Lipid accumulation product index in HIV-infected patients: a marker of cardiovascular risk

ABSTRACT The lipid accumulation product (LAP) index is an emerging cardiovascular risk marker. We aimed to assess the accuracy of this index as a marker of cardiovascular risk in HIV-infected patients. A cross-sectional study of 133 HIV-infected patients on antiretroviral drugs and 20 non-infected controls was conducted at the outpatient clinic of a referral center of infectious and parasitic diseases. Evaluations included LAP index, homeostasis model assessment (HOMA) index, anthropometric measurements, blood pressure, glucose tolerance test, and cholesterol and triglyceride levels. Body mass index (BMI) was similar in both groups; however, waist circumference was greater in the HIV-infected patients. Triglyceride levels were significantly higher (p < 0.001) and HDL cholesterol levels were lower in HIV-infected patients (p < 0.001). Plasma glucose (p = 0.01) and insulin (p = 0.005) levels two hours after a glucose load, HOMA-IR index (p < 0.001) and LAP index (p < 0.001) were higher in the HIV-infected patients. A positive and significant correlation was found between HOMA-IR index and LAP (r = 0.615; p < 0.01), BMI (r = 0.334; p < 0.01) and waist circumference (r = 0.452; p < 0.01) in the HIV-infected patients. In male HIV-infected patients and controls, ROC curve analyses revealed that the best cut-off value of LAP to define the presence of insulin resistance was 64.8 (sensitivity 86%, specificity 77% and area under the curve 0.824). These results confirm that insulin resistance is more common in HIV-patients on antiretroviral drugs than in HIV-negative controls. A positive and significant correlation was found between the LAP index and the HOMA index, with LAP ≥ 64.8 constituting an additional risk factor for cardiovascular disease in male HIV patients.

Is Lipid Accumulation Product Associated with an Atherogenic Lipoprotein Profile in Brazilian Subjects? / O Produto de Acumulação Lipídica está Associado a um Perfil Aterogênico de Lipoproteínas em Indivíduos Brasileiros?

Abstract Background: Lipid accumulation product (LAP), a simple and low-cost tool, is a novel biomarker of central lipid accumulation and represents a potential surrogate marker for atherogenic lipoprotein profile. However, its association with lipoprotein subfractions has not been described in the literature. Objective: To determine whether LAP index could be used as a marker of low- and high-density lipoprotein (LDL and HDL) size in Brazilian individuals. Methods: This cross-sectional study included patients (n = 351) of both sexes and age between 30-74 years. Clinical and sociodemographic data and family history of diseases were evaluated. Lipoprotein size, and levels of total cholesterol (TC), lipoproteins, apolipoprotein AI and B (APO AI/APO B), glucose, insulin, insulin resistance index (HOMA-IR) and non-esterified fatty acids (NEFA) were assessed in blood samples. LAP was calculated by the formulas [(waist circumference[cm]-58) × (triglycerides[mmol/L]) for women and (waist circumference [cm]-65) × (triglycerides [mmol/L]) for men]. The association between LAP and metabolic parameters were tested by linear trend (general linear model, GLM test) before and after multiple adjustments for potential confounders (sex, age, smoking, statin, fibrate, and hypoglycemic drugs) at significant level p < 0.05. Results: LAP was positively associated with TC, APO B, NEFA, glucose, insulin and HOMA-IR values, and negatively associated with HDL-C. Higher central lipid accumulation was corelated with higher percentage of intermediate HDL and of small LDL and HDL and less amount of large HDL. LDL size was also reduced in greater LAP index values. The negative impact of LAP was maintained after adjustment for multiple variables. Conclusion: LAP was robustly associated with atherogenic profile of lipoprotein subfractions, independently of multiple confounders.

Resumo Fundamento: O produto de acumulação lipídica (LAP), um instrumento simples e de baixo custo, é um novo biomarcador de acúmulo de gordura central e representa um marcador substituto potencial para o perfil aterogênico de lipoproteínas. No entanto, sua associação com subfrações de lipoproteínas ainda não foi descrita na literatura. Objetivo: Determinar se o LAP pode ser usado como um marcador de tamanho da lipoproteína de baixa densidade (LDL) e de alta densidade (HDL) em indivíduos brasileiros. Métodos: Este estudo transversal incluiu 351 pacientes de ambos os sexos e idade entre 30 e 74 anos. Dados clínicos e sociodemográficos e história familiar de doenças foram avaliados. O tamanho das lipoproteínas, e níveis de colesterol total (CT), lipoproteínas, apolipoproteína AI e B (APO AI/APO B), glicose, ácidos graxos não esterificados (AGNEs) e insulina, e índice de resistência insulínica (HOMA-IR) foram avaliados em amostras de sangue. O LAP foi calculado utilizando-se as fórmulas (circunferência da cintura (cm]-58) × (triglicerídeos[mmol/L]) para mulheres e (circunferência da cintura[cm]-65) × (triglicerídeos [mmol/L]) para homens. Associações entre LAP e parâmetros metabólicos foram testadas por tendência linear (modelo linear generalizado, GLM) antes e após ajustes por fatores de confusão (sexo, idade, tabagismo, uso de estatinas, fibratos e hipoglicemiantes) ao nível de significância de p < 0,05). Resultados: LAP apresentou uma associação positiva com CT, APO B, AGNEs, glicose, insulina, HOMA-IR, e uma associação negativa com HDL-C. Maior acúmulo de gordura central correlacionou-se com maior porcentagem de HDL intermediária e de partículas pequenas de LDL e HDL, e menor porcentagem de HDL grande. O tamanho da LDL também era reduzido em valores de LAP mais elevados. O impacto negativo do LAP foi mantido após ajuste para múltiplas variáveis. Conclusão: o LAP esteve fortemente associado com o perfil aterogênico de subfrações de lipoproteínas, independetemente dos fatores de confusão.