Hypertension and Kidney Disease Overview

• Walter Burton and W. Parker Hamernik are the presenters
• Overview of kidney disease and hypertension

Overview

• Defining the problem includes identifying hypertension and kidney disease.
• Trends and health risks associated with these conditions
• Understanding the etiology and pathophysiology
• Identifying interventions and treatments
• Role of exercise in managing these conditions

Definitions & Epidemiology - Definitions and Overview

• Hypertension: High blood pressure, specifically a systolic number ≥130 mmHg or a diastolic number ≥80 mmHg
• Chronic Kidney Disease (CKD): Kidney damage or an estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m² persisting for 3 months or more

Hypertension

• Blood Pressure Regulation: Blood pressure stems from cardiac output and peripheral resistance and factors like vessel constriction, blood volume, and heart rate factor into blood pressure.
• Hypertension Impact: High blood pressure puts strain on the heart and blood vessels and, over time, can cause to atherosclerosis increasing the risk of heart attack, stroke, and kidney damage.

Kidney Disease

• Nephrons filter blood, remove waste, and balance fluid/electrolyte levels, but damage to them can reduce kidney function.
• Kidney Function Decline: Waste products like creatinine and urea build up with decline and electrolytes and fluid get retained leading to edema, high blood pressure, and bone disease.

Major Functions of Kidneys

• remove waste and toxins
• maintain appropriate fluid and electrolyte balance
• help produce red blood cells using erythropoietin
• help remove drugs from the body
• produce renin to aids blood pressure
• produce vitamin D
• there are ~1 million nephron units per kidney

Definitions & Epidemiology - Incidence and Prevalence

• About 1 in 2 adults in the U.S. (108 million people) have hypertension
• More than 1 in 7 U.S. adults (37 million people) have CKD
• 9 in 10 adults are unaware they have CKD
• About 1 in 3 people with diabetes, and 1 in 5 with hypertension, have kidney disease

Hypertension Trends (1990 vs. 2019)

• Women: 331M - 626M, an increase of 89.1%
• Men: 317M - 652M, an increase of 106%
• Total: 648M - 1.278B (Almost doubled)

Prevalence

• Stable, but absolute cases rose due to population growth and aging
• Age-adjusted prevalence of hypertension in US adults is shown by race and ethnicity, sex, and survey year (NHANES 1999-2002, 2007-2010, 2017-2020)
• Hypertension increases with age

General Prevalence

• Diabetes: 38%
• High blood pressure: 26%
• Glomerulonephritis: 16%
• Unknown cause: 5%
• Other causes: 15%
• ESKD Prevalence, by Racial Group, United States, 2000-2021 indicates that black people have highest cases of kidney failure in the USA

Definitions & Epidemiology - Hospitalizations and costs

• From 2011 to 2021, inpatient discharges increased from 296,253 to 1,311,528.
• The number of discharges increased from 16,112,764 to 17,160,070 during the same time
• The estimated direct and indirect cost for 2020-2021 was $49 billion.
• US health care expenditures for hypertension in 2016 were $79 billion and ranked 10th in health care expenditures.
• $131 million is spent on prescriptions each year.
• The estimated yearly cost on blood pressure by 2015 is $220.9 Billion

Kidney Disease Costs and Spending

• In 2020, Medicare spent >$85.4 billion caring for people with CKD and $50.8 billion caring for people with ESKD.
• ESKD care accounts for >7% of total Medicare expenditures for just 1% of the Medicare population.
• Medicare spending per person per year decreased from $96,451 in 2010 to $79,439 in 2020.
• Data from over 1 million adults found that during a median follow-up of one year, there were 62,023 hospitalizations and $946 million CAD of costs among patients with CKD (11.1% were potentially preventable conditions).

Hypertension Hospitalization

• Between 1999 to 2019, annual hospitalization rose from 51.5 - 125.9 per 100,000 beneficiary years
• Annual medical costs for people with high blood pressure were $2,759 higher than others.

Definitions & Epidemiology - Prognosis and Mortality Rates

• Global Impact: Elevated blood pressure causes ~7.5 million deaths worldwide, about 12.8% of all global deaths.
• Life Expectancy: Elevated blood pressure in adulthood reduces life expectancy. Normotensive people live 5 years longer.
• Mortality Rates: Nephritis, nephrotic syndrome, and nephrosis caused 57,937 deaths in the United States (17.4 per 100,000 population) making it the 9th leading cause of death in 2022.
• Survival Rates: A study reported a 5-year survival rate of 54.6% for patients with CKD, indicating a substantial mortality risk.
• There is increasing mortality across the US, especially for african americans.

Etiology & Pathophysiology - Common Causes & Risk Factors

Hypertension - Primary Risk Factors

• A few identified risk factors include race, diet, CKD, sleep apnea, high cholesterol and diabetes:
  • Race: Black, Hispanic and Asian adults (males) have higher rates of high blood pressure along with cultural practices and dietary habits.
  • Diet: High sodium, calories, saturated, and trans fats, sugar increase the risk.
  • Sleep apnea may increase the risk
  • Diabetes: Most diabetic people also develop high blood pressure.

Hypertension - Secondary

• Hypertension may be the response to another medical condition:
  • Certain heart defects
  • Kidney disorders
• Person's blood pressure will often get better once the condition is resolved.

Kidney Disease primary etiologies (75-80% cases)

• Diabetes(High blood sugar levels damage kidney function, impairing their ability to filter waste and fluids).
• Hypertension(Damages blood vessels and increases pressure within the kidney)
• Cardiovascular Disease(Reduces blood flow to the kidneys, impairing their function).
• Smoking(Reduces blood flow to the kidneys, increases blood pressure and promotes kidney damage).
• Obesity(Direct kidney damage through mechanisms like glomerular hyperfiltration)
• Family History of Kidney Disease(Genetic factors predispose CKD risk).
• Older Age(Kidney function declines with age).

Etiology & Pathophysiology - Genetic/Environmental/Lifestyle Considerations

Hypertension - Genetic Influences

• The following points capture genetic variants in childhood:
  • Low birth weight
  • Early-life developmental catch-up
  • Adverse intrauterine conditions
  • Obesity
• Salt Sensitive: About 25% of population
• Genotype identified = SES plays a role in the genetic architecture of BP

Hypertension - Environmental Factors

• Some environmental factors correlated with hypertension included:
  • High Elevation
  • Latitude
  • Volcanoes
  • Hurricanes
  • Tsunamis -Pandemics -Air pollution

Kidney Disease- Genetic Factors

• A small percent has genetic variants
• Several forms including polygenic risk
• Family's raise likelihood of acquiring
• 24% has PKD1, mutation

Hypertension

• Genetic/environmental factors (e.g., high salt intake, obesity) trigger vascular tone changes.
• Kidneys retain sodium, blood volume and pressure increases
• Reduced nitric oxide leads to vasoconstriction & atherosclerosis.
• Can initiate the development of CAD
• Chronic hypertension strains the heart and worsens blood pressure: accelerates atherosclerosis and increases the risk of coronary artery plaques, leading to CAD

Kidney Disease Initial Injury and Nephron Loss

Glomeruli allow protein leakage, accelerating fibrosis and nephron loss

• These factors contribute to Coronary Artery Disease
• Severe fibrosis and nephron loss lead to eGFR < 15% and requires dialysis or transplant

Comorbidities

• Dyslipidemia
• Chronic Heart Failure
• Type 2 Diabetes
• Obesity
• Chronic Heart Disease
• Chronic Kidney Disease
• Anemia
• COPD
• Vision loss
• Cognitive Decline
• Damage to blood vessels

Kidney Disease - Consequences

• Cardiovascular Disease
• Diabetes
• Hypertension
• Bone Disease
• Reduced Quality of Life
• Reduced heart health

Hypertension Diagnosis - Tests and Indicators

• Diagnoses involves blood pressure measurement, electrocardiogram, laboratory tests. Retinal and cardiac examination, and evaluation of peripheral pulses
• BP classifications include elevated 120-129 mmHG and <80mmHG
• Hypertensive Stage 1: 130-139 mmHg or 80-89 mmHg
• Hypertensive Stage 2: 140+ mmHg or 90+ mmHg
• Hypertension Crisis: 180+ mmHg

Kidney Disease Diagnostic Tests

• Blood tests to measure serum creatinine to estimate GFR Less than 60 mL/min is typically indicative of chronic kidney disease
• Urine tests to detect albumin
• Imaging studies to assess kidney size, dimensions,detect obstructions or other abnormalities
• Physical exam can show edema and/or skin variation

Hypertension - Signs and Symptoms

• Headaches and Shortness of breath
• Nosebleeds and Blurred vision
• Chest pain and Irregular Heartbeat
• Dizziness and Nausea

Kidney Disease - Common Signs and Symptoms

• Fatigue and general sense of weakness
• Swelling (Edema)
• Changes in Urination
• Loss of Appetite
• Muscle Cramps
• Frequent urination

Management

• Reduce sodium intake, and consume heart-healthy diets
• Exercise more
• Manage weight and limit alcohol
• Less than 130/80 mmHg is recommended target

Kidney disease Medical Treatments

• Reducing Sodium and controlling blood pressure
• Monitoring glucose levels
• Restriction: Reducing sodium intake
• Statin medications
• Administering erythropoiesis-stimulating agents and iron supplementation as needed
• Monitoring and managing calcium, phosphorus, parathyroid hormone, and vitamin D levels

Hypertension-Surgical Management:

• Renal Denervation: a catheter is used to reduce sympathetic nerve activity which lowers blood pressure

Kidney Disease-Dialysis-

• Involves pumping plood through an artificial kidney (dialyzer) to remove waste products and excess fluid.
• Uses the lining of the abdomen (peritoneum) as a filter to remove waste products and excess fluid.

Other Hypertension Considerations

• Use RPE scale rather than heart rate for intensity monitoring.
• Encourage hydration particularly for individuals on diuretics.
• Monitor for dizziness and drops in blood pressure
• Allow for gradual position changes to prevent issues
• Consider longer warm-ups and cool-downs

Kidney Disease General recommendations

• Monitor blood pressure
• Watch for hypoglycemia, and
• Encourage hydration for those on diuretics or SGLT2 inhibitors
• Modify exercise intensity
• Incorporate weight-bearing exercises.
• Rate of Perceived Exertion - Use RPE, not heart rate, since some medicines blunt the heart rate response