|ISSN No. 1606-7754 Vol.15 No.3 December 2007|
Control of hypertension in Nigerians with Diabetes Mellitus: A report of the Ibadan Diabetic / Kidney Disease Study Group.
Ayodeji Arije,1 Modupe Kuti,2Adesoji Fasanmade,3Kehinde Akinlade,2Adeyinka Ashaye,4Millicent Obajimi,5Jokotade Adeleye3
Renal Unit1, Endocrine Unit3, Departments of Medicine, Department of Chemical Pathology2, Ophthalmology 4, Radiology 5, College of Medicine, University of Ibadan. Nigeria
The prevalence of high blood pressure (BP) is high among Nigerians with diabetes mellitus. This study of Nigerian patients with diabetes examines the adequacy of BP control and antihypertensive therapy as a baseline for establishing conformity with current guidelines. A total of 256 patients with diabetes, aged between 21 and 83 years (mean 59.1 + 12.8 years) attending the Diabetes/Endocrine Clinic of the University College Hospital Ibadan, Nigeria were involved in the study. Fifty seven per cent had co-existing hypertension and 15.5% of these patients were not receiving any antihypertensive agent. There was a significantly higher systolic BP among females compared to males (p < 0.05). Diabetic patients with hypertension were significantly older than those with diabetes alone (p < 0.001). The body mass index (BMI) was higher than 25 in 66% of patients with both diabetes and hypertension compared to 48% in those with diabetes alone ( p <0.005). A satisfactory mean systolic (<130 mmHg) and diastolic BP (<80 mmHg) BP was obtained in only 38.5% and 42.2% of all patients respectively. The association between BMI and blood pressure was found to be significant only for the diastolic pressure (p <0.05). Only 52% of the patients with hypertension were receiving angiotensin converting enzyme inhibitors as part of their treatment. The high prevalence and poor control of high BP among Nigerians with diabetes pose an increased risk of future development of nephropathy. There is need for a more intense awareness programme for doctors in developing countries regarding current blood pressure management guidelines and the need for adhering to them.
Key Words: Hypertension, Nigerians, Diabetes Mellitus
Hypertension is commonly associated with diabetes mellitus (DM). Its presence may antedate the onset of DM by many years or it may develop several years after the onset. Its pathogenesis also differs in type 1 and type 2 DM. A rising blood pressure is usually accompanied by the onset and progression of renal disease in type 1 DM, whereas in type 2 disease, elevated blood pressure is often present as at the time of, or shortly after, the diagnosis.
Several risk factors for the development and progression of renal disease in diabetes have been identified. Notable among these factors are hypertension, poor glycaemic control and albuminuria. These three conditions tend to have an anomalous relationship, poor glycaemic control being a predictor of microalbuminuria or incipient nephropathy, while the co-existence of nephropathy with hypertension presents a faster rate of renal function decline.1 An aggressive treatment and control of hypertension in patients with diabetes is therefore highly desirable in preventing or slowing down the progression of renal disease.
Recently, new guidelines for the treatment of hypertension in patients with diabetes have recommended the use of angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) either singly or in combination with other drugs depending on the blood pressure.2-5 Several studies in particular have documented the benefit of the use of ACE inhibitors in preventing or treating microalbuminuria (and thus preventing the progression of renal disease), as well as in overt renal disease.6-8
However, it has been observed that antihypertensive drug compliance as well as optimal BP control are often unsatisfactory in developing countries,9-10 often due to financial constraints. The high cost of these newer and beneficial drugs in developing countries like Nigeria makes compliance poor so that their reno-protective benefits are missed.
This preliminary study evaluates the magnitude of the problem of inadequate blood pressure control as a contributory risk factor for progressive renal disease in Nigerian patients with diabetes.