Hypertension management in diabetic patients: prescribing trends from 1999 to 2005 in three Japanese university hospitals.

Purpose: In hypertensive patients with diabetes, antihypertensive therapy is important in reducing the risk of macro- and microvascular complications. In contrast to the guidelines issued by the American Diabetes Association (ADA) in and after 2002, the guidelines issued by the Japanese Society of Hypertension (JSH) in 2000 and 2004 maintained the traditional view that beta-blockers and thiazides should be rated as second-line drugs. However, both sets of guidelines recommended angiotensin converting enzyme inhibitors and angiotensin II receptor blockers (ARBs) as first-line agents for such patients.

Methods: We examined the use of antihypertensives in hypertensive patients with and without diabetes using the prescription data for 1999, 2002 and 2005 from three Japanese university hospitals.

Results: When compared with 1999, the proportion of patients with and without diabetes using ARBs was dramatically increased in 2005 from 1.5 to 55% and from 1.5 to 40%, while that of angiotensin converting enzyme inhibitors decreased from 52 to 32% and 35 to 23%, respectively. A relatively stable proportion of patients (around 10% with and without diabetes) used beta-blockers and around 60% of patients with and without diabetes used calcium channel blockers (CCBs) and very few (<5%) used thiazides.

Conclusions: The rapid increase in use of ARBs and under-use of thiazides may be explained by the fee schedule in the Japanese health insurance system. The paucity of large-scale clinical trials may also hinder evaluation of the traditional view of the role of beta-blockers and thiazides in treatment of Japanese patients with diabetes.