Endocrine Abstracts

Introduction

Hypothyroidism (HT) is widespread in all age groups particularly within the increasing elderly population while its diagnosis is challenging owing to extremely varied and atypical symptoms. The objective of this study is to outline the clinical and biochemical features of HT and determine its main etiologies in a geriatric population.

Methods

We reviewed the medical charts of 53 patients aged 65 years and over, who had been diagnosed with HT and hospitalized between 2009 and 2019 at the endocrinology department of Hedi Chaker university hospital, Sfax, Tunisia.

Results

The mean age of our sample was 72.7±5.5 years with a female predominance (sex ratio=1.94). A medical history of ischemic cardiopathy or arrhythmia was found in 18.86%. HT was diagnosed based on the worsening of some “usual” aging-related symptoms such as asthenia (81%), cognitive and psychomotor limitations (77%), constipation (50%), dry skin (47%), hearing loss (19%), and myalgia (17%). A goiter was encountered in 23%. Complicated forms seem to be more frequent in seniors than in younger patients for insistence: myxomatous coma (1.88%), pericarditis (7.55%), and hypothyroid myopathy (5.66%). At diagnosis, the mean TSH and T4 levels were 68.13±55.24 mUI/l and 6.11±1.2 pmol/l, respectively. Subclinical hypothyroidism (SCH) was detected in 9.43% with a mean TSH level of 6.9 mUI/l. Lipid metabolism was troubled in 39.62% of cases with a mean total-cholesterol and triglycerides levels of 5.06±1.49 and 1.83±1.24 mmol/l, respectively. Rhabdomyolysis and hyperuricemia were observed consecutively in 23% and 13% with mean uric acid and Creatine phosphokinase levels of 1060±112.1 UI/l and 326.4±95 µmol/l, successively. Anemia was underlined in 60% and the normocytic form in 43% with a mean hemoglobin rate of 10.75±2 g/dl. Leading etiologies of HT were: autoimmune thyroiditis (81%), amiodarone use (9%), total thyroidectomy (6%), and radioactive iodine therapy (2%). Considering the severity of HT, a hormone replacement therapy (HRT) by stepwise approach was adopted by increasing the dosage by 12.5 µg every three days reaching a mean thyroxine dose of 109.57 µg/day. The evolution was favorable in all patients excepting one senior who developed atrial fibrillation during HRT. We opted for HRT in patients having SCH associated with goiter and/or positive thyroid autoantibodies.

Conclusion

Hypothyroidism should be screened for in the elderly in front of cognitive and functional changes even those usually attributable to aging. HRT must be conducted gradually and carefully considering the frailty and cardiovascular comorbidities to target an age-appropriate TSH range (age/10 mUI/l).