David C.W. Lau, MD, PhD, FRCPC, Professor of Medicine, Biochemistry and Molecular Biology; Director, Julia McFarlane Diabetes Research Centre, University of Calgary, Calgary, AB.

As the population ages, the diagnosis of Type 2 diabetes is expected to skyrocket over the next two decades. Diabetes is diagnosed by a fasting venous plasma glucose level of equal to or greater than 7mmol/L or, in the presence of classic symptoms of hyperglycemia, a casual plasma glucose value greater than 11.1mmol/L. Early diagnosis, screening and prevention of diabetes in the elderly will greatly reduce the burden of this serious chronic disease that is associated with increased morbidity and mortality.
Key words: impaired glucose tolerance, diagnosis, screening, prevention, Type 2 diabetes

The Diabetes Epidemic
Diabetes is now reaching epidemic proportions in Canada and the U.

Clarence K.W. Wong, MD, FRCPC, Gastroenterologist and Clinical Lecturer, Division of Gastroenterology, University of Alberta; Consultant, Cross Cancer Institute, Alberta Cancer Board, Edmonton, AB.

Introduction
Gastrointestinal malignancies collectively account for the greatest number of cancer deaths in Canada.¹ This is particularly evident in the elderly population in which 90% of all new cancers are diagnosed in individuals over the age of 45.² Of these new cancers, one in five are gastrointestinal cancers. As these malignancies are often lethal, improved survival depends on preventive strategies to effectively detect and manage the associated precursor conditions. This paper will review the premalignant conditions associated with three common gastrointestinal cancers. Effective management of conditions leading to esophageal, gastric and colon cancers can greatly reduce the burden of disease among the geriatric population.

Esophageal Cancer
Cancers of the esophagus are lethal, with a death to case ratio of 1.11.¹ Although this estimate is high due to incomplete registration of new cases, it underscores the lack of effective treatment for this disease. Until recently, squamous cell carcinomas were the most common type of esophageal cancer. However, in the last few decades the incidence of esophageal adenocarcinomas has increased exponentially. It is likely that this increase is linked to a rise in incidence of its only known risk factor, Barrett's esophagus.

Part 4: Reflexes and Sensory Examination

David J. Gladstone, BSc, MD, Fellow, Cognitive Neurology and Stroke Research Unit, Sunnybrook and Women's College Health Sciences Centre, Division of Neurology, University of Toronto, Toronto, ON.
Sandra E. Black, MD, FRCPC, Professor of Medicine (Neurology), University of Toronto; Head, Division of Neurology and Director, Cognitive Neurology Unit, Sunnybrook and Women's College Health Sciences Centre, Toronto, ON.

Abstract
This four-part series of articles provides an overview of the neurological examination of the elderly patient, particularly as it applies to patients with cognitive impairment, dementia or cerebrovascular disease. The focus is on the method and interpretation of the bedside physical examination; the mental state and cognitive examinations are not covered in this review. Part 1 (featured in the September issue) began with an approach to the neurological examination in normal aging and in disease, and reviewed components of the general physical, head and neck, neurovascular and cranial nerve examinations relevant to aging and dementia. Part 2 (featured in the October issue) covered the motor examination with an emphasis on upper motor neuron signs and movement disorders.

Mary Anne Cooper MSc, MD, FRCPC, Department of Medicine, University of Toronto; Lecturer, Sunnybrook and Women’s Health Sciences Centre, Toronto, ON.

Introduction
Gastroesophageal reflux disease (GERD), the abnormal reflux of gastric and duodenal contents into the esophagus, is common. Almost 50% of the North American population experience symptoms once a month and 10% have symptoms daily.¹ Patients most commonly complain of pyrosis and regurgitation, but other symptoms such as dysphagia, chest pain and nausea are not rare.¹ As well, respiratory tract symptoms such as cough, hoarseness and asthma may be attributable to GERD (Table 1).^1,2

Acid reflux into the esophagus is a normal physiologic event. It occurs after meals when the lower esophageal sphincter (LES) tone is reduced. The LES opens, creating a common cavity with the stomach. Because stomach pressures are higher than esophageal pressures, gastric contents reflux into the esophagus. Formal measurement with 24-hour pH monitoring indicates that the pH of the esophagus should be < 4 for < 4% of the time. Factors that increase acid contact time with the esophagus promote GERD.

Naveen Arya, MD, FRCP(C), Resident, Gastroenterology sub-specialty training program, Univerity of Toronto, Toronto, ON.
Peter G. Rossos, MD, FRCP(C), Staff Gastroenterologist, University Health Network; Program Director, Division of Gastroenterology, University of Toronto, Toronto, ON.

Introduction
With advancing age, the use of non-steroidal anti-inflammatory drugs (NSAIDs) for the treatment of arthritis, pain and headache increases. Although there are many benefits of NSAIDs for their analgesic and anti-inflammatory properties, there are also potential serious side effects. The side-effect profile includes dyspepsia, gastrointestinal mucosal ulceration and bleeding, cardiac dysfunction, renal toxicity and platelet dysfunction (Table 1). Chronic use of NSAIDs is associated with serious gastrointestinal (GI) toxicity, which severely restricts the use of these medications. In the United States, adverse events associated with NSAIDs result in 103,000 hospitalizations and 16,500 deaths per year.¹ In the United Kingdom, it is estimated that 1/2000 NSAID prescriptions lasting for two months will result in death.²

The average cost of both over-the-counter and prescription NSAID use in the United States is approximately $5-10 billion dollars (U.S.) per year.³ Despite significantly increased costs of therapy, newer COX-2 inhibitors are frequently prescribed in an effort to reduce complications.

Marisa Battistella, BScPhm, Pharm D, Education Coordinator & Hemodialysis Pharmacist, Pharmacy Department, University Health Network, Toronto, ON.
Shabbir M.H. Alibhai, MD, MSc, FRCP(C), Staff Physician, University Health Network, Toronto, ON.

Constipation is a common symptom in patients of all ages, but its occurrence is highest among persons 65 years of age or older.^1,2 Constipation has been shown to diminish both quality of life and feeling of well-being.^3-5 Although constipation can have many causes, it is most often functional or idiopathic.^5,6 Furthermore, constipation can lead to serious complications such as malnutrition, fecal impaction, fecal incontinence, colonic dilation and even perforation of the colon.⁷

Definition
Constipation has different meanings to patients and physicians. A patient's perception of constipation may include not only the objective observation of infrequent bowel movements but also subjective complaints of straining with defecation, incomplete evacuation, abdominal bloating or pain, hard or small stools or a need for digital manipulation to enable defecation. Because the definition of constipation can be subjective, an international committee has recommended an operational definition of chronic functional constipation in adults.

C.A. Fallone, MD, FRCP(C), Division of Gastroenterology, McGill University Health Centre, Montreal, QC.

Definition of Dyspepsia
Defining dyspepsia is a somewhat confusing endeavour mainly because the definition itself has varied somewhat over the last few decades. Moreover, the distinction between uninvestigated and investigated dyspepsia is not always clear. Clinically, dyspepsia symptoms must be distinguished from the lower gastrointestinal symptoms of irritable bowel syndrome. Furthermore, the term dyspepsia is often used synonymously for upper gastrointestinal symptoms, but because most experts feel that dyspepsia must be distinguished from gastroesophageal reflux disease (GERD), it does not represent all upper gastrointestinal symptoms.

The Rome II definition of dyspepsia is the most recent and widely accepted.¹ Dyspepsia is defined as a pain or discomfort centred in the upper abdomen. This epigastric discomfort can be associated with other gastrointestinal symptoms such as bloating, feeling full, nausea, early satiety and heartburn. It is important to note that burning sensation in the epigastrium is not heartburn. Rather, heartburn refers to a burning sensation that originates from the epigastric region and radiates up towards the neck. Heartburn alone is not considered dyspepsia according to this definition.

Christopher N. Andrews, MD, Gastroenterology Fellow, Faculty of Medicine, University of Calgary, Calgary, AB.
Eldon A. Shaffer, MD, FRCPC, Professor of Medicine, Division of Gastroenterology, Faculty of Medicine, University of Calgary, Calgary, AB.

Introduction
Diverticular disease of the colon (or diverticulosis) is an anatomical description of saccular outpouchings of mucosa through the wall of the colon. It is very common in the Western world, and its prevalence is rising. This paper will briefly review the epidemiology and pathophysiology of diverticular disease, followed by a focus on the diagnosis and management of the two most common complications of the disease: diverticulitis and diverticular bleeding.

Epidemiology
The true prevalence of diverticulosis is unknown, but autopsy reports suggest that up to half of patients over 60 years are affected.¹ The frequency increases with age and is much higher in developed societies in which fibre intake is lower. In the Western world, the most commonly affected site in the colon is the sigmoid colon, sometimes with more proximal involvement.² However, in Asian countries diverticulae tend to be right-sided (in the ascending colon) and fewer in number. The reason for this difference is unknown.

Pathophysiology
The colon is made up of circumferential and longitudinal (taenia coli) muscle layers, which act in unison to propel stool towards the rectum.

Supporting Research and Public Education in Digestive Disorders

Gary A. Levy, MD, FRCP, President, Canadian Digestive Health Foundation; Director, Multi Organ Transplant Program, Toronto General Hospital, University of Toronto, Toronto, ON.

The Burden of Digestive Disorders in Canada
Many are aware of the devastating impact that diseases such as cancer and heart disease have on Canadians. However, few might realize that digestive diseases constitute an even greater health and economic burden, and seriously impair quality of life.

Despite the staggering statistics (see sidebar), funding for education and research from provincial and federal agencies lags far behind the prevalence and burden of disease. As an example, from 1988-1998, successful government gastroenterology grants decreased from 76 to 53. The total dollar value for digestive disease research also decreased from $6 million to $4.4 million over the same period.

Introducing the Canadian Digestive Health Foundation
In 1991, the Canadian Digestive Health Foundation (CDHF; then the Canadian Digestive Disease Foundation) was formed by a small group of Canadian gastroenterologists interested in enhancing the profile of gastroenterology in Canada and generating a stable source of funds for research and education. In 1994, the Foundation became a charitable organization. Between 1995 and 2000, one to two grants in gastrointestinal research were awarded annually, funding seven young investigators who have since become key members of the Canadian GI research community. However, it was only in the last few years that the organization began to grow towards its full potential.

In 2001, renewed support allowed the Foundation to establish a National Office. The Canadian Association of Gastroenterology (CAG), a professional society of physicians, other health care professionals and basic scientists, fully endorsed the Foundation as its fundraising foundation. Strong ties with the Canadian Institutes of Health Research (CIHR) offered new research funding opportunities. With this revitalization, the organization became the Canadian Digestive Health Foundation and redefined its mandate.

In 2001/2002, the Foundation made great strides in the arenas of research and public education. A detailed listing of all CDHF-sponsored research can be found on the CDHF website.

Public Education and the CDHF
Last year the CDHF launched its website (www.cdhf.ca) as the primary means of providing education for patients and the public regarding digestive diseases. Among other resources, the site contains a growing library of information on various gastrointestinal problems, prepared by key Canadian medical experts specializing in the area. While contacts from patients have confirmed the usefulness of this information, patients clearly desire a forum to interact with medical specialists regarding their particular situation. To meet this need, the CDHF is pleased to introduce a new program coming in January 2003 called Ask a Specialist.

This program allows you and your patients to ask a Canadian gastrointestinal specialist a question about a particular digestive disorder or health issue, via e-mail, and receive an answer within seven days. Please join us for the first installment in the series, Ask a Specialist About Dyspepsia, beginning January 1, 2003 at www.cdhf.ca.

Jeff Silverman, MD, FRCPC, Fellow in Adult Hematology, University of Toronto, Toronto, ON.
William Geerts, MD, FRCPC, Consultant in Clinical Thromboembolism, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, ON.

Introduction
Thrombocytopenia, defined as a platelet count of less than 150 x 10⁹/L, is an important clinical problem most commonly encountered in hospitalized patients. Although the differential diagnosis is extensive (Table 1), it is essential to always consider heparin-induced thrombocytopenia (HIT) in patients with thrombocytopenia who are hospitalized or who have recently been in a hospital.^1,2

HIT is an adverse drug reaction induced by exposure to heparin that is followed by thrombocytopenia, platelet activation and a dramatic increase in thrombosis risk. Although it is one of the most common and serious drug reactions in hospitalized patients, HIT is frequently not recognized until a major thromboembolic complication has resulted. However, if diagnosed and treated promptly, the outcome is generally favourable. With the widespread use of heparin in the elderly, geriatric patients constitute the largest population at risk of developing HIT. Therefore, clinicians providing care for the elderly must be able to recognize and manage HIT effectively and efficiently.