Insulin Resistance: Regression and Clustering

Abstract

In this paper we try to define insulin resistance (IR) precisely for a group of Chinese women. Our definition deliberately does not depend upon body mass index (BMI) or age, although in other studies, with particular random effects models quite different from models used here, BMI accounts for a large part of the variability in IR. We accomplish our goal through application of Gauss mixture vector quantization (GMVQ), a technique for clustering that was developed for application to lossy data compression. Defining data come from measurements that play major roles in medical practice. A precise statement of what the data are is in Section 1. Their family structures are described in detail. They concern levels of lipids and the results of an oral glucose tolerance test (OGTT). We apply GMVQ to residuals obtained from regressions of outcomes of an OGTT and lipids on functions of age and BMI that are inferred from the data. A bootstrap procedure developed for our family data supplemented by insights from other approaches leads us to believe that two clusters are appropriate for defining IR precisely. One cluster consists of women who are IR, and the other of women who seem not to be. Genes and other features are used to predict cluster membership. We argue that prediction with “main effects” is not satisfactory, but prediction that includes interactions may be.

Does the sympathetic nervous system contribute to the pathophysiology of metabolic syndrome?

“…The hyperinsulinaemia reflex increases the release of triglycerides by liver into the bloodstream and subsequent decrease in the level of HDL cholesterol, increase in the level of small and dense particles of LDL cholesterol (Reaven, 1988 , 2003 ; Yoon et al, 2014 ). The hyperinsulinaemia reflex can contribute to the pathophysiology of the essential hypertension through an increase in renal water absorption and/or increase in the sympathetic activity (Reaven, 2003 ; Yoon et al, 2014 ). The insulin resistance is a major risk factor of type 2 diabetes and atherosclerotic complications such as coronary artery disease, stroke and peripheral arterial disease (Yoon et al, 2014 ).…”

“…The hyperinsulinaemia reflex can contribute to the pathophysiology of the essential hypertension through an increase in renal water absorption and/or increase in the sympathetic activity (Reaven, 2003 ; Yoon et al, 2014 ). The insulin resistance is a major risk factor of type 2 diabetes and atherosclerotic complications such as coronary artery disease, stroke and peripheral arterial disease (Yoon et al, 2014 ).…”

“…As mentioned above, the hyperinsulinaemia reflex, caused by the insulin resistance, promotes increase in the hepatic release of triglycerides to the blood. This release could decrease the level of HDL cholesterol and increase the level of small and denser particles of LDL cholesterol (Reaven, 1988 , 2003 ; Yoon et al, 2014 ).…”

Associação da rigidez arterial central e síndrome metabólica em idosos

“…Mesmo que existam debates em torno da definição da SM e de pontos de corte específicos para a idade, a literatura apresenta uma tendência crescente de novos casos de SM devido ao envelhecimento da população, ao aumento da obesidade, à ingestão excessiva de alimentos obesogênicos e ao sedentarismo (KAUR, 2014). SRINIVASAN, 2004;ZAMBONI, et al, 2005;VILLAREAL, et al, 2005 ;1988YOON et al, 2014).…”

“…O acúmulo de tecido adiposo na região abdominal é reconhecido principalmente como fator de risco para DCV, DM, dislipidemias e SM(GUS, et al, 2004;JANSSEN;KATZMARZYK, ROSS, 2002;OLINTO, et al, 2004). O tecido adiposo, por ser um órgão endócrino ativo, produz várias citocinas e altera o estado inflamatório do indivíduo(KAUR, 2014;YOON et al, 2014).…”