Dietary markers of hypertension associated with pulse pressure and arterial compliance in black South African children: the THUSA Bana Study.

AIM

The aim of the study was to determine which dietary factors contribute to the impairment of arterial compliance, stroke volume, total peripheral resistance and pulse pressure, and could thereby be identified as risk markers in the development of hypertension in black children.

METHODS

Children aged 10 to 15 years were recruited from 30 schools in the North West Province over two years (2000 to 2001). These children comprised 321 black males and 373 females from rural to urbanised communities and 40 male and 79 females subjects with identified high-normal to hypertensive blood pressure. Blood pressure was measured by means of a Finapres apparatus. Through analysis with the Fast Modelflo software program, systemic arterial compliance, pulse pressure, total peripheral resistance and stroke volume were obtained. A 24-hour dietary recall questionnaire and weight and height measurements were taken.

RESULTS

In a stepwise regression analysis the following nutrient were significantly associated (p < or = 0.05) with cardiovascular parmeters of hypertensive subjects: protein, carbohydrates, total fat, polyunsaturated fat, mono-unsaturated fat, saturated fat, fibre, vitamin A, nicotinic acid, biotin, vitamin B(12), ascorbic acid, vitamin E, magnesium, manganese, phoshorus and iron. No significant dietary markers were indicated for the normotensive groups. Dietary intakes of most of these nutrients were below the dietary reference intakes for all groups.

CONCLUSIONS

The results indicate strong associations of protein, polyunsaturated fats, fibre, vitamin A, vitamin C, vitamin E, nicotinic acid, vitamin B(12), biotin and phosphorus with the rate of hypertension in black South African children.