Hypercholesterolemia (Option D)
The most expected finding in a boy with nephrotic syndrome, proteinuria, and hypoalbuminemia (serum protein/albumin of 2.5 g/dL) is hypercholesterolemia (Option D). This occurs as a compensatory hepatic response to the massive urinary protein losses and represents one of the cardinal features of nephrotic syndrome 1.
Why Hypercholesterolemia is the Expected Finding
Hyperlipidemia develops as a direct compensatory mechanism when the liver increases protein synthesis in response to hypoalbuminemia and ongoing urinary albumin losses 1.
Nephrotic syndrome is classically defined by the tetrad of proteinuria ≥40 mg/m²/hour in children, hypoalbuminemia ≤2.5 g/dL, edema, and hyperlipidemia 2, 3.
The hyperlipidemia associated with nephrotic syndrome includes elevated total cholesterol, LDL cholesterol, and triglycerides, and persists as long as the nephrotic state continues 4, 5.
This metabolic complication contributes to accelerated coronary heart disease risk, which is four times greater in nephrotic patients than age-matched controls 6.
Why the Other Options Are Less Expected
Hypokalemia (Option A)
- Hypokalemia is not a characteristic feature of uncomplicated nephrotic syndrome 2, 3.
- Electrolyte disturbances in nephrotic syndrome typically involve sodium retention (causing edema) rather than potassium depletion.
Hypernatremia (Option B)
- Hypernatremia is distinctly uncommon in nephrotic syndrome; patients actually tend toward sodium retention with normal or low serum sodium due to dilutional effects from fluid retention 3.
- The edema in nephrotic syndrome results from sodium and water retention, not hypernatremia.
Metabolic Acidosis (Option C)
- Metabolic acidosis is not a typical feature of primary nephrotic syndrome in the absence of significant renal impairment 2, 3.
- Acid-base disturbances would only be expected if the patient had progressed to advanced chronic kidney disease with GFR <30 mL/min/1.73 m².
Clinical Context and Complications
The serum albumin of 2.5 g/dL confirms hypoalbuminemia by pediatric criteria (≤2.5 g/dL), which is the traditional threshold used in 50 years of clinical trial data 2.
Beyond hypercholesterolemia, this patient faces additional risks including thromboembolism (29% risk for renal vein thrombosis when albumin is this low), infections due to immunoglobulin losses, and potential progression to end-stage renal disease 6, 1.
The hyperlipidemia will not respond to standard lipid-lowering therapy unless the underlying proteinuria is controlled and serum albumin is restored 7.