Glomerulonephritis and nephrotic syndrome
Glomerulonephritis inflames the glomeruli: blood in urine, oedema, high BP. Nephrotic syndrome leaks protein: heavy proteinuria, low albumin, oedema. Both need salt restriction.
Acute glomerulonephritis vs nephrotic syndrome
| Feature | Acute glomerulonephritis (nephritic) | Nephrotic syndrome |
|---|---|---|
| What it is | Inflammation of the glomeruli | Glomeruli become leaky to protein |
| Common causes | After streptococcal throat or skin infection; other infections; lupus | Minimal change disease (children), diabetes, lupus, other glomerular diseases, some drugs |
| Urine | Blood (smoky or cola-coloured), less urine (oliguria), mild protein | Heavy protein (frothy urine), little or no blood |
| Oedema | Puffy face and eyes, mild | Marked, all over the body; may have ascites |
| Blood pressure | Often high | Usually normal |
| Blood | Raised urea and creatinine | Low albumin, high cholesterol and triglycerides |
Worked example: fluid allowance in oliguria
An 8-year-old boy with acute glomerulonephritis passed 400 mL of urine in the last 24 hours. How much fluid may he have today?
- Rule: fluid = previous day's urine output + about 500 mL for losses through skin and breath (insensible loss).
- Fluid = 400 + 500 = 900 mL a day.
- Count all fluids: water, milk, soups, juices, and the water in kanji and dal.
- Spread it through the day in small measured cups; give ice chips or sour sweets for thirst.
About 900 mL of fluid for the day. Add more if he has fever, vomiting or diarrhoea, as the doctor advises.
Dietary principles
| Nutrient | Acute glomerulonephritis | Nephrotic syndrome |
|---|---|---|
| Energy | Adequate (adults about 30-35 kcal/kg; children by age), mainly from carbohydrate | Adequate, about 35 kcal/kg in adults, so protein is not burned for energy |
| Protein | Restricted (about 0.5-0.6 g/kg, textbook figure) while urea is high and urine is low; normal once kidneys recover | About 0.8-1 g/kg of good-quality protein (KDIGO 2021); high-protein diets raise protein leak. Older books advise 1-1.5 g/kg |
| Sodium | Restricted: no added salt while there is oedema and high BP | Restricted: under about 2 g sodium (5 g salt) a day (KDIGO 2021) to control oedema |
| Potassium | Restricted during oliguria | Usually normal; adjust to blood reports and diuretics |
| Fluid | Previous day's urine + about 500 mL | Restricted only with severe oedema or low blood sodium |
| Fat | Normal, low in saturated fat | Low saturated fat, cholesterol under 200 mg a day, more fibre, because lipids are high |
| Others | Return slowly to a normal diet in recovery | Calcium and vitamin D (losses and steroid treatment) |
Foods to include and avoid
| Food group | Include | Avoid or limit |
|---|---|---|
| Cereals | Rice, idli, chapati made without salt, ragi, oats | Bakery items, salted biscuits, instant noodles |
| Protein foods | Measured milk, curd, egg white, fish, chicken, dal in the amount allowed | Large protein portions in acute GN; cheese, processed meats, dried salted fish |
| Vegetables and fruits | Bottle gourd, ridge gourd, cabbage, beans, apple, papaya; leached vegetables if potassium is high | High-potassium foods during oliguria: banana, tender coconut water, oranges, potato, tomato |
| Salt and fats | Lemon, herbs and jeera for taste; small amounts of vegetable oil | Pickles, papad, chips, namkeen, sauces, baking soda, ghee and butter in excess |
Sample one-day menu (nephrotic syndrome, adult, low salt)
| Meal | Menu |
|---|---|
| Early morning | Tea with toned milk |
| Breakfast | Idli (3) made without salt, with mint chutney; boiled egg white (2) |
| Mid-morning | Apple or papaya |
| Lunch | Rice, dal, bottle gourd kootu, cabbage poriyal, curd (all with very little salt) |
| Evening | Oats porridge with toned milk |
| Dinner | Salt-free chapati (2), fish or paneer curry (little salt), beans poriyal |
| Bedtime | Toned milk (small cup) |
On a paediatric ward, keep an intake-output chart for children with nephritis and set tomorrow's fluid from today's urine. Weigh daily: sudden weight gain means fluid retention, not good nutrition.
2 marks: “Name the four features of nephrotic syndrome.” Heavy proteinuria, hypoalbuminaemia, generalised oedema and hyperlipidaemia.
5 marks: “Differentiate acute glomerulonephritis and nephrotic syndrome.” Table: cause, urine (blood vs protein), oedema, BP, blood findings, and diet differences.
10 marks: “Discuss the causes, symptoms and dietary management of nephrotic syndrome.” Define with four features, causes, symptoms, principles table (energy, protein 0.8-1 g/kg, sodium, fat, fluid, calcium), foods, menu.
NephrITIS = InflammaTIon (blood, BP). NephrOSIS = prOtein lOss (oedema, low albumin). Fluid = yesterday's urine + 500 mL.