Endocrine Abstracts

Background: Hypothyroidism affects cardiac function, leading to cardiomyopathy, pericarditis, lower left ventricular performance, etc. The present study investigates different parameters (clinical, hormonal, biochemical, echocardiographic) in overt primary hypothyroidism (OPHypo) and overt central hypothyroidism (OCHypo).

Material and methods: The study included 33 untreated patients with OCHypo (5 with empty sella, 3 with idiopathic hypopituitarism, 7 with Sheehan’s syndrome, 18 with different types of pituitary macroadenomas, before or after surgery) and 67 cases with OPHypo, respectively with chronic autoimmune thyroiditis. Among the patients with OCHypo, 4 presented partial pituitary insufficiency (2 cases on gonadotropins and TSH secretion and 2 cases on growth hormone and TSH secretion), the rest of the cases showing global pituitary insufficiency. Patients with acromegaly and Cushing’s disease were excluded.

Results: The clinical picture was more severe in OPHypo as in OCHypo (dominated by fatigue, edema, dry skin, neurological alterations). The values of serum thyroxin were significantly lower in OPHypo (P<0.0001). 40% of OPHypo patients presented pericarditis, as compared to OCHypo (2 cases, P=0.0003). No statistical differences were noted between the two groups, regarding heart rate, systolic and diastolic blood pressure values, isovolumic contraction time. Nonetheless, the isovolumic relaxation time was significantly higher in OPHypo group (91.8±8.5 ms), as in OCHypo (80.2±9.9 ms, P<0.0001). Coronary artery disease was more common in OPHypo group (21 cases, 31.3%), as compared to OCHypo (5 cases, 15.1%, P=0.095). Hyponatremia was recorded in 4 patients with OPHypo and in 3 cases with OCHypo (P=0.68). The values of serum total cholesterol, LDL-cholesterol, glycemia, creatin-kinase, transaminases, creatinine were significantly higher in OPHypo group, correlated to lower values of serum thyroxin. The incidence of anemia was similar in both groups (18 cases in OPHypo group, 6 cases in OCHypo group, P=0.456).

Conclusion: The metabolic and cardiac parameters were more profound altered in primary hypothyroidism, as compared to central hypothyroidism.