BLOOD-PRESSURE CHANGES IN DIABETES IN URBAN TANZANIA

Little is known of the natural history of blood pressure (BP) levels i n diabetic patients from sub-Saharan Africa. BP levels were therefore recorded in such patients in Dar es Salaam, Tanzania, over 2, 5, and 7 years. Hypertension was found in 5% of insulin-treated diabetes melli tus (IDDM) and 29.2% of non-insulin-dependent diabetes mellitus (NIDDM ) patients at presentation with diabetes. Hypertension developed in a further 2 IDDM (3.7%) and 27 NIDDM (15.6%) patients at 2 years, and in 3 IDDM (13.0%) and 9 NIDDM (9.8%) patients at 5 years. Seven NIDDM (1 8.4%) patients had developed hypertension by 7 years. In NIDDM patient s with normal BP initially, the mean systolic BP rose from 131 to 141 mmHg (P < 0.001) 2 years later (n = 146); from 131 to 138 mmHg (P < 0. 001) for those followed for 5 years (n = 82); and from 131 to 138 mmHg (P < 0.05) for those followed for 7 years (n = 31). The mean diastoli c BP was 83 mmHg initially and 84 mmHg (NS) for those followed for 2 y ears (n = 146). There was no observed rise in mean diastolic BP at 5 o r 7 years of follow-up. In IDDM patients without hypertension, only th e systolic BP rose significantly by 5 years, from 124 to 132 mmHg (P < 0.001; n = 20). These changes were independent of age, sex, body mass index, and proteinuria. We conclude that: (1) in black Tanzanians, as in other ethnic groups, it is likely that hypertension is significant ly associated with diabetes; (2) rates of hypertension and BP levels c ontinue to increase with time, particularly in NIDDM subjects; and (3) BP measurements should be a regular feature of diabetes care in the A frican diabetic population as in other populations.