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In late 2017, the publication of the new American College of Cardiology (ACC)/American Heart Association (AHA) hypertension guidelines created considerable controversy. The threshold for hypertension was redefined as > 130/80 mmHg and target blood pressure < 130/80 mmHg. The purpose of this commentary is to give clarity on the position of the Southern African Hypertension Society (SAHS). In South Africa more than 90% of hypertensives are not controlled at < 140/90 mmHg. Furthermore, by redefining hypertension to a level of 130/80 mmHg, this will significantly increase the prevalence of hypertension by 43%. The new targets will necessitate greater use of health services for increased health visits to monitor patients, greater use of antihypertensives to achieve the lower target, and increased use of laboratory services to monitor for adverse effects. It is the position of SAHS that the new definition and targets are not relevant to low- and middle-income countries such as South Africa, the threshold for hypertension remains at 140/90 mmHg, and a universal target is < 140/90 mmHg for all categories of hypertension.

Background: A high prevalence of the R563Q mutation of the epithelial sodium channel β-subunit has been reported in South African hypertensives compared with unrelated normotensive controls. To delineate the effects of this mutation against a more uniform genetic background, this study investigated the association of the mutation with hypertension within affected kindreds. Methods: Forty-five index patients and members of their kindreds were studied. Blood pressure, serum potassium and the presence of the R563Q mutation were determined. Results: Of the 136 individuals studied, 89 were heterozygous for the R563Q mutation and 47 homozygous RR. The mean arterial pressure was significantly higher in the R563Q heterozygous group (p = 0.005) after adjusting for gender, race, age and kindred membership. Of the R563Q heterozygous subjects, 71 (80%) had hypertension, while 17 (36%) of the R563Q homozygous RR subjects were hypertensive. Six R563Q heterozygous subjects had hypokalaemia and one R563Q homozygous RR subject had hypokalaemia, but the difference was not statistically significant. Two heterozygous patients had Liddle's syndrome, both occurring during pregnancy. Conclusion: The R563Q mutation of β-ENaC is associated with hypertension within affected kindreds, but does not usually cause the full Liddle's syndrome phenotype.