Rates of thyroid disease are similar in HIV-positive patients and the general population, according to a large British study published in the January edition of HIV Medicine. The study's authors, from London's Royal Free Hospital, therefore believe that HIV-positive patients do not require thyroid screens as part of their routine HIV care.
HIV infection and treatment with potent antiretroviral therapy have been linked with various hormonal abnormalities, including diabetes and osteoporosis. Recently, some (but not all) studies have suggested a possible link between HIV infection and its treatment with thyroid disease, which can include underactivity (hypothyroidism) and overactivity (hyperthyroidism or thyrotoxicosis).
To clarify further the relationships between thyroid disease, HIV infection and potent anti-HIV therapy, a team at the Royal Free Hospital, London, examined previous thyroid function test results of 1,565 of their patients, 58% of whom were taking anti-HIV treatment.
A total of 39 individuals (2.5%) were found to have overt hypothyroidism and 61 (4%) had subclinical hypothyroidism. Eight people (<1%) had overt hyperthyroidism, five (<1%) had subclinical hyperthyroidism, and 263 (17%) had a non-thyroidal illness that had caused some changes to their thyroid function tests. Repeated measurements were available over three years for 825 patients and only eight new cases of overt thyroid disease occurred. During this period, only one of the group started anti-HIV therapy.
Although patients with overt hypothyroidism tended to be women and older, these associations also hold for the general population. Further analysis found that overt hypothyroidism was also linked with heterosexual risk, use of potent anti-HIV therapy, an AIDS diagnosis, and lower CD4 counts. However, multivariate analysis indicated that the links with markers of progressed disease (AIDS diagnosis and lower CD4 cell counts) were explained by the associations with gender and risk group. Thus, they did not detect any variables that were significantly and independently associated with hypothyroidism.
"There is no clear evidence that either subclinical hypothyroidism or subclinical hyperthyroidism should be treated. Recommendations in current guidelines are not to treat, and therefore the value of identifying subclinical disease that progresses slowly (if at all) to a clinical disease is questionable," the authors write.
Further, the team suggests that, until the results of larger studies are available, "it is wise to be cautious before drawing conclusions regarding thyroid dysfunction and HIV . . . However, our study implies that the prevalence of overt thyroid disease is likely to be similar to that observed in HIV-negative populations and that routine screening of this specific population is not necessary, especially given that patients with overt clinical disease do present clinically and that [thyroid function tests] are a test clinicians have a low threshold for performing."
Source: Bio-Bio Technology