Subclinical hypothyroidism in HIV-infected subjects

Objectives: The correlation between subclin. hypothyroidism [TSH (TSH) &rt;4 mIU/L with normal free triiodothyroxine and free thyroxine levels], HIV infection and HAART is still unclear. Patients and methods: To evaluate the predictive factors of subclin. hypothyroidism in an HIV-infected population, we identified three groups of subjects: G1, subjects on stable highly active antiretroviral therapy (HAART) (for at least 1 yr) at baseline and at month 24 (n= 97); G2, subjects naive at both baseline and month 24 (n= 47); G3, subjects starting HAART at baseline (n= 46). Results: The three groups were comparable with respect to age, gender, body wt. and prevalence of HCV infection. At baseline, subclin. hypothyroidism was detected in 14 subjects in G1 (14.4%), 5 in G2 (10.6%) and 4 in G3 (8.7%) (P= 0.18) and these were excluded from the anal. At month 24, 15 subjects had developed subclin. hypothyroidism: 4 in G1 (4.8%), 3 in G2 (7.1%) and 8 in G3 (19.0%). In the multivariable anal., the higher increase in total cholesterol was predictive of subclin. hypothyroidism (RR: 1.53 for each addnl. 10 mg/dL, 95% Cl 1.23-1.90; P < 0.01); other variables, which were statistically significant in the univariate anal., such as G3 group, body wt. and higher increase in CD4+ cell count and in triglyceride serum levels were not confirmed to be assocd. with TSH alterations. Conclusions: The occurrence of subclin. hypothyroidism in HIV-pos. patients seems to be related to the increase in total cholesterol serum levels occurring after HAART initiation. Thyroid function should be monitored in all HIV-infected subjects, esp. in those starting HAART.