Onyebuchi E Okosieme, MD
Peter N Taylor, PhD
Carol Evans, PhD
Dan Thayer, BsC
Aaron Chai, MBBCh
Ishrat Khan, MRCP
Mohd S Draman, PhD
Brian Tennant, PhD
Prof John Geen, PhD
Adrian Sayers, MSc
Robert French, PhD
Prof John H Lazarus, MD
Lakdasa D Premawardhana, FRCP
Prof Colin M Dayan, PhD
Graves' disease is routinely treated with antithyroid drugs, radioiodine, or surgery, but whether the choice of initial therapy influences long-term outcomes is uncertain. We evaluated cardiovascular morbidity and mortality according to the method and effectiveness of primary therapy in Graves' disease.
In this retrospective cohort study, we identified patients with hyperthyroidism, diagnosed between Jan 1, 1998, and Dec 31, 2013, from a thyroid-stimulating hormone (TSH)-receptor antibody (TRAb) test register in south Wales, UK, and imported their clinical data into the All-Wales Secure Anonymised Information Linkage (SAIL) Databank (Swansea University, Swansea, UK). Patients with Graves' disease, defined by positive TRAb tests, were selected for the study, and their clinical data were linked with outcomes in SAIL. We had no exclusion criteria. Patients were matched by age and sex to a control population (1:4) in the SAIL database. Patients were grouped by treatment within 1 year of diagnosis into
the antithyroid drug group,
radioiodine with resolved hyperthyroidism group (radioiodine group A), or
radioiodine with unresolved hyperthyroidism group (radioiodine group B).
We used landmark Kaplan-Meier and Cox regression models to analyse the association of treatment with the primary outcome of all-cause mortality and the secondary outcome of major adverse cardiovascular events (myocardial infarction, heart failure, ischaemic stroke, or death) with the landmark set at 1 year after diagnosis. We analysed the association between outcomes and concentration of TSH using Cox regression and outcomes and free thyroxine (FT4) concentration using restricted cubic-spline regression models.
We extracted patient-level data on 4189 patients (3414 [81·5%] females and 775 [18·5%] males) with Graves' disease and 16 756 controls (13 656 [81·5%] females and 3100 [18·5%] males). In landmark analyses, 3587 patients were in the antithyroid drug group, 250 were in radioiodine group A, 182 were in radioiodine group B. Patients had increased all-cause mortality compared with controls (hazard ratio [HR] 1·22, 95% CI 1·05–1·42). Compared with patients in the antithyroid drug group, mortality was lower among those in radioiodine group A (HR 0·50, 95% CI 0·29–0·85), but not for those in radioiodine group B (HR 1·51, 95% CI 0·96–2·37). Persistently low TSH concentrations at 1 year after diagnosis were associated with increased mortality independent of treatment method (HR 1·55, 95% CI 1·08–2·24). Spline regressions showed a positive non-linear relationship between FT4 concentrations at 1 year and all-cause mortality.
Regardless of the method of treatment, early and effective control of hyperthyroidism among patients with Graves' disease is associated with improved survival compared with less effective control. Rapid and sustained control of hyperthyroidism should be prioritised in the management of Graves' disease and early definitive treatment with radioiodine should be offered to patients who are unlikely to achieve remission with antithyroid drugs alone.
National Institute for Social Care and Health Research, Wales.
I cant access the full paper so there may be information missing.
Unfortunately, the authors have looked at TSH and T4 associations. No association between out comes and T3 levels is recorded. Seems odd to me because T3 is the active hormone. Plus there is no information on the other other health parameters that affect the patients quality of life and life outcomes e.g. overall health, patients own fitness rating, heart health before and after treatment, weight changes, fatigue levels, fitness levels, age or occupation.
other forum users have pointed out that Graves disease and hyperthyroid sufferers generally have poorer health overall so lower mortality can be ascribed to any cause.
Plus, forum users report poor after treatment, often languishing in hypothyroidism due to inadequate replacement therapy after the initial treatment.