Of the many attractive qualities of pediatric endocrinology, two in particular—its diversity of disorders and its intrinsically pediatric focus on growth and physical development—amplify the importance of practical knowledge of this specialty for the primary care provider. In the past, apart from type 1 diabetes, endocrine problems in clinical practice were relatively rare; they required a pediatric health care expert to differentiate their distinguishing features from the breadth of normal variations in ruling such disorders out much more often than in. During the past 20 years, however, as the incidence of type 1 diabetes mellitus has increased, other diseases that were infrequently seen in children— obesity-associated insulin resistance, metabolic syndrome, type 2 diabetes mellitus, and polycystic ovarian syndrome—have emerged as common occurrences in pediatric primary care. Ethnic demographic changes, growth and puberty acceleration due to excess nutrition, and possibly other factors have reduced the mean age of appearance of first puberty signs so that normal variations must now be distinguished more frequently from pathological causes of precocious puberty. The expanded availability and variety of (often controversial) growthpromoting and puberty-altering treatments have created therapeutic options for a broadening spectrum of children, for whom critical evaluation of benefit, cost, and risk is required. Further, in the United States, every new baby is now screened for congenital adrenal hyperplasia as well as congenital hypothyroidism. Because of these changes among others, the primary child health care provider ponders possible endocrine diagnoses and/or therapeutics virtually every day.
With these thoughts in mind, the editors set out to create a pediatric endocrinology text that, first and foremost, would be an outstanding clinical analysis and decision-making resource. Since an understanding of the clinical manifestations and treatments of endocrine disorders begins with knowledge of concepts of hormone action and principles of feedback control, the first chapter, "General Concepts and Physiology," links genetics, cell biology, and physiology with pathophysiology to provide a clear and approachable overview of endocrine systems. Subsequent chapters are traditional in title—disorders of growth, puberty, thyroid and adrenal glands, sex development, calcium and bone metabolism, water homeostasis, and carbohydrate metabolism and its comorbidities—but innovative in organization and emphasis.
In our second edition, contributing authors have updated all chapters. Specific additions include sections on genetics for the endocrinologist in the general concepts chapter, an overview of the physiology and treatment of metabolic syndrome and dyslipidemia in the obesity chapter, and the addition of a new chapter on enteric hormones.
Problem-oriented frameworks rather than diagnosis-oriented frameworks are emphasized so as to capture conceptual and practical approaches to clinical dilemmas of current general practice. Integration of pathophysiology with clinical management is emphasized, with extensive use of figures to illustrate principles of normal and abnormal physiology, and treatment rationale and effects. Attention is paid to guiding readers in "how to think about" the evaluation of clinical problems and "when to refer" complex or worrisome patients. Through this approach, the editors' objective is to achieve a subspecialty text that, true to its inclusion in the "Pediatric Practice" series, is distinguished not only by its effective description of state-of-the-art science, but by its clinical utility as well.
It is our added hope that this text is an equally valuable education resource for pediatric endocrinology. Talented educators have a gift for making complex phenomena understandable, a gift that cannot be displaced by the unlimited and instant access to information now provided by web-based journals and databases. The task placed before our group of internationally recognized senior authors was daunting: concisely yet comprehensively review current knowledge, link these concepts with analysis of clinical situations suggesting endocrine system problems, and provide practical recommendations for rational and efficient evaluation and treatment of children with endocrine disorders. The skill with which they accomplished this synthesis is a testament to their far-reaching experience and thoughtful analysis, and makes these chapters exceptional examples for young subspecialists developing their own conceptual approaches, and to all pediatric endocrinologists engaged in teaching others. It is the editors' hope that well-worn covers with many dogeared pages will signify that this book has adeptly filled an important niche.
The editors wish to thank Alyssa Fried, Christine Barcellona, and Christie Naglieri of McGraw-Hill for their expert assistance and firm yet always friendly prodding to remain on task and on time.
Michael S. Kappy, MD, PhD
David B. Allen, MD
Mitchell E. Geffner, MD