Subclinical thyroid dysfunction does not affect one-year mortality in elderly patients after hip fracture: A prospective longitudinal study

Mortality after hip fractures in the elderly is one of the most important patient outcome measures. Subclinical thyroid dysfunction is common in the elderly population. This is a prospective study of 131 elderly patients with a mean (SD) age of 82.0 (8.9) years (range: 61-94) admitted consecutively to our trauma unit. The aim of the study was to determine the prevalence of subclinical thyroid dysfunction in an elderly cohort of patients with hip fracture and to determine if this affects the one-year mortality.There were three times more women (n = 100) than men (n = 31) in this cohort. All patients underwent surgical treatment for the hip fracture. The prevalence of subclinical hypothyroidism (TSH > 5.5 mU/L) was 15% (n = 20) and of subclinical hyperthyroidism (TSH < 0.35 mU/L) was 3% (n = 4). Overall 18% (n = 24) of patients had a subclinical thyroid dysfunction. The twelve-month mortality was 27% (n = 36).Age, gender, heart rate at admission, pre-existing coronary heart disease, ASA grade and presence of overt or subclinical thyroid dysfunction were analysed for association with twelve-month mortality using a forward stepwise logistic regression analysis. Only ASA grade was found to significantly affect mortality at twelve months (χ² = 3.98, df = 1, p = 0.046). Independently the presence of subclinical hypo- or hyperthyroidism was not associated with a higher mortality (p = 0.477). We conclude that subclinical thyroid dysfunction does not affect the one-year mortality in elderly patients treated surgically for hip fracture.