Is screening for hypothyroidism in the diabetes clinic effective?

Abstract

The aim of this study was to determine the effectiveness of annual screening for hypothyroidism requiring thyroxine treatment (HRTT) in a hospital‐based diabetes clinic.A retrospective study of case records of patients attending a hospital‐based diabetes clinic was undertaken. Random samples of 400 patients with type 1 diabetes and 400 patients with type 2 diabetes were included. Patient data including thyroid function tests and thyroxine use were recorded. The outcomes were the prevalence of HRTT, and the cost‐per‐diagnosis of screening for HRTT in the diabetes clinic.Type 1 diabetes patients were younger (41 vs 60 years, p<0.001) and their diabetes was of longer duration (median 9.5 vs 5 years, p<0.05) than those with type 2 diabetes. Hypothyroidism was common in patients with type 1 (10.8%) or type 2 diabetes (10.8%). The prevalence of HRTT was 6.8% in type 1 diabetes and 6.0% in type 2 diabetes, with the majority being female (81% and 83%). The prevalence of HRTT increased after 50 years of age in type 1 diabetes, and somewhat later in type 2 diabetes, in the over 60s reaching 18.8% in type 1 diabetes and 8.4% in type 2 diabetes. Annual screening detected one case of HRTT for every 470 blood tests, equating to £4600 per diagnosis.In conclusion, hypothyroidism was common in patients with type 1 or type 2 diabetes who attended a hospital‐based diabetes clinic. However, annual screening at the hospital clinic only rarely found new cases of HRTT, and so is questionable from a cost:benefit viewpoint. Copyright © 2010 John Wiley & Sons.

Prevalence of thyroid dysfunction in type 2 diabetes mellitus: a case control study

“…The results of present study are in accordance with the previous studies of Michalek et al, Whitehead et al, Feely et al, Vondra et al, Moulik et al and Johnson et al, who also found high prevalence of thyroid disorders in diabetic patients with advancing age. [22][23][24][25][26][27] In the present study, the prevalence of thyroid disorders was more in females as compared to males (69% versus 31%). This was statistically significant, P value of 0.030.…”

Thyroid autoimmunity in Type 1 diabetes: systematic review and meta‐analysis

“…The British Thyroid Association state that thyroid function testing during annual diabetes review is cost-effective [46]. In contrast, Whitehead et al concluded that routine screening was not cost-effective because of the low prevalence of hypothyroidism requiring treatment in their clinic population of adults with Type 1 diabetes (6.8%) [47]. Our cost estimate of $A3.6m for annual thyroid antibody testing is substantial, in addition to thyroid-stimulating hormone screening ($A2.6m).…”

The rate of primary hypothyroidism in diabetic patients is greater than in the non-diabetic population. An observational study

“…1 On the other hand, the prevalence of thyroid dysfunction in patients with type 2 diabetes mellitus (T2DM) is in the 10-31% range, being subclinical hypothyroidism the most common, which only progresses to clinical hypothyroidism at a low rate. 2 Because of that concern, the utility of routine annual screening for thyroid dysfunction in those patients has been questioned by some authors while others recommend that it should be mandatory, especially if the population is over 50 years of age or has lipid disorders. 1 Over the last few years, multiple nontraditional risk factors for cardiovascular disease have been identified and these are related both with T2DM and PH, which is why the search for PH constitutes a priority in the overall assessment of this group of patients.…”