PREVALENCE OF HYPERTENSION IN A BLACK-AFR ICAN DIABETIC POPULATION

Background : It has been established that hypertension prevalence rate was higher in American Blacks than Whites or Mexicans. And hypertensi on is more frequent in diabetics. The prevalence of hypertension among diabetic African Blacks is not well documented. Methods : A total of 590 diabetic patients attending to Central Hospital of Yaounde (Camero on) were followed between 1990 and 1994. The 1993 WHO criteria were us ed to define hypertension (systolic blood pressure (SBP) greater than or equal to 140 or diastolic blood pressure (DBP) greater than or equa l to 90 mmHg. We also have considered as hypertensive patients being t reated with an antihypertensive medication before inclusion. All quant itative data are given as means+/-SD. Results : For the whole study po pulation characteristics were : age (at inclusion) : 54.2+/-12.8 yrs; sex distribution : 341 men for 209 women (sex ratio: 1.63:1); known du ration of diabetes: 5.7+/-5.6 yrs; Body Mass Index (BMI) : 24.4+/-4.8 kg/m(2). They are dividing into 136 IDDM, 405 NIDDM and 9 other types. In normotensive patients, blood pressure levels were: SEP 117+/-11 an d DBP 75+/-8 mmHg, while in hypertensive : SEP 156+/-23 and DBP 95+/-1 3 mmHg. The difference between normo and hypertensive diabetics was si gnificant (p greater than or equal to 0.001). Characteristics of hyper tensive group were : age : 57+/-11.2 yrs, sex repartition 229 men for 136 women (sex ratio : 1.68:1), BMI : 24.9+/-4.8 kg/m(2), diabetes cla ssification : 63 IDDM, 297 NIDDM and 5 other types. According to recen t WHO criteria (140/90) 365 subjects/550 were found to have high blood pressure, giving an overall prevalence of hypertension of 66.4% in th e study population. Using former WHO definition (160/95) the prevalenc e was 42.2%. There was no statistical difference for prevalence betwee n male (67.2%) and-female (65.1%). But the difference was strongly sig nificant (p <0.001) between IDDM (46.3%) and NIDDM (73.3%). Discussion :Hypertension prevalence studies in Africa have shown varying results (2.5-30%), with higher rates in urban than rural population. In Afric an studies hypertension prevalence rates in diabetes were reported in the range 13-44%. The result of the present study is Very near the hig h limit of known data in Africa. Conclusion :Such a prevalence rate of 66.4% in this Cameroonian diabetic population appears to be high, par ticularly in patients with NIDDM. These considerations bring to light the question of sensitiveness of African Blacks to hypertension when e xposed to high blood pressure risk factors such as inadequate food and diabetes.