Abstract | BACKGROUND: METHODS: Samples were obtained from hypertensives and normotensive controls in Cape Town and Johannesburg, and unselected San living in the rural areas of the Northern Cape and Namibia. Resistant hypertensives with the R563Q variant were treated with amiloride. RESULTS: One thousand nine hundred and thirty nine (1,468 hypertensives, 471 controls) subjects were recruited. Eighty-seven (5.9%) of the hypertensives were R563Q heterozygote vs. 8 (1.7%) of the normotensives (P < 0.0005). In the Namibian and Northern Cape San 19.5% and 18.8% of subjects were R563Q positive. There was no association with hypertension. Spot sodium excretion was lower in the San compared to urban subjects (7.3 vs. 12.2 mmol/mmol, P = 0.016). Twenty-two R563Q heterozygote patients with resistant hypertension received amiloride with a mean reduction in blood pressure (BP) of 36/17 mm Hg (P < 0.0001). CONCLUSIONS: The R563Q variant is strongly associated with hypertension in urban areas in South Africa. The San are the likely origin of the variant, but it is not associated with hypertension, presumably due to their lower sodium intake. Screening patients with resistant hypertension in South Africa for the R563Q variant provides a feasible pharmacogenetic approach to treatment.
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Authors | Erika S W Jones, E Patricia Owen, Brian L Rayner |
Journal | American journal of hypertension
(Am J Hypertens)
Vol. 25
Issue 12
Pg. 1286-91
(Dec 2012)
ISSN: 1941-7225 [Electronic] United States |
PMID | 22895453
(Publication Type: Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)
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Chemical References |
- Antihypertensive Agents
- Epithelial Sodium Channel Blockers
- Epithelial Sodium Channels
- Amiloride
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Topics |
- Adult
- Aged
- Amiloride
(therapeutic use)
- Antihypertensive Agents
(therapeutic use)
- Asian People
(genetics)
- Black People
(genetics)
- Blood Pressure
(drug effects, genetics)
- Case-Control Studies
- Chi-Square Distribution
- Epithelial Sodium Channel Blockers
(therapeutic use)
- Epithelial Sodium Channels
(drug effects, genetics)
- Female
- Gene Frequency
- Genetic Predisposition to Disease
- Genetic Variation
- Heterozygote
- Humans
- Hypertension
(drug therapy, ethnology, genetics, physiopathology)
- Male
- Middle Aged
- Namibia
(epidemiology)
- Phenotype
- Prevalence
- South Africa
(epidemiology)
- Treatment Outcome
- White People
(genetics)
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