Madhav V. Rao, MD1, Department of Medicine, Section of Nephrology, University of Chicago, Chicago, IL, USA.
Vijaykumar M. Rao, MD, FACP, FASN, President, Associates in Nephrology, Chicago, IL, USA.

Alterations in potassium balance occur frequently in all patient populations, but in particular, among older adults. Physicians commonly encounter such disorders when taking care of patients in the clinic or in the hospital. Most often the etiology of such disturbances is due to prescribed medications, but a number of clinical conditions exist which predispose people to both hyperkalemia and hypokalemia. These conditions can have grave consequences if not addressed quickly. Furthermore, the approach to definitive treatment depends on the underlying physiology that often occurs at the tubular level within the kidney.
Key words: potassium balance, hyperkalemia, hypokalemia, older adults.

Gemini Tanna, MD, FRCPC, Division of Nephrology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
Sarbjit Vanita Jassal, MB, BCh, MD, Division of Nephrology, University Health Network, University of Toronto, Toronto, Ontario, Canada

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Chronic kidney disease (CKD) is increasingly common among older adults. In the older individual, the presence of CKD is predictive of cardiovascular death, increased all- cause mortality, and progression to end-stage renal disease and the need for dialysis. Early identification of these high-risk individuals may prevent or delay such adverse outcomes. The Canadian Society of Nephrology (CSN) released a position statement in September 2006 suggesting that screening be limited to those at high risk. We recommend that clinicians follow the CSN algorithm for screening for CKD among older adults.
Key words: chronic kidney disease, estimated glomerular filtration rate, older adults, renal function, screening.

The accredited CME learning activity based on this article is offered under the auspices of the CE department of the University of Toronto. Participating physicians are entitled to one (1) MAINPRO-M1 credit by completing this program, found online at www.geriatricsandaging.ca/cme

Richard W. Norman, MD, FRCSC, Professor, Department of Urology, Dalhousie University, Halifax, NS.

Kidney stones occur frequently among the North American population and tend to be recurrent. It is usually possible to identify one or more abnormal urinary risk factors for the specific stone composition under consideration. The physician and dietician can counsel the patient on how to reduce the likelihood of further recurrences or stone growth by increasing fluid intake and dietary modification. If this is unsuccessful, a variety of medications are available depending upon which variable(s) is (are) abnormal. There are specific nuances that relate to the older adult age group.
Key words: kidney stones, nephrolithiasis, urinary risk factors, stone prevention.

MC Faes, MD, MSc, Department of Geriatric Medicine, University Medical Centre Nijmegen, The Netherlands.
MG Spigt, PhD, Department of General Practice/Research Institute CAPHRI, University of Maastricht, The Netherlands.
MGM Olde Rikkert MD, PhD, Department of Geriatric Medicine, University Medical Centre Nijmegen, The Netherlands.

Homeostasis of fluid balance is an important prerequisite for healthy aging. The high prevalence of disturbances of fluid balance among older adult patients has triggered clinical research on age- and disease-related changes in water homeostasis. Empirical findings on risk factors of dehydration and on diagnostic and therapeutic strategies are reviewed in this paper. No single measure has proved to be the gold standard in the diagnosis of dehydration. Diagnosing dehydration and monitoring fluid balance requires repeated measurements of weight, creatinine, and physical signs such as tongue hydration. Rehydration and prevention requires fluid on prescription (> 1.5 litre/day), and the route of fluid administration depends on the acuteness and severity of clinical signs.
Keywords: older adults, dehydration, fluid therapy, risk factors, diagnosis.

Tarek Rajji, MD, Geriatric Mental Health Program, Centre for Addiction and Mental Health; Department of Psychiatry, University of Toronto, Toronto, ON.
Benoit H. Mulsant, MD, MSc, FRCPC, Western Psychiatric Institute and Clinic and Department of Psychiatry, University of Pittsburgh, Pittsburgh, USA; Geriatric Mental Health Program, Centre for Addiction and Mental Health; Department of Psychiatry, University of Toronto, Toronto, ON.
Hiroyuki Uchida, MD, PhD, PET Centre, Centre for Addiction and Mental Health, Toronto, ON.
David Mamo, MD, MSc, FRCPC, PET Centre and Geriatric Mental Health Program, Centre for Addiction and Mental Health; Department of Psychiatry, University of Toronto; Centre for Addiction and Mental Health, Toronto, ON.

Antipsychotics are increasingly being prescribed to older patients for the management of a variety of neuropsychiatric conditions. Available evidence supports the use of second-generation antipsychotics (SGAs) when treating these conditions. However, given their modest clinical effect for certain conditions (e.g., behavioural and psychological symptoms of dementia), their adverse effects, and their safety profile, a careful analysis of their risks and benefits is needed before initiating treatment with an SGA for an older patient. Among SGAs, choice of medication should be guided by their respective clinical indications and adverse effect profile, with use of lower initial and target doses (compared to younger adults) and periodic reviews of whether or not their continued use is warranted.
Key words: antipsychotics, older adults, dementia, delirium, schizophrenia.

Kati Juva, MD, PhD, Department of Psychiatry, Helsinki University Central Hospital, Helsinki, Finland.
Sari Rastas, MD, PhD, Department of Neuroscience and Neurology, University of Kuopio, Kuopio, Finland; Kauniala Disabled War Veterans’ Hospital, Espoo, Finland.
Tuula Pirttilä, PhD, Professor, Department of Neuroscience and Neurology, University of Kuopio and Kuopio University Hospital, Kuopio, Finland.

The harmful effects of high blood pressure on cardiovascular morbidity and mortality are well established. However, hypertension in the very old is an extremely complex issue. Current epidemiological data suggest that high blood pressure may be a marker of survival in the very old, and lowering blood pressure may lead to an increase in total mortality. In this review we will summarize the evidence on the association between blood pressure and mortality and discuss the implications of the data.
Key words: older adults, hypertension, survival, very old, blood pressure.

Naven Duggal, MD, FRCSC, Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.

Diabetes mellitus is a major cause of nontraumatic lower extremity amputation in Canada and the United States. This multisystemic disease is most effectively managed by a team approach. Structural abnormalities and the resultant plantar ulcers will increase the risk of amputation among older adults with diabetes. Effective management of the diabetic foot begins with education and prevention.
Key words: diabetic foot, amputation, diabetic ulcers, Charcot arthropathy.

Muhammad Firdaus, MD, FACP, Section of Endocrinology, Department of Medicine, University of Oklahoma Health Sciences Center; Veterans Affairs Medical Center, Oklahoma City, OK, USA.
Timothy J Lyons, MD, FRCP, Section of Endocrinology, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.

The metabolic syndrome, though controversial due to lack of a uniform pathophysiological mechanism, is a useful clinical tool for identifying persons at risk for diabetes and cardiovascular disease. It indicates the cumulative cardiometabolic risk exerted by abdominal obesity, hyperglycemia, high triglyceride, low high density lipoprotein cholesterol (HDL-C), and high blood pressure. Lifestyle factors, high calorie intake, and less physical activity have been implicated in the causation of the metabolic syndrome, and thus older adults are at particular risk for the development of this syndrome. Current evidence indicates that the components of the metabolic syndrome can be targeted with lifestyle interventions to prevent the complications of diabetes and cardiovascular disease. This paper reviews various diagnostic criteria, etiological factors, and lifestyle interventions to combat the metabolic syndrome in order to prevent diabetes and cardiovascular disease in older adults.
Key words: metabolic syndrome, prevention, lifestyle modification, diet, physical activity.

Jeremy Gilbert, MD, FRCPC, Staff Endocrinologist, Toronto General Hospital, Toronto, ON.

Diabetes is a very common condition, especially among older adults. There are numerous benefits associated with improved glycemic control. However, achieving glycemic targets can be challenging, particularly for older adults with comorbidities. In recent years more oral antihyperglycemic agents have become available to better manage diabetes, and there are many pharmacological therapies currently in development. In order to select the most appropriate agent to use as monotherapy or in combination for an individual patient, it is important to be familiar with the mechanism, efficacy, safety, and cost of the various antihyperglycemic agents.
Key words: diabetes, older adults, oral antihyperglycemic agents, monotherapy, combination therapy.

Maitreyi Raman, MD, FRCPC, Assistant Professor, Department of Medicine, Division of Gastroenterology, University of Calgary, Calgary, AB.
Elaheh Aghdassi, PhD, Scientific Associate, University of Toronto, Toronto, ON.
Johane P. Allard, PhD, Associate Professor, Division of Gastroenterology, Department of Medicine, University of Toronto, Toronto, ON.

Zinc is one of the essential micronutrients and has an important role in the maintenance of human health. Older adults are particularly vulnerable to zinc deficiency due to poor intake of zinc-rich foods. Zinc deficiency may result from poor intake due to alterations in both olfactory and gustatory sensations in addition to difficulty in mastication from poor dentition, or due to inadequate absorption resulting from excess consumption of phytate-containing products that inhibit the absorption of zinc. This review focuses on the clinical consequences associated with zinc deficiency among older adults.
Key words: zinc, deficiency, older adults, clinical manifestations.