Selmer, Christian2; Olesen, Jonas Bjerring2; Hansen, Morten Lock2; von Kappelgaard, Lene Mia2; Madsen, Jesper Clausager2; Hansen, Peter Riis3; Pedersen, Ole Dyg2; Faber, Jens3; Torp-Pedersen, Christian2; Gislason, Gunnar Hilmar3
1 Department of Clinical Medicine, Department of Clinical Medicine, Faculty of Health and Medical Sciences, Københavns Universitet2 unknown3 Department of Clinical Medicine, Department of Clinical Medicine, Faculty of Health and Medical Sciences, Københavns Universitet
A Large Population Study
CONTEXT: Thyroid dysfunction has been associated with both increased all-cause and cardiovascular mortality, but limited data are available on mild thyroid dysfunction and cause-specific mortality. OBJECTIVE: The objective of the study was to examine the risk of all-cause mortality, major adverse cardiovascular events (MACEs), and cause-specific events in subjects with overt and subclinical thyroid dysfunction. DESIGN: This was a retrospective cohort study. SETTING AND PARTICIPANTS: Participants in the study were subjects who underwent thyroid blood tests, without prior thyroid disease, consulting their general practitioner in 2000-2009 in Copenhagen, Denmark. MAIN OUTCOME MEASURE: All-cause mortality, MACEs, and cause-specific events identified in nationwide registries were measured. RESULTS: A total of 47 327 (8.4%) deaths occurred among 563 700 included subjects [mean age 48.6 (SD ± 18.2) y; 39% males]. All-cause mortality was increased in overt and subclinical hyperthyroidism [age adjusted incidence rates of 16 and 15 per 1000 person-years, respectively; incidence rate ratios (IRRs) 1.25 [95% confidence interval (CI) 1.15-1.36] and 1.23 (95% CI 1.16-1.30)] compared with euthyroid (incidence rate of 12 per 1000 person-years). Risk of MACEs was elevated in overt and subclinical hyperthyroidism [IRRs 1.16 (95% CI 1.05-1.27) and 1.09 (95% CI 1.02-1.16)] driven by heart failure [IRRs 1.14 (95% CI 0.99-1.32) and 1.20 (95% CI 1.10-1.31)]. A reduction of all-cause mortality was observed in subclinical hypothyroidism with TSH of 5-10 mIU/L [IRR 0.92 (95% CI 0.86-0.98)]. CONCLUSIONS: Heart failure is the leading cause of an increased cardiovascular mortality in both overt and subclinical hyperthyroidism. Subclinical hypothyroidism with TSH 5-10 mIU/L might be associated with a lower risk of all-cause mortality.
Journal of Clinical Endocrinology and Metabolism, 2014, Vol 99, Issue 7, p. 2372-2382