Evaluating the treatment of hypertension in diabetes mellitus: a need for better control?

OBJECTIVES: To determine how well and to what extent blood pressure (BP) is controlled in diabetic hypertensive patients treated by primary care doctors, and to evaluate drug therapy in the backdrop of risk factors and laboratory findings.
METHODS: A therapeutic audit of the medical records of diabetic hypertensives from nine primary care health centres in Bahrain.
RESULTS: In 266 diabetic hypertensives (82 males and 184 females), the recommended target BP < 130/< 85 mmHg (WHO/ISH guidelines, 1999) was achieved in 20 (9.8%) with a BP of 119 +/- 4/76 +/- 5 mmHg. Among those who did not achieve target BP, 70 (34.5%) lacked systolic BP control (BP = 153 +/- 17/79 +/- 3 mmHg), four (2%) lacked diastolic BP control (BP = 123 +/- 3/86 +/- 3 mmHg) and 109 (53.7%) lacked both systolic and diastolic BP control (BP = 158 +/- 20/94 +/- 7 mmHg). The mean age of the group achieving target BP was significantly lower than the group which lacked systolic BP control (51.6 +/- 9 vs. 63.5 +/- 9 years; P < 0.0001). While there were no significant differences in fasting blood glucose, glycosylated haemoglobin, triglycerides, urea, creatinine, uric acid and serum electrolytes between the group achieving target BP vs. groups without target BP, a significant difference in total cholesterol was seen. PATIENTS: with ischaemic heart disease and/or isolated systolic hypertension did not achieve the target BP. Antihypertensive monotherapy was prescribed in 145 (54.5%) patients, whereas two- and three-drug combinations were prescribed in 32.3 and 8.2% of patients, respectively. As monotherapy, angiotensin-converting enzyme (ACE) inhibitors were the most frequently prescribed drugs followed by beta-blockers, calcium channel blockers (CCBs) and diuretics. As two-drug combinations, an ACE inhibitor with a beta-blocker/diuretic and a beta-blocker with a CCB/diuretic were usually prescribed.
CONCLUSIONS: According to the WHO/ISH 1999 guidelines, approximately one out of 10 diabetic hypertensives achieved target BP control. In many instances, the drug therapy prescribed was inappropriate considering the comorbidity in patients and their laboratory findings. Improved BP control is needed in treating high-risk groups such as patients with diabetes mellitus, and efforts should be made to improve the treatment of hypertension in the primary care setting.