Posthemithyroidectomy hypothyroidism. Prevalence and predictive markers. Comparison between patients with euthyroid and hyperthyroid nodular goitre.

ABSTRACT

BACKGROUND AND OBJECTIVE: Posthemithyroidectomy hypothyroidism (PHH) is a relatively common complication (22%-30%) for which we have no published information from our country. The objective of the study is to determine the prevalence of PHH and evaluate its predictive markers by comparing patients who had euthyroidism with those who had hyperthyroidism before hemithyroidectomy. PATIENTS AND METHOD: Retrospective observational cross-sectional study on 106 patients, 88 euthyroid before hemithyroidectomy and 18 hyperthyroid. RESULTS: Prevalence of PHH in euthyroid patients 42% (89.2% subclinical hypothyroidism; 10.8% manifest hypothyroidism) and in hyperthyroid patients 50% (77.8% subclinical hypothyroidism; 22.2% manifest hypothyroidism). Predictive markers in euthyroid patients preoperative thyrotropin ≥ 2.2 mIU/L (OR 4.278, 95% CI 1.689-10.833; sensitivity 54.1%, 95% CI 38%-70.1%; specificity 78.4%, 95% CI 67.1%-89.7%), age ≥50 years (OR 3.509, 95% CI 1.438-8.563; sensitivity 64.9%, 95% CI 49.5%-80.3%; specificity 64.7%, 95% CI 51.6%-77.8%) and percentage of remainder lobe ≤ 19.6% (OR 1.024, 95% 1.002-1.046; sensitivity 70.2%, 95% CI 55.5%-84.9%; specificity 48.6%, 95% CI 34.9%-62.3%). Predictive marker in hyperthyroid patients weight >70 kg (OR 28, 95% CI 2.067-379.247; sensitivity 88.9%, 95% CI 68.4%-100%; specificity 88.9%, 95% CI 68.4%-100%). CONCLUSIONS: This is the first study in our country that demonstrates a prevalence of PHH above the average in euthyroid patients, which is slightly higher and more intense in hyperthyroid patients, and that recognizes the classic predictive markers in euthyroid patients but highlights a novel predictive marker marker in hyperthyroid patients, useful to assess a different risk of PHH when indicating hemithyroidectomy and to establish closer control of postoperative hormonal evolution.