Preface

The term dyslipidemia origins from dys- + lipid (fat) + -emia (in the blood), and essentially refers to serum lipid disorders. By definition, dyslipidemia is a disorder of lipoprotein metabolism in terms of either lipoprotein overproduction or deficiency. It may be expressed by increased serum total cholesterol, low-density lipoprotein cholesterol and/or triglycerides, a decrease in high-density lipoprotein cholesterol concentration, and/or various combinations of such disorders. Lipoproteins, which contain lipids and proteins (apolipoproteins), are mainly responsible for transporting plasma lipids from the intestines and liver to peripheral tissues.

Dyslipidemia has a complex pathophysiology consisting of various genetic, lifestyle, and environmental factors. It has many adverse health impacts, and has a pivotal role in the development of chronic non-communicable diseases.

Significant ethnic differences exist due to the prevalence and types of lipid disorders. While elevated serum total and LDL-cholesterol are the main concern in Western populations, in other countries hypertriglyceridemia and low HDLcholesterol are more prevalent. The latter types of lipid disorders are considered as components of the metabolic syndrome, which is a clustering of dyslipidemia, hypertension, dysglycemia, and obesity. The rapid escalating trend of obesity at global level, which is associated with obesogenic milieus through high-calorie intake and sedentary lifestyle, as well as the environmental factors, will result in increasing prevalence of dyslipidemia, and will make it a global medical and public health threat.

This situation is not limited to adults, and the pediatric age group is being involved more and more. The results of longitudinal studies support the association of risk factors cluster in children and adolescents with future chronic diseases.

However, the processes by which lipids and lipoproteins participate in the development of non-communicable diseases at different life stages continue to be an area of controversy. Several experimental and clinical research studies are being conducted regarding issues related to the underlying mechanisms and therapeutic modalities.

#### X Preface

The current book is providing a general overview of dyslipidemia from diverse aspects of pathophysiology, ethnic differences, prevention, health hazards, and treatment.

> **Prof. Roya Kelishadi**  Faculty of Medicine & Child Health Promotion Research Center, Isfahan University of Medical Sciences, Isfahan, Iran

X Preface

treatment.

The current book is providing a general overview of dyslipidemia from diverse aspects of pathophysiology, ethnic differences, prevention, health hazards, and

Faculty of Medicine & Child Health Promotion Research Center,

Isfahan University of Medical Sciences, Isfahan,

**Prof. Roya Kelishadi** 

Iran

**1** 

*Italy*

**Obesity Related Lipid Profile and Altered** 

*Department of Obstetrics and Gynecology, University of Cagliari, Cagliari,* 

Polycystic ovary syndrome (PCOS) is the most common female endocrine disorder, present in 5 – 7% of women of reproductive age. The diagnosis of PCOS was made according to Rotterdam criteria in presence of at least two of the following: 1) oligomenorrhea and/or anovulation; 2) hyperandrogenism (clinical and/or biochemical); 3) polycystic ovaries with the exclusion of other etiologies (1). The disorder is characterized by irregular menstrual cycle, chronic anovulation and hyperandrogenism. Women with PCOS demonstrate marked clinical heterogeneity: the commonly associated features of hirsutism, acne, polycystic-appearing ovaries, obesity and acanthosis nigricans are neither uniform nor universal (2-3). In time the disorder may lead to onset of hyperinsulinemia, insulin resistance, gestational diabetes, early onset of type 2 diabetes mellitus (DM), dyslipidemia and cardiovascular disease (CVD) (4-5). PCOS is characterized by a complex physiology implicating an interaction with environmental and genetic factors, resulting in a broad spectrum of reproductive and metabolic disorders. (6-7) Adult females with PCOS may be at increased risk for atherosclerotic cardiovascular disease (CVD) due to increased prevalence of obesity and central adiposity as well as to hypertension, hyperinsulinemia, type 2 DM, and dyslipidemia in these patients (8).The prevalence of obesity and consequently the presence of metabolic abnormalities reported in Italian and American published studies differs considerably,

A percentage ranging from 30-75% of women with PCOS are obese, European women generally weighing less than their American counterparts (20,21). Hyperinsulemia and/or insulin resistance (IR) are frequently manifested in obese, and to a lesser extent (50%) in lean, PCOS patients (3, 13, 14). Hyperandrogenaemia, hyperinsulemia and obesity are considered as risk factors for the development of hypertension and dyslipidemia, diabetes mellitus and coronary disease in PCOS (15-16). The causes of metabolic disorders in PCOS remain to be clarified, but include obesity-related IR, an intrinsic abnormality of postreceptor insulin signaling (e.g. excess serine phosphorylation), and abnormal insulin secretion. On the other hand, increased resistance to insulin is a hallmark of the onset of normal pubertal development with natural to pre-pubertal values at the end of puberty in non-obese subjects. Consequently, in early adolescence a physiological resistance to insulin

underlining the presence of important ethnic differences. (9, 10, 11, 12).

should be taken into account (12).

**1. Introduction** 

**Insulin Incretion in Adolescent with** 

**Policystic Ovary Syndrome** 

Annamaria Fulghesu and Roberta Magnini
