DNAH8 and Hypertension: Previous data in a similar small group of South Africans found increased, albeit not significant platelet membrane ATPase activity, especially magnesium ATPase activity in hypertensive versus normotensive subjects.11 Our own data seemingly fit the hypothesis that insulin resistance/hyperinsulinaemia is able to modulate transmembrane cation flux in susceptible patients and thereby influence vascular tone, and also provide a unifying mechanism that explains the link between hypertension and glucose intolerance.30,31