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Investigating hypokalaemia

BMJ 2013; 347 doi: https://doi.org/10.1136/bmj.f5137 (Published 24 September 2013) Cite this as: BMJ 2013;347:f5137

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Re: Investigating hypokalaemia

The authors did mention that in primary hyperaldosteronism the patient presents with hypertension with unexplained hypokalaemia(1). However dietary potassium intake may also have this picture.

Among dietary factors playing an important role in the pathogenesis and management of essential hypertension, [2] K + is known to modulate the pressor effect of dietary NaCl. In fact, both normal and hypertensive subjects, ingesting a low K + diet may exhibit lower sodium excretion than that observed during normal K + intake; [3],[4] consequently, it has been concluded that Na + retention may contribute to blood pressure elevation during K + depletion. Dietary K + restriction increases blood pressure in patients with essential hypertension. Both Na + retention and Ca 2+ depletion may contribute to the increase in blood pressure during K + depletion. [4] K + depletion may exacerbate essential hypertension and not only Na + restriction, but also K + and Ca 2+ supplementation, could be particularly advisable in salt-sensitive hypertensive patients. [4]

References:

1. BMJ 2013;347:f5137

2. Dustan HP. Nutrition and hypertension. Ann Intern Med 1983;98:660-2.

3. Krishna GG, Chusid P, Hoeldtke RD. Mild potassium depletion provokes renal sodium retention. J Lab Clin Med 1987;109:724-30.

4. Krishna GG, Kapoor SC. Potassium depletion exacerbates essential hypertension. Ann Intern Med 1991;115:77-83.

5. Coruzzi P, Brambilla L, Brambilla V, Gualerzi M, Rossi M, Parati G, et al. Potassium depletion and salt sensitivity in essential hypertension. J Clin Endocrinol Metab 2001;86:2857-62.

Competing interests: No competing interests

13 October 2013
Neeru Gupta
Scientist E
Neeta Kumar, KK Jani
Indian Council of Medical Research
Ansari Nagar, New Delhi - 110029