Relationship of hypertension to socioeconomic status in a West African population

OBJECTIVES: To determine whether hypertension rates were positively related to socioeconomic status (SES) in males in urban northern Nigerian civil servants in order to confirm this relationship previously observed in a southern Nigerian civil servant population which differed in tribal origin, religious practices and diet. METHODS: Civil servants were recruited from the Sokoto State ministries, Sokoto, Nigeria. Professionals and administrators were designated as higher SES, and clerks and laborers as lower SES. In addition to blood pressure, the height and weight of individuals, as well as their urinary sodium- and potassium-creatinine, were also measured. RESULTS: The age-adjusted occurrence of hypertension (systolic pressure > or = 140 mmHg or diastolic pressure > or = 90 mmHg or current use of hypertension medication) was similar in male higher (n = 155) and lower (n = 255) SES groups aged 25-54, 19.3% and 19.8%, respectively. However, the age-adjusted rate of definite hypertension (systolic pressure > or = 160 mmHg or diastolic pressure > or = 95 mmHg or current use of hypertension medication) was considerably higher in the higher SES than in the lower SES men, 11.2% versus 3.6%. Age-adjusted body mass index (BMI, kg/m2) was higher among the higher than in the lower SES group, 21.4 versus 20.4. Over-night sodium excretion did not differ. Among female civil servants (n = 73) aged 20-44, there were few of higher SES (n = 19) precluding SES-specific analyses. Total and definite hypertension rates among women were 17.2% and 5.5%, respectively. Mean BMI was 22.2. In logistic regression, definite hypertensive status was related to age group, BMI tertile, sodium excretion and SES in men and to sodium excretion in women. CONCLUSION: Even in this very lean population, the higher risk for hypertension in males of higher SES was confirmed. This was explained, in part, by higher BMI.