Alteraciones del metabolismo de los lípidos en los pacientes infectados por el virus de la inmunodeficiencia humana. Una hipótesis acerca de su patogenia

Patogenia de la lipodistrofia y de las alteraciones metabólicas asociadas a la infección por el VIH

Lipodystrophy, and the metabolic alterations (dislipemia, insulin-resistance) associated with human immunodeficiency virus (HIV) infection, is a multifactorial syndrome due to the interaction of host related factors (cellular immune status, diet, gene mutations), viral factors (cytokine synthesis, polyunsaturated fatty acid or PUFA depletion), and pharmacological effects (mitochondrial DNA-polymerase inhibition, lipolysis inhibition, adiponectin synthesis reduction). HIV probably modifies the adipocyte differentiation and the lipid metabolism. This retroviral effect is mediated by proinflammatory cytokines (tumor necrosis factor) and the participation of other factors (drugs, diet), all in the context of a particular host genetic setting. The adipocyte (and several cellular receptors, fatty acids, membrane proteins, and cytokines) plays a central role in the pathogenesis of HIV-associated lipodystrophy.

Distribución anormal de la grasa corporal y tipo de tratamiento antirretroviral como predictores de riesgo de enfermedad cardiovascular en pacientes infectados por el virus de la inmunodeficiencia humana

BACKGROUND AND OBJECTIVE

Dyslipidemia, insulin resistance and body fat redistribution are respectively short and long-term complications of protease inhibitor-containing antiretroviral regimens. To establish whether differences in the type of antiretroviral therapy (protease-containing or protease-sparing) or the presence and severity of body fat redistribution, explained differences in cardiovascular risk, we undertook a cross-sectional study.

PATIENTS AND METHOD

The study was carried out in 219 consecutive HIV-infected patients attending an outpatient HIV clinic between February and April, 2002. Age, sex, smoking status, weight, height, waist circumference, blood pressure, antihypertensive treatment, total cholesterol, HDL cholesterol, triglycerides, and glucose concentrations, in addition to changes in body fat distribution were measured in 31 HIV-infected patients with no antiretroviral therapy, 35 HIV-infected patients treated with protease inhibitor-sparing regimens, and 153 HIV-infected patients treated with protease inhibitor-containing regimens. A ten-year cardiovascular disease risk was estimated according to the Framingham score.

RESULTS

Patients treated with protease inhibitor-containing regimens as well as patients treated with protease inhibitor-sparing agents showed higher concentrations of cholesterol (p < 0.001), triglycerides (p = 0.004), glucose (p = 0.028), and greater changes in body fat distribution (p = 0.001) than patients with no antiretroviral therapy. An abnormal body fat distribution score was more strongly associated (p < 0.001) with the estimated 10-year cardiovascular disease risk than the type of HAART (p = 0.036). Ten-year cardiovascular disease risk increased linearly from 7.48% to 11.16% and to 19.50% in patients with no or mild, moderate and severe lipodystrophy scores, respectively.

CONCLUSIONS

The results of this study encourage the use of cardiovascular preventive strategies in HIV-infected patients with severe lipodystrophy.

Micronutrientes en la infección por el virus de la inmunodeficiencia humana y su relación con la respuesta inflamatoria

BACKGROUND

Our aim was to measure the plasma concentrations of various vitamins and micronutrients involved in the immune response and antioxidant systems of an HIV+ population and to determine how they are related to the inflammatory response.

PATIENTS AND METHOD

We studied 86 subjects with known HIV-infection who were divided into three groups (asymptomatic HIV+; AIDS without opportunistic infection; and AIDS with active opportunistic infection) which were compared with a control group. Serum concentrations of vitamin A, vitamin E, copper and zinc were measured, as well as several inflammatory parameters. Absorption tests for fat and sugar were performed in all patients.

RESULTS

Serum vitamin A and E levels were below the reference range in 36.4% and 14.3% patients, respectively, but not in controls subjects. The prevalence of vitamin A deficiency increased with the severity of the disease. Fewer patients than controls had values below the reference range regarding serum copper. AIDS patients with active opportunistic infection showed significantly lower serum concentrations of vitamin A (p < 0.001) and significantly higher serum concentrations of copper (p < 0.0001). Both serum concentrations of vitamin A and copper were correlated with various inflammatory parameters.

CONCLUSIONS

Micronutrient deficiencies are prevalent in HIV-infected patients including asymptomatic patients. Vitamin A and copper were significantly correlated with inflammatory parameters, suggesting that their serum concentrations have more to do with the inflammatory response than with the nutritional status.