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Low on Salt | Turning the spotlight on kidney organ donors

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• GS Paper 2 Issues relating to the development and management of Social Sector/Services relating to Health, Education, and Human Resources.
• GS Paper 3  Science and Technology- developments and their applications and effects in everyday life.
• Tags: #Health #KidneyDisease #KidneyDonors #SaltIntake #GS2 #GS3 #UPSC

Global Importance of Salt Reduction Implementation

Acknowledging the critical need for global salt reduction efforts.

• World Health Organization (WHO) and medical associations’ recommendation to limit salt intake to 5 grams per day for the general population.
  • It was stressed that the 5 grams include salt naturally present in food, salt added during cooking, and hidden salt in processed or packaged foods like bread and noodles.
• The WHO observed that only a few countries have legally implemented salt reduction policies.
  • Note that while there may not be specific studies on salt intake in individuals with a single kidney, like donors, it is reasonable to assume that salt-related damage would be more pronounced.
• Positive effects of salt restriction
  • Lowers blood pressure
  • Reduces the risk of strokes
  • Reduces the risk of kidney failure
• Recent study from MIOT International emphasizes the importance of monitoring salt intake in kidney donors.
  • The study involved 104 kidney donors with an average follow-up of four years (maximum of 27 years).
  • None of the donors developed kidney failure, but their kidney function decreased by an average of 21% according to calculated GFR.
  • Alarmingly, only 13% of donors adhered to restricted salt intake.
  • The average salt intake, as measured by 24-hour urinary sodium excretion, was 9.2 grams per day, with a maximum of 14 grams per day.
    • This exceeds the general population’s salt intake as reported by the ICMR.
    • This is the first report on kidney donors’ salt intake, highlighting the need for further studies and the inclusion of urinary sodium measurement in donor follow-ups to provide appropriate advice.

Donor Care in Kidney Transplants

• Emphasizing the importance of donor well-being in organ transplantation. Ensuring donors do not encounter future health issues. Conducting thorough assessments to ensure donor suitability.
• Consideration of blood group compatibility, with exceptions like O donors. Mentioning the possibility of blood group mismatched transplants in specialized centers with successful outcomes.
• Age criteria: Typically accepting donors between 18 to 60 years.
  • Exceptional cases for donors aged 60-70 with excellent kidney function.

Health Considerations for Kidney Donors

• Minor Ailments and Donor Eligibility: Minor health issues like diabetes, pre-diabetes, obesity, hypertension, and kidney stones may not automatically disqualify potential donors. Special attention and evaluation are necessary for these conditions.
• Favorable Medical Evaluation: Donor assessments are typically biased in favor of the donor’s well-being. Exceptions can be made based on the patient’s social and family circumstances, especially if the patient is the primary breadwinner.
  • For example, diabetes in the donor is generally an absolute contraindication when the patient’s survival is crucial for the family.
  • Hypertension, if easily controlled with a single medication, may be permitted.
  • Kidney function should be at least 75 ml per minute, with no protein leakage.
  • Donors with small kidney stones should undergo metabolic workup, while those with multiple stones are usually rejected.
• Post-Donation Follow-Up: Lifelong follow-up is essential after kidney donation.
  • After surgery, kidney function temporarily drops by almost half, and the remaining kidney compensates through hyperfiltration at the microscopic level and compensatory hypertrophy at the macroscopic level.
  • Donors should regularly monitor blood pressure, kidney function, and protein loss, ideally on an annual basis.
  • Approximately one-third of donors may develop hypertension over several years, a rate similar to the general population.
  • A small percentage of donors may experience protein leakage in their urine.
  • Proper education and guidance for donors are crucial, focusing on diet, exercise, and the avoidance of kidney-toxic drugs.
• Ideal Diet for Kidney Donors
  • Recommend a DASH diet (Dietary Approach to Stop Hypertension) for kidney donors.
  • Emphasize the consumption of vegetables, fruits, whole grains, lean meat, and moderate salt and sugar restriction.
  • Encourage avoidance of trans fats in their diet. 

Early Detection of Chronic Kidney Disease (CKD)

• CKD affects nearly 10% of the global population, posing a significant burden on healthcare resources and the economy if left unchecked.
• Early detection and intervention are crucial to prevent CKD progression to end-stage kidney disease necessitating dialysis or transplantation.
• Two common markers for detecting kidney disease are
  • Proteinuria (protein leak): Proteinuria is a more sensitive test, detecting kidney diseases earlier than creatinine estimation in 85% of cases.
    • Protein appears in the urine only when the microscopic kidney vessels (glomeruli) are damaged or when it is secreted by tubules.
    • The extent of protein loss in the urine indicates the degree of kidney damage and serves as a measure to assess treatment response.
    • eGFR (Glomerular function rate) is calculated using mathematical formulas adjusting for age, weight, and sex.
  • Blood creatinine levels: Creatinine is a product of muscle metabolism, is excreted by the kidneys, and its measurement in the blood reflects kidney function.
    • Despite being sensitive, there is a lack of standardization in laboratories for creatinine measurements.

Proteinuria Assessment

• Proteinuria can be assessed both qualitatively and quantitatively.
• Laboratory urine examination routinely uses strips to screen for proteinuria/albuminuria.
• For precise data, a spot urine sample can be quantitatively measured for protein/albumin and creatinine, expressed as a protein-to-creatinine ratio.
• The gold standard is the 24-hour urine sample for protein measurement.
• Proteinuria not only serves as a marker of kidney disease but can also contribute to its progression.

Medications to Reduce Protein Loss

• Several groups of drugs have been developed to lower protein loss, thus reducing kidney damage.
• These drug groups include the anti-renin system (ACE and ARB) drugs, SGLT2 inhibitors, and anti-aldosterone medications.

Specific Treatments

• Specific treatments, such as immunosuppression for allergic disorders and discontinuation of kidney-damaging drugs, can help reverse kidney disease.
• This may involve avoiding native and herbal medications that may contain heavy metals.
• Maintaining good blood pressure control is crucial for all kidney disorders.
  • Recent studies by the ICMR and WHO have revealed that 35-40% of the world’s adult population has high blood pressure, often undiagnosed, leading to end-organ damage.
  • Even when diagnosed, control of blood pressure is often inadequate.
• Importance of Salt Reduction
  • The findings of a study among college students in Chennai, which showed 5% had hypertension, 20% were obese, and 6% had abnormal protein excretion in urine.
    • Emphasize the lack of awareness among more than 80% of students regarding recommended daily salt intake.
  • Discuss the positive impact of initiatives like the Kidney Trust in Chennai, which detected and controlled blood pressure and diabetes, reducing kidney failure rates in the covered villages.
  • Reference a study from China that demonstrated a significant reduction in strokes by using salt substitutes.
  • Stress the critical need for global awareness and action in implementing salt reduction strategies.

Source: The Hindu

Mains Question

Discuss the role of salt reduction strategies and the management of proteinuria in managing kidney disease.