Endocrine Manifestations of HIV Infection - An Overview

Introduction:

Endocrine dysfunction is acknowledged in patients affected by HIV/AIDS (human immunodeficiency virus or acquired immune deficiency syndrome). These patients are at a high risk of developing endocrine problems along with other systemic complications.

The endocrine glands are affected in several ways by this condition, including:

• The direct effect of HIV infection.

• The effects of the immunosuppressive drugs given to treat the infection.

• The effects of the opportunistic infections that occur along with HIV infection.

• Invasions by neoplasms.

• Side effects of various drugs or medications.

What is HIV or AIDS?

Human immunodeficiency virus infection or acquired immune deficiency syndrome (HIV/AIDS) is a condition that is caused by infection of the human immunodeficiency virus. It is a retrovirus which means this virus inserts a copy of its RNA (ribonucleic acid) into the DNA (deoxyribonucleic acid) of the host cell, therefore, changing its genome. AIDS can be asymptomatic for a long time because of the long incubation period of the infection. HIV spreads primarily through unprotected sex, infected mothers, and contaminated blood transfusion. AIDS causes multiple systemic complications, and several opportunistic infections also appear during this condition because of the low immunity of the patient.

The treatment of AIDS includes highly active antiretroviral therapy in which a combination of antiretroviral drugs is used to suppress the infection. It is estimated that around thirty-three million people are living with HIV infection globally, and around two million new cases are reported every year. HIV is known to be well-associated with multiple endocrine and metabolic disorders. HIV patients have dysfunctioning of the pituitary gland, adrenal gland, gonads, thyroid gland, decreased bone mineral density, etc.

How Is HIV or AIDS Diagnosed?

HIV/AIDS can be diagnosed in the following ways:

• Blood examinations.
• Saliva testing.

These tests involve checking the HIV antigen and HIV antibodies for the presence of the virus in the body through blood or saliva samples, along with nucleic acid tests to check the viral load in the affected individual’s body.

What Are the Effects of HIV or AIDS on Pituitary Gland Function?

The pituitary gland is divided into two lobes (the anterior pituitary lobe and the posterior pituitary lobe), and both of these lobes are responsible for the production and secretion of different hormones. Therefore, HIV also exerts different types of effects on the two lobes. Generally, HIV is associated with hypopituitarism. The effects of HIV on the functioning of the anterior lobe of the pituitary gland are:

Apart from the changes in the levels of these hormones, several physiological factors are also altered. For example:

• Women might attain menopause at an earlier age with worse symptoms.
• Men who are HIV positive are at a higher risk of experiencing erectile dysfunction.
• Infertility is more common in men and women who are HIV-positive.

Moreover, the effects of HIV on the posterior lobe of the pituitary gland include the following:

• There is an excessive release of the antidiuretic hormone (ADH), which results in increased renal absorption and leads to a condition known as the syndrome of inappropriate ADH secretion. This syndrome causes hyponatremia (decrease in the sodium level) in the body, a very common electrolyte imbalance seen in HIV patients.
• Studies have shown that an individual affected by HIV/AIDS will have about forty percent fewer oxytocin-expressing neurons.

What Are the Effects of HIV or AIDS on Adrenal Gland Function?

Adrenal insufficiency is one of the most common complications of HIV/AIDS that occurs in an individual who is HIV positive. Opportunistic infections are the primary cause of adrenal insufficiency in patients with advanced HIV infection. Secondary infections or organisms that may result in impaired adrenal functioning in HIV patients are:

• Mycobacterium tuberculosis.
• Mycobacterium avium intracellulare.
• Cryptococcus.
• Hemorrhage.
• Idiopathic inflammation.
• Tissue destruction by Cytomegalovirus.

HIV patients with advanced infections develop relatively low levels of cortisol in the body leading to cortisol deficiency which is largely due to a reduction in the cortisol reserve. This reduction can predispose the patient to an adrenal crisis in a period of critical illness or stress. The clinical features of adrenal insufficiency due to HIV/AIDS are complex and nonspecific, but some common symptoms that may be seen are fatigue and unusual weight loss.

What Are the Effects of HIV or AIDS on Gonadal Function?

HIV/AIDS shows different effects on male and female gonads; hypogonadism is commonly seen in both genders.

• Male Hypogonadism: The prevalence of hypogonadism in HIV-infected males is significantly higher than in non-infected males. Hypogonadism occurs in about nine to sixteen percent of the males affected by HIV infection, and secondary male hypogonadism is more common. The primary causes of gonadal dysfunction are severe illness, weight loss, and malnutrition. Moreover, secondary hypogonadism occurs in cases of advanced HIV infection due to opportunistic infections affecting the pituitary gland or the hypothalamus.
• Female Hypogonadism: Female hypogonadism occurs in about twenty-five percent of the total HIV-infected female population, and it presents as amenorrhea (absence of menstruation). The primary causes of female hypogonadism in HIV-infected females are suspected to be reduced production and secretion of gonadotropins. Early menopause is also very common in the case of female hypogonadism due to HIV infection.

What Are the Effects of HIV or AIDS on Thyroid Gland Function?

Alterations in thyroid functioning are seen very commonly in the case of HIV/AIDS. Thyroid dysfunction occurring in progressive or advanced HIV infections includes:

• Decreased triiodothyronine (T3) levels.
• Increased thyroxine-binding globulin (TBG) levels.
• Decreased reversed T3 levels.

However, asymptomatic HIV patients with stable body weights generally have normal thyroid levels. Opportunistic infections cause thyroid dysfunction in HIV-infected patients.

What Are Metabolic Changes Due to HIV or AIDS?

The following metabolic and body changes are also seen in HIV-infected patients:

• Osteoporosis: It is a condition in which new bone formation does not keep up with old bone removal leading to weak and brittle bones that are easily fractured.
• Dyslipidemia: It is a condition with abnormally elevated levels of cholesterol in the blood.
• Diabetes Mellitus: It is a metabolic disorder that causes high blood sugar levels. Insulin resistance and diabetes mellitus are extremely common in HIV patients.
• Lipodystrophy: It is an acquired condition characterized by the inability of the body to produce and maintain healthy fat tissues.
• Lipoatrophy: It is a condition in which there is diffuse loss of subcutaneous fat tissues.

What Are the Effects of Anti-HIV or AIDS Drugs on Various Endocrine Glands?

The effects of anti-HIV/AIDS drugs on various endocrine glands are as follows:

Conclusion:

Endocrine manifestations of HIV/AIDS infections have been acknowledged for a long time. The infection affects various endocrine glands by either the direct effect of the virus, by secondary opportunistic infection, or by the side effects of the drugs used to treat HIV/AIDS. Various endocrine glands produce and secrete multiple hormones that are crucial for growth, development, sexual activities, reproduction, etc. Therefore, HIV-infected patients can have problems with all of these physiological functions of the body.