Renal and Urinary Tract Diseases

 

 

 

Concerning epidemiology of renal diseases, we will focus on:

1.    Community diagnosis: magnituide of the problem and trend in renal diseases

2.    Identifying the risk factors of some renal diseases, What causes Renal Failure?

3.    Preventiive measures: Primary, Secondary, Tertiary

 

 

Scope of the problem in Egypt

•         Kidney disease is a growing problem.

•         Prevalence of dialysis patients have increased from:

  10/million population (PMP) in 1974 to 225/ million pop in 1996 (Barsoum et al, 1996). Recent data presented in the following figure points to an increasing trend accounting for 483/ million pop in 2004

Improved medical care for patients with chronic renal disease has contributed to annual increases in the numbers of patients who survive with end stage renal disease (ESRD).

The incidence of ESRD is growing. The estimated number of ESRD patients in Egypt was 14,636 in 1998, and increased to 35,751 recently (Egyptian Renal Registry,2004).

 

Globally, it is a growing problem in other countries as well.350,000 ESRD patients in US (source:annual data report 2003).

 

Stop A Disease That Comes Without Warning

Early kidney disease is a silent problem, like high blood pressure.

Kidney disease can become kidney failure with little or no warning, and is usually discovered right before the kidneys fail.

Residual undamaged glomeruli respond by increase in their Glomerular Filtration Rate (GFR). So,

•         considerable renal damage can occur before measurable reduction in GFR.

•          A drop in renal function to 20% of normal or lower, due to disease, injury, poisoning, or trauma leads to serious health problems and even death.

It is evident that developing countries with large burden of hypertension and diabetes and their susceptibility to chronic complications should evolve strategies for primary prevention of these diseases as well as for prevention of its secondary complications.

 

 

Classification of Renal Diseases:

I.    Specific Renal diseases

II. Urinary Tract Diseases

III. End Stage Renal Disease

 

I.     Specific Renal Diseases include:

1-    Diabetic renal diseases.

2-    Hypertensive renal diseases

3-    Glomerulonephritis

4-    Analgesic nephropathy

5-    Acute renal disease

6-    Renal disease and drugs

 

Epidemiology of End Stage Renal Disease (ESRD):

1-    Age: Rates of most renal diseases and of end-stage renal disease (ESRD) rise with age.

2-    Sex: Males are more affected than females except in analgesic nephropathy where females are more affected

1-    ESRD is more common in black race.

2-    Risk factors:

     In adults main risk factors are:

a)    Diabetes mellitus

b)    Hypertension

c)    Drug induced as analgesics; addicting drugs as heroine & cocaine

d)    Bilharziasis

e)    Renal stones.

f)      Occupational /environmental risk factors e.g. exposure to heavy metals as lead, mercury, lead, chromium, tin , cadmium and some compounds e.g. oxygenated hydrocarbons.

 

 

Risk factors in children include congenital diseases,urological diseases, vesicoureteric reflux, chronic glomerulonephritis, others.

 

Patients on dialysis are mainly due to complications of hypertension, diabetes, chronic glomerulonephritis and others.

 

Importance of Renal Diseases as a Public Health Problem

At the pre-pathogenic phase

•         Lots of risk factors predispose and participate in occurrence of renal diseases.

•         Control of some chronic diseases is considered to be primary prevention for renal diseases.

AT the clinical stage

•         The most frightening issue that confronts someone diagnosed with chronic kidney disease is that quality of life will dramatically change

•         Delay of end stage renal failure is possible

•         Secondary prevention: early detection and prevention of further deterioration is very important,

•          There are actions an individual can take to prolong kidney function

At the End stage Renal disease

·        ESRD treatment constitutes an economic burden on individual and national level.The whole family suffers , either economically , socially or psychologically.

·        Quality of life (QOL) assessment is of importance

·        Social rehabilitation

·        Mortality is still high.

 

1.Diabetic renal disease :

Elevated blood sugar associated with diabetes damages the nephrons (diabetic nephropathy).

•         Diabetic nephropathy is the leading cause of ESRD in the USA, accounting for one third of all patients on dialysis.The risk of developing nephropathy in IDDM is more than in NIDD and occurs after about 18-20 years of disease..

In Egypt, Afifi, El Setouhy, El Sharkawy, Ali et al in a 6-year multiple cross-sectional study ( 2004) reported an increased prevalence of diabetic nephropathy from  8.9% in 1996, to 14.5% in 2001 through investigating a sample of ESRD patients in the Egyptian renal data system.

 

Risk factors for Diabetic nephropathy:

1-    Presence of microalbuminuria is a risk factor for ESRD.

2-    Cigarette smoking

3-    Overweight together with diabetes

4-    Hypertension.

 

Screening for microalbuminuria

Microalbuminurea serves as a sensitive early indicator of adverse effect of diabetes on the kidney.

It is a powerful predictor of the subsequent course

 

Why detection of microalbuminuria is important?

Because patients with microalbuminuria (micro amounts of protiens) progress to develop overt (clear) diabetic nephropathy that is more and more excretion of protein in urine and thus enter ESRD. Treatment aims at delaying but not totally stopping the rate of deterioration of renal function.

This is the role  of the public health physician in screening.

 

 

Protinuria (renal affection) increases with increase duration of diabetes and GFR decreases.

 

Prevention of ESRD

Role of prevention for Diabetic Renal Disease:

1. Annual screening for microalbuminuria will allow the identification of patients with nephropathy at a point very early in its course. It is a late marker for diabetic nephropathy as irreversible kidney damage may have occurred by the time it is detected, however it is a very early clinical indicator.

2.Improving glycemic control.

3. Aggressive antihypertensive treatment, and the use of ACE inhibitors will slow the rate  of progression of nephropathy.

4. Avoid nephrotoxic drugs 

5. Protein restriction.

Recommendations of American Diabetes Association Clinical Practice  Diabetes care (2005)

In addition:

 

- Dietary restriction of cholesterol and weight reduction should be emphasized.

- Cigarette smoking should be discouraged as it is associated with development of microalbuminuria.

 

 

 

 

2.Hypertensive Renal Disease:

 

Hypertension can damage small blood vessels in the kidneys, decreasing their ability to filter wastes from the blood (hypertensive nephropathy).The mechanism is through glomerular ischemia.

 

Hypertensive patients lose renal function at a faster rate with aging than do normotensive patients

Hypertension can both produce and complicate renal disease.

 

Risk factors of hypertensive nephropathy:

1-    Race and ethnic groups are powerful risk factors.  It is more in blacks than whites.

2-    Degree of hypertension

3-    Presence of diabetes.

4-    Male sex

5-    Increasing age.

6-    High normal serum creatinine level.

 

3.Analgesic Nephropathy

Analgesic nephropathy is a slowly progressive renal disease caused by the long-term ingestion of analgesics.

Classically the use of combination of agents including aspirin, acetaminophen, caffeine, codeine. Non steroidal anti-inflammatory drugs also cause nephrotoxicity.

 

Risk factors of Analgesic Nephropathy:

1-    It is more common in women.

2-    It is more common in those with history of regular consumption of analgesics due to chronic pain.

3-    Those with a history of peptic ulcer or gastric complaints have a history of analgesics consumption.

 

You have the power to prevent renal diseases… HOW?

 

Prevention of Renal Diseases

Primary prevention

Kidney health promotion

1-    Have your blood pressure checked regularly: Continuous screening of blood pressure

2-    Preventing over weight

3-    Discourage prolonged regular use of analgesics

4-    Tight control of blood sugar levels.

5-    Health education about the side effects of addicting drugs on the kidneys, and some antibiotics as aminoglycosides

6-    Stay fit. Regular exercise and well balanced diet

7-    Be a NON smoker

8-    Avoid alcohol.

9-    Environmental /occupational measures: clean water supply that is devoid of metal deposits from rusty pipes or contaminated from nearby factories. Limitation of exposure to heavy metals and toxic chemicals.

10-          Intake of plenty of fluids

 

 

Secondary prevention

1-    Test your blood and urine for early signs of kidney disease

2-    Control of diabetes mellitus, screening for microalbuminuria

3-    Early treatment of acute renal failure.

 

Tertiary prevention

In the situation of chronic irreversible renal failure (ESRD), prolonged survival is not possible without dialysis or renal transplantation.

Dialysis constitutes an economic burden, transplantation is regulated by policies and the availability of suitable donor organ.

Mortality still remains high. Renal transplantation is the ideal therapy for ESRD,if successful, it enables the resumption of normal life.

Dialysis or a kidney transplant are the only options for keeping a person alive

 

 

II. Urinary Tract Infections

They are most frequently in young, sexually active women. Common also in preschool girls, postmenopausal women, elderly men & women.

UTIs can lead to renal damage if associated with:

      a)Diabetes

      b)Pregnancy

      c)Obstruction

      d)Reflux

 

Risk Factors for Urinary Tract Infections (UTIs)

Sex: females due to short urethera. Infections are related to pregnancy, diaphragm use and others.

In Egypt, urinary shistosomiasis causes stricture ureter and ascending infections (pyelonephritis).

 

Prevention

1.    General hygiene and cleanliness

2.    Screening for bacteruria in pregnant women, diabetics and treatment of asymptomatic bacteruria.