Central Diabetes Insipidus Masked by Uncontrolled Diabetes Mellitus: A Challenging Case Managed With Indapamide.

A 44-year-old man with a history of traumatic brain injury (TBI) presented to the emergency room (ER) with diabetic ketoacidosis (DKA). After resolution of DKA, the patient had persistent polyuria (up to 5.5 L/24 h) associated with low specific gravity (1.002-1.005) and severe hypernatremia (up to 186 mmol/L) that led us to consider the possibility of central diabetes insipidus (DI). Due to the lack of desmopressin availability in our country, we managed the patient using indapamide. Polydipsia and polyuria in a patient with controlled diabetes mellitus (DM) should raise suspicion for alternative etiologies, including DI. Appropriate fluid management during hospitalization is critical to avoid life-threatening complications. TBI is an important cause of central DI and should be treated with desmopressin, an arginine-vasopressin (AVP) analog. In the absence of desmopressin, alternative options can help patients with central DI, including thiazides, carbamazepine, chlorpropamide, among others less studied.

Aging Women and the Office Assessment: Clinical Updates in Women's Health Care Primary and Preventive Care Review.

This monograph is intended to serve as a practical guide to the office assessment of the aging woman and recognizes the time constraints that characterize current office practice. Obstetrician-gynecologists are increasingly becoming the primary care providers to women in their practices and especially to older women who have been long-time patients. This monograph should serve as a guide to the many tools needed to assess the health and functional and cognitive status of the aging woman. Illustrative cases demonstrate how to use these tools in a time-efficient manner to achieve a positive effect on the well-being of the patient.

Meeting the Need for Training in Geriatrics: The Geriatrics Education for Specialty Residents Program.

The imperative created by increasing numbers of aging Americans coupled with increasing longevity has generated recognition and acceptance within american medicine that education, from medical school through postgraduate training through continuing medical education, must include appropriate knowledge and skills in aging and geriatrics to provide for effective care of older adults. Such education and training is necessary not only for traditional primary care providers, but also for specialty physicians, including those in most surgical specialties and in related fields such as anesthesiology, emergency medicine and physical medicine and rehabilitation. To fill this demand, the American Geriatrics Society Geriatrics for Specialist Initiative established the Geriatrics Education for Specialty Residents Program (GSR). This article reviews the process by which the GSR created a dynamic cohort of geriatric surgical educators and researchers who in turn created a vibrant body of educational tools and scientific works that continue to advance the cause of improving medical care of older adults.

Role of arginine vasopressin receptor antagonists in hyponatremia in the elderly.

Hyponatremia can occur at any age, but it is especially prevalent among the elderly, particularly those in acute care hospitals and long-term care facilities. The increased incidence in these patient groups is attributable to age-related impairment of fluid and electrolyte balance, use of multiple drugs that can precipitate hyponatremia, and increased vulnerability to diseases associated with hyponatremia. Recent evidence suggests that even mild chronic hyponatremia can have serious consequences in the elderly. Many current treatments for hyponatremia are limited by poor compliance, inconsistent or delayed response, or risk of adverse effects. Arginine vasopressin (AVP) receptor antagonists, a new class of drugs that block the binding of AVP to V2 receptors in the kidney's collecting tubules, may provide a safe and effective alternative.

The relationship between the action of arginine vasopressin and responsiveness to oral desmopressin in older men: a pilot study.

OBJECTIVES: To identify whether oral desmopressin (ddAVP) reduced nocturnal urine volume (NUV) in older men with nocturia without obvious bladder outlet obstruction and to determine whether deficiencies in arginine vasopressin (AVP) release and action demonstrated using water deprivation testing predicted responsiveness to ddAVP. DESIGN: Participants had a 2-day Clinical Research Center (CRC) evaluation followed by a double-blinded, placebo-controlled, crossover trial of individually titrated oral ddAVP. SETTING: Participants were from a single Department of Veterans Affairs Medical Center. MEASUREMENTS: Maximum urine osmolality and percentage increase in osmolality were measured after subjects received aqueous vasopressin as part of the overnight water deprivation study; these data were used to categorize participants as normal, having partial central AVP deficiency, or having impaired renal responsiveness to AVP. Response to ddAVP was assessed using data from frequency-volume records. RESULTS: Fourteen participants completed the CRC stay and ddAVP trial. Subjects given ddAVP reduced NUV significantly from baseline (P=.02) and had significantly lower NUV than when on placebo (P=.01). The mean net reduction in NUV from ddAVP compared to placebo was 14+/-18%. Using water deprivation testing to categorize participants, 10 were normal, two had partial central AVP deficiency, and two had impaired renal responsiveness. The mean net reduction in NUV for those with abnormal water deprivation tests was 11+/-25%, versus 15+/-16% for those with normal water deprivation testing (P=.70). CONCLUSION: In this small randomized, controlled trial in older men with nocturia, ddAVP reduced NUV. Counter to expectations, participants deemed normal according to water deprivation tests had approximately equivalent responsiveness to ddAVP. Although this study cannot offer definitive conclusions on the lack of prediction of water deprivation testing for ddAVP benefit, these data offer additional information that may help clarify the pathophysiology and optimal treatment of nocturia in older men.

Hyponatremia and arginine vasopressin dysregulation: mechanisms, clinical consequences, and management.

Hyponatremia, the most common electrolyte disorder, occurs frequently in older people and in hospitalized patients. Physiological changes of aging that interact with diseases and drugs commonly present in older people put this population at greater risk for hyponatremia. It can accompany central nervous system disorders, pulmonary and renal disease, cancer, congestive heart failure, and liver cirrhosis, as well as many commonly used drugs. Delayed recognition can lead to symptomatic hyponatremia with consequent cerebral edema and possibly irreversible neurological damage. Symptoms and signs of hyponatremia may be subtle or not attributed to hyponatremia. Most cases are of the euvolemic type, in which extracellular fluid volume is normal and is often due to the syndrome of inappropriate secretion of antidiuretic hormone. Hyponatremia can also occur in association with hypervolemia or hypovolemia. Common to all of these circumstances is increased secretion of arginine vasopressin (AVP). Understanding of the pathophysiological basis of hyponatremia and of brain compensatory mechanisms is critical to safe treatment. Fluid restriction or infusion of hypertonic saline can improve symptoms and normalize serum sodium levels but does not address excess AVP, which in most cases is the underlying cause of the disorder. A major new approach to treatment of hyponatremia is the development of aquaretics: AVP-receptor antagonists that provide a targeted therapeutic approach to correcting the many kinds of hyponatremia caused by excess AVP levels.

Oral ddAVP for nighttime urinary incontinence in characterized nursing home residents: a pilot study.

OBJECTIVES: To (1) identify abnormalities in arginine vasopressin (AVP, a water-conserving hormone) secretion and release in nursing home (NH) residents with nighttime urinary incontinence (UI); and (2) perform a pilot test of desmopressin acetate (ddAVP, a synthetic analog of the naturally occurring hormone) replacement in these residents. DESIGN: Diagnostic evaluation and open-label treatment trial. SETTING: Two community nursing homes in a metropolitan area. PARTICIPANTS: Male and female NH residents 65 years of age and older with nighttime UI. INTERVENTION: Characterizations of AVP status followed by a 7-day open-label trial of oral ddAVP (either 0.1 mg or 0.2 mg). MEASUREMENTS: Water deprivation test results, AVP levels, voided volumes, number of voids, incontinent episodes, number of nighttime checks found wet (out of 6 total checks per night). RESULTS: All participants had measurable AVP levels of 2.0 pg/mL or higher. Six of 10 individuals had an abnormal water deprivation test. Two of 4 participants on 0.2 mg of ddAVP and 2 of 6 participants on 0.1 mg had a 200 mL or more mean reduction in nighttime urine volume. Both ddAVP dosages yielded a mean reduction of 0.7 fewer nighttime wet checks found wet. One participant in each group developed hyponatremia (1 of 6 on 0.1 mg and 1 of 4 on 0.2 mg). Hyponatremia resolved with discontinuation of the drug. CONCLUSION: Both 0.1 mg and 0.2 mg of ddAVP given to carefully screened NH residents for 7 days produced a modest average reduction in nighttime urine volume and number of nighttime incontinent episodes that is likely of little clinical importance. The role of ddAVP in this population requires further research.

Arginine vasopressin and nocturnal polyuria in older adults with frequent nighttime voiding.

PURPOSE: We determined in older adults whether frequent nighttime voiding is associated with urine overproduction at night or nocturnal polyuria (NP) and whether NP is associated with abnormalities of arginine vasopressin (AVP) blood levels and/or renal responsiveness to AVP. MATERIALS AND METHODS: We used a convenience sample of adults 65 years and older in home and general clinical research center settings. A total of 45 participants completed the 3-day general clinical research center stay. We used 7-day voiding diaries to determine which participants had 2 or greater nighttime voids and NP, defined as 35% or greater of 24-hour urine output at night. Abnormalities in AVP release and secretion were determined by water deprivation testing and by twice daily blood AVP measurement. RESULTS: There was a strong positive association between the number of nighttime voids and the proportion of urine produced at night (r = 0.6, p <0.001). There was no association between NP and AVP blood levels or action. Participants with and without NP had similar maximum urine osmolality following water deprivation and exogenous AVP administration (mean 549 mOsm, range 422 to 713 and 547 mOsm, range 353 to 692, respectively). CONCLUSIONS: We found no association between NP and AVP abnormalities in this sample of older adults. Study participants had low maximal urine osmolality in response to fluid deprivation and exogenous vasopressin administration irrespective of whether they were identified as having NP.