influence on the metabolic profile
of patients with type 2 diabetes mellitus (DM).
METHODS
234 type 2 diabetes patients, 117 males and 117 females, who were previously
not known to have thyroid disease, were screened for thyroid dysfunction using
serum free T3, free T4, and thyroid stimulating hormone (TSH) levels. Patients
were evaluated for clinical features of thyroid disease and investigated for
microvascular complications of DM, dyslipidaemia and cardiac disease. Individuals
with subclinical hypothyroidism were further screened for anti-thyroid peroxidase
(TPO) antibodies.
RESULTS
In this study, subclinical hypothyroidism was present in 29 (12.4 %) of 234 type
2 diabetics; no case of subclinical hyperthyroidism was detected. 25 of these 29
patients with subclinical hypothyroidism were females. Elevated TPO antibody
levels were present in 82.8 % (24 out of 29) subclinical hypothyroidism (SCH)
patients. SCH was found to be associated with higher body mass index (BMI) and
patients aged more than 50 years. No significant difference was found in glycaemic
profile or lipid profile between patients with SCH and euthyroid subjects. There
was no significant difference among SCH patients with and without microvascular
complications. Left Ventricle (LV) diastolic dysfunction was present in 34.4 % of
SCH patients.
CONCLUSIONS
SCH is common among type 2 diabetics, especially in females and most commonly
due to autoimmune thyroid disease. SCH in type 2 DM is associated with a higher
BMI and an older age group, but it does not seem to have an influence on glycaemic
profile, lipid profile or microvascular complications of diabetes.
