This lecture was conducted during the Nephrology Unit Grand Ground by Medical Student under Nephrology Division, Department of Medicine in King Saud University. Nephrology Division is not responsible for the content of the presentation for it is intended for learning and /or education purpose only.

Hypokalemia association with hypertension Presented by : Sukainah Al-khunaizi

Content :  potassium homeostsis  Definition of hypokalemia  Causes of hypokalemia with HTN  Primary hyperaldosteronism  Secondry hyperaldosteronism  Cushin’g syndome

What is potassium? Potassium, the most abundant intracellular cation, is essential for the life of the organism. It is obtained through the diet, and common potassium-rich foods include meats, beans, fruits, and potatoes.

location in body : mostly (98%) is intracellular K secretion: Most of excretion through kidney (80%) at the distal nephron. The reminder via GI tract Potassium homeostasis

Excretion is increased by (1) aldosterone (2) high Na delivery to the collecting duct (eg, diuretics) (3) high urine flow (eg, osmotic diuresis) (4) high serum K level (5) delivery of negatively charged ions to the collecting duct (eg, HCO3).

Definition of hypokalemia :- It is a serum K concentration of < 3.5 mmol / L. Aetiology :-  hyperaldosteronism (primary or (Secondary  Non aldosterone minralocorticoid ( cushing`s syndrome ).

Primary hyperaldosteronism Definition :- refers to a renin-independent increase in the secretion of aldosterone Aetiology :- 1- aldosterone – producing adrenal adenoma ( conn`s syndrome ) 40% 2- idiopathic hyperaldosteronism (IHA) 60% 3- familial hyperaldosteronism 1%

Clinical features :- HTN Fatigue – weakness -paresthesia Headache In Sever cases : tetany intermittent paralysis

Investigation :- - U & E :- hypokalemia, mild hypernatermia, hypomagnesemia - High 24 h urinary or plasma aldosterone + low random plasma renin. - CT or MRI ( for differentiate adenoma from hyperplasia ).

Treatment :- surgical :- removal of adenoma after surgery, some people still have high blood pressure and need to take medication Medical :- spironolactone ( aldosterone antagonist ) or amiolride ACEI might to be added for better blood pressure control.

Secondary hyperaldosteronism: This represents a group of disorders characterized by physiologic activation of the renin-angiotensin- aldosterone axis as a homeostatic mechanism designed to maintain serum electrolyte concentrations or fluid volume

can be divided into 2 categories depending on whether associated hypertension is present Renal artery stenosispresence of diarrhea, excessive sweating, low COP states, and hypoalbuminemia due to liver or renal disease or nephrotic syndrome Absence of HTN Presence of HTN

Renal Artery stenosis : There is decreased in renal perfusion of one or both kidneys leads to increased renin release and subsequent angiotensin production Suspected if :-  - ive family history of HTN.  Spontaneous hypokalemia.  Sudden onset or exacerbation of HTN.  Difficult to control with antihypertensive therapy.

Symptoms & Types : blood flow damage to the kidney. renal function present with fatigue, malaise, or slight confusion due to a gradual buildup of waste products in the body. 3 types :- 1- atherosclerotic plague : proximal 1/3 renal artery, usually male > 55 y. 2- fibromuscular hyperplasia :- abnormal thickening of the muscles of the artery wall affecting distal 2/3 renal artery usually in young females 3-compression of the artery by an outside mass; for example, a tumor

Investigation :- U & E Urine analysis Renal U/S -Gold standard : is renal angiography. -Treatment :- -BP lowering medication ( ACE inhibitors ). -Surgical : angioplasty & stenting.

Cushing’s syndrome : Definition :- a hormonal disorder results from chronic glucocorticoid excess – Aetiology :- 1- ACTH – dependent ( 85% ) : -ACTH secreting pituitary adenoma ( cushing`s disease 80% ). -Ectopic ACTH secreting tumor ( SCLC,thymomas ).

-2- ACTH – independent : -Long term use of exogenous glucocorticoid (asthma, post transplantation ) -Primary adrenocortical tumor ( adenoma, carcinoma ) uncommon

Symptoms :- -Weight gain ( central ) -Depression, psychosis, insomnia. -Amenorrhea, oligomenorrhoea. -Thin skin, easy bruising. -Acne. -Polyuria, polydipsia and hyperglycemia

-Signs :- -Moon face. -Proximal myopathy. -Purple striae. -Buffalo-hump. -Kyphosis.

Treatment : Pituitary :- - trans-sphenoidal resection. -Irradiation + mitotane( supress cortisol). Ectopic ACTH secreting tumers :- - surgical,Chemotherapy, radiation. -Ketoconazole, metyrapone ( block adrenal steroid synthesis ) Adrenal :- -Adenoma :- unilateral adrenalectomy ( curative ).

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