Obesity and Gynecology

Tahir A. Mahmood, Sabaratnam Arulkumaran, Frank A. Chervenak

• Publisher: Elsevier
• Year: 2020
• ISBN:
  9780128179208
• Edition: 2
• Topic: Ciencias biológicas
• Subtopic: Biología

Obesity and Gynecology, Second Edition, presents updated chapters on a variety of topics, ranging from adolescent obesity, contraception, assisted reproduction and sexual dysfunction, to bariatric surgery and improving semen parameters. The prevalence of obesity in men and women continues to dramatically increase around the world. Obesity presents specific challenges in relation to male and female infertility and general gynecology. Patients who are obese require specific considerations and knowledge.

• Presents an essential reference on the significant risks of obesity related to contraception, male and female infertility, and general gynecology
• Builds foundational knowledge, showing how obesity relates to general gynecology, including menstrual disorders, breasts cancer, menopause and sexual dysfunction
• Assembles critically evaluated chapters that focus on obesity and gynecology to meet the practical needs of gynecologists, endocrinologists and general practitioners

Section 1

Obesity and adolescence

Outline

• Chapter 1 Obesity and the onset of adolescence
• Chapter 2 Obesity in adolescence
• Chapter 3 Obesity in polycystic ovary syndrome and infertility

Chapter 1

Obesity and the onset of adolescence

Zana Bumbuliene¹, Gabriele Tridenti² and Anastasia Vatopoulou³, ¹Clinic of Obstetrics & Gynecology, Institute of Clinical Medicine, Faculty of Medicine, Vilnius University, Vilnius, Lithuania, ²Department of Obstetrics & Gynecology, Santa Maria Nuova Hospital, Reggio Emilia, Italy, ³Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki, Thessaloniki, Greece

Abstract

Overweight and obesity in childhood and adolescence has been growing epidemic in the last 30 years, with 5%–25% affected young people in Europe. Body mass index plotted on percentile charts for age and sex is the gold standard diagnostic. According to World Health Organization, cutoff points are 85th–97th percentile for overweight and ≥97th percentile for obesity. Sedentary and poor eating habits are the main etiologic factors. Being overweight and obese at a young age stimulates early puberty, a premature adrenarche, and accelerates linear growth. Increase in leptin, sex steroids, insulin, insulin growth factor-1, insulin resistance and a reduction in sex hormone–binding globulin have been identified. Almost all the systems in the human body are affected by being overweight and obese. These conditions also worsen young people’s quality of life and are linked to various psychological and behavioral problems. The increase in pediatric obesity is alarming because of its association with health and is a critical early risk factor for adult morbidity and mortality.

Keywords

Obesity; puberty; adolescence; pubertal timing; menarche; early puberty; teenage

Obesity in childhood and adolescence: definition

Being overweight and obese is characterized by varying degrees of excess of body fat, or adiposity. Universally, diagnosis rests with the calculation of body mass index (BMI), attainable by dividing the body weight in kilograms by the height in meters squared (kg/m²). In the adult, adiposity is clearly categorized. According to the World Health Organization (WHO), a BMI in adults of 25–30 kg/m² defines being overweight, whereas obesity is classified by stages or grades—Grade 1: BMI 30–34.9 kg/m², Grade 2: BMI 35–39.9 kg/m², and Grade 3: BMI≥40 kg/m² [1]. In children and adolescents, obesity has not been as well defined as in adults and, therefore, is not a perfect measurement. Even if the alternatives of measuring waist/hip ratio, using dual X-ray absorptiometry or the assessment of body fat and skinfold thickness, might be more precise diagnostic tools, the evaluation of BMI, in the context of age- and sex-specific growth charts, is much more user-friendly and generally utilized worldwide; at present, the BMI is still considered the gold standard diagnostic for obesity/being overweight in childhood and adolescence. In the young and very young the BMI changes with age; therefore, BMI percentile charts are necessary to improve its diagnostic reliability (Fig. 1.1) [2].

Figure 1.1 BMI percentile curves for girls. BMI, Body mass index.

Even by using a BMI percentile chart, different definitions of being overweight and obese exist. Cutoff points for being overweight are BMI 85th–95th percentiles for the Center of Disease Control (CDC) or at BMI 85th–97th percentiles for WHO, while obesity is defined as BMI greater or equal to the 95th percentile by CDC or as greater or equal to the 97th percentile by the WHO [3]. Other definitions, proposed by the International Obesity Task Force, the National Child Measurement Program, and the Scottish Intercollegiate Guideline Network (SIGN), are listed in Table 1.1. It is worth mentioning the SIGN categorizes “severe obesity” when the BMI is greater than 99.6th percentile.

Table 1.1

Childhood and adolescent obesity definitions as related to body mass index [2].

Definitions of childhood obesity	CDC	WHO	IOTF	NCMP	SIGN
Overweight Obesity Severe obesity	85th–95th >95th	85th–97th >97th	91st 99th	>85th >95th	>91st >98th >99.6th

CDC, Center for Disease Control; IOTF, International Obesity Task Force; NCMP, National Child Measurement Program; SIGN, Scottish Intercollegiate Guideline Network; WHO, World Health Organization.

Obesity in childhood and adolescence: incidence

According to 450 national surveys from 144 different countries in 2010, 43 million preschool children under the age of 5 years were overweight or obese (35 million in developing countries) and 92 million were at risk of being overweight [4]. Obesity among children, adolescents, and adults is set to be one of the most important public health concerns of the 21st century. More than 60% of children who are overweight before puberty will become overweight young adults, with earlier appearance of noncommunicable diseases and obesity-related health conditions, such as type 2 diabetes, hypertension, and cardiovascular disease [5]. According to other studies, 50%–77% of obese adolescents will become obese adults, at the risk of cardiovascular diseases, diabetes, and cancer [6]. Since the last three decades the incidence of obesity in childhood and adolescence has been a growing epidemic, with a rise of more than a half of overweight and a doubling of obesity [7]. All around the world, 1 in 10 young people aged 5–17 years is overweight or obese, and most of them live in developing countries, with bigger increasing rates than in the developed part of the world [8]. The worldwide prevalence of childhood overweight and obesity increased from 4.2% in 1990 to 6.7% in 2010, with 8.5% in Africa and 4.9% in Asia [9]. According to the WHO European Region, more and more youngsters are affected in Europe too, with generally higher prevalence in Southern European countries, and still show growing trends. Data collected by WHO Europe from school-age children from 36 European countries over a lot of 41 have shown a prevalence of overweight/obesity ranging from 5% to more than 25%, with great variability among countries and a still growing incidence in more than half of them. A general greater proportion of overweight/obesity was found in boys than in girls, as shown in Figs. 1.2 and 1.3 [10]. Outside Europe, 30% of North American children and adolescents are overweight or obese, with the highest rates among minorities and low-income families [2].

Figure 1.2 Prevalence of overweight (including obesity) among 11-year-olds in 36 countries and areas of the WHO European Region, 2005/2006. Source: Health Behaviour in School-aged Children.

Figure 1.3 Prevalence of overweight (including obesity) among 13-year-olds in 2001 and 2005 in 31 countries and areas of the WHO European Region. Source: Health Behaviour in School-aged Children.

Obesity in children and adolescents: etiology

Obesity is a complex multifactorial condition that involves both genetic and nongenetic factors, with environmental, cultural, lifestyle, and behavioral influences. The main determinants of the overweight state in youth are the lack of physical activity and unhealthy eating habits, resulting in excess energy intake getting stored in fat tissue. Socioeconomic status, race/ethnicity, media and marketing, and the physical environment may also play a role, but the association between socioeconomic factors and childhood obesity is heterogeneous across different countries [11]. A complex interaction between the obesogenic environment and the individual predisposition to adiposity occurs, involving a great number of hormones that are mainly secreted by the gut, such as the appetite-stimulating ghrelin and the anorexigenic peptide YY, the pancreatic polypeptide, glucagon, and others. In 2014 Güngör, from Louisiana State University, United States, published the subsequent comprehensive list of possible etiological factors of obesity in childhood and adolescence [5]:

1. 1. Genetic variations: Genetic variations with rare genetic defects of leptin secretion and more frequent genetic syndromes causing obesity, such as Prader–Willi syndrome.
2. 2. Epigenetics: Epigenetics with in utero factors acting on deoxyribonucleic acid methylation which induce heritable changes in obesity expression. Further research is needed to support this ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• List of contributors
• About the editors
• Preface—obesity in gynaecology
• Section 1: Obesity and adolescence
• Section 2: Contraception
• Section 3: Male and female Infertility
• Section 4: General Gynaecology
• Index