ASPECTS OF INSULIN-RESISTANCE IN URBANIZATION-RELATED HYPERTENSION INZIMBABWE - A PRELIMINARY-REPORT

Insulin resistance has been associated with essential hypertension, ob esity and old age. Likewise high blood pressure has been observed to d evelop in some rural people who migrate to urban areas in developing c ountries like Zimbabwe. The pathogenesis of this urbanisation-related hypertension is still unknown. We therefore investigated aspects of in sulin resistance in urbanisation-related hypertension in Zimbabwean bl acks using oral glucose tolerance tests. Thirty normotensive subjects and 30 newly diagnosed hypertensive patients participated in this stud y. All subjects had blood pressures measured by random zero sphygmoman ometry. Fasting blood samples were taken before a 75 g oral glucose lo ad was given. Four other blood samples were subsequently collected at 30 minute intervals and determination of blood glucose and insulin lev els was made. Fasting glucose (mmol/l) and fasting insulin (in muU/ml) levels were, respectively, 4.8 +/- 0.2 and 19 +/- 2 in hypertensive p atients which were significantly higher than 4.0 +/- 0.2 and 13 +/- 1. 6 in normotensive patients (P< 0.05). In addition the area under the i nsulin curve was significantly higher in hypertensive than in normoten sive patients (P < 0.05). These findings suggest that insulin resistan ce may play a role in urbanisation-related hypertension.