Manual of Clinical Nutrition

Manual of Clinical Nutrition Management III- 79 Copyright © 2013 Compass Group, Inc.

NEPHROTIC SYNDROME
Discussion
Nephrotic syndrome is characterized by urinary losses of albumin and other plasma proteins, resulting in
hypoalbuminemia. Nephrotic syndrome is caused by the failure of the glomerular capillary wall to act as an
impermeable barrier to plasma proteins. A 24-hour urinary protein excretion of 3.0 g or greater is indicative
of nephrotic syndrome (1,2). Nephrotic syndrome is associated with other metabolic disturbances including
hyperlipidemia caused by increased lipid synthesis and decreased lipid catabolism (2,3). Edema is caused by
sodium retention or imbalance, fluid retention, hypoalbuminemia, and underlying diseases such as renal,
cardiac, or liver disease (3). Causes of nephrotic syndrome include diabetes mellitus, infections, certain
medications, neoplasms, preeclampsia, and chronic allograft nephropathy (2).

Approaches (2,3) Rationale

Protein:

 Provide 0.8 to 1.0 g/kg of ideal

body weight.

 High–biological value protein

should contribute at least 50% of

protein intake.

In contrast to the treatment of protein-energy malnutrition, the

treatment of nephrotic syndrome does not include a high-protein

diet; a high-protein diet would not replenish plasma protein levels

and could cause further renal damage in patients who have

nephrotic syndrome (2,3). Mild protein restriction and provision of an

angiotensin-converting enzyme inhibitor diminish urinary protein

losses and increase serum albumin levels (2,3). Soy protein decreases

urinary protein excretion and blood lipid levels (2,4). Some studies

suggest that a low or very-low protein diet with essential amino acid

supplementation reduces proteinuria and improves protein

nutriture (5). The recommended protein intake for children who

have nephrotic syndrome is the Dietary Reference Intake for age

plus the amount of urinary protein loss. Children who have

persistent proteinuria may require 2.0 to 2.5 g/kg of protein per day

(3).

Sodium:

 See “Sodium-Controlled Diet” in

Section IF.

The level of sodium prescribed is based on the severity of edema and

hypertension. Sodium is usually restricted to 1 to 2 g/day,

depending on the severity of the patient’s signs and symptoms (3).

Fluid restriction is often necessary and should be based on the

patient’s symptoms. Diuretics can help maintain fluid and sodium

balance (3).

Energy:

 Calculate according to individual

needs.

The energy intake requirement is determined by the nutritional

evaluation and can be as high as35 kcal/kg (3). Complex

carbohydrates should be the primary source of energy intake (2).

Weight loss may be recommended for obese patients, because they

have an increased risk of comorbid diseases and complications.

Fat:

 Use the National Cholesterol

Education Program Adult

Treatment Panel III guidelines (2,3).

 Refer to Section C: “Medical

Nutrition Therapy for Disorders of

Lipid Metabolism” for the

Therapeutic Lifestyle Changes

(TLC) diet.

 Target <30% of energy from fat,

saturated fat <7% of total fat, and

cholesterol <200 mg/dL per day (2).

Hypercholesterolemia or hypertriglyceridemia) results from increased

lipid synthesis and decreased lipid catabolism (3). This disturbance

in lipid metabolism increases the risk for cardiovascular disease,

stroke, and progressive renal failure (2). A combination of statin

therapy and the Therapeutic Lifestyle Changes diet lowers serum

lipid levels (2). Fish oil supplementation (12 g/day) may be

beneficial for patients who have IgA nephropathy, which is a caused

by the deposition of immunoglobin A in the kidneys (3).