HIV-infected individuals treated with d4T-containing HAART regimens, or with low CD4 cell counts are at increased risk of hypothyroidism, according to French investigators writing in the August 15th edition of Clinical Infectious Diseases, which is now available online.
Hypothyroidism is a condition in which the body lacks enough thyroid hormone, the hormone which regulates the body’s metabolism. An increased prevalence of subclinical hypothyroidism has been observed in HAART-treated patients. Investigators in Picardie, northern France wished to determine the prevalence of thyroid dysfunction in their patients and the risk factors for the development of the condition.
The study ran between May and December 2001, and included a cohort of 350 patients. Potential risk factors for hypothyroidism assessed by the investigators included age, sex, weight, body mass index, lipodystrophy, and smoking. Data were also collected on duration of HIV infection, stage of HIV disease, CD4 cell count, viral load, hepatitis C virus coinfection, and type and duration of anti-HIV therapy.
Thyroid function was assessed by measuring thyroid-stimulating hormone levels and normal free T4 (FT4) and FT3.
Sixteen percent of patients (n=56) had hypothyroidism, of whom 2.6% had overt hypothyroidism, 6.6% subclinical hypothyroidism, and 6.8% a low FT4 level.
Patients with hypothyroidism were significantly older (43.9 years versus 40.8, p=.04), had been HIV-positive for longer (9.4 years versus 7.7 years, p=.01) and had a lower CD4 cell count (383 cells/mm3 versus 488 cells/mm3.
In univariate analysis HCV coinfection, low CD4 cell count, receipt of HAART, and treatment with efavirenz, amprenavir, ddI, ritonavir, lopinavir and d4T were all associated with hypothyroidism.
However, in multivariate analysis only treatment with d4T (OR 2.56, 95% CI, 1.3 – 4.9, p=.004) and low CD4 cell count (OR 2.5, 95% CI, 1.4 – 4.4, p<.001 factors.="" remained="" risk="" significant="">
The investigators conclude, “the prevalence of hypothyroidism is increased among HIV-positive patients, and we believe that screening is warranted, especially for patients treated with stavudine [d4T] and patients with decreased CD4 cell counts.”
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Beltran S et al. Increased prevalence of hypothyroidism among human immunodeficiency virus-infected patients: a need for screening. Clinical Infectious Diseases 37 (online edition), 2003.