KARACHI, Oct 31: A survey, the details of which were published in a reputed medical journal, has shown that there is a high prevalence of hypertension in low-income city households, which necessitates blood pressure control among the residents of such settlements.

The study, involving 405 households in a low-income settlement of Karachi, was carried out by S Safdar, A Omair, U Faisal and H Hasan of the Jinnah Medical and Dental College's department of community health sciences. A report based on the study has been published in the latest edition of the Journal of Pakistan Medical Association (JPMA), which is cited internationally.

Under the study, the blood pressures of 172 male and 685 female residents of the settlement were recorded between April and September in 2002. The mean age of the participants was 34 years. The percentage of the participants, whose age was less than 35 years, was 53 in the sample.

In the JPMA study, the overall prevalence of hypertension was found to be 26 per cent as among the 857 participants, while 223 had high blood pressure. This data compares rather poorly with the National Health Survey of 1990-94, which noted the prevalence of hypertension among adults to be as 17.9 per cent.

According to the study, the prevalence of high blood pressure among the males was higher (34 per cent) as opposed to the female participants, who had a 24 per cent prevalence of the condition. The mean pulse pressure was also higher among the males than female participants.

Substantially, more males were suffering from stage-1 hypertension than the females. This difference was not found in the case of stage-2 and stage-3 hypertension.

Forty-two per cent of the participants with hypertension knew they had high blood pressure, while the rest were unaware of their condition. In other words, there were more cases of unknown hypertension as compared to the known ones, the study revealed.

The prevalence of high blood pressure rose with increase in age. Proportionately, there were more cases of hypertension among male participants who were of 35 years or more.

Seventeen per cent of the participants were single and 83 per cent fell in the category of 'ever-married', which included the married, widowed, and divorced persons. The prevalence was higher among the 'ever-married' than those who were single, the study said.

Stratified analysis revealed that high blood pressure was 1.7 times more common among males than the female participants. And the males were 1.7 times less likely to have been aware of their condition.

The JPMA survey was carried out in the morning hours, when most adult males were on their jobs. This may have led to the participation of a less representative sample of males in the study.