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What Is The Urine Specific Gravity For Diabetes Insipidus?

Diabetes Insipidus In The Diagnosis Of Polyuria

Diabetes Insipidus In The Diagnosis Of Polyuria

www.advpm.eu 111 Case report MichaÅ‚ Graczyk1, Anna KamiÅ„ska2, MichaÅ‚ KamiÅ„ski3, Roman Junik2, MaÅ‚gorzata Krajnik1 1Chair and Department of Palliative Care, Nicolaus Copernicus University, Collegium Medicum in Bydgoszcz, Poland 2Clinic of Endocrinology and Diabetology, Nicolaus Copernicus University, Collegium Medicum in Bydgoszcz, Poland 3Endocrinology Outpatient Clinic of Prof. Franciszek Åukaszczyk, Oncology Centre in Bydgoszcz, Poland Abstract Diabetes insipidus is a rare condition, whereas polyuria may be a symptom of numerous other ailments. Polyuria intensifies thirst (polydipsia), which appears to be a natural reaction to an excessive loss of water in the organism. Before diagnosing rare conditions, hypoglycaemia and kidney failure must be excluded. Borderline cases must consult with an endocrinology specialist. Key words: polyuria, polydipsia, diabetes insipidus Adv. Pall. Med. 2011; 10, 3–4: 111–114 Address for correspondence: MichaÅ‚ Graczyk Chair and Department of Palliative Care, Nicolaus Copernicus University, Collegium Medicum in Bydgoszcz, Poland e-mail: [email protected] Advances in Palliative Medicine 2011, 10, 111–114 Copyright © 2011 Via Medica, ISSN 1898–3863 Introduction Diabetes insipidus (DI) is a rare illness caused either by vasopressin deficiency (central diabetes in- sipidus, also known as neurohormonal) or by a lack of renal canal sensitivity to vasopressin (nephrogenic diabetes insipidus) [1]. The prevalence of diabetes insipidus is one case per 25,000 population, with no sex difference. Cen- tral diabetes insipidus is the result of damage to the supraoptic nuclei in the hypothalamus, where vasopressin is secreted. In such a case, the damage leads to permanent DI. In rare cases, for exa Continue reading >>

Test Id: Sgu Specific Gravity, Urine

Test Id: Sgu Specific Gravity, Urine

As a partial assessment of the kidney’s ability to concentrate urine Specific gravity (SG), the ratio of the mass of a solution compared to the mass of an equal volume of water, is an estimate of the concentration of substances dissolved in the solution. Urine SG can be used to assess the kidney’s ability to concentrate or dilute urine. However, because protein, glucose, and contrast dye have molecular masses that are relatively large compared to other major components of urine (eg, sodium, chloride, potassium), they disproportionately affect SG. In these cases, urine osmolality is a better measure of urine concentration. Low specific gravity (SG) (1.001-1.003) may indicate the presence of diabetes insipidus, a disease caused by impaired functioning of antidiuretic hormone (ADH). Low SG also may occur in patients with glomerulonephritis, pyelonephritis, and other renal abnormalities. In these cases the kidney has lost its ability to concentrate due to tubular damage. High SG may occur in patients with adrenal insufficiency, hepatic disease, congestive heart failure, or in patients experiencing excessive water loss due to sweating, fever, vomiting, or diarrhea. Urine with contrast dye, glucose, or excessive protein should not be evaluated with this test. Urine osmolality is a better measure of urine concentration. 1. Schumann GB, Schweitzer SC: Examination of urine. In Clinical Chemistry, Theory, Analysis and Correlation. Edited by LA Kaplan, AJ Pesce. Third edition. St. Louis, Mosby-Year Book Inc. 1996 pp 1118-1119 2. Modern Urine Chemistry (Manual). Edited by HM Free. Bayer Corp, Eighth printing. 1996 pp 36-37 Continue reading >>

The Value Of Urine Specific Gravity In Detecting Diabetes Insipidus In A Patient With Uncontrolled Diabetes Mellitus

The Value Of Urine Specific Gravity In Detecting Diabetes Insipidus In A Patient With Uncontrolled Diabetes Mellitus

Go to: A 46-year-old woman was referred to our hospital because of worsening polyuria and polydipsia of 2 months duration. She had a 10-year history of type 2 diabetes mellitus, with poor glycemic control that required insulin. The patient drank an average of 5 L/d and her urine output was almost the same. Blood sampling for routine laboratory values were: hemoglobin (Hb), 8.8 mmol/L; platelet count (Plt), 230,000 per mm3; white blood cells (WBC), 6,320 per mm3; creatinine, 98 μmol/L; urea nitrogen, 5.2 mmol/L; uric acid, 351 μmol/L; aspartate transaminase (AST), 0.35 μkat/L; alanine transaminase ALT, 0.47 μkat/L; Na, 132 mmol/L; K, 4.5 mmol/L; glucose, 19.5 mmol/L (351 mg/dL); Ca, 2.3 mmol/L; albumin, 43 g/L; erythrocyte sedimentation rate, 19 mm/h; C-reactive protein 2.1 mg/L; and an HbA1C of 0.0107 Hb fraction. Urine analysis revealed +3 for glucose. A spot urine analysis revealed a urine specific gravity of 1.008 and a 24-hour urine collection revealed a urine specific gravity of 1.007 [reference range: 1.010 to 1.025].3,4 On repeated urine analysis, a 24-hour urine collection revealed a urine specific gravity of 1.008. Therefore, we suspected that diabetes insipidus might be the underlying cause, owing to the presence of a persistently low urine specific gravity. A urine and plasma osmolality was subsequently performed, which were 138 and 285 mmol/kg, respectively. These findings were consistent with diabetes insipidus. A water deprivation test was then performed. No significant increase occurred, either in urine specific gravity or urine osmolality. After the administration of desmopressin, urine specific gravity increased to 1.019 (in a 24-hour urine collection) and urine osmolality increased to 488 mmol/kg. In view of these results, a diagnosis of central di Continue reading >>

Urine Specific Gravity

Urine Specific Gravity

Specific gravity measures the kidney's ability to concentrate or dilute urine in relation to plasma. Because urine is a solution of minerals, salts, and compounds dissolved in water, the specific gravity is greater than 1.000. The more concentrated the urine, the higher the urine specific gravity. An adult's kidneys have a remarkable ability to concentrate or dilute urine. In infants, the range for specific gravity is less because immature kidneys are not able to concentrate urine as effectively as mature kidneys. Glucose, protein, or dyes used in diagnostic tests excreted into the urine increase the specific gravity. If none of these abnormal substances are present in the urine, there are two primary reasons why the kidney is producing concentrated urine with a high specific gravity. The first and most common reason for an increase in urine specific gravity is dehydration. The second reason for a high specific gravity is an increased secretion of anti-diuretic hormone (ADH). ADH causes increased tubular water re-absorption and decreased urine volume. Trauma, stress reactions, surgery, and many drugs cause an increase in ADH secretion. A low specific gravity occurs in three situations. In diabetes insipidus, there is an absence or decrease of anti-diuretic hormone. Without anti-diuretic hormone, the kidneys produce an excessive amount of urine, often up to 15 to 20 liters per day with a low specific gravity. Glomerulonephritis and pyelonephritis cause a decreased urine volume and low specific gravity. In these diseases, damage to the kidney's tubules affects the ability of the kidney to re-absorb water. As a result, the urine remains dilute. The third reason for low specific gravity is renal failure, which results in a fixed specific gravity between 1.007 and 1.010. In Continue reading >>

Urine Specific Gravity

Urine Specific Gravity

For explanation of the ratio of densities of two materials, see Relative density. Reading of a urine specific gravity of ~1.024 via a handheld refractometer. SG measurement is taken by reading the boundary between the dark and light fields against the graduations on the left column. Specific gravity, in the context of clinical pathology, is a urinalysis parameter commonly used in the evaluation of kidney function and can aid in the diagnosis of various renal diseases. Background[edit] For background on kidney function, see Renal function. One of the main roles of the kidneys in humans and other mammals is to aid in the clearance of various water-soluble molecules, including toxins, toxicants, and metabolic waste. The body excretes some of these waste molecules via urination, and the role of the kidney is to concentrate the urine, such that waste molecules can be excreted with minimal loss of water and nutrients. The concentration of the excreted molecules determines the urine's specific gravity. In adult humans, normal specific gravity values range from 1.000 to 1.030. Specific gravity and disease[edit] Adults generally have a specific gravity in the range of 1.000 to 1.030[1] Increases in specific gravity (hypersthenuria, i.e. increased concentration of solutes in the urine) may be associated with dehydration, diarrhea, emesis, excessive sweating, urinary tract/bladder infection, glucosuria, renal artery stenosis, hepatorenal syndrome, decreased blood flow to the kidney (especially as a result of heart failure), and excess of antidiuretic hormone caused by Syndrome of inappropriate antidiuretic hormone.[2] A specific gravity greater than 1.035 is consistent with frank dehydration.[3] In neonates, normal urine specific gravity is 1.003. Hypovolemic patients usually have Continue reading >>

Diabetes Insipidus

Diabetes Insipidus

Diabetes insipidus (DI) is an uncommon condition with either relative or absolute lack of anti-diuretic hormone (ADH) leading to inability to concentrate the urine and subsequent polyuria/polydypsia and potentially fluid and electrolyte imbalance. This can be seen in a variety of conditions in the paediatric population, most commonly in patients post neurosurgery or with cerebral malformations. Consideration should be given to: Hydration status/fluid balance/urine output Presence of intercurrent illness eg UTI Causes of excess fluid loss eg gastro, surgical drains Past history of DI with similar episode Change in weight as marker of fluid status Baseline investigations should include urea and electrolytes, full ward test of urine and paired serum and urine osmolality. Diabetes insipidus is present when the serum osmolality is raised (>295milliOsmol/kg) with inappropriately dilute urine (urine osmolality < 700milliOsmol/kg). The serum sodium is often elevated due to excess free water losses. After assessment of level of dehydration and ongoing losses, adequate rehydration therapy should be commenced. If the serum Na is > 150mmol/L, rehydration should occur over 48 hours (see hypernatraemia guideline). If Na >170mmol/L, contact ICU. Discussion with the endocrinologist on call is advised prior to the commencement of Desmopressintherapy Desmopressin (DDAVP, trade name: Minirin(R)) acts on the distal tubules and collecting ducts of the kidney to increase water reabsorption, as a long acting analog of anti-diuretic hormone (ADH). There are several formulations available: Intranasal solution - 100 micrograms/mL Intranasal spray (10 micrograms/spray) Parenteral (IM/IM) - 4 micrograms/ml - used rarely Oral - 200 micrograms/tablets (roughly 10 micrograms intranasal is approximate Continue reading >>

Diabetes Insipidus

Diabetes Insipidus

OBJECTIVES After completing this article, readers should be able to: Describe the simple test that will establish the diagnosis of diabetes insipidus. Explain how to differentiate central diabetes insipidus from nephrogenic diabetes insipidus and compulsive water drinking. Delineate the inheritance pattern of central diabetes insipidus and nephrogenic diabetes insipidus. Describe the treatments of choice for central diabetes insipidus and nephrogenic diabetes insipidus. Definition and Epidemiology Polydipsia and polyuria with dilute urine, hypernatremia, and dehydration are the hallmarks of diabetes insipidus in infants and children. Patients who have diabetes insipidus are unable to conserve water and can become severely dehydrated when deprived of water. The polyuria exceeds 5 mL/kg per hour of dilute urine, with a documented specific gravity of less than 1.010. The hypernatremia is evidenced by a serum sodium concentration in excess of 145 mmol/L (145 mEq/L). Three conditions give rise to polydipsia and polyuria. The most common condition is central or neurogenic diabetes insipidus related to a deficiency of vasopressin. Less common is nephrogenic diabetes insipidus, including the X-linked recessive, autosomal recessive, and autosomal dominant types due to renal tubular resistance to vasopressin. Finally, these conditions can occur in the compulsive water drinker who demonstrates physiologic inhibition of vasopressin secretion. The incidence of diabetes insipidus in the general population is 3 in 100,000, with a slightly higher incidence among males (60%). X-linked nephrogenic diabetes insipidus is very rare, with arginine vasopressin receptor2 (AVPR2) gene mutations among males estimated to be 4 in 1,000,000. The incidence of compulsive water drinking is unknown, bu Continue reading >>

Diabetes Insipidus

Diabetes Insipidus

Types of diabetes insipidus Diabetes insipidus can be divided into four different types that are caused by any one of four fundamentally different defects (Fig. 5.1): 1. pituitary, central, neurogenic, or neurohypophyseal diabetes insipidus, the most common type, results from a deficiency in the production of the antidiuretic hormone arginine vasopressin (AVP); 2. renal or nephrogenic diabetes insipidus is caused by renal insensitivity to the antidiuretic effects of AVP, for example, due to impairment of the renal vasopressin V2 receptor or aquaporin-2 water channel; 3. primary polydipsia is due to suppression of AVP secretion as a result of excessive fluid intake. Depending on whether the excessive fluid intake is due to abnormal thirst or due to a psychological disorder, primary polydipsia is subdivided into, respectively, dipsogenic diabetes insipidus11,12 psychogenic diabetes insipidus,13,14 and 4. gestational diabetes insipidus,15–18 which is primarily due to increased metabolism of AVP by circulating vassopressinase produced by the placenta in the pregnant woman but may also involve renal resistance and/or subclinical deficiency in AVP production. Complete diabetes insipidus is defined by persistently low urine osmolality (<300 mosmol/kg) during a fluid deprivation test providing plasma osmolality rises above 295 mosmol/kg. Partial diabetes insipidus is defined by a subnormal increase in urine osmolality (300–600 mosmol/kg) during a fluid deprivation test with the same rise in plasma osmolality.4 Definition Diabetes insipidus (DI) is a heterogeneous condition characterized by polyuria and polydipsia caused either due to a lack of secretion of vasopressin (antidiuretic hormone) from posterior pituitary, its physiological suppression following excessive water in Continue reading >>

Diabetes Insipidus Urine Specific Gravity

Diabetes Insipidus Urine Specific Gravity

Urine specific gravity is a laboratory test, ordered by a medical provider, which shows the concentration levels of all chemical particles that happen to be in the urine. Once a urine sample is provided, this test can be performed right away. A color-sensitive pad is dipped into the urine and the color changes which occur will let the provider know what your estimated results happen to be. Laboratories also use a refractometer to project light through the urine in order to determine its density. This method is more reliable than the dipstick testing and is the most common form of determining a person’s diabetes insipidus urine specific gravity. What Do the Urine Specific Gravity Results Mean? Density levels are based on a ratio of 1. Water would have a density of 1.000. This means any results which are closer to 1.000 mean that there are fewer contaminants in the urine and that the body is functioning with normalcy. Most laboratories interpret the range for urine specific gravity as being 1.002-1.030. This would indicate that a patient’s kidneys were functioning at a normal level. Low urine specific gravity results are typically 1.001-1.003. Anything above 1.010 may indicate that there is mild dehydration present, while higher numbers indicate that more severe dehydration is taking place. Results that are above 1.030 are considered to be high. Specific substances in the urine will also cause higher urine specific gravity results. Red blood cells, white blood cells, proteins, glucose, crystals, and even bacteria will all cause the results to be higher. Most people will never have a result above 1.035. This indicates that the test was either contaminated or that blood glucose levels are under very poor control. If there is a suspicion of high glucose or protein levels Continue reading >>

Diabetes Insipidus Workup

Diabetes Insipidus Workup

Approach Considerations In a patient whose clinical presentation suggests diabetes insipidus (DI), laboratory tests must be performed to confirm the diagnosis. A 24-hour urine collection for determination of urine volume is required. In addition, the clinician should measure the following: Perform testing with the patient maximally dehydrated as tolerated—that is, at a time when ADH release is the highest and his/her urine is the most concentrated. Water deprivation testing may be useful in situations in which the diagnosis is uncertain. A urinary specific gravity of 1.005 or less and a urinary osmolality of less than 200 mOsm/kg are the hallmark of DI. Random plasma osmolality generally is greater than 287 mOsm/kg. Suspect primary polydipsia when large volumes of very dilute urine occur with plasma osmolality in the low-normal range. Polyuria and elevated plasma osmolality despite a relatively high basal level of ADH suggests nephrogenic DI. Water deprivation followed by the administration of vasopressin may help to differentiate central from nephrogenic DI. The result of this test must be interpreted with caution, however, because patients with partial nephrogenic DI or primary polydipsia may show a response similar to that seen in central DI. Historically, diagnostic tests in DI can be traced back to the 1930s, when Gilman and Goodman first demonstrated recovery of an antidiuretic substance in the urine of rats following dehydration with hypertonic saline. When animals were provided free access to water, no antidiuretic activity was recovered from urine, and no antidiuretic activity could be recovered from the urine of hypophysectomized rats dehydrated with hypertonic saline. [25] Continue reading >>

What Is The Difference In The Specific Gravity Of Diabetes Mellitus And Diabetes Insipidus?

What Is The Difference In The Specific Gravity Of Diabetes Mellitus And Diabetes Insipidus?

Urine specific gravity (SG) is typically normal in diabetes mellitus (sweet urine). By definition urine is dilute or low SG in diabetes insipidus (tasteless or insipid urine); the kidneys are unable to produce concentrated urine. Continue reading >>

Diabetes Insipidus: A Review: Workup

Diabetes Insipidus: A Review: Workup

Earley LE, Orloff J. The mechanism of antidiuresis associated with the administration of hydrochlorothiazide to patients with vasopressin-resistant diabetes insipidus. J Clin Invest. Nov 1962;41(11):1988-97. Krahulik D, Zapletalova J, Frysak Z, et al. Dysfunction of hypothalamic-hypophysial axis after traumatic brain injury in adults. J Neurosurg. Nov 20 2009; Abstract Leonie Los E, Deen PM, Robben JH. Potential of non-peptide (ant)agonists to rescue vasopressin V2 receptor mutants for the treatment of X-linked Nephrogenic Diabetes Insipidus. J Neuroendocrinol. Feb 12 2010; Abstract Rochdi MD, Vargas GA, Carpentier E, et al. Functional Characterization of V2-Vasopressin Receptor Substitutions (R137H/C/L) Leading to Nephrogenic Diabetes Insipidus and Nephrogenic Syndrome of Inappropriate Antidiuresis; Implications for treatments. Mol Pharmacol. Feb 16 2010; Abstract Kristof RA, Rother M, Neuloh G, et al. Incidence, clinical manifestations, and course of water and electrolyte metabolism disturbances following transsphenoidal pituitary adenoma surgery: a prospective observational study. J Neurosurg. Feb 6 2009; Abstract Seckl J, Dunger D. Postoperative diabetes insipidus. BMJ. Jan 7 1989;298(6665):2-3. Abstract Hadjizacharia P, Beale EO, Inaba K, et al. Acute diabetes insipidus in severe head injury: a prospective study. J Am Coll Surg. Oct 2008;207(4):477-84. Abstract Spanakis E, Milord E, Gragnoli C. AVPR2 variants and mutations in nephrogenic diabetes insipidus: review and missense mutation significance. J Cell Physiol. Dec 2008;217(3):605-17. Abstract Hedrich CM, Zachurzok-Buczynska A, Gawlik A, et al. Autosomal dominant neurohypophyseal diabetes insipidus in two families. Molecular analysis of the vasopressin-neurophysin II gene and functional studies of three missen Continue reading >>

What Is Diabetes Insipidus?

What Is Diabetes Insipidus?

Diabetes insipidus, not to be confused with the more common diabetes mellitus, is a relatively rare disorder resulting from a failure to produce sufficient amounts of vasopressin, also known as antidiuretic hormone (ADH). Vasopressin, produced by the hypothalamus and secreted by the posterior pituitary gland, helps the kidneys to reabsorb water and maintain proper fluid balance. If the pituitary fails to produce enough ADH, water is not conserved but simply passed through the kidneys and excreted, typically in very large quantities. More rarely, the kidneys fail to respond properly to ADH; this is known as nephrogenic diabetes insipidus. Dehydration is the primary health risk associated with either form. Diabetes insipidus affects both sexes equally. With proper treatment, overall prognosis is good (except in cases caused by cancer). What Causes Diabetes Insipidus? In approximately one third of all cases, the cause of diabetes insipidus is unknown. Hereditary factors may play a role in some cases. Damage to the pituitary gland from a head injury, a hypothalmic tumor, or inflammation, radiation therapy, or surgery may lead to diabetes insipidus. The most frequent cause of nephrogenic diabetes insipidus is therapy with lithium. Tuberculosis Blockage in an artery leading to the brain Symptoms of Diabetes Insipidus Frequent and excessive urination (output may be as high as 25 to 35 quarts within 24 hours and may be as frequent as every 30 minutes, even at night) Extreme thirst Dry skin Constipation Emergency symptoms of dehydration, including dizziness, weakness, and unconsciousness Prevention of Diabetes Insipidus There is no known way to prevent diabetes insipidus. Diagnosis of Diabetes Insipidus Physical examination and patient history are performed. Diagnosis of diabete Continue reading >>

Diabetes Insipidus

Diabetes Insipidus

Central diabetes insipidus is caused by reduced secretion of antidiuretic hormone (ADH). When target cells in the kidney lack the biochemical machinery necessary to respond to the secretion of normal or increased circulating levels of ADH, nephrogenic diabetes insipidus results. It occurs infrequently in dogs, cats, and laboratory rats, and rarely in other animals. Etiology: The hypophyseal form develops as a result of compression and destruction of the pars nervosa, infundibular stalk, or supraoptic nucleus in the hypothalamus. The lesions responsible for the disruption of ADH synthesis or secretion in hypophyseal diabetes insipidus include large pituitary neoplasms (endocrinologically active or inactive), a dorsally expanding cyst or inflammatory granuloma, and traumatic injury to the skull with hemorrhage and glial proliferation in the neurohypophyseal system. Clinical Findings: Affected animals excrete large volumes of hypotonic urine and drink equally large amounts of water. Urine osmolality is decreased below normal plasma osmolality (~300 mOsm/kg) in both hypophyseal and nephrogenic forms, even if the animal is deprived of water. The increase of urine osmolality above that of plasma in response to exogenous ADH in the hypophyseal form, but not in the nephrogenic form, is useful in the clinical differentiation of the two forms of the disease. Lesions: The posterior lobe, infundibular stalk, and hypothalamus are compressed or disrupted by neoplastic cells. This interrupts the nonmyelinated axons that transport ADH from its site of production (hypothalamus) to its site of release (pars nervosa). Diagnosis: This is based on chronic polyuria that does not respond to dehydration and is not due to primary renal disease. To evaluate the ability to concentrate urine, a wa Continue reading >>

Diabetes Insipidus

Diabetes Insipidus

Anti-Diuretic Hormone (ADH) from the posterior pituitary stimulates water uptake from the distal convoluted tubule and collecting ducts of the kidney and so conserves water. Release is regulated by osmoreceptors in the hypothalamus and volume receptors in the hypothalamus. A deficiency of ADH is known as Diabetes insipidus. Causes of deficiency may be: Central: Central DI is characterized by decreased secretion of antidiuretic hormone (ADH)—also known as arginine vasopressin (AVP)—which gives rise to polyuria and polydipsia by diminishing the patient’s ability to concentrate urine. Diminished or absent ADH can be the result of a defect in 1 or more sites involving the hypothalamic osmoreceptors, the supraoptic or paraventricular nuclei, or the supraopticohypophyseal tract. Nephrogenic: failure of the nephrons to respond to ADH present in the kidney.Is characterized by a decrease in the ability to concentrate urine due to a resistance to ADH action in the kidney. Nephrogenic DI can be observed in chronic renal insufficiency, lithium toxicity, hypercalcemia, hypokalemia, and tubulointerstitial disease, rarely, diabetes insipidus may be hereditary. Psychogenic diabetes insipidus (psychogenic polydipsia) : It results from a neurological disorder of thirst control or as a result of some behavioral problem that triggers excessive water intake. In either case, the abnormally large volume of excreted urine in animals with psychogenic polydipsia is caused by excessive water intake (polydipsia), rather than by some primary problem with kidney, pituitary or hypothalamic function. Clinical Signs There will be a marked polyuria, 5-20X normal output, often resulting in nocturia and incontinence. There will also be a desperate polydipsia, animal will search for water. Other clin Continue reading >>

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