WHAT IS PROTEINURIA?
Proteinuria is the condition where the urine contains an abnormal amount of protein.

HOW PROTEIN LEAKS IN THE URINE?
Protein is found in the blood and usually is not present in the urine. Proteins are molecules that help in normal body processes such as enzymes, fighting infection (as antibodies), carriers of other substances and blood clotting.

There are millions of tiny filters called glomeruli in the kidneys. As blood passes through healthy kidneys, the glomeruli filter the waste products. Proteins are large molecules and are unable to pass through the glomeruli into the urine. However, when the glomeruli are damaged by a disease process, proteins are then able to pass through them and escape into the urine.

WHY IS PROTEINURIA DANGEROUS?
Proteinuria is not a disease. However, it is an indicator that the kidneys have been damaged in some way. Protein should not appear in the urine in large quantities. Doctors usually say there is proteinuria if more than 150 mg per day is detected in the urine.

WHAT CAUSES PROTEINURIA?
Some of the causes of proteinuria are:

a) Primary kidney disease called nephritis

b) Secondary kidney diseases due to:
Diabetes
Hypertension or high blood pressure
Cancers
Pregnancy
Medications

c) Others
Excessive weight gain
Heart failure

Slightly higher excretion of protein may occur normally in certain circumstances such as pregnancy, during fever and after strenuous exercise. These are not clinically significant if the amount is only minimally raised and returns to normal levels soon after.

ARE THERE DIFFERENT TYPES OF PROTEINURIA?
There are essentially two types of protein: albumin which is a smaller molecule and globulin which is larger. When the disease is minor or early, albumin leaks out first. The quantity is then small and not detected by conventional methods used for detecting protein. This is called microalbuminuria implying that the amount leaked out is in small amounts. When the disease is more advanced, larger molecules other than albumin leaks out and we term this state collectively as "proteinuria".

WHO ARE AT RISK OF PROTEINURIA?
People with diabetes, hypertension, or certain family backgrounds are at risk of proteinuria. In both type 1 and type 2 diabetes, the first sign of kidney damage is the presence of small amounts of albumin in the urine ( microalbuminuria ) . As kidney function declines, the amount of albumin in the urine increases, and microalbuminuria becomes full-fledged proteinuria.

WHAT ARE THE SIGNS AND SYMPTOMS OF PROTEINURIA?
By itself, proteinuria causes foamy or frothy urine. Patients may also say they see bubbles in the urine. If loss of protein is in very large quantities (more than 3 grams per day), a patient may have the nephrotic syndrome where he complains of swelling of legs, abdominal distention and breathlessness especially on lying down.

If a patient also has kidney failure, the complaints will be that experienced by other renal failure patients.

HOW CAN I TEST FOR PROTEINURIA?
Urine dipstick: This is a simple method using a test strip immersed into a urine sample to detect presence of protein in the urine. However, it only measures the concentration in that specific specimen. The concentration of urine passed throughout the day actually varies so this is not very accurate.

24-hour urine collection for protein or microalbumin is used to assess how much protein or microalbumin is passed into the urine over 24 hours.

We can grade proteinuria as follows:

Because the methods used for albumin and protein are different, there will be some difference in the amounts when albumin and protein are tested on the same sample.

The amount of proteinuria may also be reported as a ratio of protein to creatinine in the urine - urine protein/creatinine ratio. If both are measured in grams, it will parallel the 24 hour results. The urine microalbumin/creatinine ratio (both measured in mg) will also closely relate to the 24 hour urine microalbumin result.


HOW IS THE SEVERITY DETERMINED?
There are many reasons for having protein in the urine and the seriousness will depend on the cause and amount of protein leak. The doctor will perform a series of investigations which often include:

NATURAL COURSE AND PROGNOSIS OF PROTEINURIA
If left untreated, proteinuria on occasion could disappear or could remain stable for many months and years. It could also get worse and cause kidney failure especially:

TREATING PROTEINURIA
Other than treatment for specific kidney diseases, the following need to be observed to prevent deterioration to / of kidney failure

SOME USEFUL HINTS : 

WATCHING YOUR DIET - ALL ABOUT FATS AND SODIUM
Pauline Chan
Consultant Nutritionist and Dietitian
Food and Nutrition Specialists Pte Ltd

The number of Singaporeans suffering from cancer, heart disease and stroke has increased dramatically in the last 10- 20 years.  In Y2005 alone, these three major killer diseases contributed more than half of the total deaths in Singapore.

While these diseases are all unique with their own etiology, they all share many common risk factors such as smoking, obesity, physical inactivity, stress and most importantly, an unhealthy diet. For example, a high fat diet will not just cause weight gain but also increase the risk of cancer, heart disease and stroke. Similarly, diet high in sodium is linked to high blood pressure, especially among sodium-sensitive individuals, which in turn can lead to stroke, heart attack and kidney failure. Healthy changes in current dietary patterns and habits among Singaporeans could impact greatly on the reduction of the rate of these diseases.

 Saturated fats (SFA): Found mostly in foods of animal origin, and they are usually solid at room temperature. These include the fat in whole milk, cream, cheese, butter, meat and poultry. Vegetable fats and oils, such as cocoa butter, coconut oil and palm kernel oil also fall in to this category.

Monounsaturated fats (MUFA): Primarily found in foods of plant origin, and they are liquid at room temperature. Olive, peanut and canola oil are some of the common examples of oils that are a good source of MUFA.

Fat and Obesity
Studies carried out in past have shown a definite and positive link between fat and obesity. Fat provides 9 Kilocalories per gram which is twice the amount of energy obtained from the other 2 calorie-contributing nutrients, carbohydrate or protein. Hence people who regularly eat high fat diets, are likely to exceed their energy needs, and the fat get stored very efficiently in the body so they gain weight. Being overweight and obese will increase the risk of heart disease, stroke, diabetes, hypertension and certain types of cancer.

Fat and Heart Disease
Both the amount and type of fat consumed by an individual will influence the blood cholesterol levels. In the case of heart health, high level of blood cholesterol is a major cause of blocking the arteries, supplying blood to the heart, and leading to fatal heart attack.

• A high intake of fat, especially of saturated fat, raises blood cholesterol more dramatically than dietary cholesterol itself. Cutting back on saturated fats will help to maintain a healthy heart.
• Replacing saturated fats with polyunsaturated fats and monounsaturated fats while keeping the total intake within recommended level, have shown positive effect on the blood cholesterol levels. Unsaturated fats have shown to lower the LDL cholesterol (bad cholesterol) while either maintaining or raising the HDL cholesterol (good cholesterol).
• Recent research in nutrition suggests that specific polyunsaturated fatty acids like Omega-3 and Omega-6, found especially in fish and fish oils or vegetable sources such as flaxseed may benefit heart health.
• Intake of trans fatty acids has the same detrimental effect on the blood cholesterol levels as saturated fats. Limiting its intake is therefore beneficial.

Fat Intake Recommendation
Health professionals recommend the intake of fat for healthy Singaporean adults should provide not more than 25-30% of the total energy intake. This would amount to 60 gm of fat (12 teaspoon per day) for a moderately active man. Of this, less than 10% should come from saturated fat, less than 1% from trans fat, up to 10% each from polyunsaturated fat, and the remaining from monounsaturated fat.

• Use small quantities of a variety of unsaturated cooking oils that suit your taste preferences like corn, canola, olive, soybean, sunflower, safflower and peanut oils to cook your food.
• Reduce intake of saturated fat by substituting high fat meat with lean meat. Trim the visible fat from red meat. Remove the skin from the poultry. Grill, roast, broil, bake, stir-fry, stew, or braise meat instead deep-frying.
• Refrigerate meat soups and gravies to solidify the fat. Remove the fat layer from top and use these low fat soups and gravies in your food.
• Switch from whole milk to low fat milk or skim milk. Do the same for other milk and dairy products like cheese and yogurt. Increase the use of evaporated non-fat milk instead of cream to prepare desserts. Use skim milk yogurt to prepare gravies instead of coconut milk.
• Look out for the invisible fat in foods like chocolates, pastries, biscuits, cookies, potato chip, and deep fried foods.

Eating out

• Ask for less oil and fat in food.
• Ask for skin to be removed from poultry and fat be trimmed from fatty meat.
• Choose soupy dishes instead of fried or dried dishes.
• Ask for plain rice over flavoured rice such as chicken rice, nasi lemak or nasi briyani.

Shopping

• Read food labels carefully for the fat content of the food. Choose low fat items by comparing between the two products.
• Choose products labeled with the “Healthier Choice” Symbol.

SODIUM AND HEALTH
Sodium is an essential mineral that is vital to the balance of body fluids. However, studies have shown that excessive intake of sodium may result in fluid retention in the body, causing blood volume to expand. This exerts pressure on the walls of blood vessels, raising blood pressure. Uncontrolled high blood pressure (hypertension) will lead to stroke.

A review of many scientific studies suggests that a reduction in sodium intake of 2,300/day would lower systolic blood pressure by about 5-6 mm Hg and diastolic pressure by 1-2 mm Hg among hypertensive individuals. In addition, many who are not yet hypertensive respond to sodium reduction, particularly those whose blood pressure is in the high normal range.

How much sodium do you need?
The World Health Organization recommends that individuals maintain a salt intake of no more than 5 g a day or a sodium intake of no more that 2000 mg a day. A reduction of 1000 mg of dietary sodium would lead to a 50% decrease in the number of people requiring anti-hypertensive therapy. This reduction may also decrease death rate from stroke by 22 %.

It is important to note that the recommendation is not the minimum requirement needed; rather, it is the maximum limit that should not be exceeded.

Food Sources of Sodium
Sodium occurs naturally in food and can be added to food. Most of the sodium Singaporeans consume comes from salt added during preparation at eateries, at home, or during food processing. The National Nutrition Survey (2004) estimated that processed foods contribute about 17% of the sodium in our diets, the rest from cooked foods.

Sodium is found in seasonings such as soy sauce, fish sauce, black sauce, oyster sauce and monosodium glutamate. In addition, sodium is also present in food additives such as baking powder, sodium benzoate and sodium nitrate / nitrite.

The sodium content of some of the most commonly used seasonings are as listed below:

• Gradually cut down on slat and seasonings used in cooking and at the table
• Flavour food with natural seasonings such as lemon juice, herbs and spices

Eating out

• Ask for less sauce and gravy
• Taste food first. Use salt, sauce and pickles only if needed

Shopping

• Choose fresh over processed food
• Choose less salt-preserved, cured and smoked foods
• Read labels to compare the amount of sodium in processed foods and choose foods labeled as reduce slat, low sodium, lightly salted, light in sodium, no added salt, no salt added or unsalted and those with “ Healthier Choice” Symbol.