postural proteinuria


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Related to postural proteinuria: orthostatic proteinuria

or·tho·stat·ic al·bu·min·ur·i·a

the appearance of albumin in the urine when the patient is erect and its disappearance when recumbent.

postural proteinuria

proteinuria

(prot?en-ur'e-a, pro?ten?) [ protein + -uria]
Loss of proteins (such as albumin or globulins) in the urine. This finding may be transient and benign or may reflect severe underlying kidney or systemic illness. Synonym: hyperproteinuria See: albuminuria; microalbuminuria; nephrotic syndrome

Patient care

Normally, the glomerular membrane allows only low molecular weight proteins to enter the filtrate, and then most of this protein is reabsorbed via the renal tubules. Loss of protein in the urine is a common finding in diseases that damage the glomeruli and/or tubules of the kidneys. Common illnesses that contribute to urinary protein loss include diabetes mellitus, hypertension, kidney stones, multiple myeloma, polycystic kidney disease, and renal artery stenosis. All of these illnesses may result in progressive kidney failure. The degree of proteinuria can be measured with timed collections of all the urine a person produces (such as 24-hr collection with first specimen discarded and final specimen retained in a day) or by spot urine collections, i.e., by collecting a single specimen and estimating daily protein losses. The urine must not be contaminated with toilet tissue or feces. Controlling high blood pressure and hyperglycemia, taking ACE inhibitors or angiotensin receptor blockers, and limiting dietary protein intake can all have a beneficial effect on patients with urinary protein losses. Minimal proteinuria is more commonly associated with renal diseases that have less glomerular involvement, e.g., pyelonephritis. Moderate proteinuria occurs in various renal diseases or in diseases in which renal failure is a late complication (diabetes mellitus, heart failure). Heavy proteinuria is usually associated with nephritic syndrome. Many therapeutic agents (such as amphotericin B, aminoglucosides, gold preparations, polymixins) cause renal damage, resulting in proteinuria. Benign proteinuria can result from changes in body positioning. Functional proteinuria can be associated with physical exercise as well as emotional or physiologic stress and is usually transient. Proteinuria is associated with progressive kidney failure, the eventual need for dialysis, and an increased risk of death from cardiovascular diseases.

glomerular proteinuria

Loss of protein (primarily albumin and other large molecules) in the urine because of defects in the glomerular capillary membranes of the kidneys.

massive proteinuria

A nephrotic syndrome with the largest protein losses, specifically in which the urine protein-to-creatinine ratio is greater than 10 mg/mg.

nephrotic range proteinuria

Loss of large amounts of protein in the urine (more than 3 g/day or, when measured by a urine protein-creatinine ratio, more than 3.5 mg/mg).

orthostatic proteinuria

Protein present in the urine only when the patient has been standing. It is not present when the patient is in bed.
Synonym: postural proteinuria

overflow proteinuria

Release of proteins into the urine because of saturation of the normal reabsorbing capacity of the proximal tubules. It is found in conditions such as multiple myeloma and rhabdomyolysis.

postural proteinuria

Orthostatic proteinuria.

transient proteinuria

Loss of protein into the urine that appears only briefly or occasionally, e.g., during fevers or seizures). It should be evaluated in people over 50, but in younger people it is usually benign.

tubular proteinuria

The loss of relatively small amino acids, immunoglobulin light chains, and other small proteins (less than 25 kD) in the urine, because of failure of the renal tubules to reabsorb proteins that have been filtered by the glomerulus.