Renal phenotypes of essential hypertension in Caribbean women

The characterisation of phenotypes of patients with essential hypertension (EH) is an important pre-requisite for genetic research. The present study compares clinical and renal function parameters in 2 groups of patients fro m different origins. Method. Out of a cohort of essential hypertensives disclosed on routine wor k medical examinations, 21 caucasian (CC) women were paired with 21 Caribbe an (CB) women, In the 2 groups we recorded family history of hypertension ( FHH), duration of hypertension, BMI, salt intake based on 24 h urinary sodi um excretion, microalbuminuria, and blood pressure (BP). Glomerular filtrat ion rate (GFR) and renal plasma flow (RPF) were measured with inulin and pa ra-amino-hippuric acid clearances. Plasma active renin (AR) and aldosterone (Aldo) levels were measured by immune-assays. White coat (WC) effect was a ssessed on the difference between BP values measured an medical Visits and by the nurses on clearance measurements. Anova and t-test were used for ana lysis, statistical significance was assumed for p<0.05. Results. Casual BP values were 150/94 mmHg in CB and 153/95 mmHg in CC. The re were no significant differences on BMI (CB 30.6 kg/m(2) vs CC 27.1 kg/m( 2)), AR (CB 6.6 pg/mL vs CC 8.7 pg/mL) and Aldo (CB 195.1 pmol/L vs CC 202. 8 pmol/L) provided an equivalent dietary salt intake (CB 11.2 g/d vs CC 10. 7 g/d). Mother FHH was found predominantly in CB women (60% vs 30% in CC, p <0.05), whereas paternal FHH was more frequent in CC women (21% vs 8% in CB , p<0.05). At the same age, duration of hypertension was longer by 1 year i n CB. White coat effect was more marked in CC (BP > 30 mmHg: 40% in CC vs 5 % in CB, p<0.05). GFR Values were normal and similar in CB and CC women. Bu t a significantly lower RPF was measured in CB (489 vs 542 mL/min/1.73m(2) in CC, p<0.05). Higher filtration fraction and microalbuminuria were also o bserved in CB women. Conclusion. Essential hypertension occurs at younger ages in Caribbean wome n. The decrease in RPF could be genetically determined and is likely to par ticipate in early onset of hypertension, as previously described in young n ormotensive subjects. In paired women, we did not found significant differe nces in active renin and aldosterone levels. The ongoing longitudinal study should contribute to assess the consequences of these findings an renal pr ognosis and the effects of antihypertensive therapy.