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- ACTH Adrenocorticotropic hormone
- AIDS Acquired immunodeficiency syndrome
- BMD Bone mineral density
- CMV Cytomegalovirus
- CRH Corticotropin-releasing hormone
- CVD Cardiovascular disease
- DHEA Dehydroepiandrosterone
- DXA Dual energy x-ray absorptiometry
- FSH Follicle-stimulating hormone
- GH Growth hormone
- GHRH Growth hormone–releasing hormone
- GnRH Gonadotropin-releasing hormone
- HAART Highly active antiretroviral therapy
- HDL High-density lipoprotein
- HIV Human immunodeficiency virus
- IGF Insulin-like growth factor
- IL Interleukin
- IMT Intima media thickness
- LDL Low-density lipoprotein
- LH Luteinizing hormone
- M/I Glucose disposal adjusted for insulin level
- MRI Magnetic resonance imaging
- NRTI Nucleoside reverse transcriptase inhibitor
- NNRTI Nonnucleoside reverse transcriptase inhibitor
- PI Protease inhibitor
- PPARγ Peroxisome proliferator-activated receptor γ
- PTH Parathyroid hormone
- RANK Receptor activator of nuclear factor kappa
- REE Resting energy expenditure
- RXR Retinoid X receptor
- SREBP Sterol regulatory enhancer-binding protein 1
- T3 Triiodothyronine
- T4 Thyroxine
- TBG Thyroxine-binding globulin
- TNF Tumor necrosis factor
- TRH Thyrotropin-releasing hormone
- VLDL Very low density lipoprotein
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Symptoms consistent with endocrine disorders and alterations in endocrine laboratory values are not unusual in individuals infected with the human immunodeficiency virus (HIV). Some of these changes are common to any significant systemic illness; others appear to be more specific to HIV infection or its therapies. Alterations can be found in HIV infection even before clinically significant immunocompromise occurs. As the infected individual becomes immunocompromised, opportunistic infections and neoplasms—as well as the agents used in the treatment of these disorders—can give rise to further changes in endocrine function. Herein we discuss alterations in endocrine function that can accompany HIV infection and acquired immunodeficiency syndrome (AIDS), focusing on evaluation and interpretation of clinical and laboratory findings.
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In the era of highly active antiretroviral therapy (HAART), clinical thyroid dysfunction is relatively uncommon in stable HIV-infected patients. In several large studies, the prevalence of hypothyroidism was 1% to 2.5% and hyperthyroidism was 0.5% to 1%. The prevalence of subclinical disease was higher, with subclinical hypothyroidism between 3.5% and 20% and subclinical hyperthyroidism <1%, although definitions varied between studies. These data do not support screening for thyroid disease above the standard guidelines. With advanced HIV disease, alterations in thyroid function tests do occur but generally do not result in clinical dysfunction. In patients with AIDS, the effects of opportunistic infections and neoplastic involvement of the thyroid, as well as the effects of some medications used to treat HIV-infected patients, should be considered.
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Alterations in Thyroid Function Tests
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HIV-infected patients can show alterations in thyroid function tests that are largely asymptomatic. Some of the changes are similar to those seen in the classic euthyroid-sick syndrome, whereas others are unique to the HIV disease state. Advanced HIV is associated with a decrease in thyroid hormone levels, triiodothyronine (T3) and thyroxine (T4), similar to that seen in the euthyroid-sick syndrome. When HIV-infected patients were stratified by weight loss and the presence of secondary infection, a decline in T3 levels corresponded to the severity of disease, consistent with the euthyroid-sick syndrome. Deterioration in nutritional status can also contribute to the decrease in T3 and T4, because there is a strong correlation between albumin levels and both free T4 and total T3 levels. In the euthyroid-sick syndrome, decreased levels of serum thyroid hormones are due to impaired peripheral T4 to T3 conversion by 5′ deiodinase. In HIV-infected patients, decreases in serum ...