W.O. Balogun1 and B.L. Salako2

  1. Endocrinology Unit, Department of Medicine, College of Medicine, University of Ibadan, Nigeria.
  2. Endocrinology Unit, Department of Medicine, College of Medicine, University of Ibadan, Nigeria.


Background: There is a high frequency of co-occurrence of diabetes and hypertension all over the world. Such association results in higher rate of cardiovascular complications. It is however not clear whether the order of occurrence distinguishes two different groups of patients and the implications of this on morbidity and mortality. The main objective of this study is to determine if there are any clinical and metabolic differences between those first diagnosed with diabetes (hypertensive diabetics) compared to those first diagnosed with hypertension (diabetic hypertensives).

Methodology: A total of 124 patients with co-existent diabetes and hypertension were consecutively recruited into the study. Demographic and clinical history was captured on a semi-structured questionnaire, followed by measurement of anthropometry and blood pressure. Records of fasting plasma glucose, urinalysis and electrolytes, urea and creatinine were obtained from the case records.

Results: There were 83 (66.9%) females and 41 (33.1%) males with mean age of 61.1 (SD 11.1) years. Sixty or 49.6% was hypertensive diabetics while 52 or 43% was diabetic hypertensive. The rest had simultaneous diagnosis of diabetes and hypertension. The diabetic hypertensive subjects significantly had higher BMI (p= 0.04) while the hypertensive diabetics group had higher hip/waist ratio (p = 0.01). The diabetic hypertensive group had higher waist circumference statistically significant only in women (p = 0.04). Also significantly more people (21 or 42%; p = 0.04) in the diabetic hypertensive group used table salt often. A logistic regression performed showed that only use of table salt was independently associated with order of diagnosis of diabetes or hypertension.

Conclusion: There could be significant differences in some clinical characteristics of hypertensive diabetics and diabetic hypertensives, and use of table salt may be an important risk factor contributing to coexistence of both conditions.


Dr. W.O. Balogun
Department of Medicine,
University College Hospital,
PMB 5116, Ibadan,


Diabetes and hypertension are two non-communicable diseases that frequently co-exist. Several studies have shown that raised blood pressure is commoner among people with diabetes than in the general population.1-3 Both diseases are independent risk factors for cardiovascular disease (CVD), and when they co-exist they multiply morbidity and mortality of CVD.4 Hypertension in diabetes accelerates development and progression of microvascular and macrovascular complications in patients with diabetes.5 Among Nigerians, mortality is increased in diabetic patients with hypertension compared to normotensive diabetics.6 In clinical practice, usually patients present first with one condition followed by later discovery of the other, although both conditions may simultaneously be diagnosed at presentation. It is not clear whether the order of occurrence of hypertension and diabetes is important such as to make one group differ from the other clinically or/and metabolically. It is important to investigate this because, if established differences exist, there may be implications on morbidity and mortality.

The objectives of the study therefore, were to find out the commoner order of discovery of diabetes and hypertension among patients with co-occurrence of diabetes and hypertension, and to determine if there are any clinical and metabolic differences between those first diagnosed with diabetes (herein referred to as hypertensive diabetics) compared to those first diagnosed with hypertension (herein referred to as diabetic hypertensives).

A cross-sectional study was carried out at the Diabetes Clinic and Medical Wards of the University College Hospital, Ibadan, between June-July, 2009. The inclusion criteria were being type 2 diabetes based on WHO definition7, having been diagnosed as having hypertension, and consenting to participate in the study. A total of 124 subjects were recruited consecutively into the study. Patients who were moribund and those who did not give consent were excluded. A semistructured pre-tested questionnaire was first administered to all subjects. Information sought included demography, duration of diabetes and hypertension, list of hypoglycaemic and antihypertensive drugs being used, family history of diabetes and hypertension, use of table salt (especially to an already cooked food), history of alcohol and smoking. The last 3 readings of their fasting blood glucose were obtained from their case records and the average calculated. Last electrolytes, urea and creatinine done as well as urinalysis (for evidence of proteinuria) were obtained from the case records. Also confirmation of the timing of diagnosis of hypertension and diabetes was checked in their case records. Thereafter the weight, height waist circumference (WC) and hip circumference of subjects were measured according to standard procedure. BMI (Body Mass Index) was calculated as Weight/Height2, while ratio of hip/waist ratio (HWR) was also determined. The blood pressure was then measured in sitting position after 5 minutes of rest using a mercury sphygmomanometer and in accordance with standard technique.

Statistical Analysis
Data initially recorded in the questionnaire were transferred into and analysed using SPSS version 17. All quantitative variables were expressed as mean and standard deviation where these were normally distributed, and as median with range where not normally distributed. Chi-square was used to analyse group differences between categorical variables while independent t-test was used to compare group differences in continuous variables. Stepwise logistic regression was done to find out determinant of being first diagnosed as hypertensive or diabetic.