BCH Investigation OF HYPERTENSION

Question 1

Hypertension is defined as?

Answer 1

a persistently elevated blood pressure ≥140/90mmHg

Question 2

How many percent of people aged over 25yrs have hypertension?

Answer 2

• 40%
• Affects 1/4 of the global population
• Leading modifiable risk factor for CVD

Question 3

What’s the role of psychosocial stress on hypertension?

Answer 3

• Remains uncertain.
• Acute stress raises blood pressure acutely
• Chronic stress has less clear cut effects.

Question 4

Causes of hypertension ? PRIMARY

Answer 4

Essential (primary) hypertension: Found in 95% of cases. cause unknown
- related to
- familial tendency
- obesity
- high alcohol intake
- high salt diet

Question 5

Secondary causes of hypertension include?

Answer 5

1) Renovascular hypertension
2) Renal disease
3) Drug induced hypertension
4) Diabetes mellitus Insulin dependent and non-insulin dependent
5) Other endocrine diseases
6) Adrenal disease
7) Arterial disease

Question 6

Causes of Reno-vascular hypertension include?

Answer 6

• Atheromatous formations
• Fibro-muscular hyperplasia
• Extrinsic renal artery compression.

Question 7

Intrinsic renal disease causing hypertension include ?

Answer 7

• glomerulonephritis
• Pyelonephritis
• Polycystic renal disease
• Renin secreting tumours
• chronic renal failure.

Question 8

Drugs that can induce hypertension include??

Answer 8

• Oral contraceptives
• Hormone replacement therapy
• Liquorice and carbenoxolone,
• Non steriodal anti-inflammatory drugs, - Sympathomimetic amines
• Corticosteroid and ACTH therapy
• Nephrotoxic drugs.

Question 9

Endocrine Diseases that can cause Hypertension ?

Answer 9

Acromegaly
Primary hyperparathyroidism, Myxedema
Thyrotoxicosis

Question 10

Adrenal disease that can cause hypertension include

Answer 10

Catecholamine excess
- pheochromocytoma
Aldosterone excess
- aldosterone secreting adenoma
- adrenocortical hyperplasia
- adrenal carcinoma
- cushing’s disease.

Question 11

Arterial disease that can cause hypertension include?

Answer 11

• co-arctation of the aorta
• polyarteritis nodosa
• systemic lupus erythematosus
• pulseless disease
• Takayasu’s disease
• progressive systemic sclerosis

Question 12

The aim of laboratory investigation of hypertensive patients ?

Answer 12

• it is used to exclude the rare identifiable renal or adrenal causes of hypertension
• it may help to detect evidence of ‘target organ damage’ for example, renal impairment
  c)identification of hypertensive patients who are at higher risk

Question 13

Identification of hypertensive pateients who are at higher risk, what are the factors the makes a person at “higher risk”

Answer 13

• Hyperlipidemia (elevated serum cholesterol, LDL-c and TG concentrations and a low HDL cholesterol level)
• Renal impairment
• Glucose intolerance

These conditions substantially
- increase the risk of death for a given level of blood pressure
- influence the choice of antihypertensive drugs

Question 14

All patients with sustained hypertension should have blood samples taken for ?

Answer 14

• measurement of creatinine and calculate the estimated Glomerular Filtration Rate (eGFR)
• glucose- glycated haemoglobin A1c (HbA1c),
• urea, electrolytes (sodium, potassium),
• lipid profile (total cholesterol, triglycerides, high density lipoprotein cholesterol (HDL cholesterol), low density lipoprotein cholesterol (LDL cholesterol),
• thyroid function tests (free thyroxine (FT4) and thyroxine stimulating hormone (TSH),
• urate and liver function tests (LFTs: total protein (TProt), albumin, total bilirubin (TBili), alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma glutamyl transpept

Question 15

What type of urine sample is required for urinalysis ?

Answer 15

24 hour or spot urine collection should be done

Question 16

Other tests that can be done apart form ones previously listed?

Answer 16

• Plasma aldosterone concentration
• Plasma renin activity
• Plasma renin concentration
• Plasma cortisol

Can be measured in a non-fasting state

Question 17

What’s the purpose of all these blood work while evaluating hypertension?

Answer 17

measurement of these analytes
permits evaluation
- kidney
- thyroid
- liver function
the identification of
- dyslipidaemia
- glucose intolerance
- metabolic syndrome
- cardiovascular risk stratification.

Question 18

Dip stick urinalysis findings?

Answer 18

Dipstick urinalysis can detect
- significant proteinuria
- haematuria
- glycosuria.

Question 19

Proteinuria In an hypertensive patient may be due to what ?

Answer 19

• proteinuria may be due to arteriolar fibrinoid necrosis: due to the malignant phase of either essential or secondary hypertension.
• Proteinuria may also be due to hypertensive nephrosclerosis (a consequence of hypertension)
• intrinsic renal disease which may be a cause of the hypertension.

Question 20

Arteriolar fibrinoid necrosis is characterized by ?

Answer 20

• retinal haemorrhages and exudates
• If left untreated, has a 2-year mortality rate of 80 %.

Question 21

hypertensive patients the presence of proteinuria indicates?

Answer 21

a substantially worse prognosis for both renal and non-renal disease.

• May be due to UTI (nitrite and L.esterase would be positive then)

Question 22

Diabetes and hypertension

Answer 22

• Glycosuria suggests diagnosis of Diabetes mellitus (may be negative, this doesn’t rule it out)
• The presence of diabetes will affect the choice of treatment for hypertensions as (thiazide diuretics are mildly diabetogenic**’ and are best avoided.)
• Glycosuria and hypertension may be secondary to an endocrine disorder Cushing’s syndrome, pheochromocytoma, acromegaly etc

Question 23

Sodium

Answer 23

• Serum sodium levels may be normal or raised in primary hyperaldosteronism (140-150 mmol/L)24
• low or low-normal (l25-135mmoljL) in conditions with secondary hyperaldosteronism such as malignant hypertension and renal or renovascular disease, with or without renal failure.
• Sodium may be lowered by thiazide or loop diuretics

Question 24

Potassium

Answer 24

Primary hyperaldosteronism (conns syndrome) and it’s non-tumorous variants are almost always associated with marked hypokalaemia ( 2·0 mmol/L.)
- In secondary hyperaldosteronism hypokalaemia is usually less severe and serum potassium may be normal.

Question 25

The comments cause of hypokalemia is ?

Answer 25

- Diuretics - Must be stopped one month before serum potassium measurement

Question 26

Hypokalemia is usually associated with ?

Answer 26

- Metabolic alkalosis - High serum bicarbonate concentration - treatment with carbenoxolone for peptic ulcer - intestinal postasisum loss with purgative or laxative abuse

Question 27

The most useful screening test for conns syndrome (surgical remidiable)?

Answer 27

Serum postassium measurement

Question 28

Hyperkalemia can be seen where?

Answer 28

- In **acute renal failure** (when **potassium sparing diuretics** or **potassium supplements** are used) spirinolactone, amiloride, triamterene - together with ACEI - captopril, enalapril, lisinopril

Question 29

RFT should be done how frequently in hypertensives?

Answer 29

- Assessed **on presentation** and **annually** in all hypertensives. - By ***serial serum creatinine determinations***. **Notes** - Routine estimation of creatinine clearance is not necessary in the vast majority of hypertensive patients. - This test may be a more sensitive indicator of loss of renal function, but it is not easily organized in general practice and is inconvenient.

Question 30

Why is blood pressure control necessary in HYP secondary to CKD?

Answer 30

- Those patients with hypertension secondary to chronic renal failure need **careful control of their blood pressure** as this ***may slow*** the otherwise **inevitable decline in renal function**.

Question 31

When is taking serial estimation of Creatinine clearance necessary?

Answer 31

When renal impairment is severe and the need for chronic dialysis is considered to be likely in the future, **it is helpful to plot serial measurements of the reciprocal of the serum creatinine against time**. - *This provides an indication of whether renal function is deteriorating and gives some indication of whether or when chronic dialysis may be necessary*.

Question 32

Calcium

Answer 32

- Serum calcium concentrations are **raised in primary hyperparathyroidism** and **serum phosphate is usually low**. - *Hypertension is found in about 50 % of these patients*. **Notes** - The mechanism of the association is uncertain. - It is not explained by hypercalcemia-induced renal damage or by the levels of the serum calcium or parathyroidhormone concentrations. - Surgical cure of hyperparathyroidism rarely results in any improvement in blood pressure.

Question 33

Extra notes about calcium concentrations and hypertension?

Answer 33

- Hypertension in a hyperparathyroid patient is not an indication for parathyroidectomy **unless there is concurrent renal failure**.

Question 34

Relationship between thiazides and Hypercalcemia?

Answer 34

- Thiazide diuretics **may rarely cause hypercalcemia** and these **drugs should be stopped for a few weeks before rechecking** to exclude hyperparathyroidism. - If hypercalcemia persists, then a **serum parathyroid hormone assay should be performed**.

Question 35

Urate in evaluating hypertension?

Answer 35

- Serum **uric acid is raised in about 40 % of hypertensives with essential hypertension** - more common in those with renal failure. - Urate nephropathy may occasionally be the cause of the hypertension.

Question 36

Possible causes of hyperuricemia ?

Answer 36

- **Hyperuricemia may be caused or aggravated by diuretic therapy** although only a small proportion of patients develop clinical gout. - **Excessive intake of alcohol - unexplained hyperuricemia**

Question 37

Notes about Uric acid?

Answer 37

- ***It is uncertain whether a raised serum uric acid level is itself an independent cardiovascular risk factor after allowing for the relationship between uric acid and hyperlipidemia, obesity, alcohol abuse, drug therapy and the height of the blood pressure***

Question 38

Relationship between Diabetes and hypertension?

Answer 38

- About 50 % of both insulin dependent and non-insulin dependent diabetics also have hypertension - Up to 10% of hypertensives are also diabetic.

Question 39

Prognosis and RF for the development of both Hypertension and diabetes ?

Answer 39

- The combination of these two conditions becomes **increasingly common with advancing age** and **with increasing levels of obesity** - The prognosis is correspondingly bad.

Question 40

Notes about diabetes coexisting with hypertension ?

Answer 40

- **Thiazide diuretics** are best **avoided**. - Calcium channel blockers and angiotensin converting enzyme inhibitors **have no deleterious effects** - **ACEI may have major benefits by delaying the onset of renal damage**

Question 41

cholesterol and triglycerides What substantially worsens the prognosis in a hypertensive patient? .

Answer 41

- The presence of hyperlipidemia - ***Beta blockers, thiazide diuretics should be avoided in patients with overt hyperlipidemia***.

Question 42

Effects of BB, thiazide, CCB, ACEI on plasma lipids

Answer 42

- *Both beta blockers and thiazide diuretics (usually the first line drugs for hypertension) may adversely affect plasma lipid profiles and it is possible that their use has been responsible for the disappointing impact of antihypertensive therapy on coronary heart disease’*. - *The calcium channel blockers and angiotensin converting enzyme inhibitors have no such effects on plasma lipids, and the newer alpha receptor blockers terazocin and doxazocin may even modestly reduce lipid levels*

Question 43

Gamma glutamyl transpeptidase Assay

Answer 43

- **High alcohol intake is a relatively recently recognized cause of a raised blood pressure** - Hypertension appears to be readily reversible with reduction or abstinence. • It has been estimated that 10-20 % of hypertension may be related to a high alcohol intake but unless the clinician is alert to this point it may pass unnoticed.

Question 44

Importance of estimating serum gamma glutamyl transferase activity?

Answer 44

- helps to identify the commonest known cause of hypertension. - Serum **aspartate transaminase levels may also be raised** - hematological indices may show **evidence of macrocytosis** with a **normal** or even a **slightly raised hemoglobin level**

Question 45

Plasma aldosterone concentration (PAC) and Plasma renin activity (PRA) or plasma renin concentration (PRC):

Answer 45

- Plasma renin levels in peripheral blood may be **high or normal in renovascular hypertension** - However in **primary hyperaldosteronism**, the **plasma renin levels would be low** and **plasma aldosterone concentration would be high**.

Question 46

What may indicate the presence of secondary hypertension ?

Answer 46

- There is a higher chance of there being an underlying cause of hypertension **in younger patients (less than 45 years old)** - **those with severe (diastolic blood pressure > 120mm Hg)** - Those with **difficult-to-control hypertension**. *Thus, such patients should undergo further investigations to find the cause of hypertension.*

Question 47

Importance of biochemical investigations of hypertension

Answer 47

The results from biochemical investigations of hypertension - may influence the choice of drugs used to control the blood pressure - suggest that the hypertension is secondary to renal or endocrine disease.