Peripheral polyneuropathy in severely obese patients with metabolic syndrome but without diabetes: Association with low HDL-cholesterol / Polineuropatia periférica em pacientes obesos graves com síndrome metabólica sem diabetes: associação com baixo HDL-colesterol

Summary Introduction: The purpose of this study was to evaluate the prevalence of peripheral polyneuropathy (PPN) in subjects with grade II and III obesity (Ob-II,III) and metabolic syndrome (MetS) but without diabetes and to investigate possible associated factors. Method: A cross-sectional study was performed in non-diabetic Ob-II,III,MetS patients using the Michigan Neuropathy Screening Instrument (MNSI) to assess the presence of PPN. Results: A total of 24 of 218 non-diabetic Ob-II,III,MetS patients had PPN. Based on univariate analysis, serum levels of LDL-cholesterol (p=0.046) were significantly associated with PPN, while serum triglycerides (p=0.118) and low HDL-cholesterol (p=0.057) showed a tendency toward this association. On a Poisson regression analysis, when the three possible associations were included, low HDL-cholesterol (p=0.047) remained independently associated. Conclusion: In non-diabetic Ob-II,III,MetS patients, PPN defined by the MNSI showed a high prevalence and was associated with low levels of HDL-cholesterol. In order to diagnose that complication, neurological evaluation should be performed in these patients.

Resumo Objetivo: Avaliar a prevalência da polineuropatia periférica (PNP) em indivíduos obesos graus II e III com síndrome metabólica (Ob-II,III,SM) sem diabetes e buscar possíveis fatores associados. Método: Em um estudo transversal, realizado em indivíduos Ob-II,III,SM e sem diagnóstico de diabetes, o Instrumento de Screening de Michigan (MNSI) foi utilizado para avaliar a presença de PNP. Resultados: Um total de 24 de 218 pacientes Ob-II,III,SM e sem diabetes tinham PNP. Quando observamos as associações com PNP em uma análise univariada, níveis séricos de LDL-colesterol (p=0.046) estiveram significativamente associados e houve também uma tendência à associação com níveis séricos de triglicerídeos (p=0.118) e baixo HDL-colesterol (p=0.057). Em uma análise de regressão de Poisson, quando as três possíveis associações foram incluídas, baixo HDL-colesterol (p=0.047) manteve-se independentemente associado. Conclusão: Em pacientes Ob-II,III,SM, mas sem diabetes, a PNP definida pelo MNSI tem uma prevalência elevada e está associada a baixos níveis de HDL-colesterol. Para diagnóstico dessa complicação, recomenda-se realizar o exame neurológico desses pacientes.

El ácido nicotínico aumenta el transporte celular de colesterol de las lipoproteínas de alta densidad en pacientes con hipoalfalipoproteinemia / Nicotinic acid increases cellular transport of high density lipoprotein cholesterol in patients with hypoalphalipoproteinemia

Background: Plasma high density lipoproteins (HDL) are involved in reverse cholesterol transport mediated by the scavenger receptor class B type I (SR-BI). Nicotinic acid increases HDL cholesterol levels, even though its specific impact on SR-BI dependent-cellular cholesterol transport remains unknown. Aim: To determine the effect of nicotinic acid on HDL particle functionality in cholesterol efflux and uptake mediated by SR-BI in cultured cells in hypoalphalipoproteinemic patients. Material and Methods: In a pilot study, eight patients with low HDL (≤ 40 mg/dL) were treated with extended release nicotinic acid. HDL cholesterol and phospholipid levels, HDL2 and HDL3 fractions and HDL particle sizes were measured at baseline and post-therapy. Before and after nicotinic acid treatment, HDL particles were used for cholesterol transport studies in cells transfected with SR-BI. Results: Nicotinic acid treatment raised total HDL cholesterol and phospholipids, HDL2 levels as well as HDL particle size. Nicotinic acid significantly increased HDL cholesterol efflux and uptake capacity mediated by SR-BI in cultured cells. Conclusions: Nicotinic acid therapy increases SR-BI-dependent HDL cholesterol transport in cultured cells, establishing a new cellular mechanism by which this lipid-lowering drug appears to modulate HDL metabolism in patients with hypoalphalipoproteinemia.